— -CO •^^ '*■■ ^^O) o =CO g CO :^ CO CO " o [/) = ■T— ^ C£> = .,_. ^~^^^™ ^i._^ CO Digitized by the Internet Archive in 2008 with funding from IVIicrosoft Corporation http://www.archive.org/details/animalintelligenOOromauoft THE INTERNATIONAL SCIENTIFIC SERIES. Each Book Complete in One Vohime. Croivn Svo, cloth. I. FORMS OF WATER: a Familiar Exposition of the Origin and Phenomena of (GLACIERS. By J. TVNDALL,LL.D., F.R.S. With 25 Illustrations. Eighth Edition, ^s. 11. PHYSICS AND POLITICS; or, Thoughts on the Application of the Principles of ' Natural Selection ' and ' Inheritance ' to Political Society. By Walter Bagehot. Fifth Edition. ^. III. FOODS. By Edward Smith, M.D., LL.B., F.R.S. With numerous Illustrations. Seventh Edition, ^s. IV. MIND AND BODY: the Theories of their Rela- tion. By Alexander Bain, LL.D. With Four Illus- trations. Seventh Edition. 4^-. V. THE STUDY OF SOCIOLOGY. By Herbert Spencer. Tenth Edition, ^s. VI. ON THE CONSERVATION OF ENERGY. By Balfour Stewart, M.A., LL.D., F.R.S. With 14 Illustrations. Fifth Edition. 5^-. VII. ANIMAL Z(9C(9J/6>r/(97V^/ or. Walking, Swimming, and Flying. By J. B. Pettigrew, M.D., F.R.S., &c. With 130 Illustrations. Second Edition. 5J-. VIII. RESPONSIBILITY IN MENTAL DISEASE. By Henry Maudsley, M.D. Fourth Edition, ^s. London : KEGAN PAUL, TRENCH, & Co., i, Paternoster Square. 2 The International Scientific Series — continued. IX. THE NE W CHEMISTR V. By Professor J. P. Cooke, of the Harvard University. With 31 Illus- trations. Fifth Edition, ^s. X. THE SCIENCE OF LA W. By Professor Shel- don Amos. Fourth Edition. 5^-. XL ANIMAL MECHANISM : a Treatise on Terres- trial and Aerial Locomotion. By Professor E. J. Marey. With 117 Illustrations. Second Edition. XII. THE DOCTRINE OF DESCENT AND DARWINISM. By Professor Oscar Schmidt (Strasburg University). With 26 Illustrations. Fourth Edition, ^s. XIII. THE HISTORY OF THE CONFLICT BE- TWEEN RELIGION AND SCIENCE. By J. W. Draper, M.D., LL.D. Fifteenth Edition. 5^. XIV. FUNGI: their Nature, Influences, Uses, &c. By M. C. Cooke, M.A., LL.D. Edited by the Rev. M. J. Berkeley, M.A., F.L.S. With numerous Illustra- tions. Second Edition. 5^-. XV. THE CHEMICAL EFFECTS OF LIGHT AND PHOTOGRAPHY. By Dr. Hermann VoGEL (Polytechnic Academy of Berhn). Translation thoroughly revised. With 100 Illustrations. Third Edition. 5^-. XVI. THE LIFE AND GROWTH OF LANGUAGE. By William Dwight Whitney. Second Edition. XVIL MONEY AND THE MECHANISM OF EX- CHANGE. By W. Stanley Jevons,M.A., F.R.S. Fourth Edition. 5^-. London : KEGAN PAUL, TRENCH, & Co., i, Paternoster Square. The International Scientific Series — continued. 3 XVIII. THE NATURE OF LIGHT, with a General Account of PHYSICAL OPTICS. ByDr.EUGENE LOMMEL. With 188 Illustrations and a Table of Spectra in Chromo-lithography. Third Edition. 5^-. XIX. ANIMAL PARASITES AND MESSMATES. By Monsieur Van Beneden. With 83 Illustra- itions. Second Edition. 5^-. XX. FERMENTATION. By Professor Schutzen- berger. With 28 Illustrations. Third Edition. Si-. XXI. THE FIVE SENSES OF MAN. By Pro- fessor Bernstein. With 91 Illustrations. Third Edition, ^s. XXII. THE THEORY OF SOUND IN ITS RELA- TION TO MUSIC. By Professor Pietro Bla- SERNA. With numerous Illustrations. Second Edition, ^s. XXIII. STUDIES IN SPECTRUM ANALYSIS. By J. Norman Lockyer, F.R.S. With Six Photo- graphic Illustrations of Spectra, and numerous Engravings on Wood. Second Edition. 6j'. 6^. XXIV. A HISTORY OF THE GROWTH OF THE STEAM ENGINE. By Professor R. H. Thur- ston. With numerous Illustrations. Second Edition, ds. 6d. XXV. EDUCATION AS A SCIENCE. By Alex- ander Bain, LL.D. Fourth Edition. 5^-. XXVI. THE HUMAN SPECIES. By Professor A. de Quatrefages, Membre de I'lnstitut. Second 1 Edition, ^s. I XXVII. MODERN CHROMATICS. With Application I to Art and Industry. By Ogden N. Rood. Second h Edition. With 130 original Illustrations, ^s. London : KEGAN PAUL, TRENCH, & Co., i, Paternoster Square. 4 The International Scientific Series — continned. XXVIII. THE CRA YFISH : an Introduction to the Study of Zoology. By T. H. Huxley, F.R.S. Third Edition. With 82 Illustrations. 5^-. XXIX. THE BRAIN AS AN ORGAN OF MIND. By H. Charlton Bastian, M.D. Second Edition. With 184 Illustrations. 5^-. XXX. THE ATOMIC THEORY. By Professor A. WURTZ. Translated by E. Cleminshaw, F.C.S. Second Edition, ^s. XXXI. THE NATURAL CONDITIONS OF EX- ISTENCE AS THEY AFFECT ANIMAL LIFE. By Karl Semper. Second Edition. With 2 Maps and 106 Woodcuts. 5^. XXXII. GENERAL PHYSIOLOGY OF MUSCLES AND NERVES. By Professor J. Rosenthal. Second Edition. With Illustrations, ^s. XXXIII. SIGHT: an Exposition of the Principles of Mono- cular and Binocular Vision. By Joseph Le Conte, LL.D. With 132 Illustrations. 5J. XXXIV. ILLUSIONS: a Psychological Study. Second Edition. By James Sully. 55-. XXXV. VOLCANOES : what they are and what they teach. By John W. Judd, F.R.S. Second Edidon. With 96 Illustrations. 5^-. XXXVI. SUICIDE: An Essay on Comparative Moral Statistics. By Henry Morselli, M.D. XXXVII. THE BRAIN AND ITS FUNCTIONS. By J. LUYS, Physician to the Hospice de la Salpc- tri^re. With numerous Illustrations. 5^-. XXXVIII MYTH AND SCIENCE. Kyv Essay. By Tito Vignoli. 5J-. XXXIX. THE SUN By C. A. Young, Ph.D., LL.D. With numerous Illustrations. 5J. London : KEGAN PAUL, TRENCH, & Co., i, Paternoster Square. THE International Scientific Series VOL. XLI. I HAVE recently leanit from the publishers of the ' International Scientific Series ' that they have made arrangements with Sir John Lubbock to bring out in the same series a work of his on Ants and Bees. Necessarily, therefore, the material to be dealt with in his work will to a large extent overlap that which is presented by my chapters on the same insects; but after consulting with the publishers, and also with Sir John Lubbock, it has seemed to me undesirable to omit these chapters on account of the circumstances here stated. For, on the one hand, the facts will not lose their value from being twice told ; and on the other, it is desirable that the present member of the Series should form in itself, so far as its Author can make it, a complete resum^ of all the more important facts of Animal Intelligence, i^ ^0 ANIMAL INTELLIG ^^\\\><> ^ '1^ BY it<^ GEORGE J. ROMANES, M.A. LL.D. F.R.S. ZOOLOGICAL SECRETARY OF THE LDfNEAN SOCIETY LONDON" KEGAN PAUL, TRENCH, & CO., 1 PATERNOSTER SQUARE 1882 QL {The rights of translatiojt and of reproduction are reserved^ PEEFACE When I first began to collect materials for this work it was my intention to divide the book into two parts. Of these I intended the first to be concerned only with the facts of animal intelligence, while the second was to have treated of these facts in their relation to the theory of Descent. Finding, however, as I proceeded, 'that the material was too considerable in amount to admit of being comprised within the limits of a single volume, 1 have made arrangements with the publishers of the ' International Scientific Series ' to bring out the second division of the work as a separate treatise, under the title 'Mental Evolution.' This treatise I hope to get ready for press within a year or two. My object in the work as a whole is twofold. First, I have thought it desii^able that there should be something resembling a text-book of the facts of Comparative Psy- chology, to which men of science, and also metaphysicians, may turn whenever they may have occasion to acquaint themselves with the particular level of intelligence to which this or that species of animal attains. Hitherto the endeavour of assigning these levels has been almost exclu- sively in the hands of popular writers ; and as these have, for the most part, merely strung together, with dis- crimination more or less inadequate, innumerable anec- VI PEE FACE. dotes of the display of animal intelligence, their books are valueless as works of reference. So much, indeed, is; this the case, that Comparative Psychology has been vir- tually excluded from the hierarchy of the sciences. If we except the methodical researches of a few distinguished naturalists, it would appear that the phenomena of mind in animals, having constituted so much and so long the theme of unscientific authors, are now considered well- nigh unworthy of serious treatment by scientific methods. But it is surely needless to point out that the phenomena which constitute the subject-matter of Comparative Psy- chology, even if we regard them merely as facts in Nature^ have at least as great a claim to accurate classification a& those phenomena of structure which constitute the sub- ject-matter of Comparative Anatomy. Leaving aside, therefore, the reflection that within the last twenty years the facts of animal intelligence have suddenly acquired a new and profound importance, from the proved probability of their genetic continuity with those of human intelli- gence, it would remain true that their systematic arrange- ment is a worthy object of scientific endeavour. This, then, has been my first object, which, otherwise stated, amounts merely to passing the animal kingdom in review in order to give a trustworthy account of the grade of psychological development which is presented by each group. Such is the scope of the present treatise. My second, and much more important object, is that of considering the facts of animal intelligence in their rela- tion to the theory of Descent. With the exception of Mr. Darwin's admirable chapters on the mental powers and moral sense, and Mr. Spencer's great work on the Principles of Psychology, there has hitherto been no earnest attempt at tracing the principles which have been probably concerned in the genesis of Mind. Yet there is PREFACE. vii not a doubt that, for the present generation at all events, no subject of scientific inquiry can present a higher degree of interest; and therefore it is mainly with the view of furthering this inquiry that I have undertaken this work. It will thus be apparent that the present volume, while complete in itself as a statement of the facts of Comparative Psychology, has for its more ultimate purpose the laying of a firm foundation for my future treatise on Mental Evolution. But although, from what I have just said, it will be apparent that the present trea- tise is preliminary to a more important one, I desire to emphasise this statement, lest the critics, in being now presented only with a groundwork on which the picture is eventually to be painted, should deem that the art dis- played is of somewhat too commonplace a kind. If the present work is read without reference to its ultimate object of supplying facts for the subsequent deduction of principles, it may well seem but a small improvement upon the works of the anecdote-mongers. But if it is remembered that my object in these pages is the mapping out of animal psychology for the purposes of a subsequent synthesis, I may fairly claim to receive credit for a sound scientific intention, even where the only methods at my disposal may incidentally seem to minister to a mere love of anecdote. It remains to add a few words on the principles which I have laid down for my own guidance in the selection and arrangement of facts. Considering it desirable to cast as wide a net as possible, I have fished the seas of popular literature as well as the rivers of scientific writing. The endless multitude of alleged facts which I have thus been obliged to read, I have found, as may well be imagined, excessively tedious ; and as they are for the most part re- corded by wholly unknown observers, the labour of reading VUl PREFACE. them would have beei* useless without some trustworthy principles of selection. The first and most obvious principle that occurred to me was to regard only those facts which stood upon the authority of observers well known as com- petent ; but I soon found that this principle constituted much too close a mesh. Where one of my objects was to determine the upper limit of intelligence reached by this and that class, order, or species of animals, I usually found that the most remarkable instances of the display of intel- ligence were recorded by persons bearing names more or less unknown to fame. This, of course, is what we might antecedently expect, as it is obvious that the chances must always be greatly against the more intelligent individuals among animals happening to fall under the observation of the more intelligent individuals among men. Therefore I soon found that I had to choose between neglecting all the more important part of the evidence — and consequently in most cases feeling sure that I had fixed the upper limit of intelligence too low — or supplementing the principle of looking to authority alone with some other principles of selection, which, while embracing the enormous class of alleged facts recorded by unknown observers, might be felt to meet the requirements of a reasonably critical method. I therefore adopted the following principles as a filter to this class of facts. First, never to accept an alleged fact without the authority of some name. Second, in the case of the name being unknown, and the alleged fact of sufficient importance to be entertained, carefully to con- sider whether, from all the circumstances of the case as recorded, there was any considerable opportunity for mal- observation ; this principle generally demanded that the alleged fact, or action on the part of the animal, should be of a particularly marked and unmistakable kind, looking to the end which the action is said to have accomplished. PEEFACE. ix Third, to tabulate all important observations recorded by unknown observers, with the view of ascertaining whether they have ever been corroborated by similar or analogous observations made by other and independent observers. This principle 1 have found to be of great use in guiding my selection of instances, for where statements of fact which present nothing intrinsically improbable are found to be unconsciously confirmed by different observers, they have as good a right to be deemed trustworthy as state- ments which stand on the single authority of a known ob- server, and I have found the former to be at least as abun- dant as the latter. Moreover, by getting into the habit of always seeking for corroborative cases, I have frequently been able to substantiate the assertions of known observers by those of other observers as well or better known. So much, then, for the principles by which I have been guided in the selection of facts. As to the arrange- ment of the facts, I have taken the animal kingdom in ascending order, and endeavoured to give as full a sketch as the selected evidence at my disposal permitted of the psychology which is distinctive of each class, or order, and, in some cases, family, genus, or even species. The reason of my entering into greater detail with some natural groups than with others scarcely requires explana- tion. For it is almost needless to say that if the animal kingdom were classified with reference to Psychology in- stead of with reference to Anatomy, we should have a very different kind of zoological tree from that which is now given in our diagrams. There is, indeed, a general and, philosophically considered, most important parallelism running through the whole animal kingdom between structural affinity and mental development; but this parallelism is exceedingly rough, and to be traced only in broad outlines, so that although it is convenient for X PREFACE. the purpose of definite arrangement to take the animal kingdom in the order presented by zoological classifica- tion, it would be absurd to restrict an inquiry into Animal Psychology by any considerations of the apparently dis- proportionate length and minute subdivision with which it is necessary to treat some of the groups. Anatomically, an ant or a bee does not require more consideration than a beetle or a fly ; but psychologically there is need for as great a difference of treatment as there is in the not very dissimilar case of a monkey and a man. Throughout the work my aim has been to arrive at definite principles rather than to chronicle mere inci- dents — an aim which will become more apparent when the work as a whole shall have been completed. Therefore it is that in the present volume I have endeavoured, as far as the nature and circumstances of the inquiry would permit, to suppress anecdote. Nevertheless, although I have nowhere introduced anecdotes for their own sake, I have found it unavoidable not to devote much the largest part of the present essay to their narration. Hence, with the double purpose of limiting the introduction of anec- dotes as much as possible, and of not repeating more than I could help anecdotes already published, I have in all cases, where I could do so without detriment to my main object, given the preference to facts which have been communicated to me by friends and correspondents. And here I may fitly take the opportunity of expressing my thanks and obligations to the latter, who in astonish- ing numbers have poured in their communications during several years from all quarters of the globe. I make this statement because I desire to explain to all my corres- pondents who may read this book, that I am not the less sensible of their kindness because its bounty has ren- dered it impossible for me to send acknowledgments in PREFACE. xi individual cases. However, I should like to add in this connection that it does not follow, because I have only quoted a small percentage of the letters which I have re- ceived, that all of the remainder have been useless. On the contrary, many of these have served to convey infor- mation and suggestions which, even if not reserved for express quotation in my forthcoming work, have been of use in guiding my judgment on particular points. There- fore I hope that the publication of these remarks may serve to swell the stream of communications into a yet larger flow. ^ In all cases where I have occasion to quote statements of fact, which in the present treatise are necessarily numerous, I have made a point of trying to quote verbatim. Only where I have found that the account given by an author or a correspondent might profitably admit of a considerable degree of condensation have I presented it in my own words. And here I have to express my very special obligations to Mr. Darwin, who not only assisted me in the most generous manner with his immense stores of information, as well as with his valuable judgment on sundry points of difficulty, but has also been kind enough to place at my disposal all the notes and clippings on animal intelligence which he has been collecting for the last forty years, together with the original MS. of his wonderful chapter on ' Instinct.' This chapter, on being re-cast for the ' Origin of Species,' underwent so merciless an amount of compression that the original draft constitutes a rich store of hitherto unpublished material. In my second work I shall have occasion to draw upon this store more largely than in the present one, and it is needless to add ' Letters may be addressed to me directly at 18 Cornwall Terrace, Regent's Park, London, IS . W. Xli PKEFACE. that in all cases where I do draw upon it I shall be careful to state the source to which I am indebted. [The above was written when I sent this work to the publishers several months ago, and I have thought it best to leave the concluding paragraph as it originally stood. But in making this explanation, I cannot allude to the calamity which has since occurred without paying my tribute, not alone to the memory of the greatest genius of our age, but still more, and much more, to the memory of a friend so inexpressibly noble, kind, and generous, that even my immense admiration of the naturalist was surpassed by my loving veneration for the man.] CONTENTS. Introduction . page: 1 CHAPTER I. Application op the Foregoing Principles to the Lowest Animals ........ 18- MOLLUSCA CHAPTER II. 25 Ants . CHAPTER III. 31 Bees and Wasps CHAPTER IV. 143 Termites CHAPTER V. 108 CHAPTER VI. Spiders and Scorpions 204. CHAPTER VII. Remaining Articulata . 226" CHAPTER VIII. Fish 24L CHAPTER IX. Batrachians and Reptiles 254: XIV Birds CONTENTS. CHAPTER X. PAGB . . 266 Mammals CHAPTER XL 326 EODENTS . CHAPTER XII. 353 Elephant CHAPTER XIII. . 386 The Cat. CHAPTER XIV. 411 CHAPTER XV. FoxBS, Wolves, Jackals, &c. . 426 The Dog. CHAPTER XVI. 437 CHAPTER XVII. Monkeys, Apes, and Baboons . 471 Index 49.') INTEODUCTION, Before we begin to consider the phenomena of mind throughout the animal kingdom it is desirable that we should understand, as far as possible, what it is that we exactly mean by mind. Now, by mind we may mean two very different things, according as we contemplate it in our own individual selves, or in othe'r organisms. For if we contemplate our own mind, we have an immediate cognizance of a certain flow of thoughts or feelings, which are the most ultimate things, and indeed the only things, of which we are cognisant But if we contemplate mind in other persons or organisms, we have no such imme- diate cognizance of thoughts or feelings. In such cases we can only infer the existence and the nature of thoughts and feelings from the activities of the organisms which appear to exhibit them. Thus it is that we may have a subjective analysis of mind and an objective analysis of mind — the difference between the two con- sisting in this, that in our subjective analysis we are restricted to the limits of a single isolated mind which we call our own, and within the territory of which we have immediate cognizance of all the processes that are going on, or at any rate of all the processes that fall within the scope of our introspection. But in our ob- jective analysis of other or foreign minds we have no such immediate cognizance; all our knowledge of their operations is derived, as it were, through the medium of ambassadors — these ambassadors being the activities of the organism. Hence it is evident that in our study of animal intelligence we are wholly restricted to the ob- jediive method. Starting from what I know subjectively / .^ B 2 INTKODUCTION. of the operations of my own individual mind, and the activities which in my own organism they prompt, I proceed by analogy to infer from the observable activities of other organisms what are the mental operations that underlie them. Now, in this mode of procedure what is the kind of activities which may be regarded as indicative of mind ? I certainly do not so regard the flowing of a river or the blowing of the wind. Why? First, because the objects are too remote in kind from my own organism to admit of my drawing any reasonable analogy between them and it ; and, secondly, because the activities which they pre- sent are of invariably the same kind under the same cir- cumstances ; they afford no evidence of feeling or purpose. In other words, two conditions require to be satisfied before we even begin to imagine that observable activities are indicative of mind : first, the activities must be displayed by a living organism ; and secondly, they must be of a kind to suggest the presence of two elements which we recognise as the distinctive characteristics of mind as such — consciousness and choice. So far, then, the case seems simple enough. Wherever we see a living organism apparently exerting intentional choice, we might infer that it is conscious choice, and therefore that the organism has a mind. But further reflection shows us that this is just what we cannot do ; for although it is true that there is no mind without the power of conscious choice, it is not true that all apparent choice is due to mind. In our own organisms, for in- stance, we find a great many adaptive movements per- formed without choice or even consciousness coming into ' play at all — such, for instance, as in the beating of our hearts. And not only so, but physiological experiments and pathological lesions prove that in our own and in other organisms the mechanism of the nervous system is sufficient, without the intervention of consciousness, to produce muscular movements of a highly co-ordinate and apparently intentional character. Thus, for instance, if a man has his back broken in such a way as to sever the- nervous connection between his brain and lower extremi- INTKODUCTION. 3 ties, on pinching or tickling his feet they are drawn sud- denly away from the irritation, although the man is quite unconscious of the adaptive movement of his muscles ; the lower nerve-centres of the spinal cord are competent to bring about this movement of adaptive response with- out requiring to be directed by the brain. This non- mental operation of the lower nerve-centres in the pro- duction of apparently intentional movements is called Keflex Action, and the cases of its occurrence, even within the limits of our own organism, are literally numberless. Therefore, in view of such non-mental nervous adjust- ment, leading to movements which are only in appearance intentional, it clearly becomes a matter of great difficulty to say in the case of the lower animals whether any action which appears to indicate intelligent choice is not really action of the reflex kind. On this whole subject of mind-like and yet not trul}-- mental action I shall have much to say in my subsequent treatise, where I shall be concerned among other things with tracing the probable genesis of mind from non- mental antecedents. But here it is sufficient merely to make this general statement of the fact, that even within the experience supplied by our own organisms adaptive movements of a highly complex and therefore apparently purposive character may be performed without any real purpose, or even consciousness of their performance. It thus becomes evident that before we can predicate the bare existence of mind in the lower animals, we need some yet more definite criterion of mind than that which is supplied by the adaptive actions of a living organism, howsoever apparently intentional such actions may be. Such a criterion I have now to lay down, and I think it is one that is as practically adequate as it is theoretically legitimate. Objectively considered, the only distinction between adaptive movements due to reflex action and adaptive movements due to mental perception, consists in the former depending on inherited mechanisms within the nervous system being so constructed as to effect particular adaptive movements in response to particular stimula- B 2 J 4 INTEODUCTION. tions, while the latter are independent of any such in- herited adjustment of special mechanisms to the exi- gencies of special circumstances. Keflex actions under the influence of their appropriate stimuli may be com- pared to the actions of a machine under the manipu- lations of an operator ; when certain springs of action are touched by certain stimuli, the whole machine is thrown into appropriate movement ; there is no room for choice, there is no room for uncertainty ; but as surely as any of these inherited mechanisms are affected by the stimulus with reference to which it has been constructed to act, so surely will it act in precisely the same way as it always has acted. But the case with conscious mental adjustment is quite different. For, without at present going into the question concerning the relation of body and mind, or waiting to ask whether cases of mental adjustment are not really quite as mechanical in the sense of being the necessary result or correlative of a chain of physical sequences due to a physical stimulation, it is enough to point to the variable and incalculable character of mental adjustments as distinguished from the constant and foreseeable character of reflex adjustments. All, in fact, that in an objective sense we can mean by a mental adjustment is an adjustment of a kind that has not been definitely fixed by heredity as the only adjustment pos- sible in the given circumstances of stimulation. For were there no alternative of adjustment, the case, in an animal at least, would be indistinguishable from one of reflex action. It is, then, adaptive action by a living organism in cases where the inherited machinery of the nervous system does not furnish data for our prevision of what the adap- tive action must necessarily be — it is only here that we recognise the objective evidence of mind. The criterion of mind, therefore, which I propose, and to which I shall adhere throughout the present volume, is as follows : — Does the organism learn to make new adjustments, or to modify old ones, in accordance with the results of its own individual experience ? If it does so, the fact cannot be due merely to reflex action in the sense above described, INTKODUCTION. 5 for it is impossible that heredity can have provided in advance for innovations upon, or alterations of, its machi- nery dm-ing the lifetime of a particular individual. In my next work I shall have occasion to consider this criterion of mind more carefully, and then it will be shown that as here stated the criterion is not rigidly ex- clusive, either, on the one hand, of a possibly mental element in apparently non-mental adjustments, or, con- versely, of a possibly non-mental element in apparently mental adjustments. But, nevertheless, the criterion is the best that is available, and, as it will be found sufficient for all the purposes of the present work, its more minute analysis had better be deferred till I shall have to treat of the probable evolution of mind from non-mental an- tecedents. I may, however, here explain that in my use of this criterion I shall always regard it as fixing only the upper limit of non-mental action ; I shall never regard it as fixing the lower limit of mental action. For it is clear that long before mind has advanced sufficiently far in the scale of development to become amenable to the test in question, it has probably begun to dawn as nascent sub- jectivity. In other words, because a lowly organised animal does not learn by its own individual experience, we may not therefore conclude that in performing its natural or ancestral adaptations to appropriate stimuli consciousness, or the mind-element, is wholly absent ; we / can only say that this element, if present, reveals no evidence of the fact. But, on the other hand, if a lowly organised animal does learn by its own individual experi- ence, we are in possession of the best available evidence of conscious memory leading to intentional adaptation. Therefore our criterion applies to the upper limit of non- mental action, not to the lower limit of mental. Of course to the sceptic this criterion may appear un- satisfactory, since it depends, not on direct knowledge, but on inference. Here, however, it seems enough to point out, as already observed, that it is the best criterion available ; and further, that scepticism of this kind is logically bound to deny evidence of mind, not only in the case of the lower animals, but also in that of the 6 INTKODUCTION. higher, and even in that of men other than the sceptic himself. For all objections which could apply to the use of this criterion of mind in the animal kingdom would apply with equal force to the evidence of any mind other than that of the individual objector. This is obvious, because, as I have already observed, the only evidence we can have of objective mind is that which is furnished by objective activities ; and as the subjective mind can never become assimilated with the objective so as to learn by direct feeling the mental processes which there accompany the objective activities, it is clearly impossible to satisfy any one who may choose to doubt the validity of inference, that in any case other than his own mental processes ever do accompany objective activities. Thus it is that philo- sophy can supply no demonstrative refutation of idealism, even of the most extravagant form. Common sense, how- ever, universally feels that analogy is here a safer guide to truth than the sceptical demand for impossible evi- dence; so that if the objective existence of other or- ganisms and their activities is granted — without which postulate comparative psychology, like all the other sciences, would be an unsubstantial dream — common sense will always and without question conclude that the activities of organisms other than our own, when analogous to those activities of our own which we know to be accom- panied by certain mental states, are in them accompanied by analogous mental states. The theory of animal automatism, therefore, which is usually attributed to Descartes (although it is not quite clear how far this great philosopher really entertained the theory), can never be accepted by common sense ; and even as a philosophical speculation it will be seen, from what has just been said, that by no feat of logic is it possible to make the theory apply to animals to the exclusion of man. The expression of fear or affection by a dog in- volves quite as distinctive and complex a series of neuro- muscular actions as does the expression of similar emotions by a human being; and therefore, if the evidence of corresponding mental states is held to be inadequate in the one case, it must in consistency be held similarly INTRODUCTION. 7 inadequate in the other. And likewise, of course, with all other exhibitions of mental life. It is quite true, however, that since the days of Des- •cartes — or rather, we might say, since the days of Joule — the question of animal automatism has assumed a new or more defined aspect, seeing that it now runs straight into the most profound and insoluble problem that has ever been presented to human thought — viz. the relation of body to mind in view of the doctrine of the conservation of energy. I shall subsequently have occasion to consider this problem with the close attention that it demands ; but in the present volume, which has to deal only with the pheno- mena of mind as such, I expressly pass the problem aside as one reserved for separate treatment. Here I desire only to make it plain that the mind of animals must be placed in the same category, with reference to this pro- blem, as the mind of man ; and that we cannot without gross inconsistency ignore or question the evidence of mind in the former, while we accept precisely the same kind of evidence as sufficient proof of mind in the latter. And this proof, as I have endeavoured to show, is in all cases and in its last analysis the fact of a living organism showing itself able to learn by its own individual experi- ence. Wherever we find an animal able to do this, we have the same right to predicate mind as existing in such an animal that we have to predicate it as existing in any human being other than ourselves. For instance, a dog has always been accustomed to eat a piece of meat when hiis organism requires nourishment, and when his olfactory nerves respond to the particular stimulus occasioned by the proximity of the food. So far, it may be said, there is no evidence of mind ; the whole series of events com- prised in the stimulations and muscular movements may he due to reflex action alone. But now suppose that by a number of lessons the dog has been taught not to eat the naeat when he is hungry until he receives a certain verbal signal : then we have exactly the same kind of evidence that the dog's actions are prompted by mind as we have that the actions of a man are so prompted.^ Now we find * Of course it may be said that we have no evidence of prompting 8 INTHODUCTION. that the lower down we go in the animal kingdom, the more we observe reflex action, or non-mental adjustment, to predominate over volitional action, or mental adjust- ment. That is to say, the lower down we go in the animal kingdom, the less capacity do we find for changing adjustive movements in correspondence with changed conditions ; it becomes more and more hopeless to teach animals — that is, to establish associations of ideas; and the reason of this, of course, is that ideas or mental units become fewer and less definite the lower we descend through the structure of mind. It is not my object in the present work to enter upon any analysis of the operations of mind, as this will require to be done as fully as possible in my next work. Never- theless, a few words must here be said with regard to the main divisions of mental operation, in order to define closely the meanings which I shall attach to certain terms relating to these divisions, and the use of which I cannot avoid. The terms sensation, perception, emotion, and volition need not here be considered. I shall use them in their ordinary psychological significations; and although I shall subsequently have to analyse each of the organic or mental states which they respectively denote, there will be no occasion in the present volume to enter upon this subject. I may, however, point out one general con- sideration to which I shall throughout adhere. Taking it for granted that the external indications of mental processes which we observe in animals are trustworthy, so that we are justified in inferring particular mental states from particular bodily actions, it follows that in con- sistency we must everywhere apply the same criteria. For instance, if we find a dog or a monkey exhibiting marked expressions of affection, sympathy, jealousy, rage, &c., few persons are sceptical enough to doubt that the complete analogy which these expressions afford with in either case ; but this is the side issue which concerns the general relation of body and mind, and has nothing to do with the guarantee of inferring the presence of mind in particular cases. INTRODUCTION. 9 those which are manifested by man, sufficiently prove the existence of mental states analogous to those in man of which these expressions are the outward and visible signs. But when we find an ant or a bee apparently exhibiting by its actions these same emotions, few persons are sufficiently non-sceptical not to doubt whether the outward and visible signs are here trustworthy as evidence of analogous or corresponding inward and mental states. The whole organisation of such a creature is so different from that of a man that it becomes questionable how far analogy drawn from the activities of the insect is a safe guide to the inferring of mental states — particularly in view of the fact that in many respects, such as in the great preponderance of * instinct ' over * reason,' the psychology of an insect is demonstrably a widely different thing from that of a man. Now it is, of course, perfectly true that the less the resemblance the less is the value of any analogy built upon the resemblance, and therefore that the inference of an ant or a bee feeling sympathy or rage is not so valid as is the similar inference in the case of a dog or a monkey. Still it is an inference, and, so far as it goes, a valid one — being, in fact, the only in- ference available. That is to say, if we observe an ant or a bee apparently exhibiting sympathy or rage, we must either conclude that some psychological state resembling that of sympathy or rage is present, or else refuse ta think about the subject at all ; from the observable facts there is no other inference open. Therefore, having full regard to the progressive weakening of the analogy from human to brute psychology as we recede through the animal kingdom downwards from man, still, as it is the only analogy available, I shall follow it throughout the animal series. It may not however, be superfluous to point out that if we have full regard to this progressive weaken- ing of the analogy, we must feel less and less certain of the real similarity of the mental states compared ; so that when we get down as low as the insects, I think the most we can confidently assert is that the known facts of human psychology furnish the best avail- 10 INTRODUCTION. able pattern of the probable facts of insect psychology. Just as the theologians tell us — and logically enough — that if there is a Divine Mind, the best, and indeed only, conception we can form of it is that which is formed on the analogy, however imperfect, supplied by the human mind; so with 'inverted anthropomorphism' we must apply a similar consideration with a similar conclusion to the animal mind. The mental states of an insect may be widely different from those of a man, and yet most probably the nearest conception that we can form of their true nature is that which we form by assimilating them to the pattern of the only mental states with which we are actually acquainted. And this consideration, it is needless to point out, has a special validity to the evo- lutionist, inasmuch as upon his theory there must be a psychological, no less than a physiological, continuity extending throughout the length and breadth of the animal kingdom. In these preliminary remarks only one other point requires brief consideration, and this has reference to the distinction between what in popular phraseology is called ^Instinct' and 'Keason.' I shall not here enter upon any elaborate analysis of a distinction which is un- doubtedly valid, but shall confine my remarks to ex- plaining the sense in which I shall everywhere use these terms. Few words in our language have been subject to a greater variety of meanings than the word instinct. In popular phraseology, descended from the Middle Ages, ^11 the mental faculties of the animal are termed in- stinctive, in contradistinction to those of man, which are termed rational. But unless we commit ourselves to an obvious reasoning in a circle, we must avoid assuming that all actions of animals are instinctive, and then arguing that because they are instinctive, therefore they differ from the rational actions of man. The question really lies in what is here assumed, and we can only answer it by examining in what essential respect instinct -differs from reason. INTEODUCTION. 11 Again, Addison says : — I look upon instinct as upon the principle of gravitation in bodies, which is not to be explained by any known qualities inherent in the bodies themselves, nor from any laws of me- chanism, but as an immediate impression from the first Mover, and the Divine energy acting in the creatures. This mode of ' looking upon instinct ' is merely to exclude the subject from the sphere of inquiry, and so to -abstain from any attempt at definition. Innumerable other opinions might be quoted from well-known writers, 'looking upon instinct' in widely different ways ; but as this is not an historical work, I shall pass on at once to the manner in which science looks upon it, or, at least, the manner in which it will always be looked upon throughout the present work. Without concerning ourselves with the origin of in- stincts, and so without reference to the theory of evolution, we "have to consider the most conspicuous and distinctive features of instinct as it now exists. The most important point to observe in the first instance is that instinct involves Tnental operations ; for this is the only point that serves to distinguish instinctive action from reflex. Reflex action, as already explained, is non-mental neuro- muscular adaptation to appropriate stimuli; but in- stinctive action is this and something more ; there is in it the element of mind. Such, at least, is instinctive action in the sense that I shall always allude to it. I am, of course, aware that the limitation which I thus impose is one which is ignored, or not recognised, by many writers even among psychologists ; but I am per- suaded that if we are to have any approach to definiteness in the terms which we employ — not to say of clear- ness in our ideas concerning the things of which we speak — ^it is most desirable to restrict the word instinct to mental as distinguished from non-mental activity. No doubt it is often difficult, or even impossible, to decide whether or not a given action implies the presence of the mind-element — i.e., conscious as distinguished from un- conscious adaptation ; but this is altogether a separate matter, and has nothing to do with the question of 12 INTRODUCTION. defining instinct in a manner which shall be formally" exclusive, on the one hand of reflex action, and on the other of reason. As Virchow truly observes, * it is diffi- cult or impossible to draw the line between instinctive and reflex action ; ' but at least the difficulty may be narrowed down to deciding in particular cases whether or not an action falls into this or that category of defini- tion ; there is no reason why the difficulty should arise on account of any ambiguity of the definitions themselves. Therefore I endeavour to draw as sharply as possible the line which in theory should be taken to separate in- stinctive fronr- reflex action; and this line, as I have already said, is constituted by the boundary of non-mental or unconscious adjustment, with adjustment in which there is concerned consciousness or mind. Having thus, I hope, made it clear that the difficulty of drawing a distinction between reflex and instinctive actions as a class is one thing, and that the difficulty of assigning particular actions to one or the other of our categories is another thing, we may next perceive that the former difficulty is obviated by the distinction which I have imposed, and that the latter only arises from the fact that on the objective side there is no distinction im- posable. The former difficulty is obviated by the distinc- tion which I have drawn, simply because the distinction is itself a definite one. In particular cases of adjustive action we may not always be able to affirm whether con- sciousness of their performance is present or absent ; but, as I have already said, this does not affect the validity of our definition ; all we can say of such cases is that if the performance in question is attended with consciousness it is instinctive, and if not it is reflex. And the difficulty of assigning particular actions to one or other of these two categories arises, as I have said, merely because on the objective side, or the side of the aervous system, there is no distinction to be drawn* Whether or not a neural process is accompanied by a men- tal process, it is in itself the same. The advent and de- velopment of consciousness, although progressively con- verting reflex action into instinctive, and instinctive into INTRODUCTION. 13 Tational, does this exclusively in the sphere of subjec- tivity ; the nervous processes engaged are throughout the same in kind, and differ only in the relative degrees of their complexity. Therefore, as the dawn of consciousness or the rise of the mind-element is gradual and undefined, both in the animal kingdom and in the growing child, it is but necessary that in the early morning, as it were, of consciousness any distinction between the mental and the non-mental should be obscure, and generally impossible to determine. Thus, for instance, a child at birth does not close its eyes upon the near approach of a threatening body, and it only learns to do so by degrees as the result of experience ; at first, therefore, the action of closing the eyelids in order to protect the eyes may be said to be instinctive, in that it involves the mind-element : ^ yet it afterwards becomes a reflex which asserts itself even in opposition to the will. And, conversely, sucking in a new-born child, or a child in utero, is, in accordance with my definition, a reflex action ; yet in later life, when con- sciousness becomes more developed and the child seeks the breast, sucking may properly be called an instinctive action. Therefore it is that, as in the ascending scale of objective complexity the mind-element arises and advances gradually, many particular cases which occupy the undefined boundary between reflex action and instinct cannot be assigned with confidence either to the one region or to the other. We see then the point, and the only point, wherein instinct can be consistently separated from reflex action ; viz., in presenting a mental constituent. Next we must consider wherein instinct may be separated from reason. And for this purpose we may best begin by considering what we mean by reason. The term ' reason ' is used in significations almost as various as those which are applied to * instinct.' Some- > I.e., ancestral as well as individual. If the race had not always had occasion to close the eyelids to protect the eyes, it is certain that the young child would not so quickly learn to do so in virtue of its own individual experience alone ; and as the action cannot be attri- buted to any process of conscious inference, it is not rational ; but we have seen that it is not originally reflex ; therefore it is instinctive 14 INTEODUCTION, times it stands for all the distinctively human faculties taken collectively, and in antithesis to the mental faculties of the brute ; while at other times it is taken to mean the distinctively human faculties of intellect. Dr. Johnson defines it as * the power by which man deduces one proposition from another, and proceeds from premises to consequences.' This definition presupposes language, and therefore ignores all cases of inference not thrown into the formal shape of predication. Yet even in man the majority of inferences drawn by the mind never emerge as articulate propositions; so that although, as we shall have occasion fully to observe in my subsequent work, there is much profound philosophy in identifying reason with speech as they were identified in the term Logos, yet for purposes of careful definition so to identify intellect with language is clearly a mistake. More correctly, the word reason is used to signify the V power of perceiving analogies or ratios, and is in this sense equivalent to the term ' ratiocination,' or the faculty of deducing inferences from a perceived equivalency of relations. Such is the only use of the word that is strictly legitimate, and it is thus that I shall use it throughout the present treatise. This faculty, however,, of balancing relations, drawing inferences, and so of fore- casting probabilities, admits of numberless degrees ; and as in the designation of its lower manifestations it sounds "^ somewhat unusual to employ the word reason, I shall in these cases frequently substitute the word intelligence. Where we find, for instance, that an oyster profits by individual experience, or is able to perceive new relations and suitably to act upon the result of its perceptions, I J think it sounds less unusual to speak of the oyster as dis- playing intelligence than as displaying reason. On this account I shall use the former term to signify the lower degrees of the ratiocinative faculty ; and thus in my usage it will be opposed to such terms as instinct, reflex action, &c., in the same manner as the term reason is so opposed. This is a point which, for the sake of clearness, I desire the reader to retain in his memory. I shall always speak of intelligence and intellect in antithesis to instinct, emo- INTEODUCTION. 15' tion, and the rest, as implying mental faculties the same- in kind as those which in ourselves we call rational. Now it is notorious that no distinct line can be drawn between instinct and reason. Whether we look to the- growing child or to the ascending scale of animal life, we find that instinct shades into reason by imperceptible- degrees, or, as Pope expresses it, that these principles are * for ever separate, yet for ever near.' Nor is this other than the principles of evolution would lead us to expect,, as I shall afterwards have abundant occasion to show. Here, however, we are only concerned with drawing what distinction we can between instinct and reason as these faculties are actually presented to our observation. And this in a general way it is not difficult to do. We have seen that instinct involves * mental opera- tions,' and that by this feature it is distinguished from re- flex action ; we have now to consider the features by which it is distinguished from reason. These are accurately,, though not completely, conveyed by Sir Benjamin Brodie, who defines instinct as * a principle by which animals are induced, independently of experience and reason- ing, to the performances of certain voluntary acts, which are necessary to their preservation as individuals, or to the continuance of the species, or in some other way convenient to them.'^ This definition, as I have said, is accurate as far as it goes, but it does not state with sufficient generaHty and terseness that all instinctive action is adaptive ; nor does it clearly bring out the dis- tinction between instinct and reason which is thus well conveyed by the definition of Hartmann, who says in his * Philosophy of the Unconscious,' that ' instinct is action taken in pursuance of an end, but without conscious per- ception of what the end is.' This definition, however, is likewise defective in that it omits another of the im- portant differentiae of instinct — namely, the uniformity of instinctive action as performed by different individuals of the same species. Including this featiure, therefore, we- may more accurately and completely define instinct as mental action (whether in animals or human beings)^ ' Psychological Researches, p. 187. 16 INTEODUCTION. directed towards the accomplishing of adaptive movement, ^'>\^'^^ l!»*. 25 CHAPTEK II. MOLLUSCA. I SHALL treat of the Mollusca before the Articulata, because as a group their intelligence is not so high. Indeed, it is not to be expected that the class of animals wherein the * vegetative ' functions of nutri- tion and reproduction predominate so largely over the animal functions of sensation, locomotion, &c., should present any considerable degree of intelligence. Never- theless, in the only division of the group which has sense organs and powers of locomotion highly developed — viz., the Cephalopoda — we meet with large cephalic ganglia, and, it would appear, with no small develop- ment of intelligence. Taking, however, the sub-king- dom in ascending order, I shall first present all the trustworthy evidence that I have been able to collect, pointing to the highest level of intelligence that is at- tained by the lower members. The following is quoted from Mr. Darwin's MS. : — Even the headless oyster seems to profit from experience, for Dicquemase ('Journal de Physique/ vol. xxviii. p. 244) asserts that oysters taken from a depth never uncovered by the sea, open their shells, lose the water within, and perish ; but oysters taken from the same place and depth, if kept in reser- voirs, where they are occasionally left uncovered for a short time, and are otherwise incommoded, learn to keep their shells shut, and then live for a much longer time when taken out of the water. ^ * This fact is also stated by Bingley, Animal Biography, vol. iii. p. 454, and is now turned to practical account in the so-called * Oyster- schools ' of France. The distance from the coast to Paris being too great for the newly dredged oysters to travel without opening their shells, they are first taught in the schools to bear a longer and longer exposure to the air without gaping, and when their education in this respect is completed they are sent on their journey to the metropolis, where they arrive with closed shells, and in a healthy condition. 26 ANIMAL INTELLIGENCE. Some evidence of intelligence seems to be displayed by the razor-fish. For the animals dislike salt, so that when this is sprinkled above their burrows in the sand, they come to the surface and quit their habitations. But if the animal is once seized when it comes to the surface and afterwards allowed to retire into its burrow, no amount of salt will force it again to come to the surface.* With regard to snails, L. Agassiz writes : ' Quiconque a eu I'occasion d'observer les amours des limapons, ne saurait mettre en doute la seduction deployee dans les mouvements et les allures qui preparent et accomplissent le double embrassement de ces hermaphrodites.' ^ Again, Mr. Darwin's MS. quotes from Mr. W. White ^ a curious exhibition of intelHgence in a snail, which does not seem to have admitted of mal-observation. » This gentleman 'fixed a land-shell mouth uppermost in a chink of rock ; in a short time the snail protruded itself to its utmost length, and, attaching its foot vertically above, tried to pull the shell out in a straight line. Not succeeding, it rested for a few minutes and then stretched out its body on the right side and pulled its utmost, but failed. Besting again, it protruded its foot on the left side, pulled with its full force, and freed the shell. This exertion of force in three directions, which seems so geometrically suitable, must have been intentional.' If it is objected that snail shells must frequently be liable to be impeded by obstacles, and therefore that this display of manceuvring on the part of their occupants is to be regarded as a reflex, I may remark that here again we have one of those incessantly recurring cases where it is difficult to draw the line between intelligence and non- intelligence. For, granting that the action is to a certain extent mechanical, we must still recognise that the animal while executing it must have remembered each of the two directions in which it had pulled ineffectually before it began to pull in the third direction ; and it is improbable that snail shells are so frequently caught in positions from which a pull in only one direction will ' Bingley, he. cit., vol. iii. p. 449. « Be VEspece et de la Classe, Sec, 1869, p. 106. ■ A Londoner's Walk to Edinhv/rgh, p. 155 (1856). MOLLUSCA. 27 release them, that natural selection would have developed a special instinct to try pulling successively in three directions at right angles to one another. The only other instance that I have met with of the apparent display of intelligence in snails is the remark- able one which Mr. Darwin gives in his * Descent of Man,' on the authority of Mr. Lonsdale. Although the inter- pretation which is assigned to the fact seems to me to go beyond anything that we should have reason to expect of snail intelligence, I cannot ignore a fact which stands upon the observation of so good an authority, and shall therefore quote it in Mr. Darwin's words : — These animals appear also susceptible of some degree of per- manent attachment : an accurate observer, Mr. Lonsdale, in- forms me that he placed a pair of land-snails {Helix pomatia), one of which was weakly, into a small and ill-provided garden. After a short time the strong and healthy individual disap- peared, and was traced by its track of slime over a wall into an adjoining well-stocked garden. Mr. Lonsdale concluded that it had deserted its sickly mate ; but after an absence of twenty- four hours it returned, and apparently communicated the result of its successful exploration, for both then started along the same track, and disappeared over the wall.^ In this case the fact must be accepted, seeing that it stands on the authority of an accurate observer, and is of so definite a kind as not to admit of mistake. Conse- quently we are shut up to the alternative of supposing the return of the healthy snail to its mate a mere acci- dent, and their both going over the wall into the well- stocked garden another mere accident, or acquiescing in the interpretation which Mr. Darwin assigns. Now, if we look closely into the matter, the chances against the double accident in question are certainly so considerable as to render the former supposition almost impossible. On the other hand, there is evidence to prove, as I shall immediately show, that a not distantly allied animal is unquestionably able to remember a particular locality as its home, and habitually to return to this locality after feeding. Therefore, in view of this analogous and cor- * Descent of Man, pp. 262-3. 28 ANIMAL INTELLIGENCE. roborative case, the improbability of the snail remembering^ for twenty-four hours the position of its mate is very much reduced ; while the subsequent communication, if it took place, would only require to have been of the nature of * follow me,' which, as we shall repeatedly find, is a degree of communicative ability which many inverte- brated animals possess. Therefore, in view of these con- siderations, I incline to Mr. Darwin's opinion that the facts can only be explained by supposing them due to intelli- gence on the part of the snails. Thus considered, these facts are no doubt very remarkable ; for they would appear to indicate not merely accurate memory of direction and locality for twenty-four hours, but also no small degree of something akin to ' permanent attachment,' and sympa- thetic desire that another should share in the good things which one has found. ^ The case to which I have just alluded as proving- beyond all doubt that some Gasteropoda are able to retain a very precise and accurate memory of locality, is that of the common limpet. Mr. J. Clarke Hawkshaw publishes in the Journal of the Linnaean Society the following account of the habits in question : — The holes in the chalk in which the limpets are often to be . found are, I believe, excavated in a great measure by rasping from the Ungual teeth, though I doubt whether the object is to form a cavity to shelter in, though the cavities, when formed, may be of use for that purpose. It must be of the greatest im- portance to a limpet that, in order that it may insure a firm adherence to the rock, its shell should fit the rock accurately ; when the shell does fit the rock accurately, a small amount of muscular contraction of the animal would cause the shell to ad- here so firmly to a smooth surface as to be practically im- moveable without fracture. As the shells cannot be adapted daily to different forms of surface, the limpets generally return to the same place of attachment. I am sure this is the case with many ; for I found shells perfectly adjusted to the uneven surfaces of flints, the growth of the shells being in some parts > The facts, however, in order to sustain such conclusions, of course require corroboration, and it is therefore to be regretted that Mr. Lons- dale did not experimentally repeat the conditions. MOLLUSCA. 29 ^storted and indented to suit inequalities in the surface of the flints. ... I noticed signs that limpets prefer a hard, smooth surface to a pit in the chalk. On one surface of a large block, over all 45ides of which limpets were regularly and plentifully distri- buted, there were two flat fragments of a fossil shell about 3 inches by 4 inches, each embedded in the chalk. The chalk all round these fragments was free from limpets ; but on the smooth surface of the pieces of shell they were packed as closely as they could be. I noticed another case, which almost amounts, to my mind, to a proof that they prefer a smooth surface to a hole. A limpet had formed a clearing on one of the sea- weed- covered blocks before referred to. In the midst of this clearing was a pedestal of flint rather more than one inch in diameter, standing up above the surface of the chalk; it projected so much that a tap from my hammer broke it off. On the top of the smooth fractured surface of this flint the occupant of the clearing had taken up its abode. The shell was closely adapted to the uneven surface, which it would only flt in one position. The cleared surface was in a hollow with several small natural cavities, where the limpet could have found a pit ready made to shelter in; yet it preferred, after each excursion, to climb up to the top of the flint, the most exposed point in all its domain.^ It appears certain from these observations, which to some extent were anticipated by those of Mr. F. C. Lukis,^ that limpets, after every browsing excursion, return to one particular spot or home ; and the precise memory of direction and locality implied by this fact seems to justify us in regarding these actions of the animal as of a nature unquestionably intelligent. Coming now to the cephalopoda, there is no doubt that if a larger sphere of opportunity permitted, adequate observation of these animals would prove them to be much the most intelligent members of the sub-kingdom. Unfortunately, however, this sphere of opportunity has hitherto been very limited. The following meagre ac- count is all that I have been able to gather concerning the psychology of these interesting animals. According to Schneider,^ the Cephalopoda show un- * Journal Lmn. Soe. vol. xiv. p. 406 et 8eq. 2 Mag. Nat. Hist. 18.31, vol. iv. p. 346. » Thieresche Wille, § 78. 30 ANIMAL INTELLIGENCE. mistakable evidence of consciousness and intelligence. This observer had an opportunity of watching them for a long time in the zoological station at Naples ; and he says that they appeared to recognise their keeper after they had for some time received their food from him. HoUmann narrates that an octopus, which had had a struggle with a lobster, followed the latter into an adjacent tank, to which it had been removed for safety, and there destroyed it. In order to do this the octopus had to climb up a vertical partition above the surface of the water and descend the other side.^ According to Schneider, the Cephalopoda have an abstract idea of water, seeking to return to it when removed, even though they do not see it. But this probably arises from the sense of discomfort due to exposure of their skin to the air ; and if we can call it an ' idea,' it is doubtless shared, by all other aquatic MoUusca when exposed to air. * Lehen der Cephalojjodent s. 21. 31 CHAPTEK III. ANTS. Within the last ten or twelve years our information on the habits and intelligence of these insects has been so considerably extended, that in here rendering a condensed epitome of our knowledge in this most interesting branch of comparative psychology, it will be foimd that the chapter is constituted principally of a statement of observa- tions and experiments which have been conducted during the short period named. The observers to whom we aire mainly indebted for this large increase of our knowledge are Messrs. Bates, Belt, MiiUer, Moggridge, Lincecum, MacCook, and Sir John Lubbock. From the fact that these naturalists conducted their observations in different parts of the world and on widely different species of ants, it is not surprising that their results should present many points of difference ; for this only shows, as we might have ex- pected, that different species of ants differ considerably in habits and intelligence. Therefore, in now drawing all these numerous observations to a focus, I shall endeavour to show clearly their points of difference as well as their points of agreement ; and in order that the facts to be considered may be arranged in some kind of order, I shall deal with them under the following heads : — Powers of special sense ; Sense of direction ; Powers of memory ; Emotions ; Powers of communication ; Habits general in sundry species ; Habits peculiar to certain species ; Greneral intelligence of various species. Powers of Special Sense, Taking first the sense of sight, Sir John Lubbock made a number of experiments on the influence of light coloured by passing through various tints of stained glass, with the 32 ANIMAL INTELLIGENCE. following results. The ants which he observed greatly dislike the presence of light within their nests, hurrying about in search of the darkest corners when light is ad- mitted. The experiments showed that the dislike is much greater in the case of some colours than in that of others. Thus under a slip of red glass there were congregated on one occasion 890 ants, imder green 544, under yellow 495, and under violet only 5. To our eyes the violet is as opaque as the red, more so than the green, and much more so than the yellow. Yet, as the numbers show, the ants had scarcely any tendency to congregate under it : there were nearly as many under the same area of the uncovered portion of the nest as under that shaded by the violet glass. It is curious that the coloured glasses appear to act on the ants in a graduated series, which corresponds with the order of their influence on a photographic plate. Ex- periments were therefore made to test whether it might not be the actinic rays that were so particularly distasteful to the ants; but with negative results. Placing violet glass above red produces the same effect as red glass alone. Obviously, therefore, the ants avoid the violet glass because they dislike the rays which it transmits, and do not prefer the other colours because they like the rays which they transmit. Sodium, barium, strontium, and lithium flames were also tried, but not with so much effect as the coloured glass. It has just been observed that the relative dislike which Sir John Lubbock's ants showed to lights of different colours seems to be determined by the position of the colour in the spectrum — there being a regular gradation of intole- rance shown from the red to the violet end. As these ants dislike light, the question suggests itself that the reason of their graduated intolerance to light of different colours may be due to their eyes not being so much affected by the rays of low as by those of high refrangibility. In this connection it would be interesting to ascertain whether ants of the genus Atta show a similarly graduated intole- rance to the light in different parts of the spectrum ; for both Moggridge and MacCook record of this genus that it not only does not shun the light, but seeks it — coming to ANTS — SPECIAL SENSES. 33 the glass sides of their artificial nests to enjoy the light of .a lamp. Possibly, therefore, the scale of preference to lights of different colours would be found in this genus to be the reverse of that which Sir John Lubbock has found in the case of the British species. As regards hearing, Sir John Lubbock found that sounds of various kinds do not produce any effect upon the insects. Tuning-forks and violin notes, shouting, whistling, &c., were all equally inefficient in producing the slightest influence upon the animals ; and experiments with sensitive flames, microphone, telephone, &c., failed to yield any evidence of ants emitting sounds inaudible to human ears. Lastly, as regards the sense of smell, Sir John Lubbock found that on bringing a camel's-hair brush steeped in various strong scents near where ants were passing, *' some went on without taking any notice, but others stopped, and evidently perceiving the smell, turned back. Soon, however, they returned, and passed the scented pencil. After doing this two or three times, they generally took no further notice of the scent. This experiment left no doubt on my mind." In other cases the ants were observed to wave about and throw back their antennae when the scented pencil was brought near. That ants track one another by scent was long ago mentioned by Huber, and also that they depend on this sense for their power of finding supplies which have been previously found by other ants. Huber proved their power of tracking a path previously pursued by their friends, by drawing his finger across the trail, so oblite- rating the scent at that point, and observing that when the ants arrived at that point they became confused and ran about in various directions till they again came upon the trail on the other side of the interrupted space, when they proceeded on their way as before. The more numerous and systematic experiments of Sir John Lubbock have fully corroborated Huber's observations, so far as these points are concerned. Thus, to give only one or two of these experiments ; in the accompanying woodcut (Fig. 1) A is the nest, B a board, n f g slips of paper, h and m D 34 ANIMAL INTELLIGENCE. similar slides of glass, on one of whicli, h, there was placed pupae, while the other, m, was left empty. Sir John Lub- bock watched two particular (marked) ants proceeding from A to A and back again, carrying the pupae on h to the nest A^ Whenever an ant came out of A upon B he transposed the slips / and g. Therefore at the angle below n there was a choice pre- sented to the ant of taking the unscented pathway leading to the full glass h, or the scented pathway leading to the empty glass m. The two marked ants, knowing their way, always took the right turn at the angle ; but the stranger ants, being guided only by scent, for the most part took the wrong turn at the angle, so going to the empty glass m. For out of 150 stranger ants only 21 went to h, while the remaining 129 went to m. Still the fact that all the stranger ants did not follow the erroneous scent-trail to m, may be taken to indicate that they are also assisted in finding treasure by the sense of sight, though in a lesser degree. Therefore Sir John Lubbock concludes that in finding treasure ' they are guided in some cases by sight, while in others they track one another by scent.' As further evidence showing how much more ants de- pend upon scent than upon sight in finding their way, the following experiment may be quoted. In the accompany- ing woodcut (Fig. 2) the line marked 1, 2, 3 represents the edge of a paper bridge leading to the nest ; A the top of a pencil which is standing perpendicularly upon a board, represented by the general black surface ; B the top of the same pencil when moved a distance of a few inches from its first position A. On the top of this pencil were placed some pupae. Sir John Lub- bock, after contriving this arrangement, marked an ant and put it upon the pupae on the top of the pencil. After she had made two journeys carrying pupae from the pencil to the nest (the tracks she pursued being repre- sented by the two thick white lines), while she was in the nest he moved the pencil to its position at B. The thin ANTS— SPECIAL SENSES. 35 white line represents the course then pursued by the ant in its endeavours to find the pencil, which was shifted only a few inches from A to B. That is, ' the ants on their journey to the shifted object travelled very often back- Fig. 2. wards and forwards and round the spot where the coveted object first stood. Then they would retrace their steps towards the nest, wander hither and thither from side to side between the nest and the point A, and only after very repeated efforts around the original site of the larvae reach, as it were, accidentally the object desired at B.' Therefore the ants were clearly not guided by the sight of the pencil. The same thing is well shown by another form of experiment. ' Some food was placed at the point a (Figs. 3 and 4) on a board measuring 20 inches by 12 inches, D 2 36 ANIMAL INTELLIGENCE. Fig. 3. twisted as shown in Fig. 4 and so arranged that the ants in going straight from it to the nest would reach the board at the point 6, and after _i , passing under the paper tunnel c, would proceed between iive pairs of wooden bricks, each 3 inches in length and If inches in height. When they got to know their way they went quite straight along the line d e to a. The board was then ' The bricks and tunnel being arranged exactly in the same direction as be- fore, but the board having been moved, the line d e was now out- side them. The change, however, did not at all ^ discompose the ants ; but instead of going, as before, through the tunnel and between the rows of bricks to a, they walked exactly Keeping the board steady, but moving the brick pathway to the left-hand corner of the board where the food was next placed (Fig. 5), had the effect of making the ant first go to the old position of the food at a, whence it veered to a new position, which we may call X. The bricks ' and food were then moved to- Fig. 4. along the old path to e.' Fig. 6. wards the right-hand comer of the board — i.e. over a dis- tance of 8 inches (Fig. 6). The ant now first went to a. ANTS — SENSE OF DIRECTION. 37 then to ic, and not finding the food at either place, set to work to look for it at random, and was only successful after twenty-five minutes' ^ wandering. And, as evidence how much more dependence they place upon scent in finding their way than upon any other of their faculties, it is desirable to quote yet one further ex- periment, which is of great interest as showing that ^^' when their sense of smell is made to contradict their sense of direction, they follow the former, notwithstanding, as we shall presently see, the wonderful accuracy of the information which is supplied to them by the latter. ' If, when F. niger were carrying ofi* larvae placed in a cup on a piece of board, I turned the board round so that the side which had been turned towards the nest was away from it, and vice versa, the ants always returned over the same track on the board, and, in consequence, directly away from home. If I moved my board to the other side of my artificial nest, the result was the same. Evidently they followed the road, not the direction.' There can be little doubt that ants have a sense cf taste, as they are so well able to distinguish sugary sub- stances ; and it is unquestionable that in their antennae they possess highly elaborated organs of touch. Sense of Direction, As evidence of the accuracy and importance of the sense of direction in the Hymenoptera, we must here adduce Sir John Lubbock's highly interesting experiments on ants — leaving his experiments in this connection on bees and wasps to be considered in the next chapter. He first accustomed some ants (Lasius niger) to go to and fro to food over a wooden bridge. When they had got quite accustomed to the way, he watched when an ant was upon a bridge which could be rotated, and while she 38 ANIMAL INTELLIGENCE. was passing along it, he turned it round, so that end b was at c, and c at 6. ' In most cases the ant immediately turned round also ; but even if she went on to h or c, as the case might be, as soon as she came to the end of the bridge she turned round.' Next, between the nest and the food he placed a hat-box twelve inches in diameter and seven inches high, cutting two small holes, so that the ants in passing from the nest to the food had to pass in at one hole and out at the other. The box was fixed upon a central pivot, so as to admit of being rotated easily without much friction or disturbance. When the ants had well learnt their way, the box was turned half round as soon as an ant had entered it, 'but in every case the ant turned too, thus retaining her direction.' Lastly, Sir John took a disk of white paper, which he placed in the stead of the hat-box between the nest and the food. When an ant was on the disk making towards the food, he gently drew the disk to the other side of th^ food, so that the ant was conveyed by the moving surface in the same direction as that in which she was going, but beyond the point to which she intended to go. Under these circumstances ' the ant did not turn round, but went on ' to the further edge of the disk, when she seemed ' a good deal surprised at finding where she was.' These experiments seem to show that the mysterious * sense of direction,' and consequent faculty of ' homing,' are in ants, at all events, due to a process of registering, and, where desirable, immediately counteracting any change of direction, even when such change is gently made by a wholly closed chamber in which the animal is moving, and not by any muscular movements of the animal itself. And the fact that drawing the moving surface along in the same direction of advance as that which the insect is pursuing does not afifect the movements of the latter, seems conclusively to show that the power of registration has reference only to lateral movements of the travelling surface ; it has no reference to variations in the velocity of advance along the line in which the animal is pro- gressing.^ ' While this MS. is passing through the press Sir John Lubbock has ANTS— MEMOKY. 39 Powers of Memory, Little need here be said to prove that ants display some powers of memory ; for many of the observations and experiments already detailed constitute a sufficient demon- stration of the statement that they do. Thus, for instance, the general fact that whenever an ant finds her way to a store of food or larvse, she will return to it again and again in a more or less direct line from her nest, constitutes ample proof that the ant remembers the way to the store. It is of considerable interest, however, to note that the nature of this insect-memory appears to be, as far as it goes, precisely identical with that of memory in general. Thus, a new fact becomes impressed upon their memory by repetition, and the impression is liable to become effaced by lapse of time. More evidence on both these features of insect-memory will be adduced when we come to treat of the intelligence of bees ; but meanwhile it is enough to refer to the fact that in his experiments on ants. Sir John Lubbock found it necessary to teach the insects by a repetition of several lessons their way to treasure, if that way was long or unusual. With regard to the duration of memory, it does not appear that any experiments have been made ; but the following observation by Mr. Belt on this point in the case of the leaf-cutting ant may here be stated. In June 1859 he found his garden invaded by these ants, and following up their paths he found their nest about a hundred yards read another paper before the Linnsean Society, which contains some important additional matter concerning the sense of direction in ants. It seems that in the experiment above described, the hat-box was not provided with a cover or lid, i.e. was not a * closed chamber,' .and that Sir John now finds the ants to take their bearings from the ■direction in which they observe the light to fall upon them. For in the experiment with the uncovered hat-box, if the source of light {candle) is moved round together with the rotating table which sup- ports the box, the ants continue their way without making compen- sating changes in their direction of advance. The same thing happens if the hat-box is covered, so as to make of it a dark chamber. Direction of light being the source of their information that their ground is being moved, we can understand why they do not know that it is being moved when it is moved in the direction of their advance, as in the experiment with the paper slip. 40 ANIMAL INTELLIGENCE. distant. He poured down their burrows a pint of common brown carbolic acid, mixed with four buckets of water. The marauding parties were at once drawn off from the garden to meet the danger at home, and the whole formi- carium was disorganised, the ants running up and down again in the utmost perplexity. Next day he found them busily employed bringing up the ant-food from the old burrows, and carrying it to newly formed ones a few yards distant. These, however, turned out to be only intended as temporary repositories ; for in a few days both the old and the new burrows were entirely deserted, so that he supposed all the ants to have died. Subsequently, how- ever, he found that they had migrated to a new site, about two hundred yards from the old one, and there established themselves in a new nest. Twelve months later the ants again invaded his garden, and again he treated them to a strong dose of carbolic acid. The ants, as on the previous occasion, were at once withdrawn from the garden, and two days afterwards he found ' all the survivors at work on one track that led directly to the old nest of the year before, where they were busily employed in making fresh exca- vations. Many were bringing along pieces of ant-food * from the nest most recently deluged with carbolic acid ta that which had been similarly deluged a year before, and from which all the carbolic acid had long ago disappeared^ ' Others carried the undeveloped white pupae and larvae. It was a wholesale and entire migration;' and the next day the nest down which he had last poured the carbolic acid was entirely deserted. Mr. Belt adds : ' I afterwards found that when much disturbed, and many of the ants destroyed, the survivors migrate to a new locality. I do not doubt that some of the leading minds in this formicarium recol- lected the nest of the year before, and directed the. migration to it.' Now, I do not insist that the facts necessarily point to- this conclusion ; for it may have been that the leaders of the migration simply stumbled upon the old and vacant nest by accident, and finding it already prepared as a nest,, forthwith proceeded to transfer the food and pupae to it. Still, as the two nests were separated from one another by ANTS— MEMORY. 41 SO considerable a distance, this hypothesis does not seem probable, and the only other one open to us is that the ants remembered the site of their former home for a period of twelve months. And this conclusion is rendered less improbable from a statement of Karl Vogt in his * Thierstaaten,' to the effect that for several successive years ants from a certain nest used to go through certain inhabited streets to a chemist's shop 600 metres distant, in order to obtain access to a vessel filled with syrup. As it cannot be supposed that this vessel was found in suc- cessive working seasons by as many successive accidents, it can only be concluded that the ants remembered the syrup store from season to season. I shall now pass on to consider a class of highly re- markable facts, perhaps the most remarkable of the many remarkable facts connected with ant psychology. It has been known since the observations of Huber that all the ants of the same nest or community recognise one another as friends, while an ant introduced from another nest, even though it be an ant of the same species, is known at once to be a foreigner, and is usually maltreated or put to death. Huber found that when he removed an ant from a nest and kept it away from its companions for a period of four months it was still recog- nised as a friend, and caressed by its previous fellow- citizens after the manner in which ants show friendship, viz., by stroking antennae. Sir John Lubbock, after re- peating and fully confirming these observations, extended them as follows. He first tried keeping the separated ant away from the nest for a still longer period than four months, and found that even after a separation of more than a year the animal was recognised as before. He re- peated this experiment a number of times, and always with the same invariable difference between the recep- tion accorded to a foreigner and a native — no matter, apparently, how long the native had been absent. Considering the enormous number of ants that go to- make a nest, it seems astonishing enough that they should be all personally known to one another, and still more astonishing that they should be able to recognise members 42 ANIMAL INTELLIGENCE. of their community after so prolonged an absence. Think- ing that the facts could only be explained, either by all the ants in the same nest having a peculiar smell, or by all the members of the same community having a par- ticular pass-word or gesture-sign. Sir John Lubbock, with the view of testing this theory, separated some ants from a nest while still in the condition of pupae, and, when they emerged from that state as perfect insects, transferred them back to the nest from which they had been taken as pupse. Of course in this case the ants in the nest could never have seen those which had been removed, for a larval ant is as unlike the mature insect as a grub is unlike a beetle ; neither can it be supposed that a larva, hatched out away from the nest, should retain, when a perfect insect, any smell belonging to its parent nest — more especially as it had been hatched out by ants in another nest ; ^ nor, lastly, is it reasonable to imagine that the animal, while still a larval grub, can have been taught any gesture-signal used as a pass-word by the matured animals. Yet, although all these possible hypo- theses seem to be thus fully excluded by the conditions of the experiment, the result showed unequivocally that the ants recognised their transformed larvae as native-born members of their community. Lastly, Sir John Lubbock tried the experiment of going still further back in the life-history of the ants before separating them from the nest. For in September he divided a nest into two halves, each having a queen. At this season there were neither larvae nor eggs. The following April both the queens began to lay eggs, and in August — i.e. nearly a year after the original partitioning of the nest — he took some of the ants newly hatched from the pupae in one division, and placed them in the other division, and vice versa. In all cases these ants were re- ceived by the members of the other half of the divided nest as friends, although if a stranger were introduced into either half it was invariably killed. Yet the ants which * It is to be noted that although ants will attack stranger ants introduced from other nests, they will carefully tend stranger larvae r43imilarly introduced. ANTS— MEMOEY. 43 ^ere thus so certainly recognised by their kindred ants as friends had never, even in the state of an egg, been present in that division of the nest before. On this highly remarkable fact Sir John Lubbock says : — These observations seem to me conclusive as far as they go, and they are very surprising. In my experiments of last year, though the results were similar, still the ants experimented with had been brought up in the nest, and were only removed after they had become pupae. It might therefore be argued that the ants, having nursed them as larvae, recognised them when they came to maturity ; and though this would certainly be in the highest degree improbable, it could not be said to be impossible. In the present case, however, the old ants had ab- solutely never seen the young ones until the moment when, some days after arriving at maturity, they were introduced into the nest ; and yet in all ten cases they were undoubtedly recog- nised as belonging to the community. It seems to me, therefore, to be established by these experi- ments that the recognition of ants is not personal and indi- vidual; that their harmony is not due to the fact that each ant is individually acquainted with every other member of the community. At the same time, the fact that they recognise their friends •even when intoxicated, and that they know the young born in their own nest even when they have been brought out of the chrysalis by strangers, seems to indicate that the recognition is not effected by means of any sign or pass-word. We must, therefore, conclude with reference to this subject that the mode whereby recognition is undoubtedly -effected is as yet wholly unintelligible; and I have introduced these facts under the heading of memory only because this heading is not more inappropriate than any other that could be devised for their reception. It ought here to be added also that the power of thus recognising members of their community is not con- :fined by the limits of blood-relationship, for in an experi- ment made by Forel it was shown that Amazon ants Tecognised their own slaves almost instantaneously after an absence of four months. Under this heading I may also adduce the evidence as to enormous masses, or, as we might say, a whole nation of ants recognising each other as belonging to the same 44 ANIMAL INTELLIGENCE. nationality. New nests often spring up as offshoots from the older ones, and thus a nation of towns gradually spreads to an immense circumference around the original centre. Forel describes a colony of F. exsecta which comprised more than two hundred nests, and covered a space of nearly two hundred square metres. 'AH the members of such a colony, even those from the further- most nest, recognise each other and admit no stranger.' Similarly, MacCook describes an 'ant town' in the Alleghany Mountains of North America (* Trans. Amer. Entom. Soc.j'Nov. 1877) which was inhabited hj F, exsec- toides. It consists of 1,600 to 1,700 nests, which rise in cones to a height of from two to five feet. The ground below is riddled in every direction with subterranean passages of communication. The inhabitants are all on the most friendly terms, so that if any one nest is injured it is repaired by their united forces. It remains to be added in connection with this subject that the recognition is not automatically invariable, but when ' ants are removed from a nest in the pupa state, tended by strangers, and then restored, some at least of their relatives are certainly puzzled, and in many cases doubt their claims to consanguinity. I say some, because while strangers under the circumstances would have been immediately attacked, these ants were in every case amicably received by the majority of the colony, and it was sometimes several hours before they came across one who did not recognise them.' It may also be added that Lasius flavus behaves towards strangers quite differently and much more hos- pitably than is the case with L, niger. The stranger shows no alarm, but, on the contrary, will voluntarily enter the strange nest, and she is there received with kindness ; although from the attention she excites, and the numerous communications which take place between her and her new friends. Sir John was ' satisfied that they knew she was not one of themselves. . . . Very different is the behaviour of X. niger under similar circumstances. I tried the same experiment with them. There was no communications with the antennae, there was no cleaning. ANTS— EMOTIONS. 45 but every ant which the stranger approached flew at her like a httle tigress. I tried this experiment four times ; ^ach stranger was killed and borne off to the nest.' Emotions, The pugnacity, valour, and rapacity of ants are too well and generally known to require the narration of special instances of their display. With regard to the tenderer emotions, however, there is a difference of opi- nion among observers. Before the researches of Sir John Lubbock it was the prevalent view that these insects dis- play marked signs of affection towards one another, both by caressing movements of their antennae, and by showing solicitude for friends in distress. Sir John, however, has found that the species of ants on which he has experi- mented are apparently deficient both in feelings of iiffection and of sympathy — or, at least, that such feelings are in these species much less strongly developed than the sterner passions. He tried burying some specimens of Lasius niger beneath an ant-road ; but none of the ants traversing the road made any attempt to release their imprisoned com- panions. He tried the same experiment with the same result on various other species. Even when the friends in difficulty are actually in sight, it by no means follows that their companions will assist them. Of this, he says, he could give almost any number of instances. Thus, when ants are entangled in honey, their companions devote themselves to the honey, and entirely neglect their friends in distress ; and when partly drowned, their friends take no notice. When chloroformed or intoxicated their own companions either do not heed them, or else ' seem somewhat puzzled at finding their intoxicated fellow-creatures in such a condition, take them up, and oarry them about for a time in a somewhat aimless manner.' Further experiments, however, on a larger scale, went to show that chloroformed ants were treated as dead, i.e. removed to the edge of the parade-board and dropped over into the surrounding moat of water ; while intoxicated 46 ANIMAL INTELLIGENCE. ants were generally carried into the nest, if they were ants belonging to that community ; if not, they were thrown overboard. This care shown towards intoxicated friends appears to indicate a dim sense of sympathy towards afflicted individuals; but that this emotion or instinct does not in the case of these species extend to healthy individuals in distress seems to be proved, not only by thc^ experiments of burying already described, but also by the following : — On Sept. 2, therefore, I put two ants from one of my nests of F.fusca into a bottle, the end of which was tied up with muslin as described, and laid it down close to the nest. In a second bottle I put two ants from another nest of the same species. The ants which were at liberty took no notice of the bottle containing their imprisoned friends. The strangers in the other bottle, on the contrary, excited them considerably. The whole day one, two, or more ants stood sentry, as it were, over the bottle. In the evening no less than twelve were collected round it, a larger number than usually came out of the nest at any one time. The whole of the next two days, in the same way, there were more or less ants round the bottle containing the strangers; while, as far as we could see, no notice whatever was taken of the friends. On the 9 th the ants had eaten through the muslin, and effected an entrance. We did not chance to be on the spot at the moment ; but as I found two ants lying dead, one in the bottle and one just outside, I think there can be no doubt that the strangers were put to death. The friends throughout were quite neglected. Sept. 21. — I then repeated the experiment, putting three ants from another nest in a bottle as before. The same scene was repeated. The friends were neglected. On the other hand, some of the ants were always watching over the bottle containing the strangers, and biting at the muslin which pro- tected them. The next morning at 6 a.m. I found five ants thus occupied. One had caught hold of the leg of one of the strangers, which had unwarily been allowed to protrude through the meshes of the muslin. They worked and watched, though not, as far as I could see, with any system, till 7.30 in the evening, when they effected an entrance, and immediately at- tacked the strangers. Sept. 24. — I repeated the same experiment with the same nest. Again the ants came and sat over the bottle containing the strangers, while no notice was taken of the friends. ANTS— SYMPATHY. 47 The next morning again, when I got up, I found five ants round the bottle containing the strangers, none near the friends. As in the former case, one of the ants had seized a stranger by the leg, and was trying to drag her through the muslin. All day the ants clustered round the bottle, and bit perseveringly, though not systematically, at the muslin. The same thing hap- pened all the following day. On repeating these experiments with another species (viz., Formica rufescens) the ants took no notice of either bottle, and showed no sign either of affection or hatred. One is almost tempted to surmise that the spirit of these ants is broken by slavery \i.e. by the habit of keeping slaves]. But the experi- ments on F. fusca seem to show that in these curious insects hati'ed is a stronger passion than affection. We must not, however, too readily assent to this general conclusion, that ants as a whole are deficient in the tenderer emotions ; for although the case is doubtless so with the species which Sir John examined, it appears to be certainly otherwise with other species, as we shall presently see. But first it may be well to point out that even the hard-hearted species with which Sir John had to do seem not altogether devoid of sympathy with sick or mutilated friends, although they appear to be so towards healthy Mends in distress. Thus the care shown to intoxicated friends seems to indicate, if not, as already observed, a dim sense of sympathy, at least an instinct to preserve the life of an ailing citizen for the future benefit of the community. Sir John also quotes some observa^- tions of Latreille showing that ants display sympathy with mutilated companions ; and, lastly, mentions an instance which he has himself observed of the same thing. A spe- cimen of F, fused congenitally destitute of antennae was attacked and injured by an ant of another species. When separated by Sir John, another ant of her own species came by. ' She examined the poor sufferer carefully, then picked her up tenderly, and carried her away into the nest. It would have been difficult for any one who witnessed this scene to have denied to this ant the pos- session of humane feelings.' Moggridge is also of opinion that the habit of throwing sick and apparently dead ants -48 ANIMAL INTELLIGENCE. into the water, is * in part to be rid of them, and partly, perhaps, with a view to effecting a possible cure ; for 1 have seen one ant carry another down the twig which formed their path to the surface of the water, and, after dipping it in for a minute, carry it laboriously up again, and lay it in the sun to dry and recover.' But that some species of ants display marked signs of what we may call sympathy even towards healthy com- panions in distress, is proved by the following observation of Mr. Belt. He writes :^— One day, watching a small column of these ants {i.e. Eciton humata), I placed a little stone on one of them to se- cure it. The next that approached, as soon as it discovered its situation, ran backwards in an agitated manner, and soon com- municated the intelligence to the others. They rushed to the rescue ; some bit at the stone and tried to move it, others seized the prisoner by the legs and tugged with such force that I thought the legs would be pulled off, but they persevered until they got the captive free. I next covered one up with a piece of clay, leaving only the ends of its antennae projecting. It was soon discovered by its fellows, which set to work immediately, and by biting off pieces of the clay soon liberated it. Another time I found a very few of them passing along at intervals. I confined one of these under a piece of clay at a little distance from the line, with his head projecting. Several ants passed it, but at last one discovered it and tried to pull it out, but could not. It immediately set off at a great rate, and I thought it had deserted its comrade, but it had only gone for assistance, for in a short time about a dozen ants came hurrying up, evi- dently fully informed of the circumstances of the case, for they made directly for their imprisoned comrade and soon set him free. I do not see how this action could be instinctive. It was sympathetic help, such as man only among the higher mam- malia shows. The excitement and ardour with which they carried on their unflagging exertions for the rescue of their comrade could not have be«n greater if they bad been human beings. This observation seems unequivocal as proving fellow- feeling and sympathy, so far as we can trace any analogy between the emotions of the higher animals and those of * The NaturaliM in Nica/ragtia, 1874, p. 26. ANTS— COMMUNICATION. 49 insects. That insects with such highly organised social habits, and depending so greatly on the principles of co- operation, should manifest emotions or instincts of an inci- piently altruistic character, is no more than we should antecedently expect on the general principle of survival of the fittest. Our only surprise should be that these emotions, or instincts, should appear to be so feebly de- veloped in some species of ants, and, as we shall subse- quently see, also of bees. But it may be worth while in this connection to point out that the valuable observation of Mr. Belt above quoted refers to the species of ant which, as we shall subsequently find, presents the most highly organised instincts of co-operation that are to be met with among ants, and therefore the greatest dependence of the welfare of the individual on that of the community. And the same remark is applicable to our native species, F. san- guinea, which the Kev. W. W. F. White has repeatedly seen rescuing buried companions very much in the manner ■described by Mr. Belt ; and he does not appear to be ac- quainted with Mr. Belt's observations. He figures one case in which he saw three ants co-operating to dig out a buried comrade. Powers of Communication, Huber, Kirby and Spence, Dugardin, Burmeister, Franklin, and other observers have all expressed them- selves as more or less strongly of the opinion that members of the same community of ants, and other social Hymen- optera, are able to communicate information to one another by some system of language or signs. The facts, however, on which their opinion rests have not been stated with that degree of caution and detail which the accept- ance of the conclusion requires. Thus, Kirby and Spence give only one instance of supposed communication between ants,2 and even this one is inconclusive, as the facts de- scribed admit of being explained by supposing that the ants simply tracked one another by scent ; while Huber * See Leisv/re Bow, 1880, p. 390. ' Introduction to Entotnology, vol. ii. p. 524. E 50 ANIMAL INTELLIGENCE. merely deals in general statements as to ' contact of antennae,' without narrating any particulars of his observa- tions. Therefore, until within the last few years there was really no sufficient evidence to sustain the general opinion that ants are able to communicate with one another ; but the observations which I shall now detail must be regarded as fully substantiating that general opinion by facts as abundant and conclusive as the most critical among us can desire. I shall first narrate in his own words the more important of Sir John Lubbock's experiments in this connection: — I took three tapes, each about 2 feet 6 inches long, and aiTanged them parallel to one another and about 6 inches apart. An end of each I attached to one of the nests [F. niger), and at the other end I placed a glass. In the glass at the end of one tape I placed a considerable number (300 to 600) of larvae. In the second I put two or three larvae only, in the thii'd none at all. The object of the last was to see whether many ants would come to the glasses under such circumstances by mere accident, and I may at once say that scarcely any did so. I then took two ants, and placed one of them to the glass with many larvae, the other to that with two or three. Each of them took a larva and carried it to the nest, returning for another, and so on. After each journey I put another larva in the glass with only two or three larvae, to replace that which had been removed. Now, if several ants came under the above circumstances as a mere matter of accident, or accom- panying one another by chance, or if they simply saw the larvae which were being brought, and consequently concluded that they might themselves find a larva in the same place, then the numbers going to the two glasses ought to be approximately equal. In each case the number of journeys made by the ants would be nearly the same ; consequently, if it was a matter of scent, the two glasses would be in the same position. It would be impossible for an ant, seeing another in the act of bringing a larva, to judge for itself whether there were few or many left behind. On the other hand, if the strangers were brought, then it would be curious to see whether more were brought to the glass with many larvae than to that which only contained two or three. I should also mention that every stranger was imprisoned until the end of the experiment. The results of these experiments were that during ANTS — COMMUNICATION. 51 47-i hours the ants which had access to a glass containing numerous larvae brought 257 friends to their assistance ; while during an interval 5^ hours longer those which visited the glass with only two or three larvae brought only 82 friends ; and, as already mentioned, no single ant came to the glass which contained no larvae. Now, as all the glasses were exposed to similar conditions, and as the roads to the first two must, in the first instance at all events, have been equally scented by the passage of ants over them, these results look very conclusive as proving some power of definite communication, not only that larvae are to be found, but even where the largest store is to be met with. To this interesting account Sir John Lubbock adds, — One case of apparent communication struck me very much. I had had an ant {F. niger) under observation one day, during which she was occupied in carrying oflf larvae to her nest. At night I imprisoned her in a small bottle ; in the morning I let her out at 6.15, when she immediately resumed her occupation. Having to go to London, I imprisoned her again at 9 o'clock. When I returned at 4.40 I put ner again to the larvae. She examined them carefully, and went home without taking one. At this time no other ants were out of the nest. In less than a minute she came out again with eight friends, and the little heap made straight for the heap of larvae. When they had gone two-thirds of the way I again imprisoned the marked ant; the others hesitated a few minutes, and then with curious quick- ness returned home. At 5.15 I put her again to the larvae. She again went home without a larva, but after only a few seconds' stay in the nest, came out with no less than thirteen friends. They all went towards the larvae, but when they had got about two-thirds of the way, although the marked ant had on the previous day passed over the ground about 150 times, and though she had just gone straight from the larvae to the nest, she seemed to have forgotten her way, and considered ; and after she had wandered about for half an hour, I put her to the larvae. Now, in this case, the twenty-one ants must have been brought out by my marked one, for they came exactly with her, and there were no other ants out. Moreover, it would seem that they mu»t have been told, because (which is very curious in itself) she did not in either case bring a larva, and K 2 62 ANIMAL INTELLIGENCE. consequently it cannot have been the mere sight of a larva which had induced them to follow her. Further experiments proved, as we might have ex- pected, that although an ant is able to communicate to her friends in the nest that she has found treasure some- where outside, she is not able to describe to them its pre- cise locality. Thus, having exposed larvae and placed an ant upon them as before. Sir John watched every time she came out of the nest with friends to assist her, but instead of allowing her to pilot the way, he took her up and carried her to the larvae, allowing her to return with a larva upon her own feet. Under these circumstances the friends, although evidently coming out with the intention of finding some treasure, were never able to find it ; but wandered about in various directions for a while, and then returned to the nest. Thus, during two hours she brought out in her successive journeys altogether no less than 120 ants, of which number only 5 in their unguided wanderings happened to find the sought-for treasure. This result seems to prove, as we might have expected, that the communication is of the nature of some sign amounting to no more than a ' follow me.' Other experi- ments confirmed this result, and also brought out the fact that ' some species act much more in association than others — Formica fusca, for instance, much less than Lasius niger.^ Thus Sir John Lubbock placed some honey before a marked specimen of the former species ; but although she visited and revisited the honey during an entire day, she brought out no friends to share it ; and although in her journeys to and from the nest she happened to pass and repass many other individuals, they took no notice of each other. The obvious objection to these experiments, that an ant observing a friend bringing home food or a pupa might infer, without being told, that by accompanying the friend on the return journey she 'might participate in the good things,' has been partly met by the fact already stated, viz., that there is so very marked a difference in the result if, on experimenting on two ants, one had access to a large treasure and the other only to a small one. But ANTS — COMMUNICATION. 53 to put this matter beyond question, Sir John Lubbock tried the experiment of pinning down a dead fly, so that the ant which found it was unable, with all her tugging, to move it towards the nest. At length she went back to the nest for assistance, and returned accompanied by seven friends. So great was her excitement, however, that she outran these friends, ' who seemed to have come out reluctantly, as if they had been asleep, and were only half awake ; ' and they failed to find the fly, slowly meandering about for twenty minutes. After again tug- ging for a time at the fly, the first ant returned a second time to the nest for assistance, and in less than a minute came out with eight friends. They were even less energetic than the first party, and having lost sight of their guide in the same manner as happened before, they all returned to the nest. Meanwhile several of the first party, which had all the while been meandering about, found the fly, and proceeded to dismember it, carrying the trophy to the nest, and calling out more friends in the ordinary way. This experiment was repeated several times and on difi'er- ent species, always with the same result. Now, as Sir John remarks, * the two cases (i.e. those in which the ant brought out friends to her assistance even when she had no booty to show) surely indicate a distinct power of com- munication. ... It is impossible to doubt that the friends were brought out by the first ant ; and as she returned empty-handed to the nest, the others cannot have been induced to follow her by merely observing her proceedings. I conclude, therefore, that they possess the power of re- questing their friends to come and help them.' In order to ascertain whether the signs which com- municating ants make to one another are made by means of sound. Sir John Lubbock placed near a nest of Lasius flavus six small upright pillars of wood about 1^ inch high, and on one of these he put a drop of honey. ' I then put three ants to the honey, and when each had sufficiently fed, I imprisoned her, and put another ; thus always keep- ing three ants at the honey, but not allowing them to go home. If, then, they could summon their friends by sound, there ought soon to be many ants at the honey.' 54 ANIMAL INTELLIGENCE. The result showed that the ants were not able thus to call to one another from a distance. As additional proof of the general fact that at all events some ants have the power of communicating infor- mation to one another, it will be enough here to quote an exceedingly interesting observation of the distinguished geologist Hague. The quotations are taken from his letters written to Mr. Darwin, and published in Nature : ^ — On the mantelshelf of our sitting-room my wife has the habit of keeping fresh flowers. A vase stands at each end, and near the middle a small tumbler, usually filled with violets. Some time ago 1 noticed a pile of very small red ants on the wall above the left-hand vase, passing upward and downward be- tween the mantelshelf and a small hole near the ceiling, at a point where a picture nail had been driven. The ants, when first observed, were not very numerous, but gradually increased in number, until on some days the little creatures formed an almost unbroken procession, issuing from the hole at the nail, descending the wall, climbing the vase directly below the nail, satisfying their desire for water or perfume, and then returning. The other vase and tumbler were not visited at that time. As I was just then recovering from a long illness it hap- pened that I was confined to the house, and spent my days in the room where the operations of these insects attracted my atten- tion. Their presence caused me some annoyance, but I knew of no effective means of getting rid of them. For several days in succession I frequently brushed the ants in great numbers from the wall down to the floor ; but as they were not killed the re- sult was that they soon formed a colony in the wall at the base of the mantel, ascending thence to the shelf, so that before long the vase was attacked from above and below. One day I observed a number of ants, perhaps thirty or forty, on the shelf at the foot of the vase. Thinking to kill them, I struck them lightly with the end of my finger, killing some and disabling the ]-est. The effect of this was immediate and unexpected. As soon as those ants which were approach- ing arrived near to where their fellows lay dead and suffering, they turned and fled with all possible haste. In half an hour the wall above the mantelshelf was cleared of ants. During the space of an hour or two the colony from below ' Vol. vii. pp. 443-4. ANTS— COMMUNICATION. 55 continued to ascend until reaching the lower bevelled edge of the shelf, at which point the more timid individuals, although unable to see the vase, somehow became aware of trouble, and turned about without further investigation, while the more daring advanced hesitatingly just to the upper edge of the Ehelf, when, extending their antennae and stretching their necks, they seemed to peep cautiously over the edge until beholding their suffering companions, when they too turned and followed the others, expressing by their behaviour great excitement and terror. An hour or two later, the path or trail leading from the lower colony to the vase was almost entirely free from ants. I killed one or two ants on their path, striking them with my finger, but leaving no visible trace. The effect of this was that as soon as an ant ascending towards the shelf reached the spot where one had been killed, it gave signs immediately of great disturbance, and returned directly at the highest possible .«peed. A curious and invariable feature of their behaviour was that when such an ant, returning in fright, met another ap- proaching, the two would always communicate, but each would pursue its own way, the second ant continuing its journey to the spot where the first had tumod about, and then following that example. For some days after this there were no ants visible on the wall, either above or below the shelf Then a few ants from the lower colony began to reappear, but instead of visiting the vase which had been the scene of the disaster, they avoided it altogether, and following the lower front edge of the shelf to the tumbler standing near the middle, made their attack upon that. I repeated the same experiment here with precisely the same result. Killing or maiming a few of the ants and leaving their bodies about the base of the tum- bler, the others on approaching, and even before arriving at the upper surface of the shelf where their mutilated companions were visible, gave signs of intense emotion, some running away immediately, and others advancing to where they could survey the field and then hastening away precipitately. Occasionally an ant would advance towards the tumbler until it found itself among the dead and dying ; then it seemed to lose all self-possession, running hither and thither, making wide circuits about the scene of the trouble, stopping at times and elevating the antennae with a movement suggestive of wringing them in despair, and finally taking flight. After this another interval of several days passed, during which no ants 56 ANIMAL INTELLIGENCE. appeared. Now, three months later, the lower colony has been entirely abandoned. Occasionally, however, especially when fresh and fragrant violets have been placed on the shelf, a few ' prospectors ' descend from the upper nail-hole, rarely, almost never, approaching the vase from which they were first driven away, but seeking to satisfy their desire at the tumbler. To turn back these stragglers and keep them out of sight for a number of days, sometimes for a fortnight, it is sufficient to kill one or two ants on the trail which they follow descending the wall. This I have recently done as high up as I can reach, three or four feet above the mantel. The moment this spot is reached, an ant turns abruptly and makes for home, and in a little while there is not an ant visible on the wall. In a subsequent volume of * Nature ' (viii. p. 244), Mr. Darwin publishes another letter which he received from Mr. Hague upon the same subject. It seems that Mr. Mog- gridge suggested to Mr. Darwin that, as he and others had observed ants to be repelled by the mere scent of a finger drawn across their path, the observation of Mr. Hague might really resolve itself into a dislike on the part of the ants to cross a line over which a finger had been drawn, and have nothing to do with intelligent terror inspired by the sight of their slaughtered companions. The following is Mr. Hague's reply to Mr. Darwin's request for further experiments to test this point : — Acting on Mr. M 's suggestion, I first tried making simple finger-marks on their path (the mantel is of marble), and found just the results which he describes in his note as observed by himself at Mentone, that is, no marked symptoms of fear, but a dislike to the spot, and an ejSbrt to avoid it by going around it, or by turning back and only crossing it again after an interval of time. I then killed several ants on the path, using a smooth stone or piece of ivory, instead of my finger, to crush them. In this case the ants approaching all turned back as before, and with much greater exhibition of fear than when the simple finger-mark was made. This I did repeatedly. The final re- sult was the same as obtained last winter. They persisted in coming for a week or two, during which I continued to kill them, and then they disappeared, and we have seen none since. It would appear from this that while the taint of the hand is sufficient to turn them back, the killing of their fellows with a stone or other material produces the effect described in my first ANTS— SWAEMING. 57 note. This was made clear to me at that time, from the be- haviour of the ants the first day I killed any, for on that occa- sion some of them approaching the vase from below, on reaching the upper edge of the mantel, peeped over, and drew back on seeing what had happened about the vase, then turned away a little, and after a moment tried again at another and another point along the edge, with the same result in the end. More- over, those that found themselves among the dead and dying went from one writhing ant to another in great haste and ex- citement, exhibiting the signs of fright which I described. I hardly hope that any will return again, but if they do, and give me an opportunity, I shall endeavour to act further on Mr. M 's suggestion. With this quotation I shall conclude the present division of the chapter ; for, looking to all the other observations previously mentioned, there can be no question concern- ing the general fact that ants have the power of commu- nicating with one another. And under subsequent head- ings abundant additional evidence on this point will be found implicated with the other facts detailed. Habits General in Sundry Species. Swarming. — The precise facts with regara to the swarming of ants are not yet certainly established. As regards some of the facts, however, there is no doubt. The winged males and females first quit the nest in enor- mous numbers, and choose some fine afternoon in July or August for their wedding flight. The entrances to the nest are widened by the workers and increased in number, and there is a great commotion on the sur- face of the nest. The swarm takes place as a thick cloud of all the male and female insects, rising together to a considerable height. The flight continues for several hours, usually circling round some tree or tower, and it is during the flight that fertilisation is effected. After it is effected, the swarm returns to the ground, when the males perish, either from falling a prey, in their shelterless condition, to birds or spiders, or, on account of not being able to feed themselves, from starvation. ' The workers, or neuter ants, of their own 58 ANIMAL INTELLIGENCE. colony have lost all interest in them from the moment of their return, and trouble themselves no more about them, for they well know that the males have now fulfilled their vocation.' The great majority of the fertilised females share the same fate as the males. But a small proportion find concealment in holes, which they either dig for them- selves, or happen to find ready made, and there found a new colony. The first thing they do is to pull off their now useless wings, by scratching and twisting them, one after the other, with the clawed ends of their feet. They then lay their eggs, and become the queens of new colonies. Forel says that no fertilised female ever returns to her original home ; but that the workers keep back a certain number of females which are fertilised before the swarming takes place ; in this case the workers pull off the wings of the fertilised females. The majority of observers, how- ever, maintain that some of the females composing the swarm return to their native home to become mothers where they had been children. Probably both statements are correct. A writer in the ' Grroniger Deekblad ' for June 16, 1877, observes that, looking to the injurious effects of in-breeding, the facts as related by Forel are less probable than those related by other observers, and that, if they actually occur, the females fertilised before flight are probably kept by the ants as a sort of ' reserve corps to which the workers resort only in case of need, and if they fail to secure any returning queens.' Nursing. — The eggs will not develop into larvae un- less nursed. The nursing is effected by licking the surface of the eggs, which under the influence of this process increase in size, or grow. In about a fortnight, during which time the workers carry the eggs from higher to lower levels of the nest, and vice versa, according to the circumstances of heat, moisture, &c., the larvae are hatched out, and require no less careful nursing than the eggs. The workers feed them by placing mouths together and re- gurgitating food stored up in the crop or proventriculus into the intestinal tract of the young. The latter show their hunger by ' stretching out their little brown heads.' ANTS — NUESINa AND EDUCATION. 59 Oreat care is also taken by the workers in cleaning the larvae, as well as in carrying them up and down the chambers of the nest for warmth or shelter. When fully grown the larvae spin cocoons, and are then pupae, or the ' ants' eggs ' of bird-fanciers. These require no food, but still need incessant attention with reference to warmth, moisture, and cleanliness. When the time arrives for their emergence as perfect insects, the workers assist them to get out of their larval cases by biting through the walls of the latter. It is noticeable that in doing this the workers do not keep to any exact time, but free them sometimes earlier and sometimes later, in accordance with their rate of development. * The little animal when freed from its chrysalis is still covered with a thin skin, like a little shirt, which has to be pulled off. When we see how neatly and gently this is done, and how the young creature is then washed, brushed, and fed, we are involuntarily reminded of the nursing of human babies. The empty cases, or cocoons, are carried outside the nest, and may be seen heaped together there for a long time. Some species carry them far away from the nest, or turn them into building materials for the dwelling.' ' Education. — The young ant does not appear to come into the world with a full instinctive knowledge of all its duties as a member of a social community. It is led about the nest, and 'trained to a knowledge of domestic duties, especially in the case of the larvae.' Later on the young ants are taught to distinguish between friends and foes. When an ants' nest is attacked by foreign ants, the young ones never join in the fight, but confine themselves to removing the pupae ; and that the knowledge of hereditary enemies is not wholly instinctive in ants is proved by the following experiment, which we owe to Forel. He put young ants belonging to three different species into a glass case with pupae of six other species — all the species being naturally hostile to one another. The young ants did not quarrel, but worked together to tend the pupae. When the latter hatched out, an artificial colony was formed of ' Biichner, Geistesleben der Tkiere, pp. 66-7- 60 ANIMAL INTELLIGENCE. a number of naturally hostile species all living together after the manner of the ' happy families ' of the showmen. Habit of keeping Aphides. — It is well known that various species of ants keep aphides, as men keep milch cows, to supply a nutritious secretion. Huber first ob- served this fact, and noticed that the ants collected the eggs of the aphides and treated them exactly as they treated their own, guarding and tending them with the utmost care. When these eggs hatch out the aphides are usually kept and fed by the ants, to whom they yield a sweet honey-like fluid, which they eject from the abdomen upon being stroked on this region by the antennae of the ants. Mr. Darwin, who has watched the latter process, observes with regard to it, — I removed all the ants from a group of about a dozen aphides on a dock plant, and prevented their attendance during several hours. After this interval, I felt sure that the aphides would want to excrete. I watched them for some time through a lens, but not one excreted ; I then tickled them with a hair in the same manner, as well as I could, as the ants do with their antennae ; but not one excreted. Afterwards I allowed an ant to visit them, and it immediately seemed, by its eager way of running about, to be well aware what a rich flock it had dis- covered ; it then began to play with its antennae on the abdo- men, first of one aphis and then of another ; and each, as soon as it felt the antennae, immediately lifted up its abdomen and exOTeted a limpid drop of sweet juice, which was eagerly de- voured by the ant. Even quite young aphides behaved in this manner, showing that the action was instinctive, and not the result of experience. The facts also show that the yielding of the secretion to the ants is, as it were, a voluntary act on the part of the aphides, or, perhaps more correctly, that the instinct to- yield it has been developed in such a relation to the re- quirements of the ants, that the peculiar stimulation sup- plied by the antennae of the latter is necessary to start the act of secretion ; for in the absence of this particular stimu- lation the aphides will never excrete until compelled to da so by the superabundance of the accumulating secretion^ The question, therefore, directly arises how, on evolutionary ANTS — KEEPING APHIDES. 61 principles, such a class of facts is to be met ; for it is cer- tainly difficult to understand the manner in which this instinct, so beneficial to the ants, can have arisen in the aphides, to which it does not appear, at first sight, to ofier any advantages. Mr. Darwin meets the difficulty thus : * Although there is no evidence that any animal performs an action for the exclusive good of another species, yet each tries to take advantage of the instincts of others ;' and * as the secretion is extremely viscid, it is no doubt a convenience to the aphides to have it removed ; therefore probably they do not excrete solely for the good of the ants.' ^ Some ants which keep aphides build covered ways, or tunnels, to the trees or shrubs where the aphides live. Forel saw a tunnel of this kind which was taken up a wall and down again on the other side, in order to secure a safe covered way fi-om the nest to the aphides. Occasion- ally such covered ways, or tubes, are continued so as to enclose the stems of the plants on which the aphides live. The latter are thus imprisoned by the walls of the tube, which, however, expand where they take on this additional function of stabling the aphides, so that these insects are really confined in tolerably large chambers. The doors of these chambers are too small to allow the aphides to escape, while large enough for the ants to pass in and out. Forel saw such a prison or stable shaped like a cocoon, and about a centimetre long, which was hanging on the branch of a tree, and contained aphides carefully tended by the ants. Huber records similar observations. Sir John Lubbock has made an interesting addition to our knowledge respecting this habit as practised by a certain species of ant [Lasius Jlavus), which departs in a very remarkable manner from the habit as practised by other species. He says : ' The ants took the greatest care of these eggs, carrying them off to the lower chambers with the utmost haste when the nest was disturbed.' But the most interesting of Sir John Lubbock's observations in this connection is new, and reveals an astonishing ' Origin of Species, 6th ed. pp. 207-8. 62 ANIMAL INTELLIGENCE. amount of method shown by the ants in farming their aphides. He says : — When my eggs hatched I naturally thought that the aphides belonged to one of the species usually found on the roots of plants in the nests of Lasius jiavus. To my surprise, however, the young creatures made the best of their way out of the nest, and, indeed, were sometimes brought out by the ants them- selves. In vain I tried them with roots of grass, &c. ; they wandered uneasily about, and eventually died. Moreover, they did not in any way resemble the subterranean species. In 1878 I again attempted to rear these young aphides ; but though I hatched a great many eggs, I did not succeed. This year, how- ever, I have been more fortunate. The eggs commenced to hatch the first week in March. Near one of my nests of Lasius Jiavus, in which I had placed some of the eggs in question, was a glass containing living specimens of several species of plants commonly found on or around ants' nests. To this some of the young aphides were brought by the ants. Shortly after- wards I observed on a plant of daisy, in the axils of the leaves, some small aphides, very much resembUng those from my nest, though we had not actually traced them continuously. They seemed thriving, and remained stationary on the daisy. More- over, whether they had sprung from the black eggs or not, the ants evidently valued them, for they built up a wall of earth round and over them. So things remained throughout the summer, but on October 9 I found that the aphides had laid some eggs exactly resembling those found in the ants' nests ; and on examining daisy plants from outside, I found on many of them similar aphides, and more or less of the same eggs. I confess these observations surprised me very much. The statements of Huber have not, indeed, attracted so much notice as many of the other interesting facts which he has recorded ; because if aphides are kept by ants in their nests, it seems only natural that their eggs should also occur. The above case, however, is much more remarkable. Here are aphides, not living in the ants' nests, but outside, on the leaf-stalks of plants. The eggs are laid early in October on the food-plant of the in- sect. They are of no direct use to the ants, yet they are not left where they are laid, where they would be exposed to the severity of the weather and to innumerable dangers, but brought into their nests by the ants, and tended by them with the ut- most care through the long winter months until the following March, when the young ones are brought out and again placed ANTS — KEEPING APHIDES. 63 on the young shoots of the daisy. This seems to me a most remarkable case of prudence. Our ants may not perhaps lay up food for the winter, but they do more, for they keep during six months the eggs which will enable them to procure food during the following summer. The following, which is taken from Biichner's * Greistesleben der Thiere ' is perhaps a still more striking- performance of the same kind as that which Sir John Lubbock observed : — The author is debtor to Herr Nottebohm, Inspector of Build- ings at Karlsruhe, who related the following on May 24, 1876, under the title, ' Ants as Founders of Aphides' Colonies : ' — * Of two equally strong young weeping ashes, which I planted in my garden at Kattowitz, in Upper Silesia, one succeeded well, and in about five or six years showed full foliage, while the other regularly every year was covered, when it began to bud, with millions of aphides, which destroyed the young leaves and sprouts, and thus completely delayed the development of the tree. As I perceived that the only reason for this was the action of the aphides, I determined to destroy them utterly. So in the March of the following year I took the trouble to clean and wash every bough, sprig, and bud before the bursting of the latter, with the greatest care, by means of a syringe. The result was that the tree developed perfectly healthy and vigor- ous leaves and young shoots, and remained quite free from the aphides until the end of May or the beginning of June. My joy was of short duration. One fine sunny morning I saw a surprising number of ants running quickly up and down the trunk of the tree ; this aroused my attention, and led me to look more closely. To my great astonishment I then saw that many troops of ants were busied in carrying single aphides up the stem to the top, and that in this way many of the lower leaves had been planted with colonies of aphides. After some weeks the evil was as great as ever. The tree stood alone on the grass plot, and offered the only situation for an aphides^ colony for the countless ants there present. I had destroyed this colony ; but the ants replanted it by bringing new colonists from distant branches, and setting them on the young leaves.^ Again — MacCook noticed, of the mound-making ants, that of the * Loc. cit. p. 121. ()4 ANIMAL INTELLiaENCE. workers returning to the nest from the tree on which the milk- ing was going on, a far smaller number had distended abdomens than among those descending the tree itself. A closer investi- gation showed that at the roots of the trees, at the outlets of the subterranean galleries, a number of ants were assembled, which were fed by the returning ants after the fashion already described in feeding the larvae, and which were distinguished by the observer as ' pensioners.' MacCook often observed the same fact later, among, with others, the already described Pennsylvanian wood-ant. Distinguished individuals in the body-guard of the queen were fed in like fashion. MacCook is inclined to think that the reason of this proceeding is to be found in the * division of labour ' so general in the ant repub- lic, and that the members of the community which are em- ployed in building and working within the nest, leave to the others the care of providing food for themselves as well as for the younger and helpless members ; they thus have a claim to receive from time to time a reciprocal toll of gratitude, and take it, as is shown very clearly, in a way demanded by the welfare of the community.'^ Aphides are not the only insects which ants employ as cows, several other insects which yield sweet secretions being similarly utilised in various parts of the world. Thus, gall insects and cocci are kept in just the same way as aphides; but MacCook observed that where aphides and cocci are kept by the same ants, they are kept in separate chambers, or stalls. The same observer saw caterpillsirs of the genus Lycoena kept by ants for the sake of a sweet secretion which they supply. Habit of Tnaking Slaves, — This habit, or instinct, obtains among at least three species of ant, viz., Formica rufescens, F. sanguinea, and strongylognathus. It was originally observed by P. Huber in the first-named species. Here the species enslaved is F.fusca, which is appropriately coloured black. The slave-making ants attack a nest of F. fusca in a body ; there is a great fight with much slaughter, and, if victorious, the slave-makers carry off the pupae of the vanquished nest in order to hatch them out as slaves. Mr. Darwin gives an account of a battle which he himself observed.^ > Zoc. dt. p. 123. » Origin of Species, 6th ed. p. 218. ANTS —SLAVE-MAKING. 65 When the pupae hatch out in the nest of their captors, the young slaves begin their life of work, and seem to regard their master's home as their own ; for they never attempt to escape, and they fight no less keenly than their masters in defence of the nest. F, sanguinea content themselves with fewer slaves than do F. rufescens ; and the work that devolves upon the slaves differs according to the species which has enslaved them. In the nests of F. sanguinea the comparatively few captives are kept as household slaves ; they never either enter or leave the nest, and so are never seen unless the nest is opened. They are then very conspicuous from the contrast which their black colour and small size present to the red colour and much larger size of F, rufescens. As the slaves are by this species kept strictly indoors, all the outdoor work of foraging, slave-capturing, &c., is performed by the masters ; and when for any reason a nest has to migrate, the masters carry their slaves in their jaws. F, rufescens, on the other hand, assigns a much larger share of labour to the slaves, which, as we have already seen, are present in much larger numbers to take it. In this species the males and fertile females do no work of any kind ; and the workers, or sterile females, though most energetic in capturing slaves, do no other kind of work. Therefore the whole community is absolutely dependent upon its slaves. The masters are not able to make their own nests or to feed their own larvae. When they migrate, it is the slaves that determine the migration, and, reversing the order of things that obtains in F. sanguinea, carry their masters in their jaws. Huber shut up thirty masters without a slave and with abundance of their favourite food, and also with their own larvae and pupae as a stimulus to work ; but they could not feed even themselves, and many died of hunger. He then introduced a single slave, and she at once set to work, fed the surviving masters, attended to the larvae, and made some cells. ' In order to confirm this observation, Lespds placed a piece of sugar near a nest of slave-makers. It was soon found by one of the slaves, which gorged itself and re- turned to the nest. Other slaves then came out and did 66 ANIMAL INTELLIGENCE. likewise. Then some of the masters came out, and, by pulling the legs of the feeding slaves, reminded them that they were neglecting their duty. The slaves then imme- diately began to serve their masters with the sugar. Forel also has coniirmed all these observations of Huber. Indeed^ in the case of F. rufescens, the structure of the animal is such as to render self-feeding physically impossible. Its long and narrow jaws, adapted to pierce the head of an enemy, do not admit of being used for feeding, unless liquid food is poured into them by the mouth of a slave. This fact shows of how ancient an origin the instinct of slave-making must be ; it has altered in an important manner a structure which could not have been so altered prior to the establishment of the instinct in question. Mr. Darwin thus sums up the differences in the offices of the slaves in the nests of F. sanguinea and F, rufescens respectively : — The latter does not build its own nest, does not determine its own migrations, does not collect food for itself or for its fellows, and cannot even feed itself ; it is absolutely dependent on its nu- merous slaves. Formica sanguinea, on the other hand, possesses much fewer slaves, and in the early part of the summer extremely few ; the masters determine when and where a new nest shall be formed, and when they migrate, the masters carry the slaves. Both in Switzerland and England the slaves seem to have the exclusive care of the larvae, and the masters alone go on slave- making expeditions. In Switzerland the slaves and masters work together, making and bringing materials for the nest; both, but chiefly the slaves, tend and milk, as it may be called, their aphides ; and thus both collect food for the community. In England the masters alone usually leave the nest to collect building materials and food for themselves, their slaves and larvae. So that the masters in this country receive much less service from their slaves than they do in Switzerland. Mr. Darwin further observes that ' this difference in the usual habits of the masters and slaves in the two countries probably depends merely on the slaves being captured in greater numbers in Switzerland than in Eng- land ; ' and records that he has observed in a community of the English species having an unusually large stock of slaves that 'a few slaves mingled with their masters ANTS — SLAVE-MAKINa. 67 leaving the nest, and marched along the same road to a tall Scotch fir tree, twenty-five yards distant, which they ascended together, probably in search of aphides or cocci.' And, according to Huber, the principal office of the slaves in Switzerland is to search for aphides. Mr. Darwin also made the following observation : — * Desiring to ascertain whether F. sanguinea could dis- tinguish the pupae of F. fusca, which they habitually make into slaves, and which are an unwarlike species, from F, flava, which they rarely capture, and never without a severe fight,' he found ' it was evident that they did at once distinguish them ; ' for while ' they eagerly and instantly seized the pupae of F, fusca, they were much terrified when they came across the pupae, or even the earth from the nest, of F. flava, and quickly ran away ; but in about a quarter of an hour, shortly after the little yellow ants had crawled away (from their nest having been disturbed by Mr. Darwin), they took heart and carried off the pupae.' Concerning the origin of this remarkable instinct, Mr. Darwin writes : — As ants which are not slave-makers will, as I have seen, carry off pupae of other species if scattered near their nests, it is possible that such pupae originally stored as food might be- come developed, and the foreign ants thus unintentionally reared would then follow their proper instmcts, and do what work they could. If their presence proved useful to the species which had seized them — if it were more advantageous to the spe- cies to capture workers than to procreate them — the habit of collecting pupae, originally for food, might by natural selection be strengthened and rendered permanent for the very different purpose of laising slaves. When the instinct was once acquired, if carried out to a much less extent even than in our British F. sanguinea, which, as we have seen, is less aided by its slaves than the same species in Switzerland, natural selection might increase and modify the instinct, always supposing such modifi- cation to be of use to the species, until an ant was found as abjectly dependent on its slave as is the Formica rufescens. Ants do not appear .to be the only animals of which ants make slaves ; for there seems to be at least one case F 2 68 ANIMAL INTELLIGENCE. in which these wonderful insects enslave insects of another species, which therefore may be said to stand to the ants in the relation of beasts of burden. The case to which 1 allude is one that is recorded in Perty's ' Intellectual Life of Animals ' (2nd ed. p. 329), and is as follows : — According to Audubon certain leaf-bugs are used as slaves by the ants in the Brazilian forests. When these ants want to bring home the leaves which they have bitten off the trees, they do it by means of a column of these bugs, which go in pairs, kept in order on either side by accompanying ants. They compel stragglers to re-enter the ranks, and laggards to keep up by biting them. After the work is done the bugs are shut up within the colony and scantUy fed. Wars, — On the wars of ants a great deal might be said, as the facts of interest in this connection are very nume- rous ; but for the sake of brevity I shall confine myself to giving only a somewhat meagre account. One great cause of war is the plundering of ants' nests by the slave-making species. Observers all agree that this plundering is effected by a united march of the whole army composing a nest of the slave-making species, directed against some particular nest of the species which they enslave. According to Lesp^s and Forel, single scouts or small companies are first sent out from the nest to ex- plore in various directions for a suitable nest to attack. These scouts afterwards serve as guides to the marauding excursion. Forel saw several of these scouts of the species F, rufescens or Amazon carefully inspecting a nest of F, fusca which they had found, investigating especially the entrances. These are purposely made difficult to find by their architects, and it not unfrequently happens that after all precautions and inspections on the part of the invaders, an expedition fails on account of not finding the city gates. When the scouts have been successful in discovering a suitable nest to plunder, and have completed their stra- tegical investigations of the locality to their satisfaction, they return straight to their own nest or fortress. Forel has then seen them walking about on the surface of their nest for a long time, as if in consultation, or making up ANTS— WARS. 69 their minds. Then some of them entered the nest, soon after which hosts of warriors streamed out of the entrances, and ran about tapping each other with their heads and antennae. They then formed into column and set out to pillage the nest of the slave ants. The following is the account which Lesp^s gives of such expeditions : — They only take place towards the end of the summer and in autumn. At this time the winged members of the slave species [F. fusca and F. cunicularia) have left the nest, and the Amazons will not take the trouble to bring back useless con-, sumers. When the sky is clear our robbers leave their town in the afternoon at about three or four o'clock. At first no order is perceptible in their movements, but when they are all gathered together they form a regular column, which then moves forward quickly, and each day in a difierent direction. They march closely pressed together, and the foremost always appear to be seeking for something on the ground. They are each moment overtaken by others, so that the head of the column is continually growing. They are in fact seeking the traces of the ants which they propose to plunder, and it is scent that guides them. They snuff over the ground like hounds following the track of a wild animal, and when they have found it they plunge headlong forward, and the whole column rushes on be- hind. The smallest armies I saw consisted of several hundred individuals, but I have also seen some four times as large. They then form columns which may be five metres long, and as much as fifty centimetres wide. After a march, which often lasts a full hour, the column arrives at the nest of the slave species. The F. cunicularice, which are the strongest, offer keen opposition, but without much result. The Amazons soon penetrate within the nest, to come out again a moment later, while the assailed ants at the same time rush out in masses. During the whole time attention is directed solely to the larvae and pupae, which the Amazons steal while the others try to save as many as possible. They know very well that the Ama- zons cannot cHmb, so they fly with their precious burdens to the surrounding bushes or plants, whereto their enemies cannot follow them. They then pursue the retreating robbers and try to take away from them as much of their booty as possible. But the latter do not trouble themselves much about them, and hasten on home. On their return they do not follow the short- est road, but exactly the one by which they came, finding their way back by smell. An-ived at their nest, they immediately 70 - ANIMAL INTELLIGENCE. hand over their booty to the slaves, and trouble themselves no more about it. A few days afterwards the stolen pupae or nymphse emerge, without memory of their childhood, and imme- diately and without compulsion take part in all tasks. According to Biichner's account,^ — From time to time the army makes a short halt, partly to let the rearguard close up, partly because different opinions arise as to the direction of the host, or because the place at which they are is unknown to them. Forel several times saw the army completely lose its way — an incident only once ob- served by Huber. Forel puts the number of warriors in such an army at from one hundred to more than two thousand. Its speed is on an average a metre per minute, but varies much according to circumstances, and is naturally least when return- ing laden with booty. If the distance be very great, such bodily fatigue may at last be felt that the whole attack on the hostile nest is given up, and a retreat is begun ; Forel once saw this happen after they had passed over a distance of two hun- dred and forty yards. Sometimes it seems as though, on coming within sight of the hostile nest, a kind of discouragement took possession of them, and prevented their making the attack. If the nest cannot at once be found, the whole army halts, and some divisions are sent forward to search for it, and these are gradually seen returning towards the centre. Forel also saw such an army only searching the first day, advancing zigzag, and with frequent halts, whereas on the following day it went forward to its aim swiftly and without delay, having found out the road. It seems that a single ant, even if it knows the way and the place, is not able alone to lead a large army, but that a considerable number must be employed in this duty. Mistakes as to the road occur with special ease during the return journey, because the several ants are laden with booty and cannot readily understand each other. Individual ants are then seen to wander about in every direction often for a long time, until they at last reach a spot known to them, and then advance swiftly to their goal. Many never come back at all. These mistakes easily occur when the robbers which have passed into a hostile nest do not come out again at the same holes whereby they entered, but by others at some distance — for instance, by a subterranean canal. Coming out thus in a strange neighbourhood, they do not know which way to take, and only some chance to find the right road during their aimless wanderings about, and recognise and ^ Geisteslelen der Thiere, pp. 145-9. ANTS — WARS. 71 follow it by smell. On the other hand, such mistakes scarcely ever happen to individuals in an unladen train, kept in good array. Other species of ants {F.fusca, rufa, sanguinea) krvow better how to manage under such circumstances than do the Amazons. The laden ones lay down their loads, first find where they are, and only take them up again after they have found their way. If the booty seized in the nest first attacked is too large to be all taken at once, the robbers return once, or oftener, so as to complete their work The ants, as already said, have no regular leaders nor chiefs, yet it is certain that in each expedition, alteration of road, or other change, the decision during that event comes from a small knot of individuals, which have previously come to an understanding, and carry the rest and the undecided along with them. These do not always follow immediately, but only after they have received several taps on the head from the members of the * ring.' The pro- cession does not advance until the leaders have convinced them- selves by their own eyesight that the main part of the army is following. One day Forel saw some Amazons on the surface of a nest of the F. fusca seeking and sounding in all directions, without being able to find the entrance. At last one of them found a very little hole, hardly as large as a pin's head, through which the robbers penetrated. But since, owing to the smallness of the hole, the invasion went on slowly, the search was continued, and an entrance was found further off, through which the Amazon army gradually disappeared. All was quiet. About five minutes later Forel saw a booty-laden column emerge from each hole. Not a single ant was without a load. The two columns united outside and retreated together. A marauding excursion of the Amazons against the F. rufiharhis, a sub-species of the F. fusca, or small black ants, took place as follows : — The vanguard of the robber army found that it had reached the neighbourhood of the hostile nest more quickly than it had expected ; for it halted suddenly and de- cidedly, and sent a number of messengers which brought up the main body and the rearguard with incredible speed. In less than thirty seconds the whole army had closed up, and hurled itself in a mass on the dome of the hostile nest. This was the more necessary as the rufiharhes during the short halt had dis- covered the approach of the enemy, and had utilised the time to cover the dome with defenders. An indescribable struggle followed, but the superior numbers of the Amazons overcame, and they penetrated into the nest, while the defenders poured 72 AI^IMAL INTELLIGENCE. by thousands out of the same holes, with their larvae and pupae- in their jaws, and escaped to the nearest plants and bushes, running over the heaps of their assailants. These looked on the matter as hopeless, and began to retreat. But the rufi- harhes, ftirious at their proceedings, pursued them, and en- deavoured to get away from them the few pupae they had ob- tained, by trying to seize the Amazons' legs and to snatch away the pupae. The Amazon lets its jaws slip slowly along the captive pupa, as far as the head of its opponent, and pierces it, if it does not, as generally happens, draw back. But it often manages to seize the pupa at the instant at which the Amazon lets it go and flies with it. This is managed yet more easily when a comrade holds the robber by the legs, and compels it to loose its prey in order to guard itself against its assailant. Sometimes the robbers seize empty cocoons and carry them away, but they leave them on the road when they have dis- covered their mistake. In the above case the strength of the rufibarhes proved at last so great that the rearguard of 'the re- treating army was seriously pressed, and was obliged to give up its booty. A number of the Amazons also were overpowered and killed, but not without the rufibarhes also losing many people. None the less did some individuals, as though despe- rate, rush into the thickest hosts of the enemy, penetrated again into the nest, and carried off several pupae by sheer au- dacity and skill. Most of them left their prey to go to the help of their comrades when assailed by the rufiharhes. Ten minutes after the commencement of the retreat all the Amazons had left the nest, and, being swifter than their opponents, they were only pursued for about halfway back. Their attack had failed on account of a short delay ! On another occasion observed by Forel, in which several fertile Amazons also took part and killed many enemies, the nest was thoroughly ravished, but the retreat was also in this case very much disturbed and harassed by the superior numbers of the enemy. There were many slain on both sides. That in spite of the above-mentioned unanimity different opinions among the members of an expedition sometimes hinder its conduct, the following observation seems to show : — An advancing column divided after it had gone about ten yards from the nest. Half turned back, while the other half went on, but after some time hesitated and also turned back. Arrived at home, it found those which had formerly turned back putting themselves in motion in a new direction. The newly returned followed them, and the reunited army, after various wheelings, halts, &c., at ANTS — WARS. 7a last turned home again by a long way round. The whole busi- ness looked like a promenade. But apparently different parties had different nests in view, while others were entirely against the expedition. Yet perhaps it was only a march for exercise. Outer obstacles do not, as a rule, hinder the Amazons when they are once on the march. Forel saw them wade through some shallow water, although many were drowned in it, and then march over a dusty high road, although the wind blew half of them away. As they returned, booty-laden, neither wind, nor dust, nor water could make them lay down their prey. They only got back with great trouble, and turned back again to bring fresh booty, although many lost their lives. The following is also quoted from Biichner's excellent epitome of Forel's observations in this connection : — The most terrible enemy of the Amazons is the sanguine ant (F. sanguinea), which also keeps slaves, and thereby often comes into collision with the Amazons on their marauding ex- cursions. It is not equal to it in bodily strength or fighting capacity, but surpasses it in intelligence ; according to Forel it is the most intelligent of all the species of ants. If Forel, for instance, poured out the contents of a sack filled with a nest of the slave species near an Amazon nest, the Amazons apparently generally regarded the tumbled together heap of ants, larvae, pupae, earth, building materials, &c., as the dome of a hostile nest, and took all imaginable but useless pains to find out the entrances thereinto, leaving on one side for this investigation their only object, the carrying off the pupae ; but the sanguine ants under similar circumstances did not allow themselves to be deceived, but at once ransacked the whole heap. On another occasion, while a procession of Amazon ants was on its way to plunder a nest of F. fusca, before it arrived Forel poured out a sack-full of sanguine ants, and made a break in the nest ; — The sanguine ants pressed in, while the fusca came out to defend themselves. At this moment the first Amazons arrived. "When they saw the sanguine ants they drew back and awaited the main army, which appeared much disturbed at the news. But once united, the bold robbers rushed at their foes. The latter gathered together and beat back the first attack, but the Amazons closed up their ranks and made a second assault, which carried them on to the dome and into the midst of the enemy. These were overthrown, as well as a number of F. pratensisy 74 ANIMAL INTELLiaENCE. which Forel at this moment poured out on the nest. The con- querors delayed for a moment on the dome after their victory, and then entered the nest to bring out a little of the valuable booty. A few A.mazons which were mad with anger did not retui'n with the main army, but went on slaughtering blindly among the conquered and the fugitives of the three species, fusca, pratensis, and sanguinea. The ravished rufiharhes once became so desperate at their overthrow that they followed the robbers to their own nest, and the latter had some trouble in defending it. The rufiharhes let themselves be killed in hundreds, and really seemed as though they courted death. A small number of the Amazons also sank under the bites of their enemies. The nest contained slaves of the rufiharhis species, which on this emergency fought actively against their own race. There were also slaves of the species /^sca, so that the nest included three different species of ants. The same nest is often revisited many times on the same day or at different periods, until either there is no more to steal, or the plundered folk have hit upon better mode of defence. A column which was in the act of going back to such a plun- dered nest turned when halfway there, and halted, apparently on no other ground than because it had met the rearguard of the army, and had learned that the nest was exhausted, and that there was nothing more to be had there. The robbers then went off to a rufiharhis nest which was in the neighbourhood, and killed half the inhabitants while plundering the nest. The surviving rufiharhes returned after the robbery and brought up new progeny ; but thirteen days later the Amazons again reaped a rich harvest from the same nest. The Amazon army often severs itself into two separate divisions when there is not enough for both to do at the same spot. Sometimes one division finds something and the other nothing, and they then reunite. If any obstacle be placed in their way they try to overcome it, in doing which some leave the main army, lose themselves, and only find their way home again with difficulty. Forel has tried to establish the normal frequency of expeditions, and found that a colony watched by himself for a space of thirty days sent out no less than forty-four marauding excursions. Of these about eight- and-t\^enty were completely, nine partially, and the remainder not at all successful. He four times saw the army divide into two. Half the expeditions were levelled against the rufiharhes, half against the/uscce. On an average a successful expedition A^TS — WAKS, 75 would bring back to the colony a thousand pupae or larvae. On the whole, the number of future slaves stolen by a strong colony during a favourable summer may be reckoned at forty thousand ! The internecine battles which occasionally break out among the Amazons themselves are naturally the most cruel. They tear each other to pieces with incredible fury, and knots of five or six individuals which have pierced each other may be seen rolling over each other on the ground, it being impos- sible to distinguish between friend and foe. Civil wars among men are also known to be the most embittered and the most bloody. The mode of attack practised by the other best known species of slave-making ant, sanguinea, is somewhat different : — They march in small troops which, in case of need, summon reinforcements, and therefore as a rule only reach their goal slowly. Between the individual troops messengers or scouts run continually backwards and forwards. The first troop which arrives at the hostile nest does not rush at it, as do the Amazons, but contents itself with making provisional re- connaissances, wherein some of the assailants are generally made prisoners by the enemy, which have time to bethink and to collect themselves. Reinforcements are now brought up, and a regular siege of the nest begins. A sudden invasion, like that of the Amazons, is never seen. The besieging army forms a complete riog round the hostile nest, and the besiegers hold this with mandibles open and antennae drawn back, with- out going nearer. In this position they beat off all assaults of the besieged, until they feel themselves strong enough to advance to the attack. This attack scarcely ever fails, and has for its chief object the mastering of the entrances and outlets of the nest. A special troop guards each opening, and only allows such of the besieged to pass out as carry no pupae. This man- ceuvre gives rise to a number of comical and characteristic scenes. By this means the sanguine ants in a few minutes manage to have all the defenders out of the nests and the pupae left behind. This is the case at least with the rufibarbes, while the rather less timid fuscce try, even at the last moment when it is useless, to stop up or barricade the entrances. The sanguine ants do not indeed possess the terrible weapons and the warhke impetuosity of the Amazons, but they are stronger and larger. If sifusca or a rufibarbis fights with a sanguine ant for the pos- 76 ANIMAL INTELLIGENCE, session of a pupa, it is generally very soon overcome. While the main part of the army is penetrating into the nest to steal the pnpse, some divisions pursue the fugitives, to take away from them the few pupse which may chance to have been saved. They drive them even out of the cricket-holes in which they have meanwhile taken refuge. In short, it is a razzia^ or sweep- ing burglary, as complete as can be imagined. In the retreat the robbers in no wise hurry themselves, for they know that they are threatened by no danger and no loss, and the complete emptying of a large and distant nest often takes several days in accomplishing. The ants which have been so thoroughly robbed scarcely every return to their former abode. It must be admitted that a human army, robbing a foreign town or fortress, could not behave better or more prudently. Huber gives the following account of a battle waged by sanguine ants : — At ten, in a July morning, he noticed a small band of them emerge from their nest, and march rapidly towards a nest of negroes, around which it dispersed. A number of the blacks^ rushed out, gave battle, and succeeded in defeating their in- vaders, and in making several of them prisoners. Upon this, the remainder of the attacking force waited for a reinforcement. When this came up, they still declined further proceedings, and sent more aides-de-camp to their own nest. The result of these messages was a much larger reinforcement ; but even yet the pirates appeared to shun the combat. At last, the negroes marched out from their nest in a phalanx of about two feet square, and a number of skirmishes began, which soon ended in a general melee. Long before the event seemed certain, the negroes carried off their pupae to the most distant part of the nest ; and when, after a longer encounter, they appeared to think further resistance vain, they retreated, attempting to take with them their young. In this, however, they were prevented, and the invaders obtained possession of their nest and the booty. When they had done this, they put in a garrison, and occupied the night and the succeeding day in carrying off their spoil. Biichner says — Battles between ants of the same species often end with a lasting alliance, especially when the number of the workers on both sides is comparatively small. The wise little animals under such circumstances discover, much more quickly and better than men, that they can only destroy each other by fighting, while union would benefit both parties. Somedmes they drive each ANTS — WARS. 77 other out of their nests in a quite friendly way. Forel laid on a table a piece of bark with a nest of the gentle Leptothorax acervorum, and then put on it the contents of another nest of the same species. The last comers were by far the more nume- rous, and soon possessed themselves of the nest, driving out the inmates. But the latter did not know whither to go, and turned back again. They were then seized by their opponents one after the other, carried away as far as possible from the nest, and there put down. The oftener they came back the further were they carried away. One of the carriers arrived in this fashion at the edge of the table, and after it had by means of its feelers convinced itself that it had reached the end of the world, mercilessly let its burden drop into the fathomless abyss. It waited a moment to see if it had attained its object, and then turned back to the nest. Forel picked up the ant which had fallen on the floor, and put it down right in front of the return- ing ant. The latter repeated the same manoeuvre as at first, only stretching its neck further over the edge of the table. He several times reiterated his experiment, and always with the same result. Later the two colonies were shut up together in ^ glass case, and gradually learned to agree. At other times, however, warlike ants show great and needless cruelty to one another : — They slowly pull from their victim, that is rendered defence- less by wounds, exhaustion, or terror, first one feeler and then the other, then the legs one after another, until they at last kill it, or pull it in a completely mutilated and helpless con- dition to some out-of-the-way spot where it perishes miserably. Yet some compassionate hearts are to be found among the victors, which only pull the conquered to a distant place in order to get rid of them, and there let them go without injuring them. The following account is also taken from Biichner's ^Mind in Animals,' p. 87 : — The doors are often guarded by special sentries, which fulfil their important duty in various ways. Forel saw a nest of the Colohopsis truncata, the two or three very small round open- ings of which were watched by soldiers, arranged so that their thick cylindrical heads stopped them up, just as a cork stops up the mouth of a bottle. The same observer saw the Myrmecina Latreillei defend themselves against the invasions of the slave-making Strong ylognathus, by placing a worker at each of the Httle openings of the nest, which quite stops up 78 ANIMAL INTELLIGENCE. the opening either with its head or abdomen. The Ca/mpo- notus species also defend their nests by stretching their heads in front of the openings, drawing back the antennae. Each approaching enemy thus receives a sharp blow or bite delivered with the whole weight of the body. MacCook noticed in the nests of the soon to be described Pennsylvanian mound-building ants, the employment of special sentries, which lay watching within the nest entrances, and sprang out at the first sight of danger to attack the enemy ; and it was wonderful to see with what swiftness the news of such an alarm spread through the nest, and how the inhabitants came out en masse to meet the enemy. The Lasius species defend their large, strong, and very extensive nests against hostile attack or sieges with equal courage and skill, while other timid species seek to fly as speedily as possible with their larvae, pupae, and fruitful queens. There is, as Forel tells us, a regular barricade fight. Passage after passage is stopped and defended to the uttermost, so that the assailants can only advance step and step. Unless the latter are in an enormous majority, the struggle may last a very long time with these tactics. During this time, other workers are busy pre- paring subterranean passages backwards for eventual flight. Generally such passages are already made, and during a fight a new dome of the Lasius may be seen rising at a distance, it not being difficult for them to make this with the help of their ex- tended subterranean passages and communications. The F. exsecta or pressilabris fights in a peculiar way, which is due to care of their small and very tender bodies. It avoids all single combats, and always fights in closed ranks. Only when it thinks victory secure does it spi*ing on its enemy's back. But its chief strength lies in the fact that many together always attack a foe. They nail down their opponent by seizing its legs and holding them firmly to the ground, while a comrade springs on the back of the defenceless creature and tries to bite through its neck. But if threatened the holders sometimes take flight, and so it happens that in battles between the exsectce and the much stvoTigQY pratenses not a few of the latter are seen running about with a small enemy clutching their shoulders, and making violent eflTorts to tear the neck of its foe. If the bearer is then seized with cramp, the nervous cord has been injured. On the other hand, if an exsecta is seized by the back by a pratensis it is at once lost. The tactics of the turf ants resemble those of the exsectce, three or four of them seizing an opponent and pulling ofi^ his legs. In similar fashion the attack of the Lasius species is ANTS — WARS. 7& ■ chiefly directed against the legs of its enemies, three, four, or five uniting in the efibrt. They understand barricade fighting particularly well in their large well-built dwellings, and if it comes to the worst fly by subterranean passages. They are feared by most ants on account of their numerical superiority. Forel one day poured the contents of ten nests of pratenses in front of a tree trunk inhabited by Lasius fuliginosus (jet ant). The siege at once began ; but the jet ants called in help from the nests connected with their colony, and thick black columns were at once seen coming out from the surrounding trees. The pratenses were obliged to fly, and left behind them a mass of dead as well as their pupae, which last were carried ofi" by the victors to their nests to be eaten. Battles, however, are not confined to species of ants having warlike and slave-making habits. The agricultural ants likewise at times wage fierce wars with one another. The importance of seeds to these ants, and the consequent value which they set upon them, induce the animals, when supplies are scarce, to plunder each other's nests. Thus Moggridge says, — By far the most savage and prolonged contests which I have witnessed were those in which the combatants belong to two difierent colonies of the same species. . . . The most singular contests are those which are waged for seeds by A. harbara, when one colony plunders the stores of an adjacent nest belonging to the same species, the weaker nest making prolonged though, for the most part, inefficient attempts to recover their property. In the case of the other species of ant which I have watched fighting, the strife would last but a short time — a few hours or a day — but A. harhara will carry on the battle day after day and week after week. I was able to devote a good deal of time to watching the progi'ess of a predatory war of this kind, waged by one nest of harhara against another, and which lasted for forty -six days, from January 18 to March 4 ! I cannot of course declare positively that no cessation of hostihties may have taken place during the time, but I can affirm that whenever I visited the spot — and I did so on twelve days, or as nearly as possible twice a week — the scene was one of war and spoliation such as that which I shall now describe. An active train of ants, nearly resembling an ordinary harvesting train, led from the entrance of one nest to that of another lower down the slope, and fifteen feet distant ', but on 80 ANIMAL INTELLIGENCE. closer examination it appeared that though the great mass of seed-bearers were travelling towards the upper nest, some few were going in the opposite direction and making for the lower. Besides this, at intervals, combats might be seen taking place, one ant seizing the free end of a seed carried by another, and endeavouring to wrench it away, and then frequently, as neither would let go, the stronger ant would drag seed and opponent towards its nest. At times other ants would interfere and seize one of the combatants and endeavour to drag it away, this often resulting in terrible mutilations, and especially in the loss of the abdomen, which would be torn off while the jaws of the victim retained their indomitable bull-dog grip upon the seed. Then the victor might be seen dragging away his prize, while its ad- versary, though now little more than a head and legs, offered a vigorous though of course ineffectual resistance. I frequently observed that the ants during these conflicts would endeavour to seize one another's antennae,, and that if this were effected, the ant thus assaulted would instantly release his hold, whether of seed or adversary, and appear utterly discomfited. No doubt the antennae are their most sensitive parts, and injuries inflicted on these organs cause the greatest pain. It was not until I had watched this scene for some days that I apprehended its true meaning, and discovered that the ants of the upper nest were robbing the granaries of the lower, while the latter tried to recover the stolen seeds both by fighting for them and by stealing seeds in their turn from the nest of their oppressors. The thieves, however, were evidently the stronger, and streams of ants laden with seeds arrived safely at the upper nest, while close observation showed that very few seeds were successfully carried on the reverse journey into the lower and plundered nest. Thus when I fixed my attention on one of these robbed ants surreptitiously making its exit with the seed from the thieves' nest, and having overcome the opposition and dangers met with on its way, reaching, after a journey which took six minutes to accomplish, the entrance to its own home, I saw that it was violently deprived of its burden by a guard of ants stationed there apparently for the purpose, one of whom instantly started off and carried the seed all the way back again to the upper nest. This I saw repeated several times. After March 4 I never saw any acts of hostility between these nests, though the robbed nest was not abandoned. In another case of the same kind, however, where the struggle lasted thirty-one days, the robbed nest was at length completely ANTS — WABS. 81 abandoned, and on opening it I found all the granaries empty with one single exception, and this one was pierced by the matted roots of grasses and other plants, and must therefore have been long neglected by the ants. Strangely enough, not one of the seeds in this deserted granary showed traces of germination. No doubt some very pressing need is the cause of these systematic raids in search of accumulations of seeds, and there can be little doubt that the requirements of distinct colonies of ants of the same species are often different even at the same season and date. Thus these warring colonies of ants were active on many days when the majority of the nests were com- pletely closed ; and I have even seen these robbers staggering along, enfeebled by the cold, and in wind and rain, when all other ants were safe below ground. The agricultural ants of Texas do not appear to be less pugnacious than their European congeners. Thus Mac Cook says : — A young community has sometimes to struggle into perma- nent prosperity through many perils. The following example is found in the unpublished Lincecum manuscripts. One day a new ant-city was observed to be located within ten or twelve yards of a long-established nest, a distance that the doctor thought would prove too near for peaceable possession — for the agricultural seem to pre-empt a certain range of territory around their formicary as their own, within which no intrusion is allowed. He therefore concluded to keep these nests under close observation, and visited them frequently. Only a day or two had elapsed before he found that the inhabitants of the old city had made war upon the new. They had surrounded it in great numbers, and were entering, dragging out and killing the citizens. The young colonists, who seemed to be of less size than their adversaries, fought bravely, and, notwithstanding they were overwhelmed by superior numbers, killed and maimed many of their assailants. The parties were scattered in strug- gling pairs over a space ten or fifteen feet around the city gate, and the ground was strewed with many dead bodies. The new colonists aimed altogether at cutting off the legs of their larger foes, which they accomplished with much success. The old-city warriors, on the contrary, gnawed and clipped off the heads and abdomens of their enemies. Two days afterward the battle- field was revisited, and many ants were found lying dead tightly locked together by tegs and mandibles, while hundreds G 82 ANIMAL INTELLIGENCE. of decapitated bodies and severed heads were strewed over the ground. Another example, which is given in the published paper, is quite similar, and had like result. In forty-eight hours the old settlers had exterminated the new. The distance between the nests was about 20 feet. While the young colonists remained in concealment they were not disturbed, but as soon as they began to clear away their open disk war was declared. MacCook, however, says that ' these ants are not always so jealous of territorial encroachment, or at least must have different standards of rights.' For he observed many cases of nests situated within twenty, and even ten feet of one another, without a battle ever occurring between members of the two communities. Therefore, without questioning the accuracy of Lincecum's observations — which, indeed, present no scope for inaccuracy — he adds, 'That neighbouring ants, like neighbouring nations of civilised men, will fall out and wage war Lincecum's ex- amples show. Perhaps we should be quite as unsuccessful in case of these ants as of our human congeners, should we seek a sufficient reason for these wars, or satisfactory cause for these differences in dealing with neighbours which appear from the comparison of Lincecum's observa- tions with mine.' In connection with the wars of these ants, the follow- ing quotations may also be made from the same author : — The erratic ants do not appear to be held as common ene- mies by the agricultural, and they are even permitted to establish their formicaries within the limits of the open disk. Sometimes, however, the diminutive hillocks which mark the entrance to an erratic ant-nest multiply beyond the limit of the agriculturals' forbearance. But they do not declare war, nor resort to any personal violence. Nevertheless, they get rid of them, oddly enough, by a regular system of vexatious obstruc- tions. They suddenly conclude that there is urgent demand for improving their public domain. Forthwith they sally forth in large numbers, fall eagerly to work gathering the little black balls which are thrown up by the earth-worms in great quantities everywhere in the prairie soil, which they bring and heap upon the paved disk until all the en-atic ant-nests are covered ! The entire pavement is thus raised an inch or so, and pains are taken ANTS — KEEPING PETS. 83 to deposit more balls upon and around the domiciles of their tiny neighbours than elsewhere. The erratics struggle vigoi'- ously against this Pompeian treatment; they bore through the avalanche of balls, only to find barriers laid in their way. The obstructions at length become so serious that it is impos- sible to keep the galleries open. The dwarfs cease to contend against destiny, and, gathering together their household stores, quietly evacuate the premises of the inhospitable giants. It is the triumph of the policy of obstiniction, a bloodless but effec- tual opposition. Lastly, MacCook records the history of an interesting engagement which he witnessed between two nests of Tetramorium ccespitum. It took place between Broad Street and Penn Square in Philadelphia, and lasted for nearly three weeks. Although all the combatants belonged to the same species, however great the confusion of the fight, friends were always distinguished from foes — ap- parently "by contact of antennae. Habit of keeping Domestic Pets. — Many species of ants display the curious habit of keeping in their nests sundry kinds of other insects, which, so far as observation extends, are of no benefit to the ants, and which there- fore have been regarded by observers as mere domestic pets. These * pets ' are for the most part species which occur nowhere else except in ants' nests, and each species of ' pet ' is peculiar to certain species of ants. Thus Moggridge found ' a large number of a minute shining brown beetle moving about among the seeds ' in the nests of the harvesting ant of the south of Europe, ' belonging to the scarce and very restricted genus Golnocera, called by Kraatz C. attce, on account of its inhabiting the nests of ants belonging to the genus Atta.^ He also observed inhabiting the same nests a minute cricket ' scarcely larger than a grain of wheat ' (Oryllus myrmecophilus), which had been previously observed by Paolo Savi in the nests of several species of ants in Tuscany, where it lived on the best terms with its hosts, playing round the nests in warm weather, and retiring into them in stormy weather, while allowing the ants to carry it from place to place during migrations. Again, Mr. Bates observes that a 2 84 ANIMAL INTELLIGENCE. * some of the most anomalous forms of coleopterous insects are those which live solely in the nests of ants.' Sir John Lubbock also, and other observers whom we need not wait to cite, mention similar facts. The Kev. Mr. White says that altogether 40 distinct species of Coleoptera, most of which he has in his own collection, are known to inhabit the nests of various species of ants, and to occur nowhere else. As in all these cases the ants live on amicable terms with their guests, and in some cases even bestow labour upon them (as in carrying them from one nest to another during migration), it is evident that these insects are not only tolerated, but fostered by the ants. Moreover, as it seems absurd to credit ants with any mere fancy or caprice such as that of keeping pets, we can only conclude that these insects, like the aphides, are of some use to their hosts, although we are not yet in a position to surmise what this use can be. Habits of Sleep and Cleanliness. — It is probable that all species of ants enjoy periods of true sleep alternating with those of activity; but actual observations on this subject have only been made on two or three species. The following is MacCook's account of these habits in the harvesting ant of Texas : — The observation upon the ants now before me began at 8 o'clock; at 11 P.M. the cluster had nearly dissolved, only a few being asleep. To illustrate the soundness of this sleep I take the quill pen with which I write, and apply the feather end of it to an ant who is sleeping upon the soil. She has chosen a little oval depression in the surface, and lies with abdomen upon the raised edge, and face toward the lamp. Her legs are drawn up close to the body. She is perfectly still. I gently draw the feather tip along the body, stroking ' with the fur,' if I may so say. There is no motion. Again and again this action is repeated, the stroke gradually being made heavier, although always quite gentle. Still there is no change. The strokes are now directed upon the head, with the same result. Now the tip is appHed to the neck, the point at which the head is united to the pro-thorax, with a waving motion intended to produce a sensation of tickling. The ant remains motionless. After continuing these experiments for several minutes, I ANTS — SLEEP AND CLEANLINESS. 85 arouse the sleeper by a sharp touch of the quilL She stretches out her head, then her legs, which she also shakes, steps nearer to the light, and begins to cleanse herself in the manner already described. This act invariably follows the waking of ants from sleep. The above description applies to the general habit of somnolence as observed upon the two named species of harvest- ing ants for nearly four months. I have often applied the quill, and even the point of a lead pencil, to the sleeping Flo- ridians without breaking their slumber. There are some other details which have not appeared in the behaviour of the indi- vidual just put under observation. Thus, I have several times seen the ants (Crudelis) yawning after awaking. I use this word for lack of one which more accurately expresses the behaviour. The action is very like that of the human animal ; the mandibles are thrown open with the peculiar muscular strain which is familiar to all readers ; the tongue also is sometimes thrust out, and the limbs stretched with the appearance, at least, of that tension which accompanies the yawn in the genus homo. During sleep the antennae have a gentle, quivering, apparently involuntary mo- tion, which seemed to me, at times, to have the regularity of breathing. I also often noted an occasional regular lifting up and setting down of the fore-feet, one leg after another, with almost a rhythmic motion. The length of time during which sleep is prolonged appears to vary according to circumstances and, perhaps, organism. The large head-soldiers of the Floridian harvesters appear to have a more sluggish nature than the smaller workers. Their sleep is longer and heavier. The former fact the watch readily determined. The latter appeared from the greater stolidity of the creatures under disturbance. While the ants of one group are taking sleep others may be busy at work, and these stalk among and over the sleepers, jostling them quite vigorously at times. Again, new members occasionally join the group, and, in their desire to get close up to the heat and light, crowd their drowsy comrades aside. I have seen ants who had been at work in the galleries drop their pellets, push thus into the cluster, and presently be apparently sound asleep. This rough treatment is invariably received with perfect good humour, as are like jostlings when the ants are awake. I have never seen the slightest display of anger or attempt to resent disturbance even under these circumstances, so peculiarly calculated to ex- cite the utmost irritation in men. But of course some of the sleepers are aroused. They change position a little, or give 86 ANIMAL INTELLIGENCE. themselves a brief combing, and then resume their nap, unless, indeed, they are satisfied. In watching these movements it was quite evident that the Florida soldiers were far less easily dis- turbed than their smaller fellows. They slept on stolidly while all the others were in agitation around them. Moreover, their very appearance, particularly when awaking out of sleep, indi- cated the greater sluggishness of their temperament in this respect. The ordinary duration of sleep MacCook takes to be about three hours. Ants, like many other insects, are in the habit of cleaning themselves, being, like them, provided by nature with combs and brushes, &c., for the purpose. But, unlike other insects, several species of ants are also in the habit of assisting each other in the performance of their toilet. The author last quoted gives the following account of this process in the genus AUa : — We take a couple ; the cleanser has begun at the face, which is hcked thoroughly, even the mandibles being cared for, they being held apart for convenient manipulation. From the face the cleanser passes to the thorax, thence to the haunch, and so along the first leg, along the second and third in the same manner, around to the abdomen, and thence up the other side of the ant to the head. A third ant approaches and joins in the friendly task, but soon abandons the field to the original cleanser. The attitude of the cleansed all this while is one of intense satisfaction, quite resembling that of a family dog when one is scratching the back o£ his neck. The insect stretches out her limbs, and, as her friend takes them successively into hand, yields them limp and supple to her manipulation ; she rolls gently over upon her side, even quite over upon her back, and with all her limbs relaxed presents a perfect picture of mus- cular surrender and ease. The pleasure which the creatures take in being thus ' combed ' and ' sponged ' is really enjoyable to the observer. I have seen an ant kneel down before another and thrust forward the head, drooping, quite under the face, and lie there motionless, thus expressing, as plainly as sign- language could, her desire to be cleansed. I at once under- stood the gesture, and so did the supplicated ant, for she at once went to work. If analogies in nature-studies were not so apt to be misleading, one might venture to suggest that our ANTS — PLAY AND LEISURE. 87 insect friends are thus in possession of a modified sort of Emmetonian Turkish bath. The acrobatic skill of these ants, which has often furnished me amusement, and which I shall yet further illustrate, was fully shown one morning in these offices of ablution. The for- micary was taken from the study, where the air had become chilled, and placed in an adjoining chamber upon the hearth, before an open-grate fire. The genial warmth was soon difiused throughout the nest, and aroused its occupants to unusual ac- tivity. A tuft of grass in the centre of the box was presently <;overed with them. They climbed to the very top of the spires, turned round and round, hanging by their paws, not unHke gymnasts performing upon a turning-bar. They hung or clung in various positions, grasping the grass blade with the third and fourth pairs of legs, which were spread out at length, cleansing their heads with the fore-legs or bending underneath to comb and lick the abdomen. Among these ants were several pairs, in one case a triplet, engaged in the cleansing operation just described. The cleanser clxmg to the grass, having a fore-leg on one side and a hind leg on the other side of the stem, stretched out at full length, while the cleansed hung in a like position below, and reached over and up, submitting herself to the pleasant process. As the progress of the act required a change of posture on the part of both insects, it was made with the utmost agility. Similarly, Bates thus describes the cleansing process in another genus of ants (Ecitons) : — Here and there an ant was seen stretching forth first one leg and then another, to be brushed and washed by one or more of its comrades, who performed the task by passing the limb between the jaws and tongue, finishing by giving the antennae a friendly wipe. Habits of Play and Leisure, — The life of ants is not all work, or, at least, is not so in all species ; for in some species, at any rate, periods of recreation are habitually indulged in. Biichner (' Geistesleben der Thiere,' p. 163) gives the following abstract of Huber's celebrated observations in this connection : — It was of the prateTiais that Huber wrote the observations touching its gymnastic sports which became so famous. He 88 ANIMAL INTELLIGENCE. saw these ants on a fine day assembled on the surface of their nest, and behaving in a way that he could only explain as simulating festival sports or other games. They raised them- selves on their hind legs, embraced each other with their fore- legs, seized each other by the antennae, feet, or mandibles, and wrestled — but all in friendliest fashion. They then let go, ran after each other, and played hide-and-seek. When one was victorious, it seized all the others in the ring, and tumbled them over like ninepins. This account of Huber's found its way into many popular books, but in spite of its clearness won little credence from the reading public. ' I found it hard to believe Huber's obser- vation,' writes Forel, ' in spite of its exactness, until I myself had seen the same.' A colony of the pratensis several times gave him the oppoHunity when he approached it carefully. The players caught each other by the feet or jaws, rolled over each other on the ground like boys playing, pulled each other inside the entrances of their nest, only to come out again, and so on. All this was done without bad temper, or any spurting of poison, and it was clear that all the rivalry was friendly. The least breath from the side of the observer was enough to put an end to the games. 'I understand,' continues Forel, *that the affair must seem marvellous to those who have not seen it, especially when we remember that sexual attraction can here play no part.' MacCook also gives an account of habits of play as in- dulged in among ants of the other Hemisphere : — At one formicary half a dozen or more young queens were out at the same time. They would climb up a large pebble near the gate, face the wind, and assume a rampant posture. Several having ascended the stone at one time, there ensued a little playful passage-at-arms as to position. They nipped each other gently with the mandibles, and chased one another from favourite spots. They, however, never nipped the workers. These latter evidently kept a watch upon the sportive prin- cesses, occasionally saluted them with their antennae in the usual way, or touched them at the abdomen, but apparently allowed them full liberty of action. As to leisure, Bates writes : — The life of these Ecitons is not all work, for I frequently saw them very leisurely employed in a way that looked Uke recre- ANTS— FUNEKEAL HABITS. 89 ation. When this happened the place was always a sunny nook in the forest. The main column of the army and the branch columns, at these times, were in their ordinary relative posi- tions ; but instead of pressing forward eagerly and plundering right and left, they seemed to have been all smitten with a sudden fit of laziness. Some were walking sternly about, others were brushing their antennae with their fore-feet; but the drollest sight was their cleaning each other. [Here follows the above-quoted passage.] The actions of these ants looked like simple indulgence in idle amusement It is probable that these hours of relaxation and cleaning may be indispensable to the effective performance of their harder burdens ; but whilst looking at them, the conclusion that the ants were engaged merely in play was irresistible.^ Funereal Habits. — In another connection it has already been stated that Sir John Lubbock found his ants to be very careful in disposing of the dead bodies of their com- rades. This habit seems to be pretty general among many species of ants, and is no doubt due to sanitary require- ments, thus becoming developed as a beneficial instinct by natural selection. The funereal habits of the agricultural ant are thus related by MacCook : ^ — There is nothing which is apt to awaken deeper interest in the life-history of ants than what may properly be called their funereal habits. All species whose manners I have closely observed are quite alike in their mode of caring for their own dead, and for the dry carcasses of aliens. The former they appear to treat with some degree of reverence, at least to the ex- tent of giving them a sort of sepulture without feeding upon them. The latter, after having exhausted the juices of the body, they usually deposit together in some spot removed from the -nest. I did not see any of the ' cemeteries ' of the agricul- tural ant upon the field, nor, indeed, observe any of their behaviour towards the dead, but my artificial nests gave me some insight of this. In the first colony had been placed eight agri- culturals of another nest, which were literally cut to pieces. Very soon after the ants were comfortably established in their new home, a number of them laid hold upon these disjecta membra, and began carrying them back and forth around the formicarium. The next day this continued, and several of their own number » Log. cit. 2 Zoc. cit. p. 337 90 ANIMAL INTELLIGENCE. who had died were being treated in like manner. Back and forth, up and down, into every corner of the box the bearers wandered, the very embodiment of restlessness. For four days this conduct continued without any intermission. No sooner would a body or fragment thereof be dropped by one bearer than another would take it up and begin the restless circuit. The difficulty, I easily understood, was that there was no point to be found far enough removed from the living-rooms of the insects in which to inter these dead. Their desire to have their dead buried out of their sight was strong enough to keep them on this ceaseless round, apparently under the continuous influ- ence of the hope that something might turn up to give them a more satisfactory burial-ground. It does not appear greatly to the credit of their wisdom that they were so long discovering that they were limited to a space beyond their power to enlarge. "When, however, this fact was finally recognised they gave their habit its utmost bent, and began to deposit the carcasses in the extreme corner of the flat, as distant as possible from the galleries on the terrace above. Here a little hollow was made in the earth, quite up against the glass, whereiu a number of bodies were laid. Portions of bodies were thrust into the chinks formed in the dry sod. This flat became the permanent tjharnel-house of the colony, and here, in corners, crevices, and holes, for the most part out of sight, but not always so, the dead were deposited. But the living never seemed quite recon- ciled to their presence. Occasionally, restless resurrectionists would disentomb the dead, shift them to another spot, or start them once more upon their unquiet wanderings. Even after the establishment of this cemetery, the creatures did not seem able to lay away their newly deceased comrades — for there were occasional deaths in the formicary — without first indulging in this funereal promenade. In the formicaries established in glass jars, both of barhatus and crudelis, the same behaviour appeared. So great was the desire to get the dead outside the nest, that the bearers would climb up the smooth surface of the glass to the very top of the jar, laboriously carrying with them a dead ant. This was severe work, which was rarely undertaken except under the influence of this funereal enthusiasm. The jar was very smooth and quite high. Falls were frequent, but patiently the little * undertaker ' would follow the impulse of her instinct, and try and try again. Finally, as in the large box, the fact of a necessity seemed to dawn upon the ants, and a portion of the surface opposite from the entrance to the galleries, and close up against the glass, was ANTS — FUNEEEAL HABITS. 91 used as burial-ground and sort of kitchen-midden, where all the refuse of the nest was deposited. Mrs. Treat has informed me that her artificial nests of crudelis behaved in precisely the same way. An interesting fact in the funereal habits of Formica san- guinea was related to me by this lady. A visit was paid to a large colony of these slave-makers, which is established on the grounds adjoining her residence at Vineland, New Jersey. I noticed that a number of carcasses of one of the slave species, Formica fusca, were deposited together quite near the gates of the nest. These were probably chiefly the dry bodies of ants brought in from recent raids. It was noticed that the dead ants were all of one species, and thereupon Mrs. Treat informed me that the red slave-makers never deposited their dead with those of their black servitors, but always laid them by themselves, not in groups, but separately, and were careful to take them a considerable distance from the nest. One can hardly resist pointing here another likeness between the customs of these social hymenopters and those of human beings, certain of whom carry their distinctions of race, condition, or religious caste, even to the gates of the cemetery in which the poor body moulders into its mother dust ! It will be observed that none of these accounts furnish evidence of ants burying their dead, as Pliny asserts to have been the case with ants in the south of Europe. In the Proceedings of the Linnsean Society, however (1861), there is a very definite account of such a practice as obtaining among the ants of Sydney ; and although it is from the pen of an observer not well known, the observa- tion seems to have been one about which there could scarcely have been a mistake. The observer was Mrs. Hutton, and this is her account. Having killed a number of ' soldier ants,' and returning half an hour afterwards to the place where the dead bodies were lying, she says : I saw a large number of ants surrounding the dead ones. I determined to watch their proceedings closely. I followed four or five that started ofif from the rest towards a hillock a short distance oflf, in which was an ants' nest. This they entered, and in about five minutes they reappeared, followed by others. All fell into rank, walking regularly and slowly two by two, until they arrived at the spot where lay the dead bodies of tlie soldier ants. In a few minutes two of the ants advanced and took up 92 ANIMAL INTELLIGENCE. the dead body of one of their comrades ; then two others, and' so on, until all were ready to march. First walked two ants bearing a body, then two without a burden ; then two others with another dead ant, and so on, until the line was extended to about forty pairs, and the procession now moved slowly on- wards, followed by an irregular body of about two hundred ants. Occasionally the two laden ants stopped, and laying down the dead ant, it was taken up by the two walking unburdened behind them, and thus, by occasionally relieving each other, they arrived at a sandy spot near the sea. The body of ants now commenced digging with their jaws a number of holes in the ground, into each of which a dead ant was laid, where they now laboured on until they had filled up the ants' graves. This did not quite finish the remarkable circumstances attending this funeral of the ants. Some six or seven of the ants had attempted to run off without performing their share of the task of digging ; these were caught and brought back, when they were at once attacked by the body of ants and killed upon the spot. A single grave was quickly dug, and they were all dropped into it. The Rev. W. Farren White also, in his papers on ants published in the 'Leisure Hour' (1880), after alluding to the above case, corroborates it by some interesting obser- vations of his own. He says : — Several of the little sextons I observed with dead in theii mandibles, and one in the act of burying a corpse. . . . I should mention that the dead are not interred without con- siderable difficulty, in consequence of the sides of the trays being almost perpendicular. The work of the sextons continued until no dead bodies remained upon the surface of the nest, but all were inteiTcd in the extramural cemeteries. Afterwards I removed the trays, and turned the contents of the formicarium upside down, and then I placed six trays on the surface of the earth, two of which I filled with sugar for food. All six were used freely as cemeteries, being crowded with the corpses of the Httle people and their young, the larvae which had perished in the disruption of their home. I have noticed in one of my formicaria a subterranean cemetery, where I have seen some ants burying their dead by placing earth above them. One ant was evidently much affected, and tried to exhume the bodies, but the united exertions of the yellow sextons were more than sufficient to neutralise the effort of the disconsolate mourner. The cemetery was now converted LEAF-CUTTINQ ANTS. 93 into a large vault, the chamber where the dead were placed, together with the passage which led to it, being completely covered in. Habits Peculiar to Certain Species. Leaf-cutting Ants of the Amazon (CEcodoma cephal- otes). — The mode of working practised by these ants is thus described by Mr. Bates : — They mount a tree in multitudes. . . . Each one places itself on the surface of a leaf, and cuts with its sharp scissor- like jaws a nearly semicircular incision on the upper side ; it then takes the edge between its jaws, and by a sharp jerk detaches the piece. Sometimes they let the leaf drop to the ground, where a little heap accumulates, until carried off by another relay of workers ; but generally each marches off with the piece it has operated on, and as all take the same road to the colony, the path they follow becomes in a short time smooth and bare, looking like the impression of a cart-wheel through the herbage. Each ant carries its semicircular piece of leaf upright over its head, so that the home-returning train is rendered very conspicuous. Nearer observation shows that this home-returning or ladened train of workers keeps to one side of the road, while the outgoing or empty-handed train keeps to the other side ; so that on every road there is a double train of ants going in opposite directions. When the leaves arrive at the nest they are received by a smaller kind of workers, whose duty it is to cut up the pieces of leaf into still smaller fragments, whereby the leaves seem to be better fitted for the purpose to which, as we shall presently see, they are put. These smaller workers never take any part in the outdoor labours ; but they occasionally leave the nest, apparently for the sole purpose of obtaining air and exercise, for when they leave the nest they merely run about doing nothing, and fre- quently, as if in mere sport, mount some of the semi- circular pieces of leaf which the carrier ants are taking to the nest, and so get a ride home. From his continued observation of these ants. Bates con - eludes — and his opinion has been corroborated by that 94 ANIMAL INTELLIGENCE. both of Belt and Miiller — that the object of all this labour is highly interesting and remarkable. The leaves when gathered do not themselves appear to be of any service to the ants as food ; but when cut into small fragments and stored away in the nests, they become suited as a nidus for the growth of a minute kind of fungus on which the ants feed. We may therefore call these insects the * gardening ants,' inasmuch as all their labour is given to the rearing of nutritious vegetables on artificially prepared soil. They are not particular as to the material which they collect and store up for soil, provided that it is a material on which the fungus will grow. Thus they are very partial to the inside white rind of oranges, and will carry off the flowers of certain shrubs while leaving the leaves untouched. But, to quote again from Bates, — They are very particular about the ventilation of their under- ground chambers, and have numerous holes leading up to the surface from them. These they open out or close up, apparently to keep up a regular degree of temperature below. The great care they take that the pieces of leaves they carry into the nest should be neither too dry nor too damp, is also consistent with the idea that the object is the growth of a fungus that re- quires particular conditions of temperature and moisture to ensure its vigorous growth. If a sudden shower should come on, the ants do not carry the wet pieces into the burrows, but throw them down near the entrances. Should the weather clear up again, these pieces are picked up when nearly dried, and taken inside : should the rain, however, continue, they get sodden down into the ground, and are left there. On the con- trary, in dry and hot weather, when the leaves would get dried up before they could be conveyed to the nest, the ants, when in exposed situations, do not go out at all during the hot hours, but bring in their leafy burdens in the cool of the day and during the night. As soon as the pieces of leaves are carried in they must be cut up by the small class of workers into little pieces. Some of the ants make mistakes, and carry in unsuitable leaves. Thus grass is always rejected by them, but I have seen some ants, perhaps young ones, carrying leaves of grass ; but after a while these pieces are always brought out again and thrown away. I can imagine a young ant getting a severe ear- wigging from one of the major-domos for its stupidity. When a nest is disturbed and the masses of ant-food spread. LEAF-CUTTING ANTS. 95 about, the anta are in great concern to carry every morsel of it under shelter again ; and sometimes, when I had dug into a nest, I found the next day all the earth thrown out filled with little pits, that the ants had dug into it to get out the covered-up food. When they migi'ate from one part to another, they also carry with them all the ant-food from their old habita- tions. In Biichner's ' Geistesleben der Thiere ' there is pub- lished an interesting description of the habits of these ants, which was communicated to the author by Dr. Fr. Ellen- dorf of Wiedenbriick, who has lived many years in Central America. Dr. Ellendorf says that — It would be quite impossible for them to creep even through short grass with loads on their heads for miles. They therefore bite off the grass close to the ground for a breadth of about five inches, and throw it on one side. Thus a road is constructed, which is finally made quite smooth and even by the continual passing to and fro of millions upon millions night and day. . . If the road is looked down upon from a height with these millions thickly pressed together, and all moving along with their green bannerets over their heads, it looks as though a giant green snake were gliding slowly along the ground ; and this picture is all the more striking in that all these bannerets are swaying backwards and forwards.^ This observer made the experiment of interrupting the advance of a column of these ants, with the interesting result which he describes : — I wished to see how they would manage if I put an obstacle in their way. Thick high grass stood on either side of their narrow road, so that they could not pass through it with the load on their heads. I placed a dry branch, nearly a foot in diameter, obliquely across their path, and pressed it down so tightly on the ground that they could not creep underneath. The first comers crawled beneath the branch as far as they could, and then tried to climb over, but failed owing to the weight on their heads. Meanwhile the unloaded ants from the other side came on, and when these succeeded in climbing over the bough there was such a crush that the unladen ants had to clamber over the laden, and the result was a terrible muddle. I now walked along the train, and found that all the ants with their bannerets on their heads were standing still, ^ Loo. cit. p. 97. 96 ANIMAL INTELLIGENCE. thickly pressed together, awaiting the word of command from the front. When I turned back to the obstacle, I saw with astonishment that the loads had been laid aside by more than a foot's length of the column, one imitating the other. And now work began on both sides of the branch, and in about half an hour a tunnel was made beneath it. Each ant then took up its burden again, and the march was resumed in the most per- fect order. A migration of these ants is thus described by the same observer : — The road led towards a cocoa plantation, and here I soon discovered the building which I afterwards visited daily. As I again went thither one day I was met, at a considerable dis- tance from the nest, by a closely pressed column coming thence, and all the ants laden with leaves, beetles, pupae, butterflies, &c. ; the nearer I came to the nest, the greater was the activity. It was soon plain to me that the ants were in the act of leaving their dwelling, and I walked along the train to discover the new abode. They had gone for some distance along the old road, and had then made a new one through the grass to a cooler place, lying rather higher. The grass on the new road was all bitten off* close to the ground, and thousands were busy carrying the path on to the new building. At the new home itself was an unusual stir of life. There were all sorts of labourers — architects, builders, carpenters, sappers, helpers. A number were busy digging a hole in the ground, and they carried out little pellets of earth and laid them together on end to make a wall. Others drew along little twigs, straws, and grass-stalks, and put them near the place of build- ing. 1 was anxious to know why they had quitted their old home, and when the departure was complete, I dug it up with B> spade. At a depth of about a foot and a half I found several tunnels of a large marmot species, the terror of cocoa planters, because in making their passages they gnaw off the thickest roots of the cocoa plants. The interior of the ant-hill had ap- parently fallen in through these mines. Unfortunately I was unable to follow further the progress of the new building, for I was obliged to leave the next day for San Juan del Sur. When I returned at the end of a week the building was finished, and the whole colony was again busy with the leaves of the coffee plants. Marvesting Ants ( Atta). — The ants which, so far as at HAKVESTING ANTS. 97' present known, practise the peculiar and distinctive habits to be described under this division belong for the most part to one genus, Atta, which, however, comprises a number of species distributed in localised areas over all the four quarters of the globe. Hitherto nineteen species have been detected as having the habits in question. These consist of gathering nutritious seeds of grasses during summer, and storing them in granaries for winter consumption. We owe our present knowledge concerning these insects to Mr. Moggridge,* who studied them in the south of Europe, Dr. Lincecum,^ and Mr. MacCook,^ who studied them in Texas, and Colonel Sykes'^ and Dr. Jerdon,^ who made some observations upon them in India. They also occur scattered over a great part of Europe and in Palestine, where they were clearly known to Solomon and other classical writers of antiquity,^ whose claim to accu- rate observation, although long disputed (owing to the authority of Huber), has now been amply vindicated. Mr. Moggridge, who was a careful and industrious observer, found the following points of interest in the habits of the European harvesters. From the nest in various directions there proceed outgoing trains, which may be from twenty to thirty or more yards in length, and each consists of a double row of ants, moving, like the leaf-cutting ants, in opposite directions. Those in the outgoing row are empty-handed, while those in the in- coming row are laden. But here the burdens are grass seeds. The roads terminate in the foraging ground, or ant-fields, and the insects composing the columns there become dispersed by hundreds among the seed-yielding grasses. The following is their method of collecting seeds ; I quote from Moggridge : — * Harvesting Ants and Traj)-door Spiders, London, 1873 and Sup- plement, 1874. '^ Journal Linn Soc, vol. vi. p. 29, 1862. 3 Agricultural Ant of Texas, Philadelphia, 1880 * Trans. JEJnt. Soc. Lond., i. 103, 1836. * Madras Jowrn. Lit. Sc 1851. s For this see Moggridge, loc. cit. pp. 6-10, where, besides Prov. iv. 6-8, and xxx. 25, quotations are given from Horace, Virgil, Plautus, and others. H 98 A2TIMAL INTELLiaENCE. It is not a little surprising to see that the ants bring in not only seeds of large size and fallen grain, but also gi*een capsules, the torn stalks of which show that they have been freshly gathered from the plant. The manner in which they accomplish this feat is as follows. An ant ascends the stem of a fruiting plant of shepherd's-purse {Capsella bursa-pastoris), let us say, and selects a well-filled but green pod about midway up the stem, those below being ready to shed their seeds at a touch. Then, seizing it in its jaws, and fixing its hind legs firmly as a pivot, it contrives to turn round and round, and so strain the fibres of the fruit-stalk that at length they snap. It then de- scends to the stem, patiently backing and turning upwards again as often as the clumsy and disproportionate burden becomes wedged between the thickly set stalks, and joins the line of its companions on their way to the nest. In this manner capsules of chickweed [Stellaria media) and entire calyces, con- taining the nutlets of calamint, are gathered ; two ants also sometimes combine their efforts, when one stations itself near the base of the peduncle and gnaws it at the point of greatest tension, while the other hauls upon and twists it. I have never seen a capsule severed from its stalk by cutting alone, and the mandibles of this ant are perhaps incompetent to per- form such a task. I have occasionally seen ants engaged in cutting the capsules of certain plants, drop them, and allow their companions below to carry them away ; and this corresponds with the curious account given by ^lian of the manner in which the spikelets of corn are severed and thrown down ' to the people below,' tw St^/ao) tw kcitw. The recognition of the principle of the division of labour which the latter observation supplies, is further proved by the following quotation from the same author. A dead grasshopper which was being carried into their nest was — Too large to pass through the door, so they tried to dismember it. Failing in this, several ants drew the wings and legs as far back as possible, while others gnawed through the muscles where the strain was greatest. They succeeded at last in thus pulling it in. The same thing is strikingly shown by the following quotation from Lespes : — If the road from the place where they are gathering their HAK VESTING ANTS. 99 harvest to the nest is very long, they make regular depots for their provisions under large leaves, stones, or other suitable places, and let certain workers have the duty of carryiug them from dep6t to depot. Biichner {loc. cit. p. 101) also makes the following references to the statements of previous observers : — The subterranean workers of this remarkable genus are veiy clever. The Rev. H. Clark reports from Rio de Janeiro, that the Sa-uhas have made a regular tunnel under the bed of the river Parahyba, which is there as broad as the Thames at London, in order to reach a storehouse which is on the opposite bank. Bates tells us that close to the Magoary rice-mills, near Para, the ants bored through the dam of a large reservoir, and the water escaped before the mischief could be remedied. In the Para Botanical Gardens an enterprising French gardener did everything he could to drive the Sa-uhas away. He lit fires at the chief entrances of their nests, and blew sulphur vapour into their galleries by means of bellows. But how astonished was Bates when he saw the vapour come out at no less a dis- tance than seventy yards ! Such an extension have the sub- terranean passages of the Sa-uhas. The recognition of the principle of the division of labour, which is shown by the above observations, is further corroborated by the following quotation from Belt : — ■ Between the old burrows and the new one was a steep slope. Instead of descending this with their burdens, they cast them down on the top of the slope, whence they rolled down to the bottom, where another relay of labourers picked them up and earned them to the new burrow. It was amusing to watch the ants hurrying out with bundles of food, dropping them over the slope, and rushing back immediately for more. The same thing has been observed, as already stated, of the leaf-cutting ants — those engaged in cutting fre- quently throwing down the fragments of leaf which they cut to the carriers below. The prevalence of this habit among various species of ants therefore renders credible the following statements of Vincent Gredler of Botzen, which are thus recorded in ' der Zool. Gart.,' xv. p. 434 : — In Herr Gredler's monastery one of the monks had been accustomed for some months to put food regularly on his window- H 2 100 ANIMAL INTELLIGENCE. sill for ants coming up from the garden. In consequence of Herr Gredler's communications he took it into his head to put the bait for the ants, pounded sugar, into an old inkstand, and hung this up by a string to the cross-piece of his window, and left it hanging freely. A few ants were in with the bait. These soon found their road out over the string with their grains of sugar, and so their way back to their friends. Before long a procession was arranged on the new road from the window-sill along the string to the spot where the sugar was, and so things went on for two days, nothing fresh occurring. But one day the procession stopped at the old feeding-place on the window- sill, and took the food thence, without going up to the pendent sugar-jar. Closer observation revealed that about a dozen of the rogues were in the jar above, and were busily and unweary- ingly carrying the grains of sugar to the edge of the pot, and throwing them over to their comrades down below. Many other instances of the division of labour might be given besides these, and those to be mentioned here- after in other connections throughout the course of the present chapter ; but enough has been said to show that the principle is unquestionably acted upon by sundry species of ants. That ants are liable to make mistakes, and, when they do, that they profit by experience, is shown by the follow- ing experiment made by Moggridge ; and many other in- staiices might be given were it desirable : — It sometiines happens that an ant has manifestly made a bad selection, and is told on its return that what it has brought home with much pains is no better than rubbish, and is hustled out of the nest, and forced to throw its burden away. In order to try whether these creatures were not fallible like other mortals, I one day took out with me a little packet of grey and white porcelain beads, and scattered these in the path of a har- vesting train. They had scarcely lain a minute on the earth before one of the largest workers seized upon a bead, and with some difficulty clipped it with its mandibles and trotted back at a great pace to the nest. I waited for a little while, my atten- tion being divided between the other ants who were vainly en- deavouring to remove the beads, and the entrance down which the worker had disappeared, and then left the spot. On my return in an hour's time, I found the ants passing unconcernedly by and over the beads which lay where I had strewed them in HARVESTING ANTS. 101 apparently undiminished quantities ; and I conclude from this that they had found out their mistake, and had wisely returned to theii' accustomed occupations. When the grain is thus taken into the nest, it is stored in regular granaries, but not until it has been de- nuded of its ' husks ' or ' chaff.' The denuding process is carried on below ground, and the chaff is brought up to the surface, where it is laid in heaps to be blown away by the wind. It is a remarkable thing, and one not yet understood, why the seed, when thus stored in subterranean chambers just far enough below the surface to favour germination, does not germinate. Moggridge says that out of twenty- one nests and among many thousands of seeds that he examined, he only found twenty-seven cases of incipient germination. Moreover, all these cases occurred in months from November to February, while in the nests opened in October, March, April, and May, no sprouted seeds were discovered, though these are the months highly favourable to germination. He is at a loss to suggest the treatment to which the ants expose the Seeds in order to prevent their sprouting. ' Apparently it is not that moistiue or warmth or the influence of atmospheric air is denied to the seeds, for we find them in damp soil in genial weather, and often at but a trifling distance below the surface of the ground ; ' and he has proved that the vitality of the seeds is not impaired, for lie succeeded in raising crops of young plants from seeds removed from the granaries. He also says, — By a fortunate chance I have been able to prove that the seeds will germinate in an undistui'bed granary when the ants are prevented from obtaining access to it : and this goes to show not only that the structure and nature of the granary chamber is not sufficient of itself to prevent germination, but also that the presence of the ants is essential to secure the dormant condition of the seeds. I discovered in two places portions of distinct nests of Atta atructor which had been isolated owing to the destruction of the hollow wall behind which they lay, and then the granaries well filled up and literally choked with growing seeds, though the earth in which they lay completely enclosed and concealed them ]02 ANIMAL INTELLIGENCE. until by chance I laid them bare. In one case I knew that the destruction of the wall had only taken place ten days before, so that the seeds had sprouted in the interval. My experiments also tend to confirm this, and to favour the belief that the non-germination of the seeds is due to some direct influence voluntarily exercised by the ants, and not merely to the conditions found in the nest, or to acid vapours which in certain cases are given off by the ants themselves. These experiments consisted in confining a large number of harvesting ants with their queen and larvae in a glass test-tube partly filled with damp soil and various seeds, the whole being closed with a cork in the mouth of the test-tube. Under these circumstances the seeds all sprouted, showing that mere confinement in an atmo- sphere of exhalations from the ants did not prevent germi- nation. Another series of experiments, undertaken at the suggestion of Mr. Darwin, on the effects of an atmosphere of formic acid, showed that although this vapour was very injurious to the seeds, it did not prevent their incipient germination. Therefore it yet remains to be ascertained why the seeds do not germinate in the granaries of the ants. But in whatever way the ants manage to prevent ger- mination, it is certain that they are aware of the importance in this connection of keeping the seeds as dry as possible ; for Moggridge repeatedly observed that when the seeds which had been stored proved over-moist, the ants again took them out and spread them in the sun to dry, to be again brought into the nest after a sufficient exposure. Lastly, he also repeatedly observed the most surprising and interesting fact that when, as we have seen was occa- sionally the case, the seeds did begin to germinate in the nests, the ants knew the most effective method of pre- venting the germination from proceeding ; for he found that in these cases the ants gnawed off the tips of the radicles. This fact deserves to be considered as one of the most remarkable among the many remarkable facts of ant-psychology. Passing on now to the harvesting or agricultural ants HABVESTING ANTS. 103 of Texas, attention was first called to the habits of this insect by Mr. Buckley in 1860,^ and by Dr. Lincecum, who sent an account of his observations to Mr. Darwin, by whom they were communicated to the Linnaean Society in 1861. Five years later a paper was published in the Proceedings of the Academy of Natural Sciences of Philadelphia from the MS. of Dr. Lincecum. Lastly, in 1877 Mr. MacCook went to Texas expressly to study the habits of these insects, and he has recently embodied the results of his observations in a book of three hundred pages.^ These observations are for the most part confir- matory of those of Lincecum, and for this as well as for reasons to be deduced from the work itself, they deserve to be accepted as trustworthy, notwithstanding that in some cases they are provokingly incomplete. The following is an epitome of these observations. The ants clear away all the herbage above their nest in the form of a perfect circle, or 'disk,' 15 or 20 feet in diameter, by carefully felling every stalk of grass or weed that may be growing thereon. As the nests are placed in thickly grown localities, the effect of these bald or shaven disks is highly conspicuous and peculiar, exactly resembling in miniature the clearings which the settlers make in the American backwoods. The disk, however, is not merely cleared of herbage, but also carefully levelled, all inequali- ties of the surface being reduced by building pellets of soil into the hollows to an extent sufficient to make a uniformly flat surface. The action of rain and the constant motion of multitudes of ants cause this flat surface to become hard and smooth. In the centre of the disk is the gateway of the nest. This may be either a simple hole or a hollow cone. From the disk in various directions there radiate ant- roads or avenues, which are cleared and smoothed like the disk itself, and which course through the thick surround- ing grass, branching and narrowing as they go till they eventually taper away. These roads are usually three or four in number before they begin to branch, but may be * Proc. Phil. Acad. Nat. Sci., xii. p. 445. 2 Agricultural Ant of Texas (Lippincott & Co., Philadelphia, 1880)* 104 ANIMAL INTELLIGENCE. as many as seven. They are usually two to three inches wide at their origin, but in large nests may be as much as five. MacCook found no road longer than sixty feet, but Lincecum describes one of three hundred feet. Along these hard and level roads there is always passing, during the daytime of the harvesting season, a constant stream of ants — those going from the nest being empty-handed, and those returning to it being laden with seeds. Of course the incoming ants, converging from all quarters upon the road, and therefore increasing in numbers as they approach the nest, require greater space for free locomo- tion ; while the outgoing ants, diverging as they get further from home, also require greater proportional space the less their distance from the nest: hence the gradual swelling in the width of the roads as they approach the nests. The manner of collecting the seeds in the jungle sur- rounding the roads is thus described by MacCook : — At last a satisfactory seed is found. It is simply lifted from the ground, or, as often happens, has to be pulled out of the soil into which it has been tightly pressed by the rain or by passing feet. Now follows a movement which at first I thought to be a testing of the seed, and which, indeed, may be partially that; but finally I concluded that it was the adjusting of the burden for safe and convenient carriage. The ant pulls at the seed-husk with its mandibles, turning and pinching or ' feeling ' it on all sides. If this does not satisfy, and commonly it does not, the body is raised by stifiening out the legs, the abdomen is cui-ved underneath, and the apex applied to the seed. I suppose this to be simply a mechanical action for the better adjusting of the load. Now the worker starts homeward. It has not lost itself in the mazes of the grass forest. It turns directly towards the road with an unerring judgment. There are many obstacles to overcome. Pebbles, pellets of earth, bits of wood, obtruding rootlets, or bent-down spears of grass block up or hinder the way. These were scarcely noticed when the ant was empty-handed. But they ai'e troublesome barriers now that she is burdened with a seed quite as thick, twice as wide, and half as long as herself. It is most interesting to see the skill, strength, and rapidity with which the little harvester swings her treasure over or around, or pushes it beneath these obstacles. Now the seed has caught against the herbage as the HAEVESTING ANTS. 105 porter dodges under a too naiTOW opening. She backs out and tries another passage. Now the sharp points of the husk are entangled in the grass. She jerks or pulls the burden loose, and hurries on. The road is reached, and progress is comparatively easy. Holding the grain in her mandibles well above the surface, she breaks into what I may describe with suffi- cient accuracy as ' a trot,' and with little further interruption reaches the disk and disappears within the gate. There are variations from this behaviour, more or less marked, according to the nature of the grounds, the seeds, and (I suppose) the indi viduality of the harvesters ; but the mode of ingathering the crop is substantially as above. Each ant operated independently. Once only did I see anything like an effort to extend sympathy and aid. A worker minor seeming to have difficulty in testing or adjusting a large seed of buffalo-grass, was assisted (ap- parently) by one worker major, and then by another, after which she went on her way. But these ants do not confine their harvesting opera- tions to gathering fallen seeds ; they will, like the ants of Europe, also cut seeds from the stalk. In order to test the disposition of crudelis to garner the seeds from the stem, bunches of millet were obtained from the North, and stalks eighteen inches high, crowned by the boll of close-set seeds, were stuck in the mound of an active formicary. The ants mounted the stems and set to work vigorously to secui-e the seeds, clusters of twenty or more being engaged at once upon one head. The seeds were carried off and stored within the nest. This experiment proved pretty conclusively that in the seeding season crudelis does not wait for the seeds to drop, but harvests them from the plant. The ' granaries ' into which the seeds are brought are kept distinct from the ' nurseries ' for the pupae. Their walls, floor, and roof are so hard and smooth, that MacCook thinks the insects must practise upon them ' some rude mason's craft.' He traced these granaries to a depth of four feet below the surface of the ground, and believes, from the statements of a native peasant, that they, or at least the formicaries, extend to a depth of fifteen feet. As regards the care that the ants take of the gathered grain, Lincecum describes the same habit as Moggridge and Sykes describe — viz., the sunning of wet seeds to 106 ANIMAL INTELLIGENCE. dry. MacCook, however, neglected to make any experi- ments on this subject. Neither has he been able to throw any light upon the question as to why the stored seeds do not geiminate, and is doubtful whether the habit of gnawing the radicle of sprouting seeds, which prev£iils in the European species, is likewise practised by the American. On two other points of importance MacCook's observations are also incomplete. One of these has refer- ence to an alleged statement, which he is disposed to believe, that when some ants in a community have been killed by poison, the survivors avoid the poison : he, how- ever, made no experiments to test this statement. The other main point on which his observations are defective has reference to a remarkable statement made by Lincecum in the most emphatic terms. This state- ment is that upon the surface of their disk the ants sow the seeds of a certain plant, called ant-rice, for the purpose of subsequently reaping a harvest of the grain. There is no doubt that the ant-disks do very often sup- port this peculiar kind of grass, and that the ants are particularly fond of its seed; but whether the plant is actually sown in these situations by the insects, or grows there on account of these situations being more open than the general surface of the ground — this (question MacCook has failed to answer, or even to further. We are, therefore, still left with Dr. Lincecum's emphatic assur- ance that he has witnessed the fact. His account is that the seed of the ant-rice, which is a biennial plant, is sown in time for the autumnal rains to bring up. At the be- ginning of November a green row or ring of ant-rice, about four inches wide, is seen springing up round the cir- <}umference of the disk. In the vicinity of this circular ring the ants do not permit a single spire of any other grass or weed to remain a day, but leave the aristida, or ant-rice, untouched until it ripens, which occurs in June of the next year. After the maturing and harvesting of the seed, the dry stubble is cut away and removed from the pavement or disk, which is thus left unencumbered until the ensuing autumn, when the same species of grass again appears as before, and so on. Lincecum says he has seen HAEVESTING ANTS. 107 the process go on year after year on the same ant-farms, and adds, — There can be no doubt of the fact that the particular species of grain- bearing grass mentioned above is intentionally planted. In farmer-like manner the ground upon which it stands is care- fully divested of all other grasses and weeds during the time it is growing. When it is ripe the grain is taken care of, the dry- stubble cut away and carried off, the paved area being left un- •encumbered until the ensuing autumn, when the same ' ant-rice ' reappears within the same circle, and receives the same agri- cultural attention as was bestowed upon the previous crop — and so on year after year, as I know to be the case, in all situations when the ant's settlements are protected from graminivorous animals. In a second letter Dr. Lincecum, in reply to an inquiry from Mr. Darwin whether he supposed that the ants plant seeds for the ensuing crop, says : — I have not the slightest doubt of it. And my conclusions have not been arrived at from hasty or careless observation, nor from seeing the ants do something that looked a Httle like it, and then guessing at the results. I have at all seasons watched the same ant-cities during the last twelve years, and I know that what I stated in my former letter is true. I visited the same cities yesterday, and found the crop of ant- rice growing finely, and exhibiting also the signs of high cultivation, and not a blade of any other kind of grass or weed was to be seen within twelve inches of the circular row of ant-rice. — {Journ. Linn. Soc, vol. vi. p. 30-1.) Now, MacCook found the ant-rice growing as described, b)ut only on some nests. Why it does not grow upon all the nests he does not understand. So far, then, as his observations go, they confirm those of Dr. Lincecum ; but he does ' not believe that the ants deliberately sow a crop as Lincecum asserts ; ' he thinks ' that they have for some reason found it to their advantage to permit the aristida to grow upon their disks, while they clear off all other herbage ; ' but finally concludes ' that there is nothing unreasonable, nor beyond the probable capacity of the emmet intellect, in the supposition that the crop is actually sown. Simply, it is the Scotch verdict — " Not proven." ' 108 ANIMAL INTELLiaENCE. The following facts with regard to ' modes of mining *' are worth quoting from MacCook : — In sinking the galleries the difficulty of carrjing is not great in a moist or tough soil, which permits the ant to obtain goodly-sized pellets for portage. But when the soil is light and dry, so that it crumbles into dust as it is bitten off, the diffi- culty is greatly increased. It would be a very tedious task indeed to take out the diggings grain by grain. This difficulty the worker overcomes by balling the small particles against the surface of the gallery, the under side of the head, or within and against the mandibles. The fore-feet are used for this purpose, being pressed against the side face, turned under, and pushed upward with a motion similar to that of a man putting his hand upon his mouth. The abdomen is then swung underneath the body and the apex pressed against the little heap of grains of dirt massed against the under side of the mandibles, or be- tween that and the smooth under surface of the head. Thus the dust is compressed into a ball which is of sufficient size to justify deportation. The same operation is observed in the side-galleries, where the ants work very frequently upon their sides or backs, pre- cisely as I have seen colKers do in Pennsylvania coal-mines. The following is likewise worth quoting from the same author : — Seeds are evidently not the only food of our agriculturals. When the ants at disk No. 2 had broken through the sUght mud-sediment that sealed up their gate, as described above, they exhibited a peculiar behaviour. Instead of heading for the roads and pressing along them, they distributed themselves at once over the entire disk, radiating from the gate to all points in the circumference, from which they penetrated the jungle of grass beyond. In a moment a large number were returning across the roads, out of the grass, over the pavement toward the entrance. They bore in their mandibles objects which I presently found to be the males and females of white ants {Termes flavipes), which were filling the air, during and after the rain, in marriage flight. They had probably swarmed just before the shower. The agriculturals were under great excitement, and hurried forth and back at the top of their speed. The number of ants bearing termites was soon so great that the vestibule became choked, and a mass of struggling anthood was piled up around the gate. A stream of eager insects continually poured out of the door, pushing their way HAKVESTING ANTS. 109 "through the crowd that vainly but persistently endeavoured to get in with their burdens. The outcoming ants had the ad- vantage, and succeeded in jostling through the quivering rosette of antennae, legs, heads, and abdomens. Occasionally a worker gained an entrance by dint of sheer physical force and perse- verance. Again and again would the crowd i*ush from all sides upon the gate, only to be pushed back by the issuing throng. In the meanwhile quite a heap of termites, a good handful at least, had been accumulated at one side of the gate, the ants having evidently dropped them, in despair of entrance, and hurried off to garner more. In due time the pressure upon the vestibule diminished, the laden workers entered more freely, and in the end this heap was transferred to the interior. The rapidity with which the ants were distributed to all parts of their roads, after the first opening of the gates, was truly surprising. I was greatly puzzled, at the first, to know what the cause of such a rush might be. The whole behaviour was such as to carry the con- viction that they knew accurately what effect the rain would have, had calculated upon it, and were acting in accordance with previous experience. I had no doubt at the time, and have none now, that the capturing of insects beaten down by the rain is one of the well-established customs of these ants. I saw a few other insects taken in, and one milliped, but chiefly the white ants. That very afternoon I found in a formicary which I then opened several large colonies, or parts of one colony of ter- mites, nested within the limits of the disk and quite at home. The next day numbers of the winged white ants were found stored within the gi-anaries of a large formicary. There is no reason to doubt that these insects were intended for food, in accordance with the quite universal habit of the Formicarice. A curious habit has been noticed by most observers to occur in many species of ant, and it is one on which Mr. MacCook has a good deal to say. The habit in question consists in the ants transporting one another from place to place. The carrying ant seizes her comrade by the middle, and hurries along with it held aloft — the ant which is carried remaining quite motionless with all her legs drawn together. Huber supposed the process to be one enjoy- able to both the insects concerned, and to be performed by mutual understanding and consent; but MacCook, in common with most other observers, supposes that it is 110 ANIMAL INTELLIGENCE. merely a rough and primitive way of communicating to fellow-workers the locality where their services are re- quired. He says : — Keeping these facts in mind, we have a key to the solution of the press-gang operations which Lin cecum observed among the agriculturals, and which have been fully described in other species. In the absence of any common head or directory, and of all executive officers, a change of location or any other con- certed movement must be carried forward by the willing co- operation of individuals. At first sight, the act of seizing and carrying oflF workers does not appear Hke an appeal to free-will. It is indeed coercive, so far as the first act goes. But, in point of fact, the coercion ceases the moment the captive is set down within the precincts of the new movement. The carrier-ant has depended upon securing her consent and co-operation by thus bringing her within the circle of activity for which her service is sought. As a rule, no doubt, the deported ant at once yields to the influence around her, and drops into the current of fresh enterprise, in which she moves with as entire freedom and as independently as any other worker. But she is apparently under no restraint, and if she so please, may return to her former haunts. Certain Ants of Africa. — Livingstone says of certain ants of Africa : — They have established themselves on the plain where water stands so long annually as to allow the lotus and other aqueous plants to come to maturity. When all the ant-horizon is sub- merged a foot deep, they manage to exist by ascending to Httle houses built of black tenaceous loam on stalks of grass, and placed higher than the line of inundation. This must have been the result of experience, for, if they had waited till the water actually invaded their terrestrial habitations, they would not have been able to procure materials for their aerial quarters, unless they dived down to the bottom for every mouthful of clay.^ The Tree Ant of India and New South Wales, — These ants are remarkable from their habit of forming nests only in trees. According to Col. Sykes' account, the shape of the nest is more or less globular, and about ten inches in diameter. It is formed entirely of cow-dung, which the 1 Missionary Tra/oels, p. 328 HONEY-MAKING ANTS. Ill insects collect from the ground beneath, and work into the form of thin scales. These are then built together in an imbricated manner, like tiles or slates upon the roof of a house, the upper or outer scale, however, being one un- broken sheet, which covers the whole nest like a skull-cap. Below this the scales are placed one upon another in a wavy or scalloped manner, so that numerous little arched entrances are left, and yet, owing to the imbricated manner in which the scales are arranged, the interior of the nest is perfectly protected from rain. This interior consists of a number of irregular cells, the walls of whicK are formed by the same process as the exterior. In New South Wales there is another species of ant which also frequents trees, but builds within the stem and branches. In the report of Captain Cook's expedition its habits are thus described : — ' Their habitations are the insides of the branches of a tree, which they contrive to excavate, by working out the pith almost to the extremity ) 9.53 10 )} 10. 7 10.19 )) 10.22 10.35 » 10.39 10.47 )f 10.50 11. 4 j> 11. 7 11.21 j> 11.24 11.34 }> 11.37 11.49 )) 11.52 12. 3 back to 12. 5 away. the honey, 12.13 „ 12.15i „ 12.25 12.28 „ 12.39 12.43 „ 12.54 „ 12.57 „ 1.15 „ 1.19 „ 1.27 „ 1.30 „ 148 ANIMAL INTELLIGENCE. Away therefore 11 minutes. 8 10 11 11 18 „ 8 minutes,' &c., &c., the way being now clearly well learnt. But that the sense of direction is of much service to bees in finding the locality of their hives seems to be indicated by the following observation thus narrated, on the authority of the authors themselves, by Messrs. Kirby and Spence : — In vain, during my stay at St. Nicholas, I sallied out at every outlet to try to gain some idea of the extent and form of the town. Trees, trees, trees, still met me, and intercepted the view in every direction ; and I defy any inhabitant bee of this rural metropolis, after once quitting its hive, ever to gain a ghmpse of it again until nearly perpendicularly over it. The bees, therefore, .... must be led to their abodes by instinct, &c. The observation, however, is not so conclusive as its authors suppose ; for there is nothing to show that the bees did not take note of particular objects on their ac- customed routes, and so learn these routes by stages. It would be worth while in this connection to try the effect of hooding the eyes of a bee, or, if this were deemed too disturbing an experiment, removing the hive bodily to a distance from its accustomed site, and observing whether the bees start away boldly as before for long flights, or learn their new routes by stages. In this connection I may quote the following. Mr. John Topham, of Marlborough House, Torquay, writing to ' Nature,' ^ says : — On October 29, 1873, I removed a hive of bees in my garden, after it was quite dark, for a distance of 12 yards from the place in which it had stood for several months ; and between its original situation and the new one there was a bushy evergreen tree, so that all sight of its former place was » Vol. ix. p. 484. BEES AND WASPS — SENSE OF DIKECTION. 149 obstructed to a person looking from the new situation of the hive. Notwithstanding this change, the bees every day flew to the locality where they formerly lived, and continued flying around the site of what had been their home until, as night came on, they many of them sank upon the grass exhausted and chilled by the cold. Numbers, however, returned alive to their new position, after having looked in vain for their hive in its old place. At night I picked the exhausted bees up, and having restored warmth to them (by leaving them for a time on my coat-sleeve), I returned them to their companions. Here was an illustration that the faculty of memory was superior to that of observation ; but that was not all. Nearly every bee which I picked up during the 23 days through which this effort of memory lasted was an old one, as was easily de- duced from observing the worn edges of the wings ; showing that whilst the young insects were quick in receiving new im- pressions and in correcting errors, the nervous system of the old bees continued acting in the direction which early habit had effected. So true it is that 'one touch of nature makes the whole world kin.' A closely similar observation has been told me by a friend, Mr. George Turner. He found that when he removed a beehive only a yard or two from its accus- tomed site, the bees, on returning home, flew in swarms around the latter, and for a long time were unable to find the hive. And several other similar cases might be adduced. Lastly, Thompson says : — It is highly remarkable that they [bees] know their hive more from its locality than from its appearance, for if it be re- moved during their absence and a similar one be substituted, they enter the strange one. If the position of a hive be changed, the bees for the first day take no distant flight till they have thoroughly scrutinised every object in its neighbourhood.^ On the other hand, the writer of the article on ' Bees ' in the ' Encyclopaedia Britannica ' says that in certain parts of France it is the habit of bee-keepers to place a number of hives upon a boat, which, in charge of a man, floats slowly down a river. The bees are thus continuously changing their pasture-ground, and yet do not lose their locomotive hives. ' Passions of Animals, p. 53. 150 ANIMAL INTELLIGENCE. It may be here worth while to add, parenthetically, as the only authentic observation with which I am acquainted concerning the distance that bees are accustomed to forage, the following statement of Prof. Hugh Blackburn. Writing from Grlasgow University to * Nature,' ^ he says that bees are found in a certain peach-house every spring at the time of blossom, although, so far as he can ascer- tain, the beehives nearest to the peach-house in question are his own, and these are at a distance of ten miles. On the whole, then, and in the absence of further experiments, we must conclude it to be probable that the sense of direction with which hymenopterous insects are, as shown by some of Sir John Lubbock's experiments, un- questionably endowed, is of no small use to them in find- ing their way from home to food and vice versa ; although it appears certain, from other of his experiments, that this sense of direction is not in all cases a sufi&cient guide, and therefore requires to be supplemented by the definite observation of landmarks. But the most conclusive evidence on this latter point is afforded by a highly interesting observation of Mr. Bates on the sand-wasps at Santurem, which may here be suitably introduced, as the insects are not distantly allied. He describes these animals as always taking a few turns in the air round the hole they had made in the sand before leaving to se«k for flies in the forest, apparently in order to mark well the position of the burrow, so that on their return they might find it without dilfficulty. This observation has been since confirmed in a striking manner by Mr. Belt, who found that the sand- wasp takes the most precise bearings of an object the position of which she desires to remember. This observation is so interesting that it deserves to be rendered in extenso : — A specimen of Polistes carnifex (i.e. the sand-wasp noticed by Mr. Bates) was hunting about for caterpillars in my garden. I found one about an inch long, and held it out towards it on the point of a stick. It seized it immediately, and commenced biting it from head to tail, soon reducing the soft body to a mass of pulp. It rolled up about one-half of it into a ball, and pre- » Vol. xii. p. 68. BEES AND WASPS — MEMORY. 15 L pared to carry it off. Being at the time amidst a thick mass of -a fine-leaved climbing plant, it proceeded, before flying away, to take note of the place where it was leaving the other half. To do this, it hovered in front of it for a few seconds, then took small circles in front of it, then larger ones round the whole j)lant. I thought it had gone, but it returned again, and had another look at the opening in the dense foliage down which the other half of the caterpillar lay. It then flew away, but must have left its burden for distribution with its comrades at the nest, for it returned in less than two minutes, and making one circle around the bush, descended to the opening, alighted on a leaf, and ran inside. The green remnant of the cater- pillar was lying on another leaf inside, but not connected with the one on which the wasp alighted, so that in running in it missed it, and soon got hopelessly lost in the thick foliage. Coming out again, it took another circle, and pounced down on the same spot again, as soon as it came opposite to it. Three :small seed-pods, which here grew close together, formed the marks that I had myself taken to note the place, and these the wasp seemed also to have taken as its guide, for it flew directly down to them, and ran inside ; but the small leaf on which the fragment of caterpillar lay not being directly connected with any on the outside, it again missed it, and again got far away from the object of its search. It then flew out again, and the same process was repeated again and again. Always when in circling round it came in sight of the seed-pods down it pounced, alighted near them, and recommenced its quest on foot. I was surprised at its perseverance, and thought it would have given up the search ; but not so, it returned at least half-a-dozen times, and seemed to get angry, hurrying about with buzzing wings. At last it stumbled across its prey, seized it eagerly, and as there was nothing more to come back for, flew stra;ight off to its nest, without taking any further note of the locality. Such an action is not the result of blind instinct, but of a thinking mind ; and it is wonderful to see an insect so differ- ently constructed using a mental process similar to that of man. Memfiory. We may here first allude to an observation of Sir John Lubbock already quoted in another connexion (see p. 147). It is here evident that the wasp, after find- ing the store of honey in the room, and after finding the window closed in the ' wasp-line ' direction to its nest, 152 ANIMAL INTELLIGENCE. required three repeated lessons from Sir John before she learnt that the window on the other side of the room, and away from the direction of her nest, afforded no obstacle to her exit. Having learnt this, the fourth time she came she again flew to the closed window as before, and then, as if but dimly remembering that there was another opening somewhere that offered no such mysterious resistance to her passage, ' she took two or three turns round the room, and then flew out through the open window.' Having now taken the bearings of all the room upon her own wings, and having again found the difference between the two windows in respect of resistance, although in all other respects so much alike, the next time she came she made in the first instance as it were an experi- mental flight towards the closed window, but clearly had the alternative of going to the open one in her memory i for on finding the window closed as before, she did not alight, but flew straight from the closed to the open window. The same thing happened once again, but now, with the distinction between the two windows thus fully learnt, and with it the perception that in this case ' the short- est cut was the longest way round,' she never again flew tO' the closed window ; in the forty successive visits which she paid through the remainder of that day, and the hundred visits or so which she made during the two following days, she seems to have uniformly flown to the open window. As evidence of forgetfulness, it will be enough to refer to the case of another wasp which, under precisely similar circumstances to those just detailed, learnt her way out of the open window one day, having made fifty passages through it in five hours. Yet Sir John remarks, — It struck me as curious that on the following day this wasp seemed by no means so sure of her way, but over and over again went to the closed window. It is further of interest to note, as showing the simi- larity of the memory displayed by these insects with that of the higher animals, that there are considerable indi-- vidual differences to be found in the degree of its manifestation. BEES AND WASPS— MEMORY. 153 In this respect they certainly differ considerably. Some of the bees which came ont of the little postern door (already de- scribed) were able to find their way back after it had been shown to them a few times. Others were much more stupid ; thus one bee came out on the 9th, 10th, 11th, 12th, Uth, 15th, 16th, 17th, 18th, and 19th, and came to the honey; but though I repeatedly put her back through the postern, she was never able to fiiad her way for herself. I often found that if bees which were brought to honey did not return at once, still they would do so a day or two after- wards.. For instance, on July 11, 1874, a hot thundery day, and when the bees were much out of humour, I brought twelve bees to some honey ; only one came back, and that one only twice ; but on the following day several of them returned. This latter observation is important, as proving that bees can remember for at least a whole day the locality where they have found honey only once before, and that they so far think about their past experiences as to return to that locality when foraging. As the association of ideas by contiguity is the prin- ciple which forms the basis of all psychology, it is de- sirable to consider still more attentively this the earliest manifestation that we have of it in the memory of the Hymenoptera. That it is not exercised with exclusive reference to locality is proved by the following observation of Sir John Lubbock : — I kept a specimen of Polistes Gallica for no less than nine months. ^ . . . I had no difficulty in inducing her to feed on my hand ; but at first she was shy and nervous. She kept her sting in constant readiness. . . . Gradually she became quite iised to me, and when I took her on my hand apparently ex- pected to be fed. She even allowed me to stroke her without any appearance of fear, and for some months I never saw her sting. One other observation which goes to prove that other things besides locality are noted and remembered by bees may here be quoted. Sir John placed a bee in a bell jar, the closed end of which he held towards a window. The bee buzzed about at that end trying to > * Three months ' in the Journal of the Linnaean Society, but Sir John Lubbock informs me that this is a misprint. 154 ANIMAL INTELLIGENCE. make for the open air. He then showed her the way out of the open end of the jar, and after having thus learnt it, she was able to find the way out herself. This seems to show that the bee, like the wasp on the closed window- pane, was able to appreciate and to remember the differ- ence between the quality of glass as resisting and air as permeable, although to her sense of vision the difference must have been very slight. In other words, the bee must have remembered that by first flying away from the window, round the edge of the jar, and then towards the window, she could surmount the transparent obstacle; and this implies a somewhat different act of memory from that of associating a particular object — such as honey — with a particular locality. It is noteworthy that a fly under similar circumstances did not require to be taught to find its way out of the jar, but spontaneously found its own way out. This, however, may be explained by the fact that flies do not always direct their flight towards windows, and therefore the escape of this one was probably not due to any act of intelligence. While upon the subject of memory in the Hymenoptera, it is indispensable that we should again refer to the ob- servation of Messrs. Belt and Bates already alluded to on pages 150-51. For it is from that observation rendered evident that these sand- wasps took definite pains, as it were, to teach themselves the localities to which they desired to return. Mr. Bates further observed that after thus taking a careful mental note of the place, they would return to it without a moment's hesitation after an absence of an hour. The observation of Mr. Belt, already quoted in extenso, proves that these mental notes may be taken with the utmost minuteness, so that even in the most intricate places the insect, on its return, is perfectly con- fident that it has not made a mistake. With regard to the duration of memory, Stickney relates a case in which some bees took possession of a hollow place beneath a roof, and having been then re- moved into a hive, continued for several years to return and occupy the same hole with their successive swarms. ^ ' See Kirby and Spence vol. ii. p. 591. BEES AND WASPS — EMOTIONS. 155 Similarly Huber relates an observation of his own showing the duration of memory in bees. One autumn he put some honey in a window, which the bees visited in large numbers. During the winter the honey was taken away and the shutters shut. When they were again opened in the spring the bees returned, although there was no honey in the window. These two cases amply prove that the memory of bees is comparable with that of ants, which, as we have seen from analogous facts, also extends at least over a period of many months. Emotions, Sir John Lubbock's experiments on this head go to show that the social sympathies of bees are even less de- veloped than he found them to be in certain species of ants. Thus he says : — I have already mentioned with reference to the attachment which bees have been said to show for one another, that though I have repeatedly seen them lick a bee which had smeared her- self in honey, I never observed them show the slightest atten- tion to any of their comrades who had been drowned in water. Far, indeed, from having been able to discover any evidence of affection among them, they appear to be thoroughly callous and utterly indifferent to one another. As already mentioned, it was necessary for me occasionally to kill a bee ; but I never found that the others took the slightest notice. Thus on the 11th of October I crushed a bee close to one which was feeding — in fact, so close that their wings touched ; yet the survivor took no notice whatever of the death of her sister, but went on feeding with every appearance of composure and enjoymeilt, just as if nothing had happened. When the pressure was re- moved, she remained by the side of the corpse without the slightest appearance of apprehension, sorrow, or recognition. It was, of course, impossible for her to understand my reason for killing her companion ; yet neither did she feel the slightest emotion at her sister's death, nor did she show any alarm lest the same fate should befall her also. In a second case exactly the same occurred. Again, I have several times, while a bee has been feeding, held a second bee by the leg close to her ; the prisoner, of course, struggled to escape, and buzzed as loudly as she could ; yet the selfish eater took no notice whatever. So 156 ANIMAL INTELLIGENCE. far, therefore, from being at all affectionate, I doubt whether bees are in the least fond of one another. Eeaumur, however (' Insects,' vol. v., p. 265), nar- rates a case in which a hive-bee was partly drowned and so rendered insensible ; the others in the hive carefully licked and otherwise tended her till she recovered. This seems to show that bees, like ants, are more apt to have their sympathies aroused by the sight of ailing or injured companions than by that of healthy companions in distress ; but Sir John Lubbock's observations above quoted go to prove that even in this case display of sympathy is cer- tainly not the rule. Powers of Gommunication, E[uber says that when one wasp finds a store of honey ' it returns to its nest, and brings off in a short time a hundred other wasps ; ' and this statement is confirmed by Dujardin, who witnessed a somewhat similar perform- ance in the case of bees — the individual which first found a concealed store informing other individuals of the fact, and so on till numberless individuals had found it. Although the systematic experiments of Sir John Lubbock have not tended to confirm these observations with regard to bees and wasps, we must not too readily allow his negative results to discredit these positive observations — more especially as we have seen that his later experi- ments have fully confirmed the opinion of these previous authors with respect to ants. His experiments on bees and wasps consisted in exposing honey in a hidden situa- tion, marking a bee or wasp that came to it, and observing whether it afterwards brought any companions to share the booty. He found that although the same insect would return over and over again, strangers came so rarely that their visits could only be attributed to acci- dental and independent discovery. Only if the honey were in an exposed situation, where the insects could see one another feeding, would one follow the other to the food. But we have the more reason not to accept unreservedly BEES AND WASPS— POWERS OF COMMUNICATION. 157 the conclusion to which these experiments in themselves might lead, because the very able observer F. Miiller states an observation of his own which must be considered as alone sufiScient to prove that bees are able to com- municate information to one another: — Once (he says^) I assisted at a curious contest, which took place between the queen and the other bees in one of my hives, which throws some light on the intellectual faculties of these animals. A set of forty-seven cells have been filled, eight on a newly completed comb, thirty-five on the following, and four around the first cell of a new comb. When the queen had laid eggs in all the cells of the two older combs she went several times round their circumference (as she always does, in order to ascertain whether she has not forgotten any cell), and then pre- pared to retreat into the lower part of the breeding-room. But as she had overlooked the four cells of the new comb, the workers ran impatiently from this part to the queen, pushing her, in an odd manner, with their heads, as they did also other workers they met -wdth. In consequence the queen began again to go around on the two older combs ; but as she did not find any cell wanting an egg she tried to descend, but everywhere she was pushed back by the workers. This contest lasted for a rather long while, till the queen escaped without having com- pleted her work. Thus the workers knew how to advise the queen that something was as yet to be done, but they knew not how to show her where it had to be done. Again, Mr. Josiah Emery, writing to ' Nature,' ^ with reference to Sir John Lubbock's experiments, says that the faculty of communication which bees possess is so well and generally known to the ' bee-hunters ' of America, that the recognised method of finding a bees' nest is to -act upon the faculty in question : — Going to a field or wood at a distance from tame bees, with their box of honey they gather up from the flowers and imprison one or more bees, and after they have become suffi- ciently gorged, let them out to return to their home with their easily gotten load. Waiting patiently a longer or shorter time, according to the distance of the bee-tree, the hunter scarcely ever fails to see the bee or bees return accompanied with other bees, which are in like manner imprisoned till they in turn are ^ Letter to Mr. Darwin, published in Natwe, vol. x,, p. 102 2 Vol. xii., pp. 25-6. 158 ANIMAL INTELLIGENCE. filled, when one or more are let out at places distant from each other, and the direction in each case in which the bee flies noted, and thus, by a kind of triangulation, the position of the bee-tree proximately ascertained. Those who have stored honey in their houses understand very well how impoi-tant it is to prevent a single bee from dis- covering its location. Such discovery is sure to be followed by a general onslaught from the hive unless all means of access is prevented. It is possible that our American are more intelli- gent than European bees, but hardly probable ; and I certainly shall not ask an Englishman to admit it. Those in America who are in the habit of playing first, second, and third fiddle to instinct will probably attribute this seeming intelligence to that principle. According to De Fraviere, bees have a number of differ- ent notes or tones which they emit from the stigmata of the thorax and abdomen, and by which they communicate information. He says : — As soon as a bee arrives with important news, it is at once surrounded, emits two or three shrill notes, and taps a com- rade with its long, flexible, and very slender feelers, or antennae. The friend passes on the news in similar fashion, and the intel- ligence soon traverses the whole hive. If it is of an agreeable kind — if, for instance, it concerns the discovery of a store of sugar or of honey, or of a flowering meadow — all remains orderly. But, on the other hand, great excitement arises if the news presages some threatened danger, or if strange animals are threatening invasion of the hive. It seems that such intel- ligence is conveyed first to the queen, as the most important person in the state. This account, which is quoted from Biichner, no doubt bears indications of imaginative colouring ; but if the observation as to the emission of sounds is correct — and, as we shall see, this point is well confirmed by other observers — it is most likely concerned in communicating by tone a general idea of good or harm : probably in the former case it acts as a sign, ' follow me ;' and in the latter as a signal of danger. Biichner further says that, accord- ing to Landois, if a saucer of honey is placed before a hive, a few bees come out, which emit a cry of tut, tut, tut. This note is rather shrill, and resembles the cry of BEES AND WASPS — POWERS OF COMMUNICATION. 159' an attacked bee. Hereupon a large number of bees come out of the hive to collect the offered honey. Again, — The best way to observe the power of communication pos- sessed by bees by means of their interchange of touches, is to take away the queen from a hive. In a httle time, about an hour afterwards, the sad event will be noticed by a small part of the community, and these will stop working and run hastily about over the comb. But this only concerns part of the hive,, and the side of a single comb. The excited bees, however, soon leave the little circle in which they at first revolved, and when they meet their comrades they cros^ their antennse and lightly touch the others with them. The bees which have received some impression from this touch now become uneasy in their turn, and convey their uneasiness and distress in the same way to the other parts of the dwelling. The disorder increases rapidly, spreads to the other side of the comb, and at last to all the people. Then arises the general confusion before described. Huber tested this communication by the antennae by a striking experiment. He divided a hive into two quite sepa- rate parts by a partition wall, whereupon great excitement arose in the division in which there was no queen, and this was only quieted when some workers began to build royal cells. He then divided a hive in similar fashion by a trellis, through which the bees could pass their feelers. In this case all re- mained quiet, and no attempt was made to build royal cells : the queen could also be clearly seen crossing her antennse with the workers on the other side of the trellis. Apparently the feelers are also connected with the exceed- ingly fine scent of the bees, which enables them, wonderful as it may seem, to distinguish fiiend and foe, and to recognise the members of their own hive among the thousands and thousands of bees swarming around, and to drive back from the entrance stranger or robber bees. The bee-masters, therefore, when they want two separate colonies or the members of them to unite in one hive, sprinkle water over the bees, or stupefy them with some fumigating substance, so as to make them to a certain extent insensible to smell, in order to attain their object. It is always possible to unite colonies by making the bees smell of some strong-smelling stuff", such as musk.^ Lastly, under the preaent heading I shall quote one other observation, for which I am also indebted to- ^ Loo. cit. 160 ANIMAL INTELLIGENCE. Biichner's very admirable collection of facts relating to the psychology of Hymenoptera : — Herr L. Brofiib relates, in * der Zoologische Garten ' (XVIIT. Year, No. 1, p. 67), that a poor and a rich hive stood next each other on his father's bee-stand, and the latter suddenly lost its Log. cit., p. 189. 200 ANIMAL INTELLIGENCE. The termites, like many species of true ants, are divided into two distinct castes, the workers and the soldiers. If a breach is made in the walls of the dome the soldiers rush out to meet the enemy, and fight desperately with any enemy that they may find. Here, again, I cannot do better than quote Biichner's epitome of facts : — If the assailant withdraws beyond their reach and inflicts nO' further injury, they retire within their dwelling in the course of half an hour, as though they had come to the conclusion that the enemy who had done the mischief had fled. Scarcely have the soldiers disappeared when crowds of workers appear in the breach, each with a quantity of ready-made mortar in its mouth. As soon as they arrive they stick this mortar round the open place, and direct the whole operation with such swift- ness and facility that in spite of their great number they never hinder each other, nor are obliged to stop. During this spec- tacle of apparent restlessness and confusion the observer is agreeably surprised to see arising a regular wall, filling up the gap. During the time that the workers are thus busied the soldiers remain within the nest, with the exception of a few, which walk about apparently idly, never touching the mortar, among the hundreds and thousands of workers. Nevertheless one of them stands on guard close to the wall which is being built. It turns gently each way in turn, lifting its head at in- tervals of one or two minutes to strike the building with its heavy mandibles, making the before-mentioned crackling noise. This signal is immediately answered by a loud rustling from the interior of the nest and from all the subterranean passages and holes. There is no doubt that this noise arises from the workers, for as often as the sign is given they work with in- creased energy and speed. A renewal of the attack instan- taneously changes the scene. 'At the first stroke,' says Smeathman, ' the workers run into the many tunnels and pas- sages which run through the building, and this happens so- quickly that they seem regularly to vanish. In a few seconds they are all gone, and in their stead appear the soldiers once more, as numerous and as pugnacious as before. If they find no enemy, they turn back slowly into the interior of the hill,, and immediately the mortar-laden workers again appear, and among them a few soldiers, which behave just as on the first occasion. So one can have the pleasure of seeing them work and fight in turn, as often as one chooses ; and it will be found! TERMITES. 201 each time that one set- never fight, and the other never work, however great the need may be.* ^ Similar facts have been observed by Fritz Miiller of the South American species. The Termites, being like the Ecitons blind, like them make all their expeditions under the protection of covered ways. These are underground tunnels in all cases where circumstances permit, but on arriving at a rock or other impenetrable obstruction, they build a tubular passage upon the surface. According to Biichner, — They can even carry their viaducts through the air, and that in such bold arches that it is difficult to understand how they were projected. In order to reach a sack of meal which was well protected below, they broke through the roof of the room in which it was, and built a straight tube from the breach they had made down to the sack. As soon as they tried to carry off their booty to a safe place, they became convinced that it was impossible to pull it up the straight road. In order to meet this difficulty, they adopted the principle of the smooth incline, the use of which we have already seen in the interior of their nests, and built close to the first tube a second, which wound spirally within, like the famous clock tower of Venice. It was now an easy task to carry their booty up this road and so away. . . . Either from the desire to remain undiscovered, or from their liking for darkness, they have the remarkable habit of destroy- ing and gnawing everything from within outwards, and of leaving the outside shell standing, so that from the outside ap- pearance the dangerous state of the inside is not perceptible. If, for instance, they have destroyed a table or other piece of household furniture, in which they always manage from the ground upwards to hit exactly the places on which the feet of the article rest, the table looks perfectly uninjured outside, and people are quite astonished when it breaks down under the slightest pressure. The whole inside is eaten away, and only the thinnest shell is left standing. If fruits are lying on the table, they also are eaten out from the exact spot on which they rest on the surface of the table. In similar fashion things consisting wholly of wood, such as wooden ships, trees, &c., are destroyed by them so that they finally break in without any one having noticed the mischief. Yet it is said that they go so prudently to work in their de- 1 IMd., p. 119. 202 ANIMAL . INTELLIGENCE. struction that the main beams, the sudden breakage of which would threaten the whole building and themselves therewith, are either spared, or else so fastened together again with a ce- ment made out of clay and earth that their strength is greater than ever ! (?) Hagen also states that they never cub right through the corks which stop up stored bottles of wine, but leave a very thin layer, which is sufficient to prevent the out- flow of the wine and the consequent destruction of the workers. The same author relates that in order to reach a box of wax lights they made a covered road from the ground up to the second story of a house. ^ It is needless to give a special description of any of the other habits of these insects, such as their swarming, breeding, &c., for they all more or less closely resemble the analogous habits of ants and bees. It is very remark- able that insects of two distinct orders should both manifest such closely similar social habits of such high complexity, and it rather surprises me that more has not been made of this point by writers opposed to the principles of evolution. Of course if the point were raised, the argument in answer would require to be, either that the similar instincts were derived from common and very remote progenitors (in which case the fact would form by far the most remarkable instance of the permanency of instincts among changing species), or more probably, that similar causes operating in the two orders have produced similar effects — complex and otherwise unique though these effects undoubtedly are. In connection with the theory of evolution I may conclude this chapter with the following quotation from Smeathman, as it shows how natural relation may develop for the benefit of the species instincts which are detri- mental to the individual. Speaking of the soldiers he says : — I was always amused at the pugnacity displayed when, in making a hole in the earthy cemented archway of their covered roads, a host of these little fellows mounted the breach to cover the retreat of the workers. The edges of the rupture bristled with their armed heads as the courageous warriors ranged » Geisteslehen der Thiere, pp. 194 and 199-200. TERMITES. 203 themselves in compact line around them. They attacked fiercely any intruding object, and as fast as their front ranks were de- stroyed, others filled up their places. When the jaws closed in the flesh, they suffered themselves to be torn in pieces rather than loosen their hold. It might be said that this instinct is rather a cause of their ruin than a protection when a colony is attacked by the well-known enemy of termites, the ant-bear ; but it is the soldiers only which attach themselves to the long worm-like tongue of this animal, and the workers, on whom the prosperity of the young brood immediately depends, are left for the most part unharmed. I always found, on thrusting my finger into a mixed crowd of termites, that the soldiers only fastened upon it. Thus the fighting caste do in the end serve to protect the species by sacrificing themselves to its good ^ ' Phil. Trans., loc. cit 204 CHAPTEK VI. SPIDERS AND SCORPIONS. Emotions, The emotional life of spiders, so far as we can observe it as expressed in their actions, seems to be divided between sexual passion (including maternal affection) and the sterner feelings incidental to their fiercely predatory habits. But the emotions, although apparently few and simple in character, are exceedingly strong in force. In many species the male spider in conducting his courtship has to incur an amount of personal danger at the hands (and jaws) of his terrific spouse, which might well daunt the courage of a Leander. Eidiculously small and weak in build, the males of these species can only conduct the rites of marriage with their enormous and voracious brides by a process of active manoeuvring, which if unsuccessful is certain to cost them their lives. Yet their sexual emotions are so strong that, as proved by the continuance of the species, no amount of personal risk is sufficient to deter them from giving these emotions full play. There is no other case in the animal kingdom where courtship is attended with any approach to the gravity of danger that is here observable. Among many animals the males have to meet a certain amount of inconvenience from the coquetry or disinclination of the females ; but here the coquetry and disinclination has passed into the hungry determination of a ferocious giantess. The case, therefore, because unique, is of interest from an evolutionary point of view. We can see a direct advantage to species from the danger incurred by males on account of mutual jealousy ; for this, giving rise to what Mr. Darwin has SPIDEES— EMOTIONS. 205 called * the law of battle,' must obviously be a constant source of the creation and the maintenance of specific proficiency ; the law of battle determines that only the strongest and most courageous males shall breed. But the benefit to species is not so obvious where the danger of courtship arises from the side of the female. Still, that there must be some benefit is obvious, seeing that the whole structure of the male, if we take that of the female as the original type, has been greatly modified with refer- ence to this danger : had the latter been wholly useless, either it would not have been allowed to arise, or the species must have become extinct. The only suggestion I can make to meet this aberrant case is that the courage and determination required of the male, besides being no doubt of use to him in other relations in life, may be of benefit to the species by instilling these qualities into the psychology both of his male and female descendants. The courage and rapacity of spiders as a class are too well and generally known to require special illustration. One instance, however, may be quoted to show the strength of their maternal emotions. Bonnet threw a spider with her bag of eggs into the pit of an ant-lion. The latter seized the eggs and tore them away from the spider ; but although Bonnet forced her out of the pit, she returned, and chose to be dragged in and buried alive rather than leave her charge. The only other point that occurs to me with reference to the emotions of spiders is the somewhat remarkable one concerning their apparent fondness of music. The testi- mony is so varied and abundant on this matter that we can scarcely doubt the truth of the facts. These simply are that spiders — or at any rate some species or individuals — approach a sounding musical instrument, ' especially when the music is tender and not too loud.' They usually approach as near as possible, often letting themselves down from the ceiling of the room by a line of web, and remain suspended above the instrument. Should the music become loud, they often again retreat. Professor C. Eeclain, during a concert at Leipsic, saw a spider descend in this way from one of the chandeliers while a violin solo 206 ANIMAL INTELLIGENCE. was being played ; but as soon as the orchestra began to sound it quickly ran back again. ^ Similar observations have been published by Eabigot, Simonius, von Hartmann, and others. A highly probable explanation of these facts has re- cently been given by Mr. C. V. Boys, which relieves us of the necessity of imputing to animals so low in the scale any rudiment of assthetic emotion as aroused by musical tones. As the observation is an interesting one, I shall quote it in extenso : — Having made some observations on the garden spider which are I beheve new, I send a short account of them, in the hope that they may be of interest to the readers of Nature. Last autumn, while watching some spiders spinning their beautiful geometrical webs, it occurred to me to try what effect a tuning-fork would have upon them. On sounding an A fork, and lightly touching with it any leaf or other support of the web, or any portion of the web itself, I found that the spider, if at the centre of the web, rapidly slues round so as to face the direction of the fork, feeling with its fore-feet along which radial thread the vibration travels. Having become satisfied on this point, it next darts along that thread till it reaches either the fork itself or a junction of two or more threads, the right one of which it instantly determines as before. If the fork is not removed when the spider has arrived it seems to have the same charm as any fly ; for the spider seizes it, em- braces it, and runs about on the legs of the fork as often as it is made to sound, never seeming to learn by experience that other things may buzz besides its natural food. If the spider is not at the centre of the web at the time that the fork is appUed, it cannot tell which way to go until it has been to the centre to ascertain which radial thread is vibrating, unless of course it should happen to be on that particular thread, or on a stretched supporting thread in contact with the fork. If, when a spider has been enticed to the edge of the web the fork is withdrawn, and then gradually brought near, the spider is aware of its presence and of its direction, and reaches out as far as possible in the direction of the fork ; but if a sounding fork is gradually brought near a spider that has not been disturbed, but which is waiting as usual in the middle of ^ Body and Mind, p. 275. SPIDEKS — WEB-BUILDING. 207 the web, then, instead of reaching out towards the fork, the spider instantly drops — at the end of a thread, of course. If under these conditions the fork is made to touch any part of the web, the spider is aware of the fact, and climbs the thread and reaches the fork with marvellous rapidity. The spider never leaves the centre of the web without a thread along which to travel back. If after enticing a spider out we cut this thread with a pair of scissors, the spider seems to be unable to get back without doing considerable damage to the web, generally gum- ming together the sticky parallel threads in groups of three and four. By means of a tuning-fork a spider may be made to eat what it would otherwise avoid. I took a fly that had been drowned in paraffin and put it into a spider's web, and then at- tracted the spider by touching the fly with a fork. When the spider had come to the conclusion that it was not suitable food, and was leaving it, I touched the fly again. This had the same efiect as before, and as often as the spider began to leave the fly I again touched it, and by this means compelled the spider to eat a large portion of the fly. The few house-spiders that I have found do not seem to appreciate the tuning-fork, but retreat into their hiding-places as when frightened ; yet the supposed fondness of spiders for music must surely have some connection with these observations ; and when they come out to listen, is it not that they cannot tell which way to proceed 1 The few observations that I have made are necessarily im- perfect, but I send them, as they afford a method which might lead a naturalist to notice habits otherwise difficult to observe, and so to arrive at conclusions which I in my ignorance of natural history must leave to others.^ General Habits, Coming now to general habits, our attention is claimed by the only general habit that is of interest — namely, that of web-building. The instinct of constructing nets for the capture of prey occurs in no other class of animals, while in spiders it not only attains to an extraordinary degree of perfection (so that, in the opinion of some geometers, the instinct is not less wonderful in this re- spect than is that displayed by the hiv^-bee in the con- * Nature, xxiii., pp. 149-50. 208 ANIMAL INTELLIGENCE. struction of its cells), but also ramifies into a number of diverse directions. Thus we have, in different species, wide open networks spread between the branches of bushes, &c., closely woven textures in the comers of buildings, earth tubes lined with silk, the strong muslin-like snare of the Mygale, which, as first noticed by Madame Merian,^ and since confirmed by Bates, ^ is able to retain a struggling humming-bird while this most beautiful animal in creation is being devoured by the most repulsive ; and many other varieties might be mentioned. It may at first sight ap- pear somewhat remarkable that this instinct of spreading snares should on the one hand occur only in one class of the animal kingdom, while on the other hand, in the class where it does occur, it should attain such extreme perfec- tion, and run into so much variety. But we must here remember that the development of the instinct obviously depends upon the presence of a web-secreting apparatus, which is a comparatively rare anatomical feature. In caterpillars, which are not predaceous, the web is used only for the purposes of protection and locomotion ; and it is easy to see that the spreading of snares would here be of no use to the animals. But in spiders, of course, the case is otherwise. Once granting the power of forming a web, and it is evident that there is much potential service to which this power may be put with reference to the vora- cious habits of the animal ; and therefore it is not to be wondered that both the anatomical structures and their correlated instincts should attain to extreme perfection in sundry lines of development. The origin of the web- building structure was probably due to the use of the web for purposes of locomotion or of cocoon-spinning, as we see it still so used in the same way that it is used by caterpillars for descending from heights, and in the case of the gossamer spider for travelling immense distances through the air. As the anatomical structures in question differ very greatly in the case of spiders and in that of caterpillars, we may wonder why analogous if not homolo- * Naturalist on the Amazon, p. 83. 2 For many other confirmations see SirE. Tennent, Nat. Hist.Ceylony pp. 468-69. SPIDERS — WEB-BUILDD^G. 209 sgons structures should never have been developed in the case of any other animal having predaceous habits — especially, perhaps, in that of the imago form of preda- ceous insects. It is easy to see how, if there were any original tendency to secrete a viscid substance in the .neighbourhood of the anus, this might be utilised in de- scending from low elevations (as certain kinds of slugs use their viscid slime as threads whereby to let themselves down from low branches to the ground) ; and so we can understand how natural selection might thus have the material supplied out of which to develop such highly specialised organs as the spinnerets of a spider. But if we are inclined to wonder why this should not have happened among other animals, we must remember that any expectation that it should rests on negative grounds ; we have no reason to suppose that in any other case the initial tendency to secrete a viscid substance was present. One inference, however, in the case of spiders seems per- fectly valid. As this comparatively rare faculty of web- spinning occurs so generally throughout the class, it must have had its earliest origin very far back in the history of that class, though probably not so far back as to include the common progenitors of the spiders and the scorpions, seeing that the latter do not spin webs. I shall now give a few details on the manner in which spiders' webs are made. Without going into the ana- tomy of the subject further than to observe that a spider's ' thread ' is a composite structure made up of a number of finer threads, which leave their respective spinneret-holes in an almost fluid condition, and immedi- ately harden by exposure to the air, I shall begin at once to describe the method of construction. The so-called ' geometric spider ' constructs her web by first laying down the radiating and unadhesive rays, and then, beginning from the centre, spins a spiral line of unadhesive web, like that of the rays which it intersects. This line, in being woven through the radii in a spiral from centre to xjircumference, serves as a scaffolding for the spider to walk over, and also keeps the rays properly stretched. She next spins another spiral line, but this 210 ANIMAL INTELLIGENCE. time from the circumference to near the centre, an(| formed of web, covered with a viscid secretion to retain prey. Lastly, she constructs her lair to hide and watch for prey, at some distance from the web but connected with it by means of a line of communication or telegraph,, the vibrations of which inform her of the struggling of an insect in the net.^ According to Thompson, — The web of the garden spider — the most ingenious and per- fect contrivance that can be imagined — is usually fixed in a perpendicular or somewhat oblique direction in an opening between the leaves of some plant or shrub ; and as it is obvious that round its whole extent lines will be required to which those ends of radii that are farthest from the centre can be at- tached, the construction of those exterior lines is the spider's first operation. It seems careless about the shape of the area they are to enclose, well aware that it can as readily inscribe a circle in a triangle as a square ; and in this respect it is guided by the distance or proximity of the points to which it can attach them. It spares no pains, however, to strengthen and keep them in a proper degree of tension. With the former view it com- poses each line of five or six or even of more threads glued together ; and with the latter it fixes to them from different points a numerous and intricate apparatus of smaller threads ; and having thus completed the foundation of its snare, it pro- ceeds to fill up the outline. Attaching a thread to one of the main hnea, it walks along it, guiding it mth one of its hind legs, that it may not touch in any part and be prematurely glued, and crosses over to the opposite side, where, by applying its spinners, it firmly fixes it. To the middle of this diagonal thread, which is to form the centre of its net, it fixes a second, which in like manner it conveys and fastens to another part of the lines in- cluding the area. The work now proceeds rapidly. During the preliminary operations it sometimes rests, as though its plan required meditation ; but no sooner are the marginal lines of the net firmly stretched, and two or three radii spun from its centre, than it continues its labour so quickly and unremittingly that the eye can scarcely follow its progress. The radii, to the number of about twenty, giving the net the appearance of a wheel, are speedily finished. It then proceeds to the centre, quickly turns itself round, pulls each thread with its feet to ascertain its strength, breaking any one that seems defective, and ' Kirb}^ vol. ii., p. 208. SPIDEKS~WEB-BUILDINa. 2 1 1 replacing it by another. Next it glues, immediately round the centre, five or six small concentric circles, distant about half a line from each other, and then four or five larger ones, each separated by the space of half an inch or more. These last serve as a sort of temporary scaffolding to walk over, and to keep the radii properly stretched while it glues to them the concentric circles that are to remain, which it now proceeds to construct. Placing itself at the circumference, and fastening its tiiread to the end of one of the radii, it walks up that one, towards the centre, to such a distance as to draw the thread from its body of a sufficient length to meet the next. Then stepping across and conducting the thread with one of its hind legs, it glues it with its spinners to the point in the adjoining radius to which it is to be fixed. This process it repeats until it has filled up nearly the whole space from the circumference to the centre with concentric circles, distant from each other about two lines. It always, however, leaves a vacant interval around the smallest first spun circles that are nearest to the centre, and bites away the small cotton-like tuft that united all the radii, which being held now together by the circular threads have thus probably their elasticity increased ; and in the cir- cular opening, resulting from this procedure, it takes its station and watches for its prey, or occasionally retires to a little apart- ment formed under some leaf, which it also uses as a slaughter- house.^ According to Biichner, — The long main threads, with the help of which the spider begins and attaches its web, are always the thickest and strong- est ; while the others, forming the web itself, are considerably weaker. Injuries to the web at any spot the spider very quickly repairs, but without keeping to the original plan, and without taking more trouble than is absolutely necessary. Most spiders' webs, therefore, if closely looked into, are found to be somewhat irregular. When a storm threatens, the spider, which is very economical with its valuable spinning material, spins no web, for it knows that the storm will tear it in pieces and waste its pains, and it also does not mend a web which has been torn. If it is seen spinning or mending, on the other hand, fine weather may be generally reckoned on. . . . The emerged young at first spin a very irregular web, and only gradually learn to make a larger and finer one, so that here, as everywhere else, practice and experience play a great part. . , * Thompson, Passions of Animals, p. 145. p 2 212 ANIMAL INTELLIGENCE. The position must also oflfer favourable opposite points for the attachment of the web itself. People have often puzzled their brains, wondering how spiders, without being able to fly, had managed first to stretch their web through the air between two opposite points. But the little creature succeeds in accomplish- ing this diflSicult task in the most various and ingenious ways. It either, when the distance is not too great, throws a moist viscid pellet, joined to a thread, which will stick where it touches ; or hangs itself by a thread in the air and lets itself be driven by the wind to the spot ; or crawls there, letting out a thread as it goes, and then pulls it taut when arrived at the desired place ; or floats a number of threads in the air and waits till the wind has thrown them here or there. The main or radial threads which fasten the web possess such a high degree of elasticity, that they tighten themselves between two distant points to which the spider has crawled, without it being necessary for the latter to pull them towards itself. When the little artist has once got a single thread at its disposition, it strengthens this until it is sufficiently strong for it to run back- wards and forwards thereupon, and to spin therefrom the web.^ Special Habits, Water-spider, — The water-spider {Argyroneta aqua- tica), as is well known, displays the curious instinct of building her nest below the surface of water, and construct- ing it on the principle of a diving-bell. The animal usually selects still waters for this purpose, and makes her nest in the form of an oval hollow, lined with web, and held secure by a number of threads passing in various directions and fastened to the surrounding plants. In this oval bell, which is open below, she watches for prey, and, according to Kirby,^ passes the winter after having closed the opening. The air needful for respiration the spider carries from the surface of the water. To do this she swims upon her back in order to entangle an air- bubble upon the hairy surface of her abdomen. With this bubble she descends, ' like a globe of quicksilver,' to the opening of her nest, where she liberates it and returns for more. ' Zoo. oH., p. 316 «^ seq. 2 Hist. Habits and Inst, of Animals, vol. ii., p. 296. WOLF- AND TKAP-DOOR SPIDEES. 213 The Vagrant or Wolf Spider, — This insect catches its prey by stealthily stalking it until within distance near enough to admit of a sudden dart being successful in effecting capture. Some species, before making the final dart {e.g. Salticiis scenicus), fix a line of web upon the surface over which they are creeping, so that whether their station is vertical or horizontal with reference to the prey, they can leap fearlessly, the thread in any case preventing their fall. Dr. H. F. Hutchinson says that he has seen this spider crawling over a looking-glass stalking its own reflection.^ The following is quoted from Biichner : — Less idyllic than the water-spider is our native hunting- spider (JDolomedes fimhriata), which belongs to those species which spin no web, but hunt their victims like animals of prey. As the Argyroneta is the discoverer of the diving-bell, so may this be regarded as the discoverer or first builder of a floating raft. It is not content with hunting insects on land, but follows them on the water, on the surface of which it runs about with ease. It, however, needs a place to rest on, and makes it by rolling together dry leaves and such like bodies, binding them into a firm whole with its silken threads. On this raft-like vessel it floats at the mercy of wind and waves ; and if an unlucky water-insect comes for an instant to the sur- face of the water to breathe, the spider darts at it with light- ning speed, and carries it back to its raft to devour at its ease. Thus everywhere in nature are battle, craft, and ingenuity, all following the merciless law of egoism, in order to maintain their own lives and to destroy those of others ! Trap-door Spiders. — These display the curious in- stinct of providing their nests with trap-doors. The nest consists of a tube excavated in the earth to the depth of half a foot or more. In all save one species the tube is unbranched ; it is always lined with silk, which is con- tinuous with the lining of the trap-door or doors, of which it forms the hinge. In the species which constructs a branching tube, the branch is always single, more or less straight, takes origin at a point situated a few inches from the orifice of the main tube, is directed upwards at an acute 1 Nature, vol. xx., p. 581. ' Loc. cit., p. 323. 214 ANIMAL INTELLIGENCE. angle with that tube, and terminates blindly juist below the surface of the soil. At its point of junction with or departure from the main tube it is provided with a trap- door resembling that which closes the orifice of the main tube, and of such a size and arrangement that when closed against the opening of the branch tube it just fills that opening ; while when turned outwards, so as to uncork this opening, it just fills the diameter of the main tube : the latter, therefore, is in this species provided with two trap-doors, one at the surface of the soil, and the other at the fork of the branched tube. Each species of trap-door spider is very constant in building a particular kind of trap-door ; but among the different species there are four several kinds of trap- doors to be distinguished. 1st. The single-door cork nest, wherein the trap-door is a thick structure, and fits into the tube like a cork into a bottle. 2nd. The single- door wafer nest, wherein the trap-door is as thin as a piece of paper. 3rd The double-door unbranched nest, wherein there is a second trap-door situated a few inches below the first one. And 4th, the double-door branched nest already described. In all cases the trap-doors open outwards, and when the nest is placed, as it usually is, on a sloping bank, the trap-door opens upwards ; hence there is no fear of its gaping, for gravity is on the side of holding it shut. The object of the trap-door is to conceal the nest, and for this purpose it is always made so closely to resemble the general surface of the ground on which it occurs, that even a practised eye finds it difficult to detect the struc- ture when closed. In order to make the resemblance to the surrounding objects as perfect as possible, the spider either constructs the surface of its door of a portion of leaf, or weaves moss, grass, &c., into the texture. Mog- gridge says,^ — Thus, for example, in one case where I had cut out a little clod of mossy earth, about two inches thick and three square on the surface, containing the top of the tube and the moss- covered cork door of W. ccementaria, I found, on revisiting the ' Hanwstinff Ants and Trap-door Spiders, p. 120. TEAP-DOOE SPIDERS. 215 place six days later, that a new door had been made, and that the spider had mounted up to fetch moss from the undisturbed bank above, planting it in the earth which formed the crown of the door. Here the moss actually called the eye to the trap, which lay in the little plain of brown earth made by my digging. If an enemy should detect the trap-door and en- deavour to open it, the spider frequently seizes hold of its internal surface, and, applying her legs to the walls of the tube, forcibly holds the trap-door shut. In the double trap-door species it is surmised that the second trap-door serves as an inner barrier of defence, behind which the spider retires when obliged to abandon the first one. In the branched tube species (which, so far as at present known, only occurs in the south of Europe) it is surmised that the spider, when it finds that an enemy is about to gain entrance at the first trap-door, runs into the branch tube and draws up behind it the second trap-door. The surface of this trap-door, being overlaid with silk like the walls of the tube, is then invisible ; so that the enemy no doubt passes down the main tube to find it empty, without observing the lateral branch in which the spider is concealed behind the closed door. As showing that these animals are to no small extent able to adapt their dwellings to unusual circumstances, I shall here quote the following from Moggridge (loc, cit, p. 122):— Certain nests which were furnished with two doors of the cork type were observed by Mr. S. S. Saunders in the Ionian Islands. The door at the surface of these nests was normal in position and structure, but the lower one was placed at the very bottom of the nest, and inverted, so that, though apparently in- tended to open downwards, it was permanently closed by the surrounding earth. The presence of a carefully constructed door in a situation which forbade the possibility of its ever being opened seemed, indeed, something difficult to account for. However, it occurred to Mr. Saunders that, as these nests were found in the cultivated ground round the roots of olive trees, they may occasionally have got turned topsy-turvy when the :Soil was broken up. The spider then, finding her door buried t)elow in the gi'ound and the bottom of the tube at the surface, 216 AI^IMAL INTELLIGENCE. would have either to seek new quarters or to adapt the nest to its altered position, and make an opening and door at the ex- posed end. In order to try whether one of these spiders would do this, Mr. Saunders placed a nest, with its occupant inside, upside down in a flower-pot. After the lapse of ten days a new door was made, exactly as he had conjectured it would be, and; the nest pres^ited two doors like those which he had found at first. The most remarkable fact connected with these animals, if we regard their peculiar instinct from the standpoint of the descent theory, is the wide range of their geographical distribution. In all quarters of the globe species of trap-door spiders are found occurring in more or less localised areas ; and as it is improbable that so peculiar an instinct should have arisen independently in more than one line of descent, we can only conclude that the wide dispersion of the species presenting it has been subsequent to the origin and perfecting of the in- stinct. This conclusion of course necessitates the suppo- sition that the instinct must be one of enormous antiquity ; and in this connection it is worthy of remark that we seem to have independent evidence to show that such is the case. It is a principle of evolution that the earlier any structure or instinct appears in the development of the race, the sooner will it appear in the development of the individual ; and read by the light of this principle we should conclude, quite apart from all considerations as to the wide geographical distribution of trap-door spiders, that their instincts — as, indeed, is the case with the characteristic instincts of many other species of spiders — must be of immense age. Thus, again to quote Mog- gridge,— It seems to be the rule with spiders generally that the off- spring should leave the nest and construct dwellings for them- selves when very young. Mr. Blackwall, speaking of British spiders, says : — ' Com- plicated as the processes are by which these symmetrical nets are produced, nevertheless young spiders, acting under the influence of instinctive impulse, display, even in their first attempts to fabricate them, as consummate skill as the most .experienced individuals,' TEAP-DOOK SPIDEKS. 21T Again, Mr. F. Pollock* relates of the young of Epeira attrelia, •which he observed in Madeira, that when seven weeks old they made a web the size of a penny, and that these nets have the same beautiful symmetry as those of the full-grown spider. And, speaking of trap-door spiders, Moggridge says, — I cannot help thinking that these very small nests, built as they are by minute spiders probably not very long hatched from the egg, must rank among the most marvellous structures of this kind with which we are acquainted. That so young and weak a creature should be able to excavate a tube in the eaj-th many times its own length, and know how to make a perfect miniature of the nest of its parents, seems to be a fact which has scarcely a parallel in nature.^ Kegarding the steps whereby the instinct of building trap -doors probably arose, Btichner quotes Moggridge thus : — To show, lastly, how various are the transitional forms and gradations so important in deciding upon the gradual origin of the forms of nests, Moggridge also alludes to the similar build- ings made by other genera of spiders. Lycosa Narhonensis, a spider of Southern France much resembling the Apuleian tarantula, and belonging to the family of the wolf spiders, makes cylindrical holes in the earth, about one inch wide and three or four inches deep, in a perpendicular direction ; when they have attained this depth they run further hol'izontally, and end in a three-cornered room, from one to two inches broad, the floor of which is covered with the remnants of dead in- sects. The whole nest is lined within with a thick silken material, and has at its opening — closed by no door — an above- ground chimney-shaped extension, made of leaves, needles, moss, wood, &c., woven together with spider threads. These chimneys show various differences in their manner of building, and are intended chiefly, according to Moggridge, to prevent the sand blown about by the violent sea- winds from penetrating into the nests. During winter the opening is wholly and con- tinuously woven over, and it is very well possible, or probable, that the process of reopening such a warm covering in the spring, * • The History and Habits of Epeira aurelia,' in Annals and Mag. of Nat. Hist, for June 1865. 2 Harvesting Ants and Trap-door Spiders, p. 126. This admirable work, with its appendix, contains a very full account of the whole- economy of the interesting animals with which it is concerned. 218 ANIMAL INTELLIGENCE. after this opening was three-quarters completed, and was large enough to let the spider pass out, may have long ago awaked in the brain of some species of spider the idea of making a per- manent and moveable door. But from this to the practical construction of so perfect a door as we have learned to know, and even to the building of the exceedingly complicated nest of the N. Manderstjernce, through all the gradations which we already know, and which doubtless exist in far greater number, is no great or impossible step. General Intelligence. Coming now to the general intelligence of spiders, I think there can be no reasonable doubt, from the force of concurrent testimony, that they are able to distinguish between persons, and approach those whom they have found to be friendly, while shunning strangers. This power of discrimination, it will be remembered, also occurs among bees and wasps, and therefore its presence in spiders is not antecedently improbable. I myself know a lady who has ' tamed ' spiders to recognise her, so that they come out to be fed when she enters the room where they are kept ; and stories of the taming of spiders by prisoners are abundant. The following anecdote recorded by Biichner is in this connection worth quoting : — Dr. Moschkau, of Gohlis, near Leipsic, writes as follows to the author, on August 28, 1876 : — 'In Oderwitz (?), where I lived in 1873 and 1874, 1 noticed one day in a half-dark corner of the anteroom a tolerably respectable spider's web, in which a well-fed cross-spider had made its home, and sat at the nest- opening early and late, watching for some flying or creeping food. I was accidentally several times a witness of the craft with which it caught its victim and rendered it harmless, and it soon became a regular duty to carry it flies several times during a day, which I laid down before its door with a pair of pincers. At first this feeding seemed to arouse small confidence, the pincers perhaps being in fault, for it let many of the flies escape again, or only seized them when it knew that they were within reach of its abode. After a while, however, the spider came each time and took the flies out of the pincers and spun them over. The latter business was sometimes done so super- ificially, when I gave flies very quickly one after the other, that SPIDERS — GENERAL INTELLIGENCE. 219 «ome of the already ensnared flies found time and opportunity to escape. This game was carried on by me for some weeks, as it seemed to me curious. But one day when the spider seemed Tery ravenous, and regularly flew at each fly ofiered to it, I began teasing it. As soon as it had got hold of the fly I pulled it back again with the pincers. It took this exceedingly ill. The first time, as I finally left the fly with it, it managed to forgive me, but when I later took a fly right away, our friend- ship was destroyed for ever. On the following day it treated my offered flies with contempt, and would not move, and on the iihird day it had disappeared.^ Jesse relates the following anecdote, which seems to •display on the part of a spider somewhat remote adapta- tion of means to novel circumstances. He confined a spider with her eggs under a glass upon a marble mantel- piece. Having surrounded the eggs with web, — She next proceeded to fix one of her threads to the upper part of the glass which confined her, and carried it to the further end of the piece of grass, and in a short time had succeeded in Taising it up and fixing it perpendicularly, working her threads from the sides of the glass to the top and sides of the piece of grass. Her motive in doing this was obvious. She not only rendered the object of her care more secure than it would have been had it remained flat on the marble, but she was probably aware that the cold from the marble would chill her eggs, and prevent their arriving at maturity : she therefore raised them from it in the manner I have described.^ Mr. Belt gives the following account of the intelligence which certain species of South American spiders display in escaping from the terrible hosts of the Eciton ants : — Many of the spiders would escape by hanging suspended by a thread of silk from the branches, safe from the foes that swarmed both above and below. I noticed that spiders generally were most intelligent in ■escaping, and did not, like the cockroaches and other insects, take shelter in the first hiding-place they found, only to be driven out again, or perhaps caught by the advancing army of ants. I have often seen large spiders making ofi^ many yards in advance, and apparently determined to put a good distance » Log. cU., p. 319. * Gleanings, vol. 1., p. 103. 220 ANIMAL INTELLIGENCE. between themselves and the foe. I once saw one of the faJsa spiders, or harvest-men {Phalangidce), standing in the midst of an army of ants, and with the greatest circumspection and cool- ness lifting, one after the other, its long legs, which supported its body above their reach. Sometimes as many as five out of its eight legs would be lifted at once, and whenever an ant ap- proached one of those on which it stood, there was always a clear space within reach to put down another, so as to be able to hold up the threatened one out of danger.^ Mr. L. A. Morgan, writing to « Nature ' (Jan. 22, 1880),. gives an account of a spider conveying a large insect from the part of the web where it was caught to the ' larder,' by the following means. The spider first went two or three times backwards and forwards between the head of the insect and the main strand of the web. After this he went about cutting all the threads around the insect till the latter bung by the head strands alone. The spider then fixed a thread to the tail end, and by this dragged the carcass as far on its way to the larder as the head strands would permit. As soon as these were taut, he made the tail rope fast, went back to the head rope and cut it ; then he attached himself to the head and pulled the body towards the larder, until the tail rope was taut. In this way, by alternately cutting the head and tail ropes and dragging the insect bit by bit, he con- veyed it safely to the larder. But the practical acquaintance with mechanical prin- ciples which this observation displays is perhaps not so remarkable as that which is sometimes shown by spiders when they find that a widely spread web is not tightly enough stretched, and as a consequence is to an incon- venient extent swayed about by the wind. Under such, circumstances these animals have been observed to sus- pend to their webs small stones or other heavy objects, the weight of which serves to steady the whole system^ Grleditsch saw a spider so circumstanced let itself down to^ the ground by means of a thread, seize a small stone, re- mount, and fasten the stone to the lower part of its web,., at a height sufficient to enable animals and men to walk * Natwaligt m Nicaragua, p. 19. SPIDEKS— GENEEAL INTELLIGENCE. 221 beneath it. After alluding to this case, Biicliner observes iloc. ciL, p. 318),— But a similar observation was made by Professor E. H. Weber, the famous anatomist and physiologist, and was pub- lished many yeai-s ago in Miiller's Journal. A spider had stretched its web between two posts standing opposite each other, and had fastened it to a plant below for the third point. But as the attachment below was often broken by the garden work, by passers-by, and in other ways, the little animal extri- cated itself from the difficulty by spinning its web round a little ;Stone, and fastened this to the lower part of its web, swinging freely, and so to draw the web down by its weight instead of festening it in this direction by a connecting thread. Carus {^Yergl. Psycho.,' 1866, p. 76) also made a siroilar observation. But the most interesting observation on this head is related by J. G. Wood (' Glimpses into Petland '), and repeated by Watson (loc. cit., p. 455). One of my friends, says Wood, was accustomed to gi'ant shelter to a number of garden spiders under a large verandah, and to watch their habits. One day a shai-p storm broke out, and the wind raged so furiously through the garden that the spiders suflfered damage from it, although sheltered by the verandah. The mainyards of one of these webs, as the sailors would call them, were broken, so that the web was blown hither and thither, like a slack sail in a storm. The spider made no fresh threads, but tried to help itself in another way. It let itself down to the ground by a thread, and crawled to a place where lay some splintered pieces of a wooden fence thrown down by the storm. It fastened a thread to one of the bits of wood, turned back with it, and hung it with a strong thread to the lower part of its nest, about five feet from the ground. The performance was a wonderful one, for the weight of the wood sufficed to keep the nest tolerably firm, while it was yet light enough to yield to the wind, and so prevent further injury. The piece of wood was about two and a half inches long, and as thick as a goose-quill. On the following day a careless servant knocked her head against the wood, and it fell down. But in the course of a few hours the spider had found it and brought it back to its place. When the storm ceased, the spider mended her web, broke the supporting thread in two, nand let the wood fall to the ground ! If so well-observed a fact requires any further confir- mation, I may adduce the following account, which is of the more value as corroborative evidence from the writer 222 ANIMAL INTELLIGENCE. not appearing to be aware that the fact had been observed before. This writer is Dr. John Topham, whom the late Dr. Sharpey, F.R.S., assured me is a competent observer, and who publishes the account in * Nature ' (xi. 18) : — A spider constructed its web in an angle of my garden, the sides of which were attached by long threads to shrubs at the height of nearly three feet from the gravel path beneath. Being much exposed to the wind, the equinoctial gales of this autumn destroyed the web several times. The ingenious spider now adopted the contrivance hero represented. It secured a conical fragment of gravel with its larger end upwards by two cords, one attached to each of its opposite sides, to the apex of its wedge-shaped web, and left it suspended as a moveable weight to be opposed to the effect of such gusts of air as had destroyed the webs previously occupy- ing the same situation. The spider must have descended to the gravel path for this special object, and having attached threads to a stone suited to its purpose, must have afterwards raised this by fixing itself upon the web, and pulling the weight up to a height of more than two feet from the ground, where it hung suspended by elastic cords. The excellence of the contrivance is too evident to require further comment. An almost precisely analogous case, with a sketch, is published by another observer in ' Land and Water,' Dec. 12, 1877. Scorpions. Before quitting the Arachnida I must allude to some recent correspondence on the alleged tendency of the scorpion to commit suicide when surrounded by fire. This alleged tendency has long been recognised in popular fables, and has been used by Byron as a poetical metaphor in certain well-known lines. But until the publication of the correspondence to which I allude, no one supposed the tendency in question to have any existence in fact. This correspondence took place in 'Nature' (vol. xi.), and as the subject is an interesting one, I shall reproduce the more important contributions to it in ex- tenso. It was opened by Mr. W. G-. Biddie as follows : — I shall feel obliged if you will record in * Nature ' a fact with SCORPIONS. 223 reference to the common black scorpion of Southern India, which was observed by me some years ago in Madras. One morning a servant brought to me a large specimen of this scorpion, which, having stayed out too long in its nocturnal rambles, had apparently got bewildered at daybreak, and been unable to find its way home. To keep it safe the creature was at once put into a glazed entomological case. Having a few leisure minutes in the course of the forenoon I thought I would see how my prisoner was getting on, and to have a better view of it the case was placed in a window in the rays of the hot sun. The light and heat seemed to irritate it very much, and this recalled to my mind a story which I had read somewhere that a scorpion, on being surrounded with fire, had committed suicide. I hesitated about subjecting my pet to such a terrible ordeal, but taking a common botanical lens, I focussed the rays of the sun on its back. The moment this was done it began to run hurriedly about the case, hissing and spitting in a very fierce way. This experiment was repeated some four or five times with like results, but on trying it once again, the scorpion turned up its tail and plunged the sting, quick as lightning, into its own back. The infliction of the wound was followed by a sudden escape of fluid, and a friend standing by me called out, ' See, it has stung itself : it is dead ;' and sure enough in less than half a minute life was quite extinct. I have written this brief note to show (1) that animals may commit suicide; (2) that the poison of certain animals may be destructive to them- selves. The following corroborative evidence on the subject was then supplied by Dr. Allen Thomson, F.E.S. (' Nature,' vol. XX., p. 577) : — Doubts having been expressed at various times, even by learned naturalists, as to the reality of the suicide or self-de- struction of the scorpion by means of its own poison, and these doubts having been again stated in ' Nature,' vol. xx.,p. 553, by Mr. B. F. Hutchinson, of Peshawur, as the result of his own observations, I think it may be useful to give an articulate account of the phenomenon as it has been related to me by an eye-witness, which removes all possible doubt as to its occurrence under certain cii'cumstances. While residing many years ago, during the summer months, at the baths of Sulla in Italy, in a somewhat damp locality, my informant together with the rest of the family was much annoyed by the frequent intrusion of small black scorpions into 224 ANIMAL INTELLIGENCE. the house, and their being secreted among the bedclothes, in shoes, and other articles of dress. It thns became necessary to be constantly on the watch for these troublesome creatures, and to take means for their removal and destruction. Having been informed by the natives of the place that the scorpion would destroy itself if exposed to a sudden light, my informant and her friends soon became adepts in catching the scorpions and disposing of them in the manner suggested. This consisted in <;onfining the animal under an inverted drinking-glass or tumbler, below which a card was inserted when the capture was made, and then, waiting till dark, suddenly bringing the light of a candle near to the glass in which the animal was confined. No sooner was this done than the scorpion invariably showed signs of great excitement, running round and round the interior of the tumbler with reckless velocity for a number of times. This state having lasted for a minute or more, the animal suddenly became quiet, and turning its tail on the hinder part of ite body over its back, brought its recurved sting down upon the middle of the head, and piercing it forcibly, in a few seconds became quite motionless, and in fact quite dead. This observa- tion was repeated very frequently ; in truth, it was adopted as the best plan of getting rid of the animals. The young people were in the habit of handling the scorpions with impunity im- mediately after they were so killed, and of preserving many of them as curiosities. In this narrative the following circumstances are worthy of attention : — (1) The effect of light in producing the excitement amount- ing to despair, which causes the animal to commit self-destruc- tion ; (2) The suddenness of the operation of the poison, which is probably inserted by the puncture of the head into the upper ■cerebral ganglion; and (3) The completeness of the fataV symptoms at once in- duced. I am aware that the phenomena now described have been observed by others, and they appear to have been familiarly known to the inhabitants of the district in which the animals are found. Sufficient confirmation of the facts is also to be found in the narratives of ' G. Biddie ' and ' M. L.' contained in * Nature,' vol. ix., pp. 29-47, and it will be observed that the circumstances leading the animal to self-destruction in these in- stances were somewhat similar to those narrated by my inform- ant. It is abundantly clear, therefore, that the view taken SCOEPIONS. 225 "by Mr. Hutchinson, viz., that the 'popular idea regarding ficorpionic suicide is a delusion based on an impossibility,' is wholly untenable ; indeed, the recurved direction of the sting, ■which he refers to as creating the impossibility of the animal destroying itself, actually facilitates the operation of inflicting the wound. I suppose Mr. Hutchinson, arguing from the ana- logy of bees or wasps, imagined that the sting would be bent forwards upon the body, whereas the wound of the scorpion is invariably inflicted by a recurvation of the tail over the back of "the animal. It will be perceived that these observations were not made by Dr. Allen Thomson himself, and that there are <;ertain inherent discrepancies in the account which he has published — such, for instance, as the reason given for trying and repeating the experiment, the method being ■clearly a cumbersome one to employ if the only object were that of 'disposing of the animals. Nevertheless, as Dr. Thomson is a high authority, and as I learn from him that he is satisfied regarding the capability and vera- city of his informant, I have not felt justified in suppress- ing his evidence. Still I think that so remarkable a fact unquestionably demands further corroboration before we should be justified in accepting it unreservedly. For if it is a fact, it stands as a unique case of an instinct detrimental alike to the individual and to the species. <''Vi-iiiH-4 n 226 ANIMAL INTELLIGENCE. CHAPTER VII. REMAINING ARTICULATA. The Hjmenoptera being so much the most intelligent order, not merely of insects, but of Invertebrata, and the Arachnida having been now considered, very little space need be occupied with the remaining classes of the Articu- lata. Goleoptera, Sir John Lubbock, in his first paper on Bees and Wasps, quotes the following case from Kirby and Spence, with the remarks which I append : — The first of these anecdotes refers to a beetle (Ateuchus pilu- larius) which, having made for the reception of its eggs a pellet of dung too heavy for it to move, repaired to an adjoining heap, and soon returned with three of his companions. 'AH four now applied their united strength to the pellet, and at length suc- ceeded in pushing it out ; which being done, the three assistant beetles left the spot and returned to their own quarters.' This observation rests on the authority of an anonymous German artist ; and though we are assured that he was a 'man of strict veracity,' I am not aware that any similar fact has been re- corded by any other observer. Catesby, however, says : — I have attentively admired their industry, and their mutual assisting of each other in rolling these globular balls from the place where they made them, to that of their interment, which is usually a distance of some yards, more or less. This they perform back foremost, by raising their hind parts and pushing away the ball with their hind feet. Two or three of them are sometimes engaged in trundling one ball, which from meeting with impediments, on account of the unevenness of the ground, is sometimes deserted by them. It is, however, attempted by others with success, unless it happen to roll into some deep hollow or ditch, where they are accustomed to leave it; but BEETLES. 227 they continue their work by rolling off the next ball that comes in their way. None of them seem to know their own balls, but an equal care for the whole appears to affect all the community. They form these pellets while the dung remains moist, and leave them to harden in the sun before they attempt to roll them. In their rolling of them from place to place, both they and the balls may frequently be seen tumbling about over the little eminences that are in their way. They are not, however, easily discouraged, and by repeating their attempts usually surmount the difficulties.^ Biichner speaks of the fact that dung-beetles co-operate in their work as one that is well established, but gives no authorities or references.^ A friend of my own, however, informs me that she has witnessed the fact ; and in view of analogous observations made on other species of Coleop- tera, I see no reason to doubt this one. Some of these observations I may here append. Herr Gollitz writes to Biichner thus : — Last summer, in the month of July, I was one day in my field, and found there a mound of fresh earth like a molehill, on which a striped black and red beetle, with long legs, and about the size of a hornet, was busy taking away the earth from a hole that led Hke a pit into the mound, and levelling the place. After I had watched this beetle for some time, I noticed a second beetle of the same kind, which brought a little lump of earth from the interior to the opening of the hole, and then disappeared again in the mound ; every four or five minutes a pellet came out of the hole, and was carried away by the first- named beetle. After I had watched these proceedings for about half an hour, the beetle which had been working underground came out and ran to its comrade. Both put their heads together, and clearly held a conversation, for immediately afterwards they changed work. The one which had been working outside went into the mound, the other took the outside labour, and all went on vigorously. I watched the affair still for a little longer, and went away with the notion that these insects could understand each other just Hke men. Klingelhoffer, of Darmstadt (in Brehm, loc. cit., ix., p. 86), says : — A golden running beetle came to a cockchafer lying on its back in the garden, intending to eat it, but was unable to master it ; it ran to the next bush, and ^ Quoted by Bingley, Animal Biography, vol. ill., p. 118. 2 Log. cit., p. 344. Q 2 228 ANIMAL INTELLIGENCE. returned with a friend, whereupon the two overpowered the cockchafer, and pulled it off to their hiding-place. Similarly, there is no doubt that the burying beetles (NicTophorus) co-operate. Several of them unite together to bury under the ground, as food and shelter for their young, some dead animal, such as a mouse, a toad, a mole, a bird, &c. The burial is performed because the corpse, if left above ground, would either dry up, or grow rotten, or be eaten by other animals. In all these cases the young would perish, whereas the dead body lying in the earth and withdrawn from the outer air lasts very well. The burying beetles go to work in a very well-considered fashion, for they scrape away the earth lying under the body, so that it sinks of itself deeper and deeper. When it is deep enough down, it is covered over from above. If the situation is stony, the beetles with united forces and great efforts drag the corpse to some place more suitable for burying. They work so diligently that a mouse, for instance, is buried within three hours. But they often work on for days, so as to bury the body as deeply as possible. From large carcasses, such as those of horses, sheep, &c., they only bury pieces as large as they can manage.^ Lastly, Clarville gives a case of a burying beetle which wanted to carry away a dead mouse, but, finding it too heavy for its unaided strength, went off, like the beetles previously mentioned, and brought four others to its as- sistance.^ A friend of Grleditsch fastened a dead toad, which he desired to dry, upon the top of an upright stick. The burying beetles were attracted by the smell, and finding that they could not reach the toad, they undermined the stick, so causing it to fall with the toad, which was then buried safe out of harm's way.^ A converse exemplification of beetle-intelligence is given by Gr. Berkeley.'* He saw a beetle carrying a dead spider up a heath plant, and hanging it upon a twig of the heath in so secure a position, that when the insect had left it Mr. Berkeley found that a sharp shake of the heather would not bring the dead spider down. As the burying ' Biichner, loc. cit., p. 344. 2 Quoted in Strauss, Insects^ s. 389. ' Kirby and Spence, loc. cit., pp. 321-2. * Idfe and Recollections, vol. ii., p. 356. EARWIG. 229 beetle preserves its treasure by hiding it out of sight below ground, so this beetle no doubt secured the same end but by other means ; * seeing,' as Mr. Berkeley observes, ' that if it did not hang up its prey, it might fall into the hands of other hunters, it took all possible pains to find out the best store-room for it.' The above instances of beetle-intelligence lead me to credit the following, which has been communicated to me by Br. Garraway, of Faversham. On a bank of moss in the Black Forest he saw a beetle alight with a caterpillar which it was carrying, and proceed to excavate a cylindrical hole in the peat, about an inch and a half deep, into which, when completed, it dropped the caterpillar, and then flew away through the pines. 'I was struck,' says my corre- spondent, ' with the creature's folly in leaving the whole uncovered, as every curious wayfaring insect would doubt- less be tempted to enter therein. However, in about a minute the beetle returned, this time carrying a small pebble, of which there were none in the immediate vicinity, and having carefully fitted this into the aperture, fled away into space.' Earwig, I must devote a short division of this chapter to the earwig. M. Geer describes a regular process of incubation as practised by the mother insect. He placed one with her eggs in a box, and scattered the eggs on the floor of the latter. The earwig, however, carried them one by one into a certain part of the box, and then remained con- stantly sitting upon the heap without ever quitting it for a moment. When the eggs were hatched, the young ear- wigs kept close to their mother, following her about every- where, and often running under her abdomen, just as chickens run under a hen.^ A young lady, who objects to her name being published, informs me that her two younger sisters (children) are in the habit of feeding every morning with sugar an earwig, which they call 'Tom,' and which crawls up a certain curtain regularly every day at the same hour, with the apparent expectation of getting its breakfast. This re- ' Quoted by Bingley, loc. cit., vol. iii., pp. 160-51. 230 ANIMAL INTELLIGENCE. sembles analogous instances which have been mentioned in the case of spiders. Dipterous Insects, The gad-fly, whose eggs are hatched out in the intes- tines of the horse, exhibits a singular refinement of instinct in depositing them upon those parts of the horse which the animal is most likely to lick. For, according to Bingley and other writers, *the inside of the knee is the part on which these flies principally deposit their eggs ; and next to this they fix them upon the sides, and the back part of the shoulder; but almost always in places liable to be licked by the tongue.' The female fly deposits her eggs while on the wing, or at least scarcely appears to settle when she extends her ovidepositor to touch the horse. She lays only a single egg at a time — flying away a short distance after having deposited one in order to prepare another, and so on. The following anecdote, which I quote from Jesse, seems to indicate no small degree of intelligence on the part of the common house-fly — intelligence, for instance, the same both in kind and degree as that which was dis- played by Sir John Lubbock's pet wasp already mentioned : Slingsby, the celebrated opera dancer, resided in the large house in Cross-deep, Twickenham, next to Sir Wathen Waller's, looking down the river. He was fond of the study of natural history, and particularly of insects, and he once tried to tame some house-flies, and preserve them in a state of activity through the winter. For this purpose, quite at the latter end of autumn, and when they were becoming almost helpless, he selected four from off his breakfast-table, put them upon a large handful of cotton, and placed it in one corner of the window nearest the fireplace. Not long afterwards the weather became so cold that all flies disappeared except these four, which constantly left their bed of cotton at his breakfast-time, came and fed at the table, and then returned to their home. This continued for a short time, when three of them became lifeless in their shelter, and only one came down. This one Slingsby had trained to feed upon his thumb-nail, by placing on it some moist sugar mixed with a little butter. Although there had been at intervals several days of sharp frost, the fly never missed taking his daily meal in this way till after Christmas, when, his kind FLIES— CRABS. 231 preserver having invited a friend to dine and sleep at his house, the fly, the next morning, perched upon the thumb of the visitor, who, being ignorant that it was a pet of his host's, clapped his hand upon it, and thus put an end to Mr. Slingsby's •experiment.^ Crustacea. There is no doubt that these are an intelligent group of animals, although I have been able to collect but wonderfully little information upon the subject. Mr. Moseley, F.R.S., in his very interesting work, ' Notes by a N'aturalist on the Challenger,^ says (p. 70) : — In the tropics one becomes accustomed to watch the habits of various species of crabs, which there live so commonly an aerial life. The more I have seen of them, the more have I been a.stonished at their sagacity. And again (pp. 48-9) : — A rock crab (Grapsus stringosus) was very abundant, run- ning about all over the rocks, and making off into clefts on one's approach. I was astonished at the keen and long sight of this crab. I noticed some made off at full speed to their hiding- places at the instant that my head showed above a rock fifty yards distant. ... At Still Bay, on the sandy beach of which a heavy surf was breaking, I encountered a sand crab [CEcypoda ippeus), which was walking about, and got between it and its hole in the dry sand above the beach. The crab was a large one, at least three inches in breadth of its carapace. . . . With its curious column- like eyes erect, the crab bolted down towards the surf as the only escape, and as it saw a great wave rushing up the shelving shore, dug itself tight into the sand, and held on to prevent the undertide from caiTying it into the sea. As soon as the wave had retreated, it made off full speed for the shore. I gave chase, and whenever a wave approached, the crab repeated the manoeuvre. I once touched it with my hand whilst it was buried and blinded by the sandy water, but the surf compelled me to retreat, and I could not snatch hold of it for fear of its powerful claws. At last I chased it, hard pressed, into the surf in a hurry, and being unable to get proper hold in time, it was washed into the sea. The crab evidently dreaded going into the sea. . . . They soon die when kept a short time be- neath the water. ' Gleanings, vol. ii., pp. 165-6. 232 ANIMAL INTELLIGENCE. The land crabs of the West Indies and North America descend from their mountain home in May and June, to deposit their spawn in the sea. They travel in such swarms that the roads and woods are covered with them. They migrate in a straight line, and rather than allow them- selves to be deflected from it, * they scale the houses, and surmount every other obstacle that lies in their way^ (Kirby). They travel chiefly by night, and when they arrive at the sea-shore they ' bathe three or four different times,' and then ' commit their eggs to the waves.' They return to the mountains by the same route, but only the most vigorous survive the double journey. Prof. Alex. Agassiz details some interesting observations on the behaviour of young hermit crabs reared by himself ' from very young stages,' when first presented with shells of moUusks. ' A number of shells, some of them empty,, others with the animal living, were placed in a glass dish with the young crabs. Scarcely had the shells reached the bottom before the crabs made a rush for the shells, turned them round and round, invariably at the mouthy and soon a couple of the crabs decided to venture in,, which they did with remarkable alacrity.' The crabs which obtained for their share the shells still inhabited by living mollusks, 'remained riding round upon the mouth of their future dwelling, and, on the death of the mollusk, which generally occurred soon after in captivity ^ commenced at once to tear out the animal, and having^ eaten him, proceeded to take its place within the shell.' ^ There is a species of small crustacean {Podocerus cajoillatus) described by Mr. Bates, which builds a nest to contain its eggs. The nest is in the form of a hollow cone, built upon seaweed, and composed of fine thread- like material closely interlaced. ' These nests,' says Mr- Bates, * are evidently used as a place of refuge and security,, in which the parent protects and keeps her brood of young until they are old enough to be independent of the mother's care.' Dr. Erasmus Darwin tells us, on the authority of a; friend on whose competency as an observer he relied, that the common crab during the moulting season stations a& * Americcm Jowm. Sc. and Art, vol. x., Oct. 1875. CKABS AND LOBSTEES. 233- sentinel an unmoulted or hard- shelled individual, to prevent marine enemies from inj iiring moulted individuals in their unprotected state. While thus mounting guard the hard-shelled crab is much more courageous than at other times, when he has only his own safety to consider. But these observations require to be corroborated. In ' Nature ' (xv., p. 415) there is a notice of a lobster {Homarus marinus) in the Kothesay Aquarium which attacked a flounder that was confined in the same tank with him, and having devoured a portion of his victim, buried the rest beneath a heap of shingle, on which he ' mounted guard.' ' Five times within two hours was the fish unearthed, and as often did the lobster shovel the gravel over it with his huge claws, each time ascending the pile and turning his bold defensive front to his com- panions.' The following is quoted from Mr. Darwin's 'Descent of Man '(pp. 270-1):— A trustworthy naturalist, Mr. Gardner, whilst watching a shore-crab (Gelasimus) making its burrow, threw some shells towards the hole. One rolled in, and three other shells re- mained within a few inches of the mouth. In about five minutes the crab brought out the shell which had fallen in, and carried it away to the distance of a foot ; it then saw the three other shells lying near, and evidently thinking that they might likewise roll in, carried them to the spot where it had laid the first. It would, I think, be difficult to distinguish this act from one performed by man by the aid of reason. Mr. Darwin also alludes to the curious instinctive habits of the large shore-crab {Birgus latro), which feeds on fallen cocoa-nuts ' by tearing off the husk fibre by fibre ; and it always begins at that end where the three eye-like depressions are situated. It then breaks through one of these eyes by hammering with its heavy front pincers, and turning round, extracts the albuminous core with its narrow posterior pincers.' Eemarkable cases occur of commensalism between certain crabs and sea-anemones, and they betoken much intelligence. Thus Professor Mobius says in his ' Beitrage zur Meeresfauna der Insel Mauritius' (1880) that there are two crabs belonging to different genera which have 234 ANIMAL INTELLIGENCE. the habit of firmly grasping a sea-anemone in each claw and carrying them about, presumably to secmre some benefit to themselves. The more familiar case of the species of anemone which lives on the shells tenanted by hermit crabs is of special interest to us on account of a remarkable observation published by Mr. Grosse, F.R.S. {Zoologist, June, 1859). He found that on his detaching the anemone {Adamsia) from the shell, the hermit crab always took it up in its claws and held it against the shell 'for the space of ten minutes at a time, until fairly attached by a good strong base.' It was said by the late Dr. Eobert Ball that when the common Sagartia para- sitica is attached to a stone and a hermit crab is placed in its vicinity, the anemone will leave the stone and attach itself to the hermit's shell {Critic, March 24, 1860). Intelligence of Larvoe of Certain Insects. I shall now allude to some of the more interesting facts touching the psychology of insects when in their immature or larval state. This is an interesting topic from the point of view which we occupy as evolutionists, because a caterpillar is really a locomotive and self-feeding embryo, whose entire mental constitution is destined to undergo a metamorphosis no less complete and profound than that which is also destined to take place in its corporeal struc- ture. Yet although the caterpillar has an embryo psy- chology, its instincts and even intelligence often seem to be higher or more elaborated than is the case with the imago form. Where such is the case the explanation of course must be that it is of more importance to the species that the larval form should be in a certain measure in- telligent than that the imago form should be so. Every larva is a potential imago, or breeding individual ; there- fore its life is of no less value to the species during its larval than during its adult existence ; and if certain instincts or grades of intelligence are of more use to it during the former than during the latter period, of course natural selection would determine the unusual event which Tre seem here in some cases to see — namely, that the INTELLIGENCE OF LAEViE— ANT-LION. 235 embryo should stand on a higher level of psychological development than the adult. I may most fitly begin under this heading with the remarkable instincts of the so-called ' ant-lion,' which is the larva of a neuropterous insect, the common Myrmeleon {M. formicarium). I quote the following account of its habits from Thompson's ' Passions of Animals ' (p. 258) : — The devices of the ant-lion are still more extraordinary if possible. He forms, with astonishing labour and perseverance, a pit in the shape of a funnel, in a dry sandy soil, under some old wall or other spot protected from the wind. His pit being finished, he buries himself among the sand at the bottom, leaving only his horns visible, and thus waits patiently for his prey. When an ant or any other small insect happens to walk on the edge of the hollow, it forces down some of the particles of sand, which gives the ant-lion notice of its presence. He immediately throws up the sand which covers his head to overwhelm the ant, and with its returning force brings it to the bottom. This he continues to do till the insect is overcome and falls between his horns. Every endeavour to escape, when once the incau- tious ant has stepped within the verge of the pit, is vain, for in all its attempts to climb the side the deceptive sand shps from under its feet, and every struggle precipitates it still lower. When within reach its enemy plunges the points of its jaws into its body, and having sucked out all its juices, throws out the empty skin to some distance. According to Bingley, if the ant-lion, while excavating its pitfall, — Comes to a stone of some moderate size, it does not desert the work on this account, but goes on, intending to remove that im- pediment the last. When the pit is finished, it crawls back- ward up the side of the place where the stone is ; and, getting its tail under it, takes great pains and time to get it on a true poise, and then begins to crawl backward with it up the edge to the top of the pit, to get it out of the way. It is a common thing to see an ant-lion labouring in this manner at a stone four times as big as its own body ; and as it can only move backwards, and the poise is difficult to keep, especially up a slope of such crumbling matter as sand, which moulders away from under its feet, and necessarily alters the position of its body, the stone very frequently rolls down, when near the verge, quite to the bottom. In this case the animal attacks it again 236 ANIMAL INTELLIGENCE. in the same way, and is often not discouraged by five or six miscarriages, but continues its struggle so long that it at length gets over the verge of the place. When it has done this,, it does not leave it there, lest it should roU in again ; but is- always at the pains of pushing it further on, till it has removed it to a necessary distance from the edge of the pit.* Passing on now to the intelligence of caterpillars,. Mr. G-. B. Buckton, F.E.S., writing from Haslemere, Many caterpillars of Pieris rapce have, during this autumn,, fed below my windows. On searching for suitable positions for passing into chrysalides, some eight or ten individuals, in their direct march upwards, encountered the plate-glass panes of my windows ; on these they appeared to be unable to stand. Ac- cordingly in every case they made silken ladders, some of them five feet long, each ladder being formed of a single continuous thread, woven in elegant loops from side to side. . . . The reasoning, however, seems to be but narrow, for one ladder was constructed parallel to the window-frame for nearly three feet, on which secure footing could be had by simply diverting the track two inches. ^ In this case it appears clear that we have to do with instinct, and not with reason. No doubt it is the congenital habit of these caterpillars to overcome impediments in this way ; but the instinct is one of sufficient interest to be here stated. The following is quoted from Kirby and Spence : — A caterpillar described by Bonnet, which, from being confined, in a box, was unable to obtain a supply of the bark with which its ordinary instinct directs it to make its cocoon, substituted pieces of paper that were given to it, tied them together with silk, and constructed a very passable cocoon with them. In another instance the same naturahst having opened several cocoons of a moth {Noctura verhasci), which are composed of a mixture of grains of earth and silk, just after being finished, the larvae did not repair the injury in the same manner. Some employed both earth and silk ; others contented themselves with spinning a silken veil before the opening.^ The same authorities state, as result of their own observation, that the — * Animal Biography^ vol. ill., pp. 244-5. ' Nature^ vii., p. 49. « Intr. to Ent., ii., p. 475. INTELLIGENCE OF LARVAE— CATEKPILLAES. 237 Common cabbage caterpillar, which, when building web under stone or wooden surfaces, previously covers a space with a web -to form a base for supporting its dependent pupa, when building a web beneath a muslin surface dispenses with this base altogether : it perceives that the woven texture of the muslin forms facilities for attaching the threads of the cocoon securely enough to support the weight of the cocoon without the neces- sity of making the usual square inch or so of basal support.^ The instincts of the larva of the Tinea moth are thus •described by Keaumur : — It feeds upon the elm, using the leaves both as food and ■clothing. To do this it only eats the parenchyma of the leaf, preserving the upper and under epidermal membranes, between which it then insinuates itself as it progressively devours the parenchyma. It, however, carefully avoids separating these membranes where they unite at the extreme edge of the leaf, which is designed to form ' one of the seams of its coat.' The cavity when thus excavated between the two epidermal mem- branes is then lined with silk, made cylindrical in shape, cut off at the two ends and all along the side remote from the * seam,' and then the two epidermal membranes sewn together along the side where they have had to be cut in order to separate them from the tree. The larva now has a coat exactly fitting its body, and open at each end. By the one opening it feeds, and by the other discharges its excrement, ' having on one side a nicely jointed seam — that which is commonly applied to its back — composed of the natural marginal junction of the membranes of the leaf.' Eeaumur cut off the edge of a newly finished coat, so as to expose the body of the larva at that point. The animal did not set about making a new coat ab initio, as we might expect that it would on the popular supposition that a train of instinctive actions is always as mechanical as the running down of a set of cog-wheels, and that wherever a novel element is introduced the machinery must be thrown out of gear, so that it cannot meet a new emergency of however simple a character, and must there- fore re-start the whole process over again from the be- ginning. In this case the larva sewed up the rent ; and not only so, but * the scissors having cut off one of the projections intended to enter into the construction of > Ibid., p. 475. 238 ANIMAL INTELLIGENCE. the triangular end of the case, it entirely changed the original plan, and made that end the head which had been first designed for the tail.' Another remarkable case of the variation of instinct in the Lepidoptera is stated by Bonnet. There are usually, he says, two generations of the Angoumois moth : the first appear in early summer, and lay their eggs upon the ears of wheat in the fields ; the second appear later in the summer, or in the autumn, and these lay their eggs upon wheat in the granaries ; from these eggs there comes the first generation of next year's moths. This is a highly remarkable case — supposing the facts to be as Bonnet states ; for it seems that the early summer moths, although born in the granaries, immediately fly to the unreaped fields to lay their eggs in the standing corn, while the autumn moths never attempt to leave the granaries, but lay their eggs upon the stored wheat.^ Westwood says that — A species of Tasmanian caterpillar [Noctua Ewingii) swarms over the land in enormous companies, which regularly begin ta march at four o^clock in the morning, and as regularly halt at midday. Liparis chrysorrhaca, a kind of caterpillar, spins for the winter a common web, in which several hundred individuals find a common shelter.*^ According to Kirby and Spence, — The larva of the ichneumon, while feeding upon its caterpillar host, spares the walls of the intestines until it is time for it to escape, when, the life of the caterpillar being no longer necessary to its development, it perforates these walls.^ The larvae Theda isocrates live in a group of seven or eight in the fruit of pomegranate. In consequence of their excava- tions within the fruit, the latter is apt to faU ; and to prevent its doing so the larvae throw out a thread of attachment where- with to secure the friiit to the branch, so that if the stalk withers, this thread serves to suspend the fruit.'^ The caterpillar of the Bombyx moth, which is a native of France, exhibits very wonderful instincts. The larva is gre- garious in its habits, each society (family) consisting of perhaps » (Euvres, ix., p. 370. ^ Trans. Ent. Soc, vol. ii. 3 Introd. Mit., Letter xi. * Westwood, Tra7is. Ent. Soc, vol. ii., p. 1. INTELLIGENCE OF LA.EV^ — CATERPILLAES. 239 600 or 800 individuals. When young they have no fixed habi- tation, but encamp sometimes in one place, and sometimes in another, under the shelter of their web ; but when they have attained two-thirds of their growth, they weave for themselves a common tent. About sunset the regiment leaves its quarters, ... At their head is a chief, by whose movements their pro- cession is regulated. When he stops all stop, and proceed when he proceeds ; three or four of his immediate followers succeed in the same line, the head of the second touching the tail of the first ; then comes an equal series of pairs, next of threes, and so on, as far as fifteen or twenty. The whole procession moves regularly on with an even pace, each file treading in the steps of those that precede it. If the leader, arriving at a particular point, pursues a different direction, all march to that point before they turn. ^ The following additional facts concerning these remark- able habits may be quoted. I take them from the ac- count published by Mr, Davis in 'Loudoun's Magazine of Natural History : ' — The caterpillars, he observed, were Bombyces, and were seen crossing a road in single file, each so close to its predecessor that the line was quite continuous, 'moving like a living cord.' The number of caterpillars was 154, and the length of the line 27 feet. When Mr. Davis removed one from the line the caterpillar immediately in front suddenly stood still, then the next, and next, and so on to the leader. Similarly, those behind the point of interruption successively halted. After a pause of a few moments, the first caterpillar behind the break in the line endeavoured to fill up the vacant space, and so recover con- tact or communication, which after a time it succeeded in doing, when the information that the line was again closed was passed forward in some way from caterpillar to caterpillar till it reached the leader, when the whole line was again put in motion. The individual which had been abstracted remained rolled up and motionless ; but on being placed near the moving column it immediately unrolled, and made every attempt to get readmitted into the procession. After many endeavours it succeeded, the one below falling into the rear of the interloper. On repeating the experiment by removing a caterpillar fifty from the head of the procession, Mr. Davis found that it took just thirty seconds by his watch for information of the fact to reach the leader. All the same results followed as in the previous * Kirby and Spence, Entomology^ Letter xvi. 240 ANIMAL INTELLIGENCE. case. It was observable that the animals were guided neither by sight nor smell while endeavouring to close up the inter- rupted line ; for the caterpillar next behind the interruption, on whom the duty of closing up devolved, * turned right and left, and often in a wrong direction, when within half an inch of the one immediately before him ; when he at last touched the ob- ject of his search, the fact was communicated again by signal ; and in thii'ty seconds the whole line was in rapid march.' This gentleman adds that the object of the march was the search for new pasture. The caterpillars feed on the Eucalyptus, and when they have completely stripped one tree of its leaves, they all con- gregate on the trunk, and proceed as described to another tree. De Villiers ^ gives an account of his observations on the manner in which these caterpillars {Gnethocampii pitzo- campa) are able to pass information, which does not quite agree with the above observation of Mr. Davis. For he says that, in a train of 600 caterpillars, interference by him in any part of the train was communicated through the whole series instantaneously — all the 600 caterpillars stopping immediately and with one consent like a single organism. According to Kirby and Spence there is a kind of caterpillar {Pieris cratcegi) which lives in little colonies of ten or twelve in common chambers hned with silk. In one part they make of the same material a little bag or pocket, which is used by the community or household as a water-closet. When full of excrement the caterpillars €mpty it by turning out the pellets with their feet.^ Only two other instances of noteworthy intelligence as exhibited by larvae have fallen within my reading. One of these is mentioned by Eeaumur, who says that the larvae of liemerobius chrysops chase aphides, and having killed them, clothe themselves in their skins ; and the other case is the very remarkable one mentioned in his newly published work by W. MacLachlan, F.R.S., of caddis- worms adjusting the specific gravity of their tubes to suit that of the water in which they live, by attaching heavy or light material to them according as they require sinking or flotation. ^ Trans. Ent. Soc. France, vol. i., p, 201. 2 Introduction to Entomology, Letter xxvi. 241 CHAPTEK VIII. FISH. Although we here pass into the sub-kingdom of animals the intelligence of which immeasurably surpasses that of the other sub-kingdoms, it is remarkable that these lowest representatives of the higher group are psychologically in- ferior to some of the higher members of the lower groups. Neither in its instincts nor in general intelligence can any fish be compared with an ant or a bee — a fact which shows how slightly a psychological classification of animals depends upon zoological affinity, or even morphological or- ganisation. For although a highly competent authority, namely Van Baer, has said that a bee is as highly organised an animal as a fish, though on a difi'erent type,^ no one would be found to assert that an ant or a bee is so much more highly organised than a fish as its higher intelligence would require, supposing degrees of intelligence to stand in necessary relation to degree of organic development. And this consideration is not materially altered if, instead of regarding the whole organism, we look to the nervous system alone. There is no doubt that the cerebral hemi- spheres of a fish, although small as compared with these organs in the higher Vertebrata, are, bulk for bulk, enormous as compared with the oesophageal ganglia or ' brain ' of an insect ; while the disproportion becomes still greater if the cerebral hemispheres of a fish are com- pared with their supposed analogues in the brain of an ant, viz., the pedunculated and convoluted lobes which surmount the cephalic ganglion. But here the relative smallness of the ant as a whole must be taken into con- 1 Phil. Frags., translated by Huxley, Taylor's Mag., 1853, p. 196. K 242 ANIMAL INTELLIGENCE. sideration, and also the fact that its brain is relatively much more massive as well as more highly organised than that which occm-s in any other order of invertebrated animals, except, perhaps, the octopus and his allies. There- fore, although the brain of a fish is formed upon a type which by increase of size and complexity is destined in function far to eclipse all other types of nerve-centre, we have to observe that in its lowest stage of evolution as presented to science in the fishes, this type is functionally inferior to the invertebrate type, where this reaches its highest stage of evolution in the Hymenoptera. Emotions, Fish display emotions of fear, pugnacity ; social, sexual, and parental feelings ; anger, jealousy, play, and curiosity. So far the class of emotions is the same as that with which we have met in ants, and corresponds with that which is distinctive of the psychology of a child about four months old. I have not, however, any evidence of sympathy, which would be required to make the list of emotions identical ; but sympathy may nevertheless be present. Fear and pugnacity are too apparent in fish to require special proof. The social or gregarious feelings are strongly shown by the numberless species which swim in shoals, the sexual feelings are proved by courtships, and the parental by those species which build nests and guard their young. Schneider saw several species of fish at the Naples Aquarium protecting their eggs. In one case the male mounted guard over a rock where the eggs were de- posited, and swam with open mouth against intruders. The following accounts of the nidification of certain species of fish show that the parental instincts are not unhke those which obtain in birds, and are comparable in point of strength with the same instincts as they occur in ants, bees, and spiders. Agassiz remarks ^ that while examining the marine products of the Sargasso Sea, Mr. Mansfield picked up and brought to him a round mass of sargassum, about the size of the two ^ Silliman's American Journal, Feb. 1872. FISH — EMOTIONS. • 243 fists placed together. The whole consisted, to all appearance, of nothing but gulf-weed, the branches and leaves of which were, however, evidently knit together, and not merely balled into a roundish mass. The elastic threads which held the gulf-weed together were beaded at intervals, sometimes two or three beads being close together, or a branch of them hanging from the cluster of threads. This nest was full of eggs scattered through- out the mass, and not placed together in a cavity. It was evidently the work of the Chironectes. This rocking fish-cradle is carried along as an undying arbour, affording at the same time protection and afterwards food for its living freight. It is suggested that the fish must have used their peculiar pectoral fins when constructing this elaborate nest. The well-known tinker or ten-spined stickleback (Gaster- osteus pungitius) is one of our indigenous fish which constructs a nest. On May 1, 1864, a male ^ was placed in a well-estab- lished aquarium of moderate size, to which, after three days, two ripe females were added. Their presence at once roused him into activity, and he soon began to build a nest of bits of dirt and dead fibre, and of growing confervoid filaments, upon a jutting point of rock among some interlacing branches of Myriophyllum spicatum — all the time, however, frequently in- terrupting his labours to pay his addresses to the females. This was done in most vigorous fashion, he swimming, by a series of little jerks, near and about the female, even pushing against her with open mouth, but usually not biting. After a little coquetting she responds and follows him, swimming just above him as he leads the way to the nest. When there, the male commences to flirt — he seems unaware of its situation, will not swim to the right spot, and the female, after a few ineffectual attempts to find the proper passage into it, turns tail to swim away, but is then viciously pursued by the male. When he first courts the female, if she, not being ready, does not soon respond, he seems quickly to lose his temper, and, attacking her with great apparent fury, drives her to seek shelter in some crevice or dark corner. The coquetting of the male near the nest, which seems due to the fact that he really has not quite finished it, at length terminates by his pushing his head well into the entrance of the nest, while the female closely follows him, placing herself above him, and apparently much excited. As he withdraws she passes into the nest, and pushes quite through it, after a very brief delay, during which she deposits her ova. The male now fertilises the eggs, and drives the female * Kansom, Ann. and Mag. Nat. Hist, 1865, xvi., p. 449, B 2 244 ANIMAL INTELLIGENCE. away to a safe distance ; then, after patting down the nest, he proceeds in search of another female. The nest is built and the ova deposited in about twenty-four hours. The male continued to watch it day and night, and during the light hours he also continually added to the nest. The marine fifteen-spined stickleba Ihid. 246 ANIMAL INTELLIGENCE. incubating their eggs in their pouches, also displays highly elaborated parental feeling.^ M. Eisso says that when the young of the pipe-fish are hatched out, the parents show them marked attachment, and that the pouch then serves them as a place of shelter or retreat from danger. 2 M. Garbonnier has recorded how the male of the curiously grotesque telescope-fish, a variety of Carassius auratus (Linn.), acts as accoucheur to the female. Three males pursued one female which was heavy with spawn, and rolled her like a ball upon the ground for a distance of several metres, and continued this process without rest or relaxation for two days, until the exhausted female, who had been unable to recover her equili- brium for a moment, had at last evacuated all her ova.^ That adult fish are capable of feeling afiection for one another would seem to be well established : thus Jesse relates how he once captured a female pike {Esox Lucius) during the breeding season, and that nothing could drive away the male from the spot at which he had perceived his partner slowly dis- appear, and whom he had followed to the edge of the water. Mr. Arderon '* gave an account of how he tamed a dace, which would lie close to the glass watching its master; and subsequently how he kept two rufis (Acerina cernua) in an aquarium, where they became very much attached to one another. He gave one away, when the other became so miser- able that it would not eat, and this continued for nearly three weeks. Fearing his remaining fish might die, he sent for its former companion, and on the two meeting they became quite happy again. Jesse gives a similar account of two gold carp.^ Anger is strikingly shown by many fish, and notori- ously by sticklebacks when their territory is invaded by a neighbour. These animals display a strange instinct of appropriating to themselves a certain part of the tank in which they may be confined, and furiously attacking any other stickleback which may presume to cross the imagi- nary frontier. Uunder such circumstances of provocation I have seen the whole animal change colour, and, darting at ' Kaup, Catal. LopTio. Fish in Brit. Mus. 1856, p. i. 2 Yarrell, Brit. Fishes, 2nd ed. ii. p. 436. 8 Com]7t. Rend., Nov. 4, 1872, p. 1127. « Phil. Trans. Royal Society, 1747. fi F. Day, loc. cit. FISH-A.NGER, JEALOUSY, CUEIOSITY, ETC. 247 the trespasser, show ra.ge and fury in every movement. Of course, here, as elsewhere, it is impossible to be sure how far apparent expression of an emotion is due to the presence of that mental state which we recognise as the •emotion in ourselves ; but still the best guide we have to follow is that of apparent expression. Following this principle, we are also entitled to at- tribute to fish the emotions conducive to play; for nothing can well be more expressive of sportive glee than many of their movements. As for jealousy, the fights of many male fish for the possession of females constitutes evi- dence of emotion which would be called by this name in the higher animals. Schneider, in his recent work already often quoted, says that he has observed a male fish (Lahrus) show jealousy only towards other individual males of his own species — chasing these away from the neighbourhood of his female, but not objecting to the approach of fish of other species. Curiosity is shown by the readiness, or even eagerness, with which fish will approach to examine any imfamiliar object. So much is this the case that fishermen, like hunters, sometimes trade upon this faculty: — And the fisher, with his lamp And spear, about the low rocks damp Crept, and struck the fish which came To worship the delusive flame. ^ Stephenson, the engineer, on sinking lighted lanterns in the water, also found that fish were attracted to them.^ Special Habits. As curious instances of special instincts in fish we may notice the well-known habit of the angler (^Lophius pis- cator), which conceals itself in mud and seaweed, while waving in the water certain filaments with which it is provided above its snout. Other fish, attracted by these moving objects, approach, and are thereupon seized by the * Shelley, Lines written in tTbe Bay of Zerici. ^ See Smiles, Lives of JEngmeers, vol. iii., p. 69. 248 ANIMAL INTELLIGENCE. angler. "We must also allude to the Ghelmon rostratusy which shoots its prey by means of a drop of water projected from the mouth with considerable force and unerring aim* The mark thus shot at is always some small object, such as a fly, at rest above the surface of the water, so that when suddenly hit it falls into the water. ^ This remark- able instinct can only, I think, have originated as a primordially intentional adjustment, and as such shows a high degree of intelligence on the part of these fishes' an- cestors. Moreover, the wonderful co-ordination of sight and muscular movements required to judge the distance, to make due allowance for refraction, and to aim correctly, shows that the existing representatives are not unworthy of their ancestors. Several species of fish in different parts of the world have the habit of quitting pools which are about to dry up, and taking excursions across country in search of more abundant water. Eels have this habit, and perform their migrations by night. Dr. Hancock, in the 'Zoological Journal,' gives an account of a species of Doras, the indi- viduals of which are about a foot in length, and travel by night in large shoals, or ' droves,' when thus searching for water. A strong serrated arm constitutes the first ray of the pectoral fin; and, using this as a kind of foot, the animal pushes itself forward by means of its tail, thus moving nearly as fast as a man can walk. Another migrating fish (^Hydrargzra) was found by thousands in the fresh waters of Carolina by Bosc. It travels by leaps, and, according to Bosc, always directs itself towards the nearest water, although he purposely placed them so that they could not see it. But perhaps the strangest among this class of habits is that of the climbing perch {Perca scandens), first dis- covered by Daldorff in Tranquebar; for this animal not only creeps over land, but even climbs the fan palm in search of certain Crustacea which form its food. In climb- ing it uses its open gill-covers as hands wherewith to' suspend itself, while it deflects its tail laterally upwards so< as to bring to bear upon the bark certain little spines with ^ See ' On the Jaculator-Fish,' by Schlosser, Phil. Trans. 1764. FISH — MIGRATIONS. 24^ which its anal fin is provided ; it then pushes itsejf up- wards by straightening the tail, while it closes the gill- covers not to prevent progress, and so on. Sir E. Tennent, however, without disputing the evidence that these fish do climb trees, says, — The probability is, as suggested by Buchanan, that the ascent which was witnessed by Daldorff was accidental, and ought not to be regarded as the habit of the animal.^ A great number of species of fish perform migrations. In relation to intelligence, the most interesting of these is the migration of salmon, which annually leave the sea to spawn in rivers, though there is some doubt whether the same individuals spawn every year. There is no doubt, however, that the same individuals frequently, though not invariably, revisit the same rivers for their successive spawnings. This fact may be due either to the remem- brance of locality, similar to that which is unquestionably manifested by birds, or to the salmon not swimming far along the coast during other seasons of the year, and there- fore in the spawning season when seeking a river happen- ing to hit upon the same one. The latter hypothesis is one which Mr. Herbert Spencer tells me he is inclined to adopt, and, being a salmon-fisher, he has paid attention to the subject. He informs me of an observation by a friend of his own, who saw a salmon, when about to spawn, swim- ming along the coast-line, and all round a boathouse, apparently seeking any stream that it might first en- counter. The distances up rivers to which salmon will swim in the spawning season is no less surprising than the energy with which they perform the feat, and the determination with which they overcome all obstacles. They reach Bohemia by the Elbe, Switzerland by the Khine, and, which is much more wonderful, the Cordilleras of America by the Maragnon. They employ only three months in ascending to the sources of the Maragnon (a journey of 3,000 miles), the cun-ent of which is remarkably rapid, which is at the rate of nearly forty * Natural History of Ceylon, p. 351. 250 ANIMAL INTELLIGENCE. miles a day ; in a smooth stream or lake their progress would increase in a fourfold ratio. Their tail is a very powerful organ, and its muscles have wonderful energy ; by placing it in their mouths they make of it a very elastic spring, for letting it go with violence they raise themselves in the air to the height of from twelve to fifteen feet, and so clear the cataract that impedes their course : if they fail in their first attempt, they continue their efibrts till they have accomplished it.^ General Intelligence, With reference to the general intelligence of fish, allusion may first be made to their marked increase of wariness in waters which are much fished. This shows no small degree of intelligence, for the caution is proved to be the result of observation by the fact that young trout under such circumstances are less wary than old ones. Moreover, many fish will abandon old haunts when much disturbed. Again, according to Kirby, the carp thrusts itself into the mud in order that the net may pass over it, or, if the bottom be stony, makes great leaps to clear it. At the Andaman Islands fish are captured by the convicts by means of weirs fixed across the openings of creeks. After existing a week or so, it is observed that captures invariably cease; and it is believed that such is due to barnacles, &c., clustering on to the wood of which they are composed. It does not seem improbable that the fish have learned to avoid a loca- lity out of terror at those which enter but do not again return.^ Lacep^de^ relates that some fish, which had been kept for many years in a basin of the Tuileries, would come when called by their names. Probably it was the sound of the voice and not the articulate words to which they responded ; for Lacepede also relates that in many parts of Grermany trout, carp, and tench were summoned to their food by the sound of a bell ; and the same thing has been recorded of various fish in various localities, notably by Sir Joseph Banks, who used to collect his fish by sound- ing a bell.'* ' Kirby, Hist. Habits and Instincts of Animals, vol. i. p. 119. 2 F. Day, loc. cit. • Hist, des Poiss., Introd., cxxx. * For sundry other similar cases see Mr. Day's excellent paper already quoted. FISH— GENERAL INTELLIGENCE. 251 In 'Nature ' (vol. xi., p. 48) Mr. Mitchell gives the following instance of intelligence on the part of a small perch. Having one day disturbed its nest full of young fry, Mr. Mitchell next day went to look for the nest; ' but we searched in vain for the fish and her young. At length, a few yards further up stream, we discovered the parent guarding her fry with jealous care in a cavity scooped out of the coarse sand. . . . This is the first and only instance that has come under my notice of a fish watching over her young, and conveying them, when threatened with danger, to some other place.' In * Nature' (December 19, 1878) there is also pub- lished a communication which was made by Mr. J. Faraday to the Manchester Anglers' Association, concerning a skate which he observed in the aquarium of that town : — A morsel of food thrown into the tank fell directly in an angle formed by the glass front and the bottom. The skate, a large example, made several vain attempts to seize the food, owing to its mouth being on the underside of its head and the food being close to the glass. He lay quite still for a while as though thinking, then suddenly raised himself into a slanting posture, the head inclined upwards, and the under surface of the body towards the food, when he waved his broad expanse of fins, thus creating an upward current or wave in the water, which hfted the food from its position and carried it straight to his mouth. It will be observed, however, that this observation is practically worthless, from the observer having neglected to repeat the conditions in order to show that the move- ments of the fish were not, in their adaptation to these circumstances, purely accidental. Therefore I should not have alluded to this observation, had I not found that it has been quoted by several writers as a remarkable display of intelHgence on the part of the fish. I must not take leave of this class without making some aUusion to the alleged habits of the so-called ' pilot- fish,' and also to those of ' thresher ' and ' sword-fish.' I class these widely different habits together because they are alike in being dubious ; different observers give differ- ent accounts, and therefore, until more information is 252 Al^IMAL INTELLIGENCE. forthcoming, we must suspend our judgment with regard to the habits in question. The following describes what these habits are believed by many observers to be. Captain Eichards, E.N., says that he saw a blue shark following a bait which was thrown out to him from the ship. The shark, which was attended by four pilot-fish, repeatedly approached the bait ; but every time he did so one of the latter rushed in and prevented him. After a time the shark swam away; but when he had gone a con- siderable distance, he turned back again, swam quickly after the vessel, and before the pilot-fish could overtake him, seized the bait and was caught. While hoisting him on board, one of the pilots was seen to cling to his side until above water, when it dropped off. All the pilots then swam about for a time, as if searching for their friend, 'with every apparent mark of anxiety and distress.'^ Colonel Smith fully corroborates this observation; but Mr. Greoffrey, on the other hand, saw a pilot-fish take great pains to bring a shark to the bait.^ Probably the truth is that the pilot-fish attend the shark in order to obtain the crumbs that fall from his feasts, and that the cases in which they appear to prevent his taking the bait are without any psychological significance. With regard to the alleged co-operation of the thresh- ing and sword-fish in the destruction of whales, all that can be said is that the statements, although antecedently improbable, are sufficient in number not to be ignored. Mr. Day appears to accept the evidence as adequate, and gives the following cases : — Captain Am, in a voyage to Memel in the Baltic, gives the following interesting narrative : — One morning during a calm, when near the Hebrides, all hands were called up at 2 a.m. to witness a battle between several of the fish called threshers or fox-sharks [Alopecias vulpes), and some sword-fish on one side, and an enormous whale on the other. It was in the middle of the summer ; and the weather being clear, and the fish close to the vessel, we had a fine opportunity of witnessing the contest. As soon as the whale's back appeared above the water, the * Cuv., Ani7fi. Kingd. x. p. 636. 2 F. Day, loc. cit. FISH — GENERAL INTELLIGENCE. 253 threshers springing several yards into the air descended with great violence upon the object of their rancour, and inflicted upon him the most severe slaps with their long tails, the sounds of which resembled the reports of muskets fired at a distance. The sword-fish in their turn attacked the distressed whale, stab- bing from below : and thus beset on all sides and wounded, when the poor creature appeared, the water around him was dyed with blood. In this manner they continued tormenting and wounding him for many hours, until we lost sight of him ; and I have no doubt they in the end completed his destruction. The master of a fishing-boat has recently observed that the thresher-shark serves out the whales, the sea sometimes being all blood. One whale, attacked by these fish, once took refuge under his vessel, where it lay an hour and a half without moving a fin. He also remarked having seen the threshers jump out of the water as high as the mast-head and down upon the whale, while the sword fish was wounding him from beneath the two sorts of fish evidently acting in concert. 254 ANIMAL INTELLIGENCE. CHAPTEK IX. BATRACHIANS AND REPTILES. On the intelligence of frogs and toads very little has to be said. Frogs seem to have definite ideas of locality; for several of my correspondents inform me that they have known cases in which these animals, after having been removed for a distance of 200 or 300 yards from their habitual haunts, returned to them again and again. This, however, may I think perhaps be due to these haunts having a moistness which the animals are able to perceive at a great distance. But be this as it may, certainly the distance at which frogs are able to perceive moisture is surprising. Thus, for instance. Warden gives a case in which a pond containing a number of frogs dried up, and the frogs thereupon made straight for the nearest water, although this was at a distance of eight kilometres.^ A curious special instinct is met with in the toad Bufo ohstetricans, from which it derives its name ; for the male here performs the function of an accoucheur to the female, by severing from her body the gelatinous cord by which the ova are attached. Another special instinct or habit manifested by toads is described by M. Duchemin in a paper before the Academy of Sciences at Paris.^ The habit consists in the killing of carp by squatting on the head of the fish and forcing the fore-feet into its eyes. Probably this habit arises from sexual excitement on the part of the toads. I have one case, communicated to me by a corre- spondent, of a frog which learnt to know her voice, and to come when called. As fish will sometimes do the same ■ • Account of the United States, vol. ii., p. 9. 2 April 11, 1870. FROGS, TOADS, AND REPTILES. 255 thing, the account is sufficiently credible for me to quote : — I used to open the gate in the railings round the pond, and call out * Tommy ' (the name I had given it), and the frog would jump out from the bushes, dive into the water, and swim across to me — get on my hand sometimes. When I called * Tommy,' it would nearly always come, whatever the time of day, though it was only fed after breakfast ; but it seemed quite tame. A very similar case is recorded by Mr. Pennent ' of a toad which was domesticated for thirty-six years, and knew all his Mends. There is no doubt that frogs are able to appreciate coming changes of weather, and to adapt their movements in anticipation of them; but these facts show delicate sensibility rather than remarkable intelligence. The following observation of Edward, the Scottish naturalist, however, shows considerable powers of observa- tion on the part of frogs. After describing the great noise made by a number of frogs on a moonlight night, he says :— Presently, when the whole of the vocalists had reached their highest notes, they became hushed in an instant. I was amazed at this, and began to wonder at the sudden termination of the concert. But, looking about, I observed a brown owl drop down, with the silence of death, on to the top of a low dyke close by the orchestra.^ Rejptiles. Like the other cold-blooded Vertebrata, the reptiles are characterised by a sluggishness and low development of mental power which is to some extent proverbial. Never- theless, that some members of the class present vivid emotions is not to be questioned. Thus, to quote from Thompson : — Th.Q common guana {Lacerta iguana) is naturally extremely gentle and harmless. Its appearance, however, is much against ^ See Bingley, Animal Biography, vol. ii., p. 406, * Smiles, Life of Edwards, p. 124. 256 AlflMAL INTELLIGENCE. it, especially when agitated by fear or anger. Its eyes then seem on fire; it hisses like a serpent, swells out the pouch under its throat, lashes about its long tail, erects the scales on its back, and extending its wide jaws, holds its head, covered over with tubercles, in a menacing attitude. The male, during the spring of the year, exhibits great attachment towards the female. Throwing aside his usual gentleness of character, he defends her even with fury, attacking with undaunted courage every animal that seems inclined to injure her ; and at this time, though his bite is by no means poisonous, he fastens so firmly, that it is necessary either to kill him or to beat him with great violence on the nose, in order to make him quit his hold.^ Several species of snake incubate their eggs and show parental affection for their young when they are hatched out; but neither in these nor in any other of their emotions do the reptiles appear to rise much above the level of fish. The case, however, which I shall after- wards quote, of the tame snakes kept by Mr. and Mrs. Mann, seems to show a somewhat higher degree of emo- tional development than could be pointed to as occurring in any lower Vertebrata. Moreover, according to Pliny, so much affection subsists between the male and female asp, that when the one is killed the other seeks to avenge its death ; and this statement is so far confiirmed — or rather, its origin explained — by Sir Emerson Tennent that he says when a cobra is killed, its mate is often found on the same spot a day or two afterwards. Passing on to the general intelligence of reptiles, we shall find that this also, although low as compared with the intelligence of birds and mammals, is conspicuously higher than that of fish or batrachians. Taking first the case of special instincts, Mr. W. F. Barrett, in a letter to Mr. Darwin, bearing the date May 6, 1873, and contained among the MSS. already alluded to, gives an account of cutting open with a penknife the egg of an alligator just about to hatch. The young animal, although blind, ' instantly laid hold of the finger, and attempted to bite.' Similarly, Dr. Davy, in his ' Ac- count of Ceylon,' gives an interesting observation of his own on a young crocodile, which he cut out of the egg, ^ Passiom of Aniinals, p. 229. ALLIGATOKS AND TUKTLES. 257 and which, as soon as it escaped, started off in a direct line for a neighbouring stream. Dr. Davy placed his stick before it to try to make the little animal deviate from its course ; but it stoutly resisted the opposition, and raised itself into a posture of offence, just as an older animal would have done. Humboldt made exactly the same observation with jregard to young turtles, and he remarks that as the young normally quit the egg at night, they cannot see the water which they seek, and must therefore be guided to it by •discerning the direction in which the air is most humid. He adds that experiments were made which consisted in putting the newly hatched animals into bags, carrying them to some distance from the shore, and liberating them ^th their tails turned towards the water. It was in- Tariably found that the young animals immediately faced round, and took without hesitation the shortest way to the water. Scarcely less remarkable thaii the instincts of the young turtles are those of the old ones. Their watchful timidity at the time of laying their eggs is thus described by Bates : — Great precautions are obliged to be taken to avoid disturb- ing the sensitive turtles, who, previous to crawling ashore to lay, assemble in great shoals off the sand-bank. The men during this time take care not to show themselves, and warn off any •fisherman who wishes to pass near the place. Their fires are made in a deep hollow near the borders of the forest, so that the smoke may not be visible. The passage of a boat through the shallow waters where the animals are congregated, or the sight -of a man or a fire on the sand-bank, would prevent the turtles from leaving the water that night to lay theii* eggs ; and if the causes of alarm were repeated once or twice they would forsake the praia for some other quieter place. ... I rose from my hammock by daylight, shivering with cold — a praia, on account of the great radiation of heat in the night from the sand, being towards the dawn the coldest place that can be found in this cUmate. Cardozo and the men were already up watching the turtles. The sentinels had erected for this purpose a stage about fifty feet high, on a tall tree near their station, the ascent to which was by a roughly made ladder of woody lianas. They are ena- bled, by observing the turtles from this watch-tower, to ascertain S 258 ANIMAL INTELLIGENCE. the date of successive deposits of eggs, and thus guide the com- mandante in fixing the time for the general invitation to the Ega people. The turtles lay their eggs by night, leaving the water, when nothing disturbs them, in vast crowds, and crawl- ing to the central and highest part of the praia. These places are, of course, the last to go under water when, in unusually wet seasons, the river rises before the eggs are hatched by the heat of the sand. One could almost believe, from this, that the animals used forethought in choosing a place ; but it is simply one of those many instances in animals where unconscious habit has the same result as conscious prevision. The hours between midnight and dawn ai-e the busiest. The turtles ex- cavate with their broad webbed paws deep holes in the fine sand : the first comer, in each case, making a pit about three feet deep, laying its eggs (about 120 in number) and covering them with sand ; the next making its deposit at the top of that of its predecessor, and so on until every pit is full. The whole body of turtles frequenting a praia does not finish laying in less than fourteen or fifteen days, even when there is no interrup- tion. When all have done, the area (called by the Brazilians taholeiro) over which they have excavated is distinguishable from the rest of the praia only by signs of the sand having been a little disturbed.^ The same naturalist says of the alligator, — These little incidents show the timidity and cowardice (? prudence and caution) of the alligator. He never attacks man when his intended victim is on his guard; but he is cunning enough to know when this may be done with impunity. Of this we had proof a few days afterwards, &c.^ Of the alligator, Jesse writes : ^ — But a most singular instance of attachment between twa animals, whose natures and habits were most opposite, was re- lated to me by a person on whose veracity I can place the great- est reHance. He had resided for nine years in the American States, where he superintended the execution of some extensive works for the American Government. One of these works con- sisted in the erection of a beacon in a swamp in one of the rivers^ * Naturalist on the Amazon, pp. 285-6, 2 Ibid. The astonishing facts relating to the migration of turtles- in the laying season will be treated under the general heading ' Migra- tion ' in my forthcoming work. ' Gleanings, vol. i., pp. 163-4. TORTOISES. 259 where he caught a young alligator. This animal he taade so perfectly tame that it followed him about the house like a dog, scrambling up the stairs after him, and showing much affection and docility. Its great favourite, however, was a cat, and the friendship was mutual. When the cat was reposing herself before the fire (this was at New York), the alligator would lay himself down, place his head upon the cat, and in this attitude go to sleep. If the cat was absent the alligator was restless ; but he always appeared happy when the cat was near him. The only instance in which he showed any ferocity was in attacking a fox, which was tied up in the yard. Probably, however, the ""•«' resented some playful advances which the other had made, and thus called forth the anger of the alligator. In attacking the fox he did not make use of his mouth, but beat him with so much severity with his tail, that, had not the chain which con- fined the fox broken, he would probably have killed him. The alligator was fed on raw flesh, and sometimes with milk, for which he showed a great fondness. In cold weather he was shut up in a box, with wool in it ; but, having been forgotten one frosty night, he was found dead in the morning. This is not, I believe, a solitary instance of amphibia becoming tame, and showing a fondness for those who have been kind to them. Blumenbach mentions that crocodiles have been tamed ; and two instances have occurred under my own observation of toads knowing their benefactors, and coming to meet them with con- siderable alacrity. With regard to the higher intelligence of reptiles, I may quote the following instances. Three or four different correspondents tell me of cases which they have themselves observed, of snakes and tortoises unmistakably distinguishing persons. In one of these cases the tortoise would come to the call of the favoured person, and when it came would manifest its affection by tapping the boot of this person with its mouth ; ' but it would not answer anyone else.' A separation of some weeks did not affect the memory of this tortoise for his friend.^ ^ The tortoise which has gained such immortal celebrity by having fallen under the observation of the author of the Natwal History of Selborne, likewise distinguished persons in this way. For * whenever the good old lady came in sight, who had wailed on it for more than thirty years, it always hobbled with awkward alacrity towards its benefactress, whilst to strangers it was altogether inattentive.' s 2 260 ANIMAL INTELLIGENCE. The following interesting observation on the intelli- gence of snakes shows, not only that these animals are well able to distinguish persons, and that they remember their friends for a period of at least six weeks, but also that they possess an intensity of amiable emotion scarcely to be expected in this class. Clearly the snakes in question were not only perfectly tame, but entertained a remark- able affection for those who tended and petted them. The facts were communicated to me by Mr. Walter Severn, the well-known artist, who was a friend of Mr. and Mrs. Mann, the gentleman and his wife to whom the snakes belonged. Mr. and Mrs. Mann having got into trouble with their neighbours on account of the fear and dislike which their pets occasioned, legal proceedings were instituted, and so the matter came before the public. Mr. Severn then wrote a letter to the Times, in order to show that the animals were harmless^ From this letter the following is an extract : — I happen to know the gentleman and lady against whom a complaint has been made because of the snakes they keep, and I should like to give a short account of my first visit to them. Mr. M., after we had talked for a little time, asked if I had any fear of snakes; and after a timid 'No, not very,' from me, he produced out of a cupboard a large boa-constrictor, a python, and several small snakes, which at once made themselves at home on the writing-table among pens, ink, and books. I was at first a good deal startled, especially when the two large snakes coiled round and round my friend, and began to notice me with their bright eyes and forked tongues; but soon finding how tame they were, I ceased to feel frightened. After a short time Mr. M. expressed a wish to call Mrs. M., and left me with the boa deposited on an arm-chair. I felt a little queer when the animal began gradually to come near, but the entrance of my host and hostess, followed by two charming little children, put me at my ease again. After the first interchange of civilities, she and the children went at once to the boa, and, calling it by the most endearing names, allowed it to twine itself most grace- fully round about them. I sat talking for a long time, lost in wonder at the picture before me. Two beautiftil little girls with their charming mother sat before me with a boa-constrictor (as thick round as a small tree) twining playfully round the lady's waist and neck, and forming a kind of turban round her SNAKES. 261 head, expecting to be petted and made much of like a kitten. The children over and over again took its head in their hands and kissed ite mouth, pushing aside its forked tongue in doing so. The animal seemed much pleased, but kept turning its head continually towards me with a curious gaze, until I allowed it to nestle its head for a moment up my sleeve. Nothing could be prettier than to see this splendid serpent coiled all round Mrs. M. while she moved about the room, and when she stood to pour out our coffee. He seemed to adjust his weight so nicely, and every coil with its beautiful marking was relieved by the black velvet dress of the lady. It was long before I could make up my mind to end the visit, and I returned soon after with a friend (a distinguished M.P.^), to see my snake- taming acquaintance again. . . . These (the snakes) seemed very obedient, and remained in their cupboard when told to do so. About a year ago Mr. and Mrs. M. were away for six weeks, and left the boa in charge of a keeper at the Zoo. The poor reptile moped, slept, and refused to be comforted, but when his master and mistress appeared he sprang upon them with delight, coiling himself round them, and showing every symptom of in- tense delight. 2 The end of this python was remarkable and pathetic. Mr. Severn tells me that some years after he had published the above letter Mr. Mann was seized with an apo;_ '.^ctic lit. His wife, being the only other person in the house at the time, ran out to fetch a doctor. She was absent about ten minutes, and on returning found that the serpent during her absence had crawled upstairs from the room below into that where her husband was lying, and was stretched beside him dead. Such being the fact, we are left to speculate whether the double seizure of the man and the snake was a mere coincidence, or whether the sight of its stricken mastei, ^jting on the emotions of a possibly not healthy animal, precipitated its death. Look- ing to the extreme suddenness of the latter, as well as to the fact of the animal having pined so greatly for his friends while it was confined at the Zoological Grardens, I think the probability rather points to the death of the * This gentleman was Lord Arthur Kussell. 2 The Times, July 25, 1872. 262 ANIMAL INTELLIGENCE. animal having been accelerated by emotional shock. But of course the question is an open one. So much for the power of reptiles to establish such definite and complete associations as are required for the recognition of persons —associations, however, to which, as we have seen, frogs, and even insects may attain. As for other associations, a correspondent writes to me : — I believe tortoises are able to establish a definite association between particular colours on a flat surface and food. Only the day before reading your article on animal intelligence I noticed the endeavours of a small tortoise to eat the yellow flowers of an inlaid writing-table, and I have often remarked the same recognition with regard to red. Lord Monboddo relates the following anecdote of a serpent : — I am well informed of a tame serpent in the East Indies, which belonged to the late Dr. Yigot, and was kept by him in the suburbs of Madras. This serpent was taken by the French, when they invested Madras in the late war, and was carried to Pondicherry in a close carriage. But from thence he found his way back again to his old quarters, which it seems he liked better, though Madras is distant fi'om Pondicherry about one hundred miles. This information, he adds, I have from a lady who then was in India, and had seen the serpent often before his journey and after his return. Considering the enormous distances over which turtles are able to find their way in the season of migration, this display of the homing faculty to so great a degree in a serpent is not to be regarded as incredible. Mr. E. L. Layard, in his ' Eambles in Ceylon ' says of the cobra : ^ — I once watched one which had thrust its head through a narrow aperture and swallowed one {i.e. a toad). With this encumbrance he could not withdraw himself. Finding this, he reluctantly disgorged the precious morsel, which began to move oflf. This was too much for snake philosophy to bear, and the toad was again seized ; and again, after violent efibrts to escape, was the snake compelled to part with it. This time, howe^^er, a lesson had been learnt, and the toad was seized by one leg, withdrawn, and then swallowed in triumph. * See Annas, and Mag. of Nat, Hist., 2nd series, vol. ix., p. 333. FASCINATION. 263 Mr. E. C. Buck, B.C.S., says in 'Nature' (vol. viii., p. 303):— I have witnessed exEictly a similar plan pursued by a large number of Granges crocodiles, which had been lying or swimming about all day in front of my tent, at the mouth of a small stream which led from some large inland lakes to the Ganges. Towards dusk, at the same moment every one of them left the bank on which they were lying, or the deep water in which they were swimming, and formed a line across the stream, which was .a,bout twenty yards wide. They ha,d to form a double line, as there was not room for all in a single line. They then swam slowly up the shallow stream, driving the fish before them, and I saw two or three fish caught before they disappeared. An account of reptile psychology would be incomplete without some reference to the alleged facts of snakes charming other animals by ' fascination,' and being them- selves charmed by the arts of music, &c. The testimony on both subjects is conflicting, and especially with regard to the fascination of other animals by snakes. Thus : — Mr. Pennant says that this snake (rattle-snake) will fre- quently lie at the bottom of a tree on which a squirrel is seated. He fixes his eyes on the animal, and from that moment it can- not escape ; it begins a doleful outcry, which is so well known that a passer-by, on hearing it, immediately knows that a snake is present. The squirrel runs up the tree a little way, comes down again, then goes up, and afterwards comes still lower. The snake continues at the bottom of the tree with its eyes fixed on the squirrel, and his attention is so entirely taken up, that a person accidentally approaching may make a considerable noise without so much as the snake turning about. The squirrel comes lower, and at last leaps down to the snake, whose mouth is already distended for its reception. Le Yaillant confirms this fascinating terror by a scene he witnessed. He saw on the branch of a tree a species of shrike, trembling as if in convul- sions, and at the distance of nearly four feet, on another branch, a large snake that was lying with outstretched neck and fiery eyes, gazing steadily at the poor animal. The agony of the bii-d was so great that it was deprived of the power of moving away; and when one of the party killed the snake, it (i.e. the bird) was found dead upon the spot— and that entirely from fear; for, on examination, it appeared not to have received the slightest wound. The same traveller adds that a short time afterwards 264 ANIMAL INTELLIGENCE. he observed a small mouse in similar agonising convulsions,, about two yards from a snake, whose eyes were intently fixed upon it ; and on frightening away the reptile, and taking up the mouse, it expired in his hand.^ Many other observations, more or less similar, might be quoted ; but, on the other hand, Sir Joseph Fayrer tells me that ' fascination is only fright ; ' and this appears to be the opinion of all persons who have had the oppor- tunity of looking into the subject in a scientific manner. The truth probably is that small animals are occasionally much alarmed by the sight of a snake looking at them,, and as a consequence of this more easily fall a prey. In some cases, it is likely enough, strong terror so unnerves the animal as to make it behave in the manner which the witnesses describe ; in making half-palsied eflforts to' escape, it may actually fall or draw nearer to the object of its dread. Perhaps, therefore. Dr. Barton, of Philadelphia, is a little too severe on previous observers when he says that — The report of this fascinating property has had its rise in nothing more than the fears and cries of birds and other animals in the protection of their nests. . . . The result of not a little attention has taught me that there is but one wonder in the business — the wonder that the story should ever have been believed by any man of understanding and observation. But, be this as it may, it is certainly remarkable, as Sir J. Fayrer in his letter to me observes, ' how little fear some animals show until the moment that they are seized and struck.' As for snake-charming, the facts seem to be that cobras and other serpents are attracted by the sound of a pipe to creep out of their hiding-places, when they are captured and tamed. It is certain that the fangs are not always drawn, and also that from the first moment of capture, before there has been time for any process of training, a real snake-charmer is able to make the reptile * dance.' Thus, for instance, Sir E. Tennent publishes the, following letter from Mr. Reyne. After describing all hi& ^ Thompson, Passions of Animals, p. 118; see also Bingley, Animal Biography, vol. ii., pp. 447-8. SNAKE-CHARMING. 265- precautions to ensure that tte snake-eliarmer had no tamed snakes concealed about his person, Mr. Keyne proceeds to tell how he made the man accompany him to the jungle, where, attracted by the music of a pipe which the man played, a large cobra came from an ant-hill which Mr. Keyne knew it to occupy : — On seeing the man it tried to escape, but he caught it by the tail and kept swinging it round until we reached the bungalow. He then made it dance, but before long it bit him above the knee. He immediately bandaged the leg above the bite and applied a snake-stone to the wound to extract the poison. He was in great pain for a few minutes, but after that it gradually went away, the stone falling off just before he was relieved.^ Thus the only remarkable thing about the charming of a freshly caught snake seems to be that the charmer is able to make the animal ' dance ' — for the fact of the snake approaching the unfamiliar sound of music is not in itself any more remarkable than a fish approaching the unfamiliar sight of a lantern. It does not, however, ap- pear that this dancing is anything more than some series of gestures or movements which may be merely the expres- sions, more or less natural, of uneasiness or alarm. Any- thing else that charmed snakes may do is probably the result of training ; for there is no doubt that cobras admit of being tamed, and even domesticated. Thus, for instance. Major Skinner, writing to Sir E. Tennent, says : — In one family near Negombo, cobras are kept as protectors, in the place of dogs, by a wealthy man who has always large sums of money in his house. But this is not a solitary case of the kind. . . . The snakes glide about the house, a terror to the thieves, but never attempting to harm the inmates.^ Thus, on the whole, we may accept Dr. Davey's opinion — who had good opportunities for observation — that the snake-charmers control the cobras by working upon the well-known timidity and reluctance of these animals to- use their fangs till they become virtually tame. » Natural History of Ceylon, p. 314. 2 Tennent, lac. elt., p. 299 266 ANIMAL INTELLiaENCE. CHAPTER X. BIRDS. Adequately to treat of the intelligence of birds a separate volume would be required ; here it must be enough to deal with this class as I shall afterwards deal with the Mammalia — namely, by giving an outline sketch of the more prominent features of their psychology. Memory, The memory of birds is well developed. Thus, although we are much in the dark on the whole subject of migration — so much so that I reserve its discussion with all the problems that this presents for a separate chapter in my next work — we may at least conclude that the return of the same pair of swallows every year to the same nest must be due to the animals remembering the precise locality of their nests. Again, Buckland gives an account of a pigeon which remembered the voice of its mistress after an absence of eighteen months ; ^ but I have not been able to ^ Curiosities, &c., p. 126. Wilson also, in his American Ornithology, gives the followingsufficiently credible account of the memory of a crow: — * A gentleman who resided on the Delaware, a few miles below Easton, had raised [reared] a crow, with whose tricks and society he used frequently to amuse himself. This crow lived long in the family, but at length disappeared, having, as was then supposed, been shot by some vagrant gimner, or destroyed by accident. About eleven months after this, as the gentleman one morning, in company with several others, was stand- ing on the river shore, a number of crows happened to pass by ; one of them left the flock, and flying directly towards the company, alighted on the gentleman's shoulder, and began to gabble away with great volubility, as one long-absent friend naturally enough does on meeting another. On recovering from his surprise the gentleman instantly recognised his old acquaintance, and endeavoured, by several civil but sly manoeuvres, to lay hold of him ; but the crow, not altogether relish- ing quite so much famiUarity, having now had a taste of the sweets of BIEDS— MEMORY. 267 meet with satisfactory evidence of the memory of a bird -enduring for a longer time than this. As it is a matter of interest in comparative psychology to trace as far as possible into detail the similarities of a mental faculty as it occurs in difierent groups of animals, and ^s the faculty of memory first admits of detailed study in the class which we are now considering, I shall here devote ■s. paragraph to the facts concerning the exhibition of memory by birds where its mechanism best admits of being analysed ; I refer to the learning of articulate phrases and tunes by talking and musical birds. The best observa- tions in this connection with which I am acquainted are those of Dr. Samuel Wilks, F.E.S., and therefore I shall quote in extenso the portion of his paper which refers to the memory of parrots : other portions of this paper I shall have occasion to quote in my next work : — When my parrot first came into my possession, several years ago, it was quite unlettered, and I therefore had an opportunity of observing the mode in which it acquired the accomplishment of speech. I was very much struck with its manner of learn- ing, and the causes for its speaking on special occasions. The first seemed to resemble very much the method of children in learning their lessons, and the second to be due to some associa- tion or suggestion — the usual provocative for set speeches at all periods of human life. A parrot is well known to imitate sounds in a most perfect manner, even to the tone of the voice, besides having a compass which no human being can approach, ranging from the gravest to the most acute note. Mj bird, though possessing a good vocabulary of words and sentences, can only retain them for a few months imless kept constantly in practice by the suggestive recurrence of some circumstance which causes their continual utterance. If forgotten, however, they are soon revived in the memory by again repeating them a few times, and much more speedily than any new sentence can be acquired. In beginning to teach the parrot a sentence, it has to be repeated many times, the bird all the while listening most attentively by turning the opening of the ear as close as pos- sible to the speaker. After a few hours it is heard attempting liberty, cautiously eluded all his attempts ; and suddenly glancing his eye on his distant companions, mounted in the air after them, soon overtook and mingled with them, and was never afterwards seen to return.' ' 268 ANIMAL INTELLIGENCE. to say the phrase, or, I should" say, trying to learn it. It evi- dently has the phrase somewhere in store, for eventually this is utter«d perfectly, but at first the attempts are very poor and ludicrous. If the sentence be composed of a few words, the first two or three are said over and over again, and then another and another word added, until the sentence is complete, the pronunciation at first being very imperfect, and then becoming gradually more complete, until the task is accomplished. Thus hour after hour will the bird be indefatigably working at the sentence, and not until some days have elapsed will it be perfect. The mode of acquiring it seems to me exactly what I have ob- served in a child learning a French phrase; two or three words are constantly repeated, and then others added, until the whole is known, the pronunciation becoming more perfect as the repetition goes on. I found also on whistling a popular air to my parrot that she picked it up in the same way, taking note by note until the whole twenty-five notes were complete. Then the mode of forgetting, or the way in which phrases and airs pass from its recollection, may be worth remarking. The last words or notes are first forgotten, so that soon the sentence re- mains unfinished or the air only half whistled through. The first words are the best fixed in the memory ; these suggest others which stand next to them, and so on till the last, which have the least hold on the brain. These, however, as I have before mentioned, can be easily revived on repetition. This is also a very usual process in the human subject : for example, an Englishman speaking French will, in his own country, if no opportunity occur for conversation, apparently forget it ; he no sooner, however, crosses the Channel and hears the language than it very soon comes back to him again. In trying to recall poems learned in childhood or in school days, although at that period hundreds of lines may have been known, it is found that in manhood we remember only the two or three first lines of the 'IKad,' the '^neid,' or the 'Paradise Lost.'^ The following is communicated to me by Mr. Venn, of Cambridge, the well-known logician : — I had a grey parrot, three or four years old, which had been taken from its nest in West Africa by those through whom ■ I received it. It stood ordinarily by the window, where it could! equally hear the front and back door bells. In the yard, by the back door, was a collie dog, who naturally barked violently at nearly all the comers that way. The parrot took to imitating the * Jowrnal of Mental Science, July 1879. BIRDS— MEMOEY. 269 -dog. After a time I was interested in observing the discrimi- native association between the back-door bell and the dog's bark in the parrot's mind. Even when the dog was not there, or for any other cause did not bark, the parrot would constantly bark when the back-door bell sounded, but never (that I could hear) when the front-door bell was heard. This is but a trifle in the way of intelligence, but it struck me as an iuteresting analogous case to a law of association often noticed by writers on human psychology. The celebrated parrot that belonged to the Buffon family and of which the Comte de Buffon wrote, exhibited in a strange manner the association of its ideas. For he was frequently in the habit of asking himself for his own claw, and then never failed to comply with his own request by holding it out, in the same way as he did when asked for his claw by anybody else. This, however, probably arose, not, as Buffon or his sister Madame Nadault sup- posed, from the bird not knowing its own voice, but rather from the association between the words and the gesture. According to Margrave, parrots sometimes chatter their phrases in their dreams, and this shows a striking simi- larity of psychical processes in the operations of memory with those which occur in ourselves. Similarly, Mr. Walter Pollock, writes me of his own parrot : — In this parrot the sense of association is very strongly de- veloped. If one word picked up at a former home comes into its head, and is uttered by it, it immediately follows this word up with all the other words and phrases picked up at the same place and period. Lastly, parrots not only remember, but recollect ; that is to say, they know when there is a missing link in a train of association, and purposely endeavour to pick it up. Thus, for instance, the late Lady Napier told me an interesting series of observations on this point which she had made upon an intelligent parrot of her own. They were of this kind. Taking such a phrase as ' Old Dan Tucker,' the bird would remember the beginning and the end, and try to recollect the middle. For it would say 270 ANIMAL INTELLIGENCE. very slowly, * Old — old — old — old ' (and then very quickly) * Lucy Tucker.' Feeling that this was not right, it would try again as before, ' Old — old — old — old — old Bessy Tucker,' substituting one word after another in the place of the sought-for word ' Dan.' And that the process was one of truly seeking for the desired word was proved by the fact that if, while the bird was saying, 'Old — old — old — old,' any one threw in the word 'Dan,' he immediately supplied the ' Tucker.' Emotions, As regards emotions, it is among birds that we first meet with a conspicuous advance in the tenderer feelings of affection and sympathy. Those relating to the sexes and the care of progeny are in this class proverbial for their intensity, offering, in fact, a favourite type for the poet and moralist. The pining of the ' love-bird ' for its absent mate, and the keen distress of a hen on losing her chickens, furnish abundant evidence of vivid feelings of the kind in question. Even the stupid-looking ostrich has heart enough to die for love, as was the case with a male in the Eotund of the Jardin des Plantes in Paris, who, having lost his wife, pined rapidly away. It is remark- able that in some species — notably pigeons — conjugal fidelity should be so strongly marked ; for this shows, not only what may be called a refinement of sexual feeling, but also the presence of an abiding image in the mind's eye of the lover. For instance, — Referring to the habits of the mandarin duck (a Chinese species) Mr. Bennett says that Mr. Beale's aviary afibrded a singular corroboration of the fidelity of the birds in question. Of a pair in that gentleman's possession, the drake being one night purloined by some thieves, the unfortunate duck displayed the strongest marks of despair at her bereavement, retiring into a corner, and altogether neglecting food and drink, as well a« the care of her person. In this condition she was courted by a drake who had lost his mate, but who met with no encourage- ment from the widow. On the stolen drake being subsequently recovered and restored to the aviary, the most extravagant demonstrations of joy were displayed by the fond couple ; but this was not all, for, as if informed by his spouse of the gallant BIKDS— CONJUGAL FIDELITY. 271 proposals made to her shortly before his arrival, the drake at* tacked the luckless bird who would have supplanted him, beat out his eyes, and inflicted so many injuries as to cause his death. ^ Similarly, to give an instance or two with regard to other birds, Jesse states the following as his own obser- vation : — A pair of swans had been inseparable companions for three years, during which time they had reared three broods of cygnets ; last autumn the male was killed, and since that time the female has separated herself from all society with her own species; and, though at the time I am writing (the end of March) the breeding season for swans has far advanced, she re- mains in the same state of seclusion, resisting the addresses of a male swan, who has been making advances towards forming an acquaintance with her, either driving him away, or flying from him whenever he comes near her. How long she will continue in this state of widowhood I know not, but at present it is quite evident that she has not forgotten her former partner. This reminds me of a circumstance which lately happened at Chalk Farm, near Hampton. A man, set to watch a field of peas which had been much preyed upon by pigeons, shot an old cock pigeon which had long been an inhabitant of the farm. His mate, around whom he had for many a year cooed, whom he had nourished from his own crop, and had assisted in rear- ing numerous young ones, immediately settled on the ground by his side, and showed her grief in the most expressive manner. The labourer took up the dead bird, and tied it to a short stake, thinking that it would frighten away the other depredators. In this situation, however, the widow did not forsake her de- ceased husband, but continued, day after day,walking slowly round the stick. The kind-hearted wife of the bailiff of the farm at last heard of the circumstance, and immediately went to afford what relief she could to the poor bird. She told me that, on arriving at the spot, she found the hen bird much exhausted, and that she had made a circular beaten track round the dead pigeon, making now and then a little spring towards him. On the removal of the dead bird the hen returned to the dove- cote. ^ As evidence of the intensity of the maternal instinct,. * Couch, Illustrations of Instinct, p. 165 2 Gleanings, vol. i., pp. 112-13. -'272 ANIMAL INTELLIGENCE. even in the case of barren birds, I may quote the follow- ing from the naturalist Couch. I do so because, although the instance is a trivial one, and also one of frequent occurrence, it is interesting as showing that a deeply rooted instinct or emotion may assert itself powerfully even in the absence of what may be termed its natural stimulus or object : — I was once witness to a curious instance of the yearning for progeny in a diminutive bantam hen. There was at this time a nest of the common hen in a se- cluded part of the garden, and the parent had been sitting on its eggs, till compelled by hunger she left them for a short time. This absence was fatal ; for the bantam had in the meantime found its situation in a covered recess in the hedge, and I saw her creep into it with all the triumph of the discoverer of a treasure. The real mother now returned, and great was her agony at finding an intruder in her nest. The expression of her eye and the attitude of her head were emphatic of surprise at the impudence of the proceeding. But after many attempts to recover possession she was compelled to resign her rights, for the bantam was too resolute to be contended with ; and though its body was not big enough to cover the whole of the eggs, and thus some of them were not hatched, yet in due season the pride of this audacious step-mother was gratified by strutting at the head of a company of robust chickens, which she passed ofi" upon the feathered public as a brood of her own.^ As evidence of sympathy I shall quote in extenso an interesting case which has been communicated to me by a young lady, who desires her name withheld. There are several more or less corroborative cases in the anecdote- books,^ so that I have no doubt as to the substantial ac- curacy of the account : — My grandfather had a Swan River gander, which had been reared near the house, and had consequently attached himself to the members of the family ; so much so that, on seeing any of them at a distance, he would run to meet them with all possible demonstrations of delight. But ' Swanny ' was quite an outcast from his own tribe ; and as often as he made humble overtures to the other geese, so ^ Couch, Illustrations of Instinct, p. 232. 2 See especially Bingley, Animal Biography, vol. ii., pp. 327-29. BIRDS — AFFECTION AND SYMPATHY. 273 •often was he driven away with great contempt, and on such occasions he would frequently run to some of his human friends, and laying his head on their laps, seem to seek for sympathy. At last, however, he found a friend among his own species. An old grey goose, becoming blind, was also discarded by her more fortunate companions, and Swanny lost no opportunity of recognising this comrade in distress. He ut once took her under his protection and led her about. When he considered it well for her to have a swim, he would gently take her neck in his bill, and thus lead her, sometimes a considerable distance, "to the water's edge. Having fairly launched her, he kept close by her side, and guided her from dangerous places by arching his neck over hers, and so turning her in the right direction. After cruising about a sufficient time, he would guide her to a convenient landing-place, and taking her neck in his bill as before, lead her to terra fir ma again. When she had goslings, he would proudly convoy the whole party to the water-side ; and if any ill-fated gosling got into difficulties in a hole or deep cart-rut, Swanny with ready skill would put his bill under its body, and carefully raise it to the level ground. My grandfather had also another gander who attached him- self to him, and would follow him for hours through fields and lanes, pausing when he stood still, and waddling gravely by his «ide as he proceeded. This gander was not, like the other, dis- carded by his kind, but would leave them any time to walk with his master, and was exceedingly jealous of any one else who tried to share this privilege, excepting only his mistress. On one occasion, a gentleman venturing to place his hand on my grand- father's arm, the gander flew at him, and beat him severely with his wings, and it was with great difficulty that he was induced to let go. The solicitude which most gregarious birds display when one of their number is wounded or captured, ■constitutes strong evidence of sympathy. As Jesse ob- serves, — There is one trait in the character of the rook which is, I believe, peculiar to that bird, and which does him no little credit; it is the distress which is exhibited when one of his fellows has been killed or wounded by a gun while they have been feeding in a field or flying over it. Instead of being scared away by the report of the gun, leaving their wounded or dead companion to his fate, they show the greatest anxiety and sympathy for him, uttering cries of distress, and plainly proving T 274 ANIMAL INTELLIGENCE. that they wish to render him assistance by hovering over him^ or sometimes making a dart from the air close up to him, ap- parently to try and find out the reason why he did not follow them. ... I have seen one of my labourers pick up a rook which he had shot at for the purpose of putting him up as a scarecrow in a field of wheat, and while the poor wounded bird was still fluttering in his hand, I have observed one of his com- panions make a wheel round in the air, and suddenly dart past him so as almost to touch him, perhaps with the last hope that he might still afford assistance to his unfortunate mate or com- panion. Even when the dead bird has been hung, in terror em, to a stake in the field, he has been visited by some of his former friends, but as soon as they found that the case was hopeless, they have generally abandoned that field altogether. When one considers the instinctive care with which rooks avoid any one carrying a gun, and which is so evident that I have often heard country people remark that a rook can smell gunpowder, one can more justly estimate the force of their love or friendship in thus continuing to hover round a person who has just destroyed one of their companions with an instrument the dangerous nature of which they seem fully capable of appre- ciating. ^ The justice of these remarks may be better appreciated in the light of the following very remarkable observation^ as an introduction to which I have quoted them. Edward, the naturalist, having shot a tern, which fell winged into the sea, its companions hovered around the floating bird, manifesting much apparent soHcitude, as terns and gulls always do under such circumstances. How far this apparent solicitude is real I have often speculated, as in the analogous case of the crows — wondering whether the emotions concerned were really those of sympathy or mere curiosity. The following observation, however, seems to set this question at rest. Having begun to make pre- parations for securing the wounded bird, Edward says: 'I expected in a few moments to have it in my possession, being not very far from the water's edge, and drifting shorewards with the wind.' He continues : — While matters were in this position I beheld, to my utter astonishment and surprise, two of the un wounded terns take ' Gleanings, pp. 58-9. BIRDS— SYMPATHY. 275 hold of their disabled comrade, one at each, wing, lift him out of the water, and bear him out seawards. They were followed by two other birds. After being carried about six or seven yards, he was let gently down again, when he was taken up in a similar manner by the two who had been hitherto inactive. In this way they continued to carry him alternately, until they had conveyed him to a rock at a considerable distance, upon which they landed him in safety. Having recovered my self-possession, I made toward the rock, wishing to obtain the prize which had been so unceremoniously snatched from my grasp, I was ob- served, however, by the terns ; and instead of four, I had in a short time a whole swarm about me. On my near approach to the rock I once more beheld two of them take hold of the wounded bird as they had done already, and bear him out to sea in triumph, far beyond my reach. This, had I been so inclined, I could no doubt have prevented. Under the circumstances, however, my feelings would not permit me ; and I willingly allowed them to perform without molestation an act of mercy, and to exhibit an instance of affection which man himself need not be ashamed to imitate.* According to Clavigero,^ the inhabitants of Mexico utilise the sympathy of the wild pelican for the procuring- of fish. First a pelican is caught and its wing broken, The bird is then tied to a tree, and being both in pain and captivity, it utters cries of distress. Other pelicans are attracted by the cries, and finding their friend in such a sorry case, their bowels of compassion become moved in a very literal sense ; for they disgorge from their stomachs and pouches the fish which they have caught, and deposit •them within reach of the captive. As soon as this is done the men, who have been lying in wait concealed, run to the spot, drive off the friendly pelicans, and secure their fish, leaving only a small quantity for the use of the captive. The parrot which belonged to the Buffon family showed much sympathy with a female servant to whom it was attached when the girl had a sore finger, which it dis- played by its never leaving her sick room, and groaning as if itself in pain. As soon as the girl got better the bird again became cheerful. * Smiles, Life of Edna/rd^ p. 240. ^ History of Mexico^ p. 220. T 2 276 ANIMAL INTELLIGENCE. I shall conclude this brief demonstration of the keen sympathy which may exist in birds, by quoting the follow- ing very conclusive case in the words of its distinguished observer, Dr. Franklin : * — I have known two parrots, said he, which had lived together four years, when the female became weak, and her legs swelled. These were symptoms of gout, a disease to which all birds of this family are very subject in England. It became impossible for her to descend from the perch, or to take her food as formerly, but the male was most assiduous in carrying it to her in his beak. He continued feeding her in this manner during four months, but the infirmities of his companion increased from day to day, so that at last she was unable to support herself on the perch. She remained cowering down in the bottom of the cage, making, from time to time, ineffectual efforts to regain the perch. The male was always near her, and with all his strength aided the feeble attempts of his dear better half. Seizing the poor invahd by the beak, or the upper part of the wing, he tried to raise her, and renewed his efforts several times. His constancy, his gestures, and his continued solicitude, all showed in this affectionate bird the most ardent desire to relieve the sufferings and assist the weakness of his companion. But the scene became still more interesting when the female was dying. Her unhappy spouse moved around her incessantly, his attention and tender cares redoubled. He even tried to open her beak to give some nourishment. He ran to her, then re- turned with a ti'oubled and agitated look. At intervals he uttered the most plaintive cries ; then, with his eyes fixed on her, kept a mournful silence. At length his companion breathed her last ; from that moment he piued away, and died in the course of a few weeks. ^ The jealousy of birds is proverbial ; and that they also manifest the kindred passion of emulation, no one can doubt who has heard them singing against one another. Mr. Bold relates that a mule canary would always sing at his own image in a mirror, becoming more and more excited, till he ended by flying in rage against his supposed rival. The late Lady Napier wrote me, among other ' anec- dotes of a grey parrot left on a long visit to the family of Greneral Sir William Napier, at the time residing in Grer- ' Zoologist, vol. ii. BIEDS — EMULATION AND VINDICTIVENESS. 277 many,' the following graphic description of the exultation displayed by the bird when it baffled the imitative powers of its master. The bird was the same as that already mentioned under the head of * Memory ': — Sometimes when only two or three were in the room, at quiet occupations instead of talking, she would utter at short inter- vals a series of strong squalls or cries in an interjectional style, each more strange and grotesque than the previous one. My father on these occasions sometimes amused himself by imitat- ing these cries as she uttered them, which seemed to excite her ingenuity in the production of them to the uttermost. As a last resource she always had recourse to a very peculiar one, which completely baffled him ; upon which, with a loud ha ! ha ! ha ! she made a somersault round her perch, swinging with her head downwards, sprung from one part of the cage to another, and tossed a bit of wood she used as a toy over her head in the most exulting triumph, repeating at intervals the inimitable cry, followed by peals of ha ! ha ! ha ! to the great amusement of all Allied to emulation is resentment, of which the follow- ing, communicated to me by a correspondent, may be taken as an example. If space permitted I could give confirmatory cases : — One day the cat and the parrot had a quarrel. I think the cat had upset Polly's food, or something of that kind ; however, they seemed all right again. An hour or so after, Polly was standing on the edge of the table ; she called out in a tone of extreme affection, * Puss, puss, come then— come then, pussy.' Pussy went and looked up innocently enough. Polly ^vith her beak seized a basin of milk standing by, and tipped the basin and all its contents over the cat; then chuckled diabolically, of course broke the basin, and half drowned the cat. Several strange but mutually corroborative stories seem to show cherished vindictiveness on the part of storks. Thus, in Captain Brown's book there occurs an account of a tame stork which lived in the college yard at Tiibingen, — And in a neighbouring house was a nest, in which other storks, that annually resorted to the place, used to hatch their eggs. At this nest, one day in autumn, a young collegian fired a shot, 278 ANIMAL INTELLIGENCE. by which the stork that was sitting on it was probably wounded, for it did not fly out of the nest for some weeks afterwards. It was able, however, to take its departure at the usual time with the rest of the storks. But in the ensuing spring a strange stork was observed on the roof of the college, which, by clapping his wings and other gestures, seemed to invite the tame stork to come to him ; but, as the tame one's wings were clipped, he was unable to accept the invitation. After some days the strange stork appeared again, and came down into the yard, when the tame one went out to meet him, clapping his wings as if to bid him welcome, but was suddenly attacked by the visitor with great fury. Some of the neighbours protected the tame bird, and drove off the assailant, but he returned several times after- wards, and incommoded the other through the whole summer. The next spring, instead of one stork only, four storks came together into the yard, and fell upon the tame one ; when all the poultry present — cocks, hens, geese, and ducks — flocked at once to his assistance, and rescued him from his enemies. In consequence of this serious attack, the people of the house took precaution for the tame stork's security, and he was no more molested that year. But in the beginning of the third spring came upwards of twenty storks, which rushed at once into the yard and killed the tame stork before either man or any other animal could afford him protection. A similar occurrence took place on the premises of a farmer near Hamburg, who kept a tame stork, and, having caught another, thought to make it a companion for the one in his pos- session. But the two were no sooner brought together than the tame one fell upon the other, and beat him so severely that he made his escape from the place. About four months after- wards, however, the defeated stork returned with three othere, who all made a combined attack upon the tame one and killed him.^ The curiosity of birds is highly developed, so much so, indeed, that in this and other countries it is played upon by sportsmen and trappers. Unfamiliar objects being ' Watson, Reasoning Power of Animals, pp. 375-76, where see also some curious cases of male storks slaying their females upon the latter hatching out eggs of other birds. He gives an exactly similar case as having occurred vnth the domestic cock ; and in Bingley (loc. eit.t vol. ii., p. 241) there is quoted from Dr. Percival another case of the same kind, in which a cock killed his hen as soon as she had hatched out a brood of young partridges from eggs which had been set to her. BIRDS— CUBIOSITY, PRIDE, PLAY. 279 placed within sight, say of ducks, the birds approach to examine them, and fall into the snares which have been prepared. Similarly, in oceanic islands unfrequented by man, the birds fearlessly approach to examine the first human beings that they have seen. That birds exhibit pride might be considered doubtful if we had to rely only on the evidence supplied by the display of the peacock, and the strutting of the turkey- gobbler ; for these actions, although so expressive of this emotion, may not really be due to it. But I think that the evident pleasure which is taken in achievement by talking birds can only be ascribed to the emotion in ques- tion. These birds regularly practise their art, and when a new phrase is perfected they show an unmistakable de- light in displaying the result. Play is exhibited by many species in various ways, and it seems to be this class of feelings in their most organised form which have led to the extraordinary instincts of the bower-birds of New South Wales. The 'playhouses' of the animals have been described by Mr. Grould in his * History of the Birds of New South Wales.' Of course the play-instincts are here united with those of courtship, which are of such general occurrence among birds ; but I think no one can read Mr. Grould's description of the bowers and the uses to which they are put without feeling that the love of sportive play must have been joined with the sexual instincts in producing the result. But, be this as it may, there can be no question that these bowers are highly interesting structures, as furnishing the most un- exceptionable evidence of true aesthetic, if not artistic feeling on the part of the bird which constructs them ; and, according to Mr. Herbert Spencer, the artistic feelings are physiologically allied with those of play. It is a matter of importance to obtain definite proof of an aesthetic sense in animals, because this constitutes the basis of Mr. Dar- win's theory of sexual selection ; but as he has treated the evidence on this subject in so exhaustive a manner, I shall not enter upon so wide a field further than to point out that the case of the bower-bird, even if it stood alone, would be amply sufficient to carry the general conclusion 280 ANIMAL INTELLIGENCE. that some animals exhibit emotions of the beautifuL The following is Mr. Grould's description, in extenso, of the habits of the bird in question : — The extraordinary bower-like structure, alluded to in 1117 remarks on the genus, first came under my notice in the Sydney Museum, to which an example had been presented by Charles Cox, Esq. . . . On visiting the cedar bushes of the Liverpool range, I discovered several of these bowers or playing-houses on the ground, under the shelter of the branches of the overhang- ing trees, in the most retired part of the forest ; they difiered considerably in size, some being a third larger than others. The base consists of an extensive and rather convex platform of sticks firmly interwoven, on the centre of which the bower itself is built. This, like the platform on which it is placed, and with which it is interwoven, is formed of sticks and twigs, but of a more slender and flexible description, the tips of the twigs being so arranged as to curve inwards and nearly meet at the top ; in the interior the materials are so placed that the forks of the twigs are always presented outwards, by which arrangement not the shghtest obstruction is offered to the passage of the birds. The interest of tins curious bower is much enhanced by the manner in which it is decorated with the most gaily coloured articles that can be collected, such as the blue tail-feathers of the Rose-bill and Pennantian parakeets, bleached bones and shells of snails, &c.; some of the feathers are inserted among the twigs, while others with the bones and shells are strewed near the entrances. The propensity of these birds to fly off" with any attractive object is so well known to the natives that they always search the runs for any small missing article that may have been accidentally dropped in the bush . I myself found at the entrance of one of them a small neatly worked stone tomahawk of an inch and a half in length, together with some slips of blue cotton rag, which the birds had doubtless picked up at a deserted encampment of the natives. It has now been clearly ascertained that these curious bowers are merely sporting-places in which the sexes meet, when the males display their finery, and exhibit many remarkable actions ; and so inherent is this habit, that the living examples, which have been from time to time sent to this country, continue it even in captivity.^ Those belonging to the Zoological Society have constructed * See Darwin, Descent of Man, pp. 92, 381, 406, 413. BIRDS — ESTHETIC EMOTIONS. 281 their bowers, decorated and kept them in repair, for several years. In a letter from the late Mr. F. Strange, it is said : — My aviary is now tenanted by a pair of satin-birds, which for the last two months have been constantly engaged in con- structing bowers. Both sexes assist in their erection, but the male is the principal workman. At times the male will chase the female all over the aviary, then go to the bower, pick up a gay feather or a large leaf, utter a curious kind of note, set all his feathers erect, run round the bower, and become so excited that his eyes appear ready to start from his head, and he con- tinues opening first one wing and then another, uttering a low whistling note, and, like the domestic cock, seems to be picking up something from the ground, untU at last the female goes gently towards him, when after two turns round her, he sud- denly makes a dash, and the scene ends.' ^ I have said that if this case stood alone it would con- stitute ample evidence that some animals possess emotions of the beautiful. But the case does not stand alone. Certain humming-birds, according to Mr. Grould, decorate the outsides of their nests ' with the utmost taste ; they instinctively fasten thereon beautiful pieces of flat lichen, the larger pieces in the middle, and the smaller on the part attached to the branch. Now and then a pretty feather is intertwined or fastened to the outer sides, the stem being always so placed that the feather stands out beyond the surface.' Several other instances might be rendered of the display of artistic feeling in the architec- ture of birds ; and, as Mr. Darwin so elaborately shows^ there can scarcely be question that these animals take emotional pleasure in surveying beautiful plumage in the opposite sex, looking to the careful manner in which the males of many species display their fine colours to the females. Doubtless the evidence of aesthetic feeling is much stronger in the case of birds than it is in that of any other class ; but if this feeling is accepted as a suflS- cient cause, through sexual selection, of natural decoration in the members of this class, we are justified in attribut- ing to sexual selection, and so to aesthetic feeling, natural ' Gonld, Birds of Australia, vol. i., pp. 442-45. .282 ANIMAL INTELLIGENCE. decoration in * other classes, at least as low down in the scale as the Articulata. But, as I have said, Mr. Darwin has dealt with this whole subject in so exhaustive a manner that it is needless for me to enter upon it further than to say in general terms, that whatever we may think of his theory of sexual selection, his researches have unquestion- ably proved the existence of an aesthetic sense in animals. The same fact appears to be shown in another way by the fondness of song-birds for the music of their mates. There can be no doubt that male birds charm their females with their strains, and that this, in fact, is the reason why song in birds has become developed. Of course it may be said that the vocal utterances of birds are not alwajrs, or even generally, musical ; but this does not affect the fact that birds find some aesthetic pleasure in the sounds which they emit ; it only shows that the standard of aesthetic taste differs in different species of birds as it does in different races of men. Moreover, the pleasure which birds manifest in musical sounds is not always re- stricted to the sounds which they themselves produce. Parrots seem certainly to take delight in hearing a piano play or a girl sing ; and the following instance, published by the musician John Lockman, reveals in a remarkable manner the power of distinguishing a particular air, and of preferring it above others. He was staying at the house of a Mr. Lee in Cheshire, whose daughter used to play ; and whenever she played the air of ' Speri si ' from Handel's opera of ' Admetus,' a pigeon would descend from an adjacent dovecot to the window of the room where she sat, ' and listen to the air apparently with the most pleas- ing emotions,' always returning to the dovecot immedi- ately the air was finished. But it was only this one air that would induce the bird to behave in this way.^ Special Habits, Under this heading we shall have a number of facts to consider, which are more or less of a disconnected cha- racter. ' Bingley, Animal Biography^ vol. ii., p. 220. BIRDS— SPECIAL HABITS OF FEEDING. 283 Taking first those special habits connected with the procuring of food, we may notice the instinct manifested by blackbirds and thrushes of conveying snails to con- siderable distances in order to hammer and break their shells against what may happen to be the nearest stone, ^ and the still more clever though somewhat analo- gous instinct exhibited by certain gulls and crows of flying with shell-fish to a considerable height and letting them fall upon stones for the purpose of smashing their shells.^ Both these instincts manifest a high degree of intelligence, either on the part of the birds themselves, or on that of their ancestors ; for neither of these instincts can be re- garded as due to originally accidental adjustments favoured and improved by natural selection ; they must at least originally have been intelligent actions purposely designed to secure the ends attained. An interesting instinct is that of piracy, which in the animal kingdom reaches its highest or most systematic development among the birds. It is easy to see how it may be of more advantage to a species of strong bird that its members should become parasitic on the labours of other species than that they should forage for themselves, and so there is no difficulty in understanding the develop- ment of the plundering instinct by natural selection. We find all stages of this development among the sea-birds. Thus the gulls, although usually self-foragers, will, as I have often observed, congregate in enormous numbers where the guillemots have found a shoal of fish. Eesting ^ For full information, see Buckland, Curiosities of Natwal History ^ p. 183. 2 Of the crow (carrion and hooded), Edward says : * He goes aloft with a crab, and lets it fall upon a stone or a rock chosen for the purpose. If it does not break, he seizes it again, goes up higher, lets it fall, and repeats his operation again and again until his object is accomplished. When a convenient stone is once met with, the birds resort to it for a long time. I myself know a pretty high rock, that has been used by successive generations of crows for about twenty years 1' Also, as Handcock says, ' a friend of Dr. Darwin saw on the north coast of Ireland above a hundred crows preying upon mussels, which is not their natural food ; each crow took a mussel up into the air, twenty or forty yards high, and let it fall on the stones, and thus breaking the shell, got possession of the animal. Ravens, we are told, often resort to the same contrivance.' 284 ANIMAL INTELLIGENCE. on or flying over the surface of the water, the gulls wait till a guillemot comes to the surface with a fish, and then wrest the latter from the beak of the former. In the robber-tern this instinct has proceeded further, so that the animal gains its subsistence entirely by plunder of other terns. I have often observed this process, and it is inte- resting that the common tern well knows the appearance of the robber ; for no sooner does a robber-tern come up than the greatest consternation is excited among a flock of common terns, these flying about and screaming in a frantic manner. The white-headed eagle has also de- veloped the plundering instinct in great perfection, as is shown by the following graphic account of Audubon : — During spring and summer, the white-headed eagle, to procure sustenance, follows a different course, and one much less suited to a bird apparently so well able to supply itself without inter- fering with other plunderers. No sooner does the first hawk make its appearance along the Atlantic shore, or around the numerous and large rivers, than the eagle follows it, and, like a selfish oppressor, robs it of the hard-earned fruits of its labour. Perched on some tall summit, in view of the ocean or of some watercourse, he watches every motion of the osprey while on the wing. When the latter rises from the water, with a fish in its grasp, forth rushes the eagle in pursuit. He mounts above the fish-hawk, and threatens it by actions well understood; when the latter, fearing perhaps that its hfe is in danger, drops its prey. In an instant the eagle, accurately estimating the rapid descent of the fish, closes its wings, follows it with the swiftness of thought, and the next moment grasps it. The prize is carried off in silence to the woods, and assists in feeding the ever- hungry brood of the eagle. The frigate pelican is likewise a professional thief, and attacks the boobies not only to make them drop the fish which they have newly caught, but also to disgorge those which are actually in their stomachs. The latter process is effected by strong punishment, which they con- tinue until the unfortunate booby yields up its dinner. The punishment consists in stabbing the victim with its powerful beak. Catesby and Dampier have both observed and described these habits, and it seems from their account that the plunderer may either commit highway robbery in BIRDS— SPECIAL HABITS OF FEEDING. 285 the air, or lie in wait for the boobies as they return tc rest. In antithesis to this habit of plundering other birds I may quote the following from ' Nature ' (July 20, 1871), to show that the instinct of provident labour, so common among insects and rodents, is not altogether unrepresented in birds: — The ant-eating woodpecker (Melanerpes formicivorus), a common Californian species, has the curious and peculiar habit of laying up provision against the inclement season. Small round holes are dug in the bark of the pine and oak, into each of which is inserted an acorn, and so tightly is it fitted or driven in, that it is with difficulty extricated. The bark of the pine trees, when thus filled, presents at a short distance the appear- ance of being studded with nails. The following may also be quoted : — It is the nature of this bird (guillemot), as well as of most of those birds which habitually dive to take their prey, to per- form all their evolutions under water with the aid of their wings ; but instead of dashing at once into the midst of the terrified group of small prey, by which only a few would be captured, it passes round and round them, and so drives them into a heap ; and thus has an opportunity of snatching here one and there another as it finds it convenient to swallow them ; and if any one pushes out to escape, it falls the first prey of the devourer. The manner in which this bird removes the egg of a gull or hen to some secui'e place to be devoured, when com- pared with that in which a like conveyance is made by the parent for the safety of its future progeny, affi)rds a striking manifestation of the difierence between appetite and affection. When influenced by affection, the brittle treasure is removed without flaw or fracture, and is replaced with tender care ; but the plunderer at once plunges his bill into its substance, and carries it off on its point. ^ Speaking of the feeding habits of the lapwing, Jesse says : — When the lapwing wants to procure food, it seeks for a worm's cast, and stamps the ground by the side of it with its feet. After doing this for a short time, the bird waits for the * Couch, Illustrations of Instinct, pp. 192-93. 286 ANIMAL INTELLIGENCE. issue of the worm from its hole, which, alarmed at the shaking of the ground, endeavours to make its escape, when it is imme- diately seized, and becomes the prey of the ingenious bird. The lapwing also frequents the haunts of moles, which, when in pursuit of worms on which they feed, frighten them, and the worm, in attempting to escape, comes to the surface of the ground, when it is seized by the lapwing.^ Again,— A lady of Dr. E. Darwin's acquaintance saw a little bird re- peatedly hop on a poppy stem, and shake the head with his bill, till many seeds were scattered, when it settled on the ground and picked up the seeds.* It is a matter of common remark that in countries where vultures abound, these birds rapidly 'gather to- gether where the carcass is,' although before the death of their prey no bird was to be seen in the sky. The question has always been asked whether the vultures are guided to the carcass by their sense of smell or by that of sight ; but this question is really no longer an open one. When Mr. Darwin was at Valparaiso he tried the following experi- ment. Having tied a number of condors in a long row, and having folded up a piece of meat in paper, he walked backwards and forwards in front of the row, carrying the meat at a distance of three yards from them, 'but no notice whatever was taken.' He then threw the meat upon the ground, within one yard of an old male bird ; ' he looked at it for a moment with attention, but then regarded it no more.' With a stick he next pushed the meat right under the beak of the bird. Then for the first time the bird smelled it, and tore open the paper 'with fury, and at the same moment every bird in the long row began struggling and flapping its wings.' ^ Thus there can be no doubt that vultiu-es do not depend on their sense of smell for finding carrion at a distance. Nor is it myste- rious why they should find it by their sense of sight. If over an area of many square miles there are a number of vultures flying as they do at a very high elevation, and if * Qleanings, &c., vol. i., p. 71. lUd. 2 lUd. ' Voyage of a Naturalist, &c., p. 184. BIRDS — SPECIAL HABITS OF INCUBATION. 287 one of the number perceives a carcass and begins to de- scend, the next adjacent vultures would see the descent of the first one, and follow him as a guide, while the next in the series would follow these in the same way, and so on. Coming now to special instincts relating to incubation and the care of offspring, a correspondent writes : — Last spring I had a pair of canaries, in an ordinary breed- ing cage (with two small boxes for nests in a compartment at one end). In due course the first egg was laid, which I inspected through the Uttle door made for that purpose. The next day I looked again ; still only one egg, and so for four or five days. It being evident, from the appearance of the hen, that there were more eggs coming, and as she seemed in good health, I supposed she might have broken some ; and I took out the box, and exa- mined it carefully for the shells (but without pulling the nest to pieces), and found nothing, until towards the beginning of another week I went to take the one egg away, as the hen seemed preparing to sit upon it. There were two eggs ! The next morning, to my surprise, she was sitting upon six eggs ! She must therefore have buried four of them in the four comers of the box, and so deep that I had been unable to find them. At first I thought that she had done so merely from dislike at their being looked at, but on reflection it has occurred to me that she did it that all might be hatched at the same time (as they subsequently were) ; for she was perfectly tame, and would almost suffer herself to be handled when on her nest. Wild birds never seem to conceal their eggs before sitting; but then (having more amusements than cage birds) they do not revisit their eggs after laying, until they have laid their number, whereas a caged bird, having nothing to divert her attention from her nest, often sits on it the greater part of the day. I am not aware that this curious display of forethought on the part of a caged bird has been hitherto recorded, and seeing, as my correspondent points out, that it has reference to the changed conditions of life brought about by domestication, it may be said to constitute the first step in the development of a new instinct, which, if the conditions were of sufficiently long continuance, might lead to an important and permanent change of the ances- tral instinct. I have several interesting facts, also communicated to 288 ANIMAL INTELLIGENCE. me by correspondents, similarly relating to individual vari- ations of the ancestral instinct of incubation in order to meet the requirements of a novel environment. Thus Mr. J. F. Fisher tells me that while he was a commander in the East India trade he always took a quantity of fowls to sea for food. The laying-boxes being in a confined space, the hens used to quarrel over their occupancy ; and one of the hens adopted the habit of removing the ' nest- eggs ' which Mr. Fisher placed in one of the boxes to another box of the same kind not very far away. He watched the process through a chink of a door, and ' saw her curl her neck round the egg, thus forming a cup by which she lifted the egg,^ and conveyed it to the other box. He adds : — I can give no information as to the more recondite question why the egg was removed, or the fastidious preference of the one box over the other, or the inventive faculty that suggested the neck as a makeshift hand; but from the despatch with which she effected the removal of the egg in the case I saw, I have no doubt that this hen was the one which had performed the feat so often before. The explanation of the preference shown for the one box over the other may, I think, be gathered from another part of my correspondent's letter, for he there mentions incidentally that the box in which he placed the nest-egg, and from which the hen removed it, was standing near a door which was usually open, and thus situated in a more exposed position than the other box. But be this as it may, considering that among domestic fowls the habit of conveying eggs is not usual, such isolated cases are inte- resting as showing how instincts may originate. Jesse gives an exactly similar case (' Crieanings,' vol. i., p. 149) of the Cape goose, which removed eggs from a nest at- tacked by rats, and another case of a wild duck doing the same. In the same connection, and with the same remarks, I may quote the following case in which a fowl adopted the habit of conveying, not her eggs, but her young chickens. I quote it from Houzeau (' Journ.,' i., p. 332), who gives BIRDS— SPECIAL HABITS. 289 the observation on the authority of his brother as eye- intness. The fowl had found good feeding-ground on the further side of a stream four metres wide. She adopted the habit of flying across with her chickens upon her back, taking one chicken on each journey. She thus transferred her whole brood every morning, and brought them back in a similar way to their nest every evening. The habit of carrying young in this way is not natural to Orallinacese, and therefore this particular instance of its •display can only be set down as an intelligent adjustment bj a particular bird. Similarly, a correspondent (Mr. J. Street) informs me of a case in which a pair of blackbirds, after having been disturbed by his gardener looking into their nest at their young, removed the latter to a distance of twenty yards, and deposited them in a more concealed place. Partridges •are well known to do this, and similarly, according to Audubon, the goatsucker, when its nest is disturbed, re- moves its eggs to another place, the male and female both transporting eggs in their beaks.^ Still more curiously, a case is recorded in ' Comptes Rendu' (1836) of a pair of nightingales whose nest was threatened by a flood, and who transported it to a safe place, the male and the female bearing the nest between them. Now, it is easy to see that if any particular bird is in- telligent enough, as in the cases quoted, to perform this adjustive action of conveying young — whether to feeding- grounds, as in the case of the hen, or from sources of danger, as in the case of partridges, blackbirds, and goat- suckers — inheritance and natural selection might develop the originally intelligent adjustment into an instinct common to the species. And it so happens that this has actually occurred in at least two species of birds — viz., the woodcock and wild duck, both of which have been re- peatedly observed to fly with their young upon their backs to and from their feeding-ground. Couch gives some facts of interest relating to the mode of escape practised by the water-rail, swan, and some other aquatic birds. This consists in sinking under water, with ' Orn. Biog., i., p. 276. U 290 ANIMAL INTELLIGENCE. only the bill remaining above the surface for respiration. When the swan has young, she may sink the head quite under water in order to allow the young to mount on it^ and so be carried through even rapid currents. The same author remarks thai> — Many birds will carefully remove the meetings of the young from the neighbourhood of their nests, in order not to attract the attention of enemies ; for while we find that birds which make no secret of their nesting-places are careless in such matters, the woodpecker and the marsh-tit in particular are at pains to remove even the chips which are made in excavating the cavities where the nests are placed, and which might lead an observer to the sacred spot. Similarly, Jesse observes : — The excrement of the young of many birds who build their nests without any pretensions to concealment, such as the swallow, crow, &c., may at all times be observed about or under the nest ; while that of some of those birds whose nests are more indus- triously concealed is conveyed away in the mouths of the parent birds, who generally drop it at a distance of twenty or thirty yards from the nest. Were it not for this precaution, the ex- crement itself, from its accumulation, and commonly from its very colour, would point out the place where the young were concealed. When the young birds are ready to fly, or nearly so, the old birds do not consider it any longer necessary to remove the excrement. Sir H. Davy gives an account of a pair of eagles which he saw on Ben Nevis teaching their young ones to fly ; and every one must have observed the same thing among commoner species of birds. The experiments of Spalding, however, have shown that flying is an instinctive faculty ; so that when he reared swallows from the nest and liberated them only after they were fully fledged, they flew well im- mediately on being liberated. Therefore, the ' teaching to fly' by parent birds must be regarded as mere en- couragement to develop instinctive powers, which in virtue of this encouragement are probably developed sooner than would otherwise be the case. A few observations may here be offered on some BIEDS — NIDIFICATION. 291 habits which do not fall under any particular head- ing. The habit which many small birds display of mobbing carnivorous ones is probably due to a desire to drive off the enemy, and perhaps also to warn friends by the hubbub. It may therefore perhaps be regarded as a display of con- certed action, of which, however, we shall have better evidence further on. I have seen a flock of common terns mob a pirate tern, which shows that this combined action may be directed as much against robbery as against murder. Couqh says he has seen blackbirds mobbing a cat which was concealed in a bush, and here the motive would seem to be that of warning friends rather than that of driving away the enemy. I have observed among the sea-gulls at the Zoological Grardens a curious habit, or mode of challenge. This con- sists in ostentatiously picking up a small twig or piece of wood, and throwing it down before the bird challenged, in the way that a glove used to be thrown down by the old knights. I observed this action performed repeatedly by several individuals of the glaucous and black-back species in the early spring-time of the year, and so it probably has some remote connection with the instinct of nest- building. Nidification. In connection with the habits and instincts peculiar ta certain species of birds, I may give a short account of the more remarkable kinds of nidification that are met with in this class of animals. As the account must necessarily be brief, I shall only mention the more interesting of the usual types. Petrels and puffins make their nests in burrows which they excavate in the earth. The great sulphur mountain in Gruadaloupe is described by Wasser as ' all bored like a rabbit warren with the holes that these imps {i.e, petrels) excavate.' In the case of the puffin it is the male that does the work of burrowing. He throws himself upon his back in the tunnel which he has made, and digs it longer and longer with his broad bill, while casting out u 2 292 ANIMAL INTELLIGENCE. the mould with his webbed feet. The burrow when finished has several twists and turns in it, and is about ten feet deep. If a rabbit burrow is available, the puffin saves himself the trouble of digging by taking possession of the one already made. The kingfisher and land-martin also make their nests in burrows. Certain auks lay their single egg on the bare rock while the stone curlew and goatsucker deposit theirs on the bare soil, returning, however, year after year to the same spot. Ostriches scrape holes in the sand to serve as extemporised nests for their eggs promiscuously dropped, which are then buried by a light coating of sand, and in- cubated during the day by the sunbeams, and at night by the male bird. Sometimes a number of female ostriches deposit their eggs in a common nest, and then take the duty of incubation by turns. Similarly, gulls, sandpipers, plovers, &c., place their eggs in shallow pits hollowed out of the soil. The kingfisher makes a bed of undigested fish-bones ejected as pellets from her stomach, and ' some of the swifts secrete from their salivary glands a fluid which rapidly hardens as it dries on exposure to the air into a substance resembling isinglass, and thus furnish the " edible birds' nests " that are the delight of .the Chinese epicures.' ^ The house-martin builds its nest of clay, which it sticks upon the face of a wall, and renders more tenacious by working into it little bits of straw, splinters of wood, &c. According to Mr. Grilbert White : — That this work may not, while it is soft and green, pull itself down by its own weight, the provident architect has prudence and forbearance enough not to advance her work too fast ; but by building only in the morning, and by dedicating the rest of the day to food and amusement, gives it sufficient time to dry and harden. About half an inch seems a sufficient layer for a day. Thus careful workmen, when they build mud walls (informed at first perhaps by these little birds), raise but a moderate layer at a time, and then desist, lest the work should become top-heavy, and ruined by its own weight. By this method, in about ten or twelve days is formed a hemispheric nest, with a small aperture towards the top, strong, compact, * Newton, Encycl. Brit., art. ' Birds.' BIRDS — NIDIFICATION. 293 and warm, and perfectly fitted for all the purposes for which it was intended. Other birds build in wood. The tomtit and the woodpecker excavate a hole in a tree, and carefully carry away the chips, so as not to give any indication of the whereabouts of their nests. Wilson says that the American woodpecker makes an excavation five feet in depth, of a . tortuous form, to keep out wind and rain. The orchard starling suspends its nest from the branches of a tree, and uses for its material tough kinds of grass, the blades of which it weaves together. Wilson found one of these blades to be thirteen inches long, and to be woven in and out thirty-four times. We may next notice the weaver (Ploceus textor) and tailor {Prinia, Orthotomus, and Sylvia). The former intertwines slender leaves of grass so as to produce a web sufficiently substantial for the protection of its young. The tailor-birds sew together leaves wherewith to make their nests, using for the purpose cotton and thread where they can find it, and natural vegetable fibres where they cannot obtain artificial. Colonel Sykes says that he has found the threads thus used for sewing knotted at the ends.^ Forbes saw the tailor-bird of the East Indies construct- ing its nest, and observed it to choose a plant with large leaves, gather cotton which it regularly spun into a thread by means of its bill and claws, and then sew the leaves together, using its beak as a needle, or rather awl. This instinct is rendered particularly interesting to evolutionists from the fact that it is exhibited by three distinct genera. For, as the instinct is so peculiar and unique, it is not likely to have originated independently in the three genera, but must be regarded as almost certainly derived from a common ancestral type — thus showing that an instinct may be perpetuated unaltered after the difieren- tiation of structure has proceeded beyond a specific distinc- tion. The genus Sylvia inhabits Italy, the other two inhabit India. Sylvia uses for thread spiders' web col- * Catalogue of Birds, Sec, p. 16. 294 ANIMAL INTELLIGENCE. lectedfrom the egg-pouches, whicli is stitched through holes made in the edges of leaves, presumably with the beak. The baya bird of India ' hangs its pendulous dwelling from a projecting bough, twisting it with grass into a form somewhat resembling a bottle with a prolonged neck, the entrance being inverted, so as to baffle the approaches of its enemies, the tree snakes and other reptiles.' Sir E. Tennent, from whom this account is taken, adds : — The natives assert that the male bird carries fire-flies to the nest, and fastens them to its sides by particles of soft mud. Mr. Layard assures me that although he has never succeeded in finding the fire-fly, the nest of the male bird (for the female occupies another during incubation) invariably contains a patch of mud on each side of the perch. Dr. Buchanan confirms the report of the natives here alluded to, and says : — At night each of the habitations is lighted up by a fire-fly stuck on the top with a bit of clay. The nest consists of two rooms; sometimes there are three or four fire-flies, and their blaze in the little cells dazzles the eyes of the bats, which often kill the young of these birds. While this work is passing through the press I meet with the following, which appears to refer to some inde- pendent, and therefore corroborative observation concern- ing the above-stated fact, and in any case is worth adding, on account of the observation concerning the rats, which, if trustworthy, would furnish a sufficient reason for the instinct of the birds. The extract is taken from a letter to * Nature ' (xxiv., p. 165), published by Mr. H. A. Severn : I have been informed on safe authority that the Indian bottle-bird protects his nest at night by sticking several of these glow-beetles around the entrance by means of clay ; and only a few days back an intimate friend, of my own was watching three rats on a roof rafter of his bungalow when a glow-fly lodged very close to them ; the rats immediately scampered ofi*. TheTalegallus of Australia is, in the opinion of Grould, — Among the most important of the ornithological novelties which the exploration of Western and Southern Australia has BIEDS — NIDIFICATION. 295 unfolded to us, and this from the circumstance of its not hatch- ing its own eggs, which, instead of being incubated in the usual way, are deposited in mounds of mixed sand and herbage, and there left for the heating of the mass to develop the young, which, when accomplished, force their way through the sides of the mound, and commence an active life from the moment they see the light of day.^ Sir Greorge Grey measured one of these mounds, and found it to be 'forty-five feet in circumference, and if rounded in proportion on the top (it being at the time unfinished) would have been full five feet high.' The heat round the eggs was taken to be 89°. A curious aberration of the nest-building instinct is sometimes shown by certain birds — particularly the com- mon wren — which consists in building a supernumerary nest. That is to say, after one nest is completed, another is begun and finished before the eggs are laid, and the first nest is not used, though sometimes it is used in pre- ference to the second. As showing at once the eccentricity which birds some- times display in the choice of a site, and also the deter- mination of certain birds to return to the same site in successive years, I may allude to the case published by Bingley, of a pair of swallows which built their nest upon the wings and body of a dead owl, which was hanging from the rafters of a barn, and so loosely as to sway about with every gust of wind. The owl with the nest upon ^ it was placed as a curiosity in the museum of Sir Ashton Lever, and he directed that a shell should be hung upon the rafters in the place which had been previously oc- cupied by the dead owl. Next year the swallows re- turned and constructed their new nest in the cavity of the shell.2 The following is quoted from Thompson's ' Passions of Animals,' p. 205 : — The sociable gi'osbeak of Africa is one of the few instances of birds living in community and uniting in constructing one ' Gould, Birds of Australia, vol. il., p. 155, where see for further de- scription. 2 Animal Biography, vol. ii., p. 204. 296 ANIMAL INTELLiaENCE. huge nest for the whole society. L. Valiant's account has beeni fully confirmed by other travellers. He says : * I observed on the- way a tree with an enormous nest of these birds, which I have called republicans ; and as soon as I arrived at my camp I de- spatched a few men with a waggon to bring it to me, that I might open and examine the hive. When it arrived, I cut it in pieces with a hatchet, and saw that the chief portion of the structure consisted of a mass of Boshman's grass, without any mixture, but so compact and firmly basketed together as to be impene- trable to the rain. This is the commencement of the structure, and each bird builds its particular nest under this canopy. But the nests are formed only beneath the eaves, the upper surface remaining void, without, however, being useless ; for as it has a projecting rim, and is a little inclined, it serves to let the water run off", and preserves each little dwelling from the rain. Figure to yourself a huge irregular sloping roof, all the eaves of which are covered with nests, crowded one against another, and you will have a tolerably accurate idea of these singular edifices. Each individual nest is three or four inches in diameter, which is sufficient for the bird; but, as they are all in contact with one another around the eaves, they appear to the eye to form but one building, and are distinguishable from each other only by a little external aperture which serves as an entrance to the nest; and even this is sometimes common to three difierent nests, one of which is situated at the bottom and the other two at the sides. This large nest, which was one of the most considerable I had anywhere seen in the course of my journey, contained 320 inhabited cells, which, supposing a male and female to each, would form a society of 640 individuals; but as these birds are polygamous, such a calculation would not be exact.' The following is quoted from Couch ( ' Illustrations of Instinct,' p. 227 et seq.) : — Mr. Waterton says there is a peculiarity in the nidification of the domestic swan too singular to be passed over without notice. At the time it lays its first egg the nest which it has prepared is of veiy moderate size; but as incubation proceeds we see it increase vastly in height and breadth. Every soft material, such as pieces of grass and fragments of sedges, is laid hold of by the sitting swan as they float within her reach, and are added to the nest. This work of accumulation is performed by her during the entire period of incubation, be the weather wet or dry, settled or unsettled; and it is perfectly astonishing to see with what assiduity she plies her work of aggrandisement I BIRDS — NIDIFICATION. 297 to a nest already sufficient in strength and size to answer every end. My swans generally form their nest on an island quite above the reach of a flood ; and still the sitting bird never ap- pears satisfied with the quantity of materials which are provided for her nest. I once gave her two huge bundles of oaten straw, and she performed her work of apparent supererogation by apply- ing the whole of it to her nest, already very large, and not exposed to destruction had the weather become ever so rainy. This same author continues : — It is probable that this disposition to accumulation, in its general bearing, has reference to heat rather than the flood ; but that the wild swan has a foresight regarding danger, and a quick perception as to the means of securing safety, appears from an instance mentioned by Captain Parry, in his Northern voyage. When everything was deeply involved in ice, the voyagers were obliged to pay much attention to discern whether they were travelling over water or land ; but some birds, which formed their nest at no great distance from the ships, were under no mistake in so important a matter; and when the thaw took place it was seen that the nest was situated on an islaiid in the lake. The following cases are likewise taken from Couch {loc, cit, p. 225) :— This swan was eighteen or nineteen years old, had brought up many broods, and was highly valued by the neighboui-s- She exhibited, some eight or nine years past, one of the most remarkable powers of instinct ever recorded. She was sitting on four or five eggs, and was observed to be very busy in collect- ing weeds, grasses, &c., to raise her nest; a farming man was ordered to take down half a load of haulm, with which she most industriously raised her nest and the eggs two feet and a half ; that very night there came down a tremendous fall of rain, which flooded all the malt-shops and did great damage. Man made no preparation, the bird did; instinct prevailed over reason. Her eggs were above, and only just above, the water. During the early part of the summer of 1835, a pair of water-hens built their nest by the margin of the ornamental pond at Bell's Hill, a piece of water of considerable extent, and ordinarily fed by a spring from the height above, but into which the contents of another large pond can occasionally be admitted. This was done while the female was sitting; and as the nest had been built when the water level stood low, the sudden influx 298 ANIMAL INTELLIGENCE. of this large body of water from the second pond caused a rise of several inches, so as to threaten the speedy immersion and consequent destruction of the eggs. This the birds seem to have been aware of, and immediately took precautions against so imminent a danger ; for when the gardener, upon whose veracity I can safely rely, seeing the sudden rise of the water, went to look after the nest, expecting to find it covered and the eggs destroyed, or at least forsaken by the hen, he observed, whilst at a distance, both birds busily engaged about the brink where the nest was placed ; and when near enough he clearly perceived that they were adding, with all possible despatch, fresh materials to raise the fabric beyond the level of the increased contents of the pond ; and that the eggs had by some means been removed from the nest by the .birds, and were then de- posited upon the grass about a foot or more from the margin of the water. He watched them for some time, and saw the nest rapidly increase in height ; but I regret to add that he did not remain long enough, fearing he might create alarm, to witness the interesting act of replacing the eggs which must have been effected shortly after ; for, upon his return in less than an hour, he found the hen quietly sitting upon them in the newly raised nest. In a few days afterwards the young were hatched, and, as usual, soon quitted the nest and took to the water with theii' parents. The nest was shown to me in situ shortly aft^r, and I could then plainly discern the formation of the new with the older pai-t of the fabric. We must not conclude these remarks on nidification without alluding to Mr. Wallace's chapters on the ' Philo- sophy of Birds' Nests,' in his work on * Natural Selection.' This writer is inclined to suppose that birds do not build their nests distinctive of their various species by the teach- ings of hereditary instinct, but by the young birds intelli- gently observing the construction of the nests in which they are hatched, and purposely imitating this construc- tion when in the following season they have occasion to build nests of their own. With reference to this theory it is only needful to say that it is antecedently improbable, and not well substantiated by facts. It is antecedently improbable because, when any habit has been continued for a number of generations — especially when the habit is of a peculiar and detailed character — the probability is that it has become instinctive ; we should have almost as BIKDS— NIDIFICATION. 299 much reason to anticipate that the nest of the little crus- tacean Podocerus, or the cell of the hive-bee, is constructed by a process of conscious imitation, as that this is the case with the nests of birds. And this theory is not well sub- stantiated by facts because, if the theory were true, we should expect considerable differences to be usually pre- sented by nests of the same species. Unless the con- struction of the nest of any given species were regulated by a common instinct, numberless idiosyncratic peculi- arities would necessarily require to arise, and there would only be a very general uniformity of type presented by the nests of the same species. A more valuable contribution to the ' Philosophy of Birds' Nests ' is furnished by this able naturalist when he directs attention to a certain general correlation between the form of the nest and the colour of the female. For, on reviewing the birds of the world, he certainly makes good the proposition that, as a general rule, liable however to frequent exceptions, dull-coloured females sit on open nests, while those that are conspicuously coloured sit in domed nests. But Mr. Darwin, in a careful review of all the evidence, clearly shows that this interesting fact is to be attributed, not, as Mr. Wallace supposed, to the colour of the female having been determined through natural selection by the form of the nest, but to the reverse process of the form of the nest having been determined by the colour of the female.^ Another general fact of interest connected with nidifica- tion must not be omitted. This is that the instincts of nidification, although not so variable as the theory of Mr. Wallace would require, are nevertheless highly plastic. The falcon, which usually builds on a cliff, has been known to lay its eggs on the ground in a marsh ; the golden eagle sometimes builds in trees or on the ground ; while the herorn varies its site between trees, cliffs, and open fen.2 Again, Audubon, in his ' Ornithological Bio- graphy,' gives many cases of conspicuous local variations in the nests of the same species in the northern and ' See Descent of Man, p. 452 et seq. • tSi.e Newton, Enoy. Brit., art. ' Birds.' 300 ANIMAL INTELLIGENCE. southern United States ; and, as Mr. Wallace truly ob- serves, — Many facts have already been given which show that birds do adapt their nests to the situations in which they place them ; and the adoption of eaves, chimneys, and boxes by swallows, wrens, and many other birds, shows that they are always ready to take advantage of changed conditions. It is probable, there- fore, that a permanent change of climate would cause many birds to modify the form or materials of their abode, so as better to protect their young. ^ In America the change of habits in this respect under- gone by the house-swallow has been accomplished within the last three hundred years. Closely connected, if not identical, with this fact is another, namely, that in some species which have been watched closely for a sufficient length of time, a steady im- provement in the construction of nests has been observed. Thus C. G. Leroy, who filled the post of Eanger of Ver- sailles about a century ago, and therefore had abundant opportunities of studying the habits of animals, wrote an essay on ' The Intelligence and Perfectibility of Animals from a Philosophical Point of View.' In this essay he has anticipated the American observer Wilson in noticing that the nests of young birds are distinctly inferior to those of older ones, both as regards their situation and construction. As we have here independent testimony of two good observers to a fact which in itself is not im- probable, I think we may conclude that the nest-making instinct admits of being supplemented, at any rate in some birds, by the experience and intelligence of the individual. M. Pouchet has also recorded that he has found a decided improvement to have taken place in the nests of the swallows at Kouen during his own lifetime ; and this accords with the anticipation of Leroy that if our observation extended over a sufficient length of time, and in a manner sufficiently close, we should find that the ac- cumulation of intelligent improvements by individuals of successive generations would begin to tell upon the in- * Natural Selection, pp. 232-3. CUCKOO. 301 herited instinct, so that all the nests in a given locality would attain to a higher grade of excellence. Leroy also says that when swallows are hatched out too late to migrate with the older birds, the instinct of migration is not sufficiently imperative to induce them to undertake the journey by themselves. ' They perish, the victims of their ignorance, and of the tardy birth which made them unable to follow their parents.' Guckoo, Perhaps the strangest of the special instincts mani- fested by birds is that of the cuckoo laying its eggs in the nests of other birds. As the subject is an important one from several points of view, I shall consider it at some length. It must first be observed that the parasitic habit in question is not practised by all species of the genus — the American cuckoo, for instance, being well known to build its nest and rear its young in the ordinary manner. The Australian species, however, manifests the same in- stinct as the European. The first observer of the habit practised by the European cuckoo was the illustrious Jenner, who published his account in the ' Philosophical Transactions.^ From this account the following is an extract : — The cuckoo makes choice of the nests of a great variety of small birds. I have known its eggs entrusted to the care of the hedge-sparrow, water- wagtail, titlark, yellowhammer, green lin- net, and winchat. Among these it generally selects the three former, but shows a much greater partiality to the hedge-sparrow than to any of the rest ; therefore, for the purpose of avoiding confusion, this bird only, in the following account, will be con- sidered as the foster-parent of the cuckoo, except in instances which are particularly specified. When the hedge-sparrow has sat her usual time, and disen- gaged the young cuckoo and some of her own ofi*spring from the shell,2 l^e^ Qyf^ young ones, and any of her eggs that remain unhatched, are soon turned out, the young cuckoo remaining * Phil. Trans., vol. Ixxviii., p. 221 et seq. 2 The young cuckoo is generally hatched first. 302 ANIMAL INTELLIGENCE. possessor of the nest, and sole object of her future care. The young birds are not previously killed, nor are the eggs de- molished, but ajl are left to perish together, either entangled about the bush which contains the nest, or lying on the ground under it. On June 18, 1787, I examined the nest of a hedge-sparrow^ which then contained a cuckoo's and three hedge-sparrow's eggs. On inspecting it the day following, I found the bird had hatched, but that the nest now contained a young cuckoo and only one young hedge-sparrow. The nest was placed so near the extremity of a hedge, that I could distinctly see what was going forward in it; and, to my astonishment, saw the young cuckoo, though so newly hatched, in the act of turning out the young hedge- sparrow. The mode of accomplishing this was very curious. The little animal, with the assistance of its rump and wings, contrived to get the bird upon its back, and making a lodgment for the burden by elevating its elbows, clambered backward with it up the side of the nest till it reached the top, when, resting for a moment, it threw oflf its load with a jerk, and quite disengaged it from the nest. It remained in this situation a short time, feeling about with the extremities of its wings, as if to be con- vinced whether this business was properly executed, and then dropped into the nest again. With these (the extremities of its wings) 1 have often seen it examine, as it were, an egg and ne&t- ling before it began its operations ; and the sensibility which these parts appeared to possess seemed sufficiently to compensate the want of sight, which as yet it was destitute of. I afterwards put in an egg, and this by a similar process was conveyed to the edge of the nest and thrown oilt. These experiments I have since repeated several times in different nests, and have always found the young cuckoo disposed to act in the same manner. In climbing up the nest it sometimes drops its bui'den, and thus is foiled in its endeavours ; but after a little respite the work is resumed, and goes on almost incessantly till it is effected. It is wonderful to see the extraordinary exertions of the young cuckoo, when it is two or three days old, if a bird be put into the nest with it that is too weighty for it to lift out. In this state it seems ever restless and uneasy. But this disposition for turning out its companions begins to decline from the time it is two or three till it is about twelve days old, when, as far as I have hitherto seen, it ceases. Indeed, the disposition for throwing out the egg appears to cease a few days sooner ; for I have frequently seen the young cuckoo, after it had been hatched CUCKOO. 303 nine or ten days, remove a nestling that had been placed in the nest with it, when it suffered an egg, put there at the same time, to remain unmolested. The singularity of its shape is well adapted to these purposes; for, different from other newly hatched birds, its back from the scapulae downwards is very broad, with a considerable depression in the middle. This depression seems formed by nature for the design of giving a more secure lodg- ment to the egg of the hedge-sparrow, or its young one, when the young cuckoo is employed in removing either of them from the nest. When it is about twelve days old this cavity is quite filled up, and then the back assumes the shape of nefetling birds in general. . . . The circumstance of the young cuckoo being destined by nature to throw out the young hedge-sparrows seems to account for the parent cuckoo dropping her egg in the nests of birds so small as those I have particularised. If she were to do this in the nest of a bird which produced a large egg, and consequently a large nestling, the young cuckoo would probably find an insurmountable difficulty in solely pos- sessing the nest, as its exertions would be unequal to the labour of turning out the young birds. (I have known a case in which a hedge-sparrow sat upon a cuckoo's egg and one of her own. Her own egg was hatched five days before the cuckoo's, when the young hedge-sparrow had gained such a superiority in size that the young cuckoo had not powers sufficient to lift it out of the nest till it was two days old, by which time it had grown very considerably. This egg was probably laid by the cuckoo several days after the hedge-sparrow had begun to sit ; and even in this case it appears that its presence had created the disturbance before alluded to, as all the hedge-sparrow's eggs had, gone except one.) . . . June 27, 1787. — Two cuckoos and a hedge-sparrow were hatched in the same nest this morn- ing ; one hedge-sparrow's egg remained unhatched. In a few hours after, a contest began between the cuckoos for the pos- session of the nest, which continued undetermined till the next afternoon ; when one of them, which was somewhat superior in size, turned out the other, together with the young hedge- sparrow and the unhatched egg. This contest was very remark- able. The combatants alternately appeared to have the advan- tage, as each carried the other several times nearly to the top of the nest, and then sunk down again oppressed with the weight of its burden ; till at length, after various efforts, the strongest prevailed, and was afterwards brought up by the hedge-sparrows. To what cause, then, may we attribute the singularities of 304 ANIMAL INTELLIGENCE. the cuckoo 1 May they not be owing to the following circum- stances, — the short residence this bird is allowed to make in the country where it is destined to propagate its species, and the call that nature has upon it, during that short residence, to produce a numerous progeny ? The cuckoo's first appearance here is about the middle of April, commonly on the 17th. Its egg is not ready for incubation till some weeks after its arrival, seldom before the middle of May. A fortnight is taken up by the sitting bird in hatching the egg. The young bird generally continues three weeks in the nest before it flies, and the foster- parents feed it more than five weeks after this period ; so that, if a cuckoo should be ready with an egg much sooner than the time pointed out, not a single nestling, even one of the earliest, would be fit to provide for itself before its parent would be in- stinctively directed to seek a new residence, and be thus com- pelled to abandon its young one ; for old cuckoos take their final leave of this country the first week in July. Had nature allowed the cuckoo to have stayed here as long as some other migrating birds, which produce a single set of young ones (as the swift or nightingale, for example), and had allowed her to have reared as large a number as any bird is capable of bringing up at one time, there might not have been sufficient to have answered her purpose ; but by sending the cuckoo from one nest to another, she is reduced to the same state as the bird whose nest we daily rob of an egg, in which case the stimulus for incubation is suspended. A writer in ' Nature ' (vol. v., p. 383 ; and vol. ix., p. 123), to whom Mr. Darwin refers in the latest edition of ^The Origin of Species ' as an observer that Mr. Gould has found trustworthy, precisely confirms, from observations of his own, the above description of Jenner. So far, therefore, as the observations are common I shall not quote his statements ; but the following additional matter is worth rendering : — But what struck me most was this : the cuckoo was per- fectly naked, without a vestige of a feather or even a hint of future feathers ; its eyes were not yet opened, and its neck seemed too weak to support the weight of its head. The pipits (in whose nest the young cuckoo was parasitic) had well- developed quills on the wings and back, and had bright eyes partially open ; yet they seemed quite helpless under the mani- pulations of the cuckoo, which looked a much less developed CUCKOO. 305 -creature. The cuckoo's legs, however, seemed very muscular, and it appeared to feel about with its wings, which were abso- lutely featherless, as with hands — the 'spurious wing* (unusually large in proportion) looking like a spread-out thumb. The most singular thing of all was the direct purpose with which the blind ilittle monster made for the open side of the nest, the only part where it could throw its burden down the bank. [The latter remark has reference to the position of the nest below a heather bush, on the declivity of a low abrupt bank, where the only chance of dislodging the young birds was to eject them over the side of the nest remote from its support upon the bank.] As the young cuckoo was blind, it must have known the part of the nest to choose by feeling from the inside that that part was ^unsupported. Such being the facts, we have next to ask how they are to be explained on the principles of evolution. At first sight it seems that although the habit saves the bird which practises it much time and trouble, and so is clearly of benefit to the individual, it is not so clear how the in- stinct is of benefit to the species ; for as cuckoos are not social birds, and therefore cannot in any way depend on mutual co-operation, it is difficult to see that this saving of time and trouble to the individual can be of any use to the species. But Jenner seems to have hit the right cause in the concluding part of the above quotation. If it is an advantage that the cuckoo should migrate early, it clearly becomes an advantage, in order to admit of this, that the habit should be formed of leaving her eggs for other birds to incubate. At any rate, we have here a suffi- ciently probable explanation of the raison d'etre of this curious instinct ; and whether it is the true reason or the only risason, we are justified in setting down the instinct to the creating influence of natural selection. Mr. Darwin, in his ' Origin of Species,' has some in- teresting remarks to make on this subject. First, he is informed by Dr. Merrell that the American cuckoo, although as a rule following the ordinary custom of birds in incubating her own eggs, nevertheless occasionally de- posits them in the nests of other birds. Now let us suppose that the ancient progenitor of our Euro- pean cuckoo had the habits of the American cuckoo, and that X 306 ANIMAL INTELLIGENCE. she occasionally laid her egg in another bird's nest. If the old bird profited by this occasional habit through being able ta migrate earlier, or through any other cause; or if the young were made more vigorous by advantage being taken of the mis- taken instinct of another species than when reared by their own mother, encumbered as she could hardly fail to be by having eggs and young at the same time ; ^ then the old birds or the fostered young would gain an advantage. ^ The instinct would seem to be a very old one, for there are two great changes of structure in the European cuckoo which are manifestly correlated with the instinct. Thus,, the shape of the young bird's back has abeady been noted ;. and not less remarkable than this is the small size of the egg from which the young bird is hatched. For the egg of the cuckoo is not any larger than that of the skylark,, although an adult cuckoo is four times the size of an adult skylark. And * that the small size of the egg is a real case of adaptation (in order to deceive the small birds in whose nests it is laid), we may infer from the fact of the non-parasitic American cuckoo laying full-sized eggs.' Yet, although the instinct in question is doubtless of high antiquity, there have been occasional instances observed in cuckoos of reversion to the ancestral instinct of nidifica- tion ; for, according to Adolf Miiller, ' the cuckoo occasion- * Allusion is here made to the fact that the cuckoo lays her eggs at intervals of two or three days, and therefore that if all were incubated by the mother, they would hatch out at different times — a state of things which actually obtains in the case of the American cuckoo, whose nest contains eggs and young at the same time. ^ It is worth while to observe, as bearing on this theory of the origin of this parasitic habit, that even non-parasitic birds occasionally deposit their eggs in nests of other birds. Thus, Professor' A. Newton writes in his admirable essay on ' Birds ' in the Encyclopaedia Britannica, ' Cer- tain it is that some birds, whether by mistake or stupidity, do not un- frequently lay their eggs in the nests of others. It is within the know- ledge of many that pheasants' eggs and partridges' eggs are often laid in the same nest ; and it is within the knowledge of the writer that gulls' eggs have been found in the nests of eider-ducks, and vice versa ; that a redstart and a pied flycatcher will lay their eggs in the same con- venient hole — the forest being rather deficient in such accommodation : that an owl and a duck will resort to the same nest-hole, set up by the scheming woodman for his own advantage ; and that the starling, which constantly dispossesses the green woodpecker, sometimes discovers that the rightful heir of the domicile has to be brought up by the intruding tenant.' CUCKOO. 307 ally lays her eggs on the bare ground, sits on them, and feeds her young.' In * Nature ' for November 18, 1869, Professor A. Newton, P\R.S., has published an article on a somewhat obscure point connected with the instincts of the cuckoo. He says that Dr. Baldamus has satisfied him, by an exhibi- tion of sixteen specimens of cuckoos' eggs found in the nests of dififerent species of birds, ' that the egg of the cuckoo is approximately coloured and marked like those of the bird in whose nest it is found,' for the purpose, no doubt, of deceiving the foster-parents. Professor Newton adds, however : — Having said this much, and believing as I do the Doctor to be partly justified in the carefully worded enunciation of what he calls a ' law of nature,' I must now declare that it is only * approximately,' and by no means universally true that the cuckoo's egg is coloured like those of the victims of her imposi- tion, &c. Still, when so great an authority as Professor Newtou expresses himself satisfied that there is a marked tendency to such imitation, which in some cases leads to extra- ordinary variations in the colouring of the cuckoo's eggy the alleged fact becomes one which demands notice. The question, of course, immediately arises, How is it conceiv- able that the fact, if it is a fact, can be explained ? We cannot imagine the cuckoo to be able consciously to colour her egg during its formation in order to imitate the eggs among which she is about to lay it ; nor can we suppose that having laid an egg and observed its colouring, she then carries it to the nest of the bird whose eggs it most resembles. Professor Newton suggests another theory, which he seems to think sufficient, but which I confess seems to me little more satisfactory than the impossible theories just stated. He says : — Only one explanation of the process can, to my mind, be offei'ed. Every person who has studied the habits of birds with sufficient attention will be convei^ant with the tendency which certain of those habits have to become hereditary. It is, I am sure, no violent hypothesis to suppose that there is a very reasonable probability of each cuckoo most commonly placing X 2 308 ANIMAL INTELLIGENCE. her eggs in the nest of the same bird, and of this habit being transmitted to her posterity. Now it will be seen that it requires but only an application to this case of the principle of ' natural selection/ or ' survival of the fittest,' to show that if my argument be sound, nothing can be more likely than that, in the course of time, that prin- ciple should operate so as to produce the facts asserted, the eggs which best imitated those of particular foster-parents having the best chance of duping the latter, and so of being hatched out. Now, granting to this hypothesis the assumption that individual cuckoos have special predilections as to the species in whose nests they are to lay their eggs, and that some of these species require to be deceived by imitative colouring of the egg to prevent their tilting it out, there is still an enormous difficulty to be met. Supposing that one cuckoo out of a hundred happens to lay eggs suffi- ciently like those of the North African magpies (a species alluded to by Professor Newton) to deceive the latter into supposing the egg to be one of their own. This I cannot think is too small a proportion to assume, seeing that, ex hypothesi, the resemblance must be tolerably close, and that the egg of the magpie does not resemble the great majority of eggs of the cuckoo. Now, in order to sustain the theory, we must suppose that the particular cuckoo which happens to have the peculiarity of laying eggs so closely resembling those of the magpie, must also happen to have the peculiarity of desiring to lay its eggs in the nest of a magpie. The conjunction of these two pecu- liarities would, I should think, at a moderate estimate reduce the chances of an approximately coloured egg being laid in the appropriate nest to at least one thousand to one. But supposing the happy accident to have taken place, we have next to suppose that the peculiarity of laying these exceptionably coloured eggs is not only con- stant for the same individual cuckoo, but is inherited by innumerable generations of her progeny; and, what is much more difficult to grant, that the fancy for laying eggs in the nest of a magpie is similarly inherited. I think, therefore, notwithstanding Professor Newton's strong opinion upon the subject, that the ingenious hypothesis I CUCKOO. 309 must be dismissed as too seriously encumbered by the difficulties which I have mentioned. We may with philo- sophical safety invoke the influence of natural selection to explain all cases of protective colouring when the modus operandi need only be supposed simple and direct ; but in a case such as this the number and complexity of the conditions that would require to meet in order to give natural selection the possibility of entrance, seem to me much too considerable to admit of our entertaining the possibility of its action — at all events in the way that Professor Newton suggests. Therefore, if the facts are facts, I cannot see how they are to be explained. Cuckoos are not the only birds which manifest the parasitic habit of laying their eggs in other birds' nests. Some species of Melothrus, a widely distinct genus of American birds, alHed to our starlings, have parasitic habits like those of the cuckoo ; and the species present an interesting gradation in the perfection of their instincts. The sexes of Melothrus cadius are stated by an excellent observer, Mr. Hudson, sometimes to live promiscuously together in flocks and sometimes to pair. They either build a nest of theii* own, or seize on one belonging to some other bird, occasionally throwing out the nestlings of the stranger. They either lay their eggs in the nest thus appropriated, or oddly enough build one for them- selves on the top of it. They usually sit on theii* own eggs and rear their own young ; but Mr. Hudson says it is probable that they are occasionally parasitic, for he has seen the young of this species feeding old birds of a distinct kind and clamouring to be fed by them. The parasitic habits of another species of Melothrus f the M, Canariensis, are much more highly developed than those of the last, but are still far from perfect. This bird, as far as it is known, invariably lays its eggs in the nests of strangers, but it is remarkable that several together sometimes commence to build an irregular untidy nest of their own, placed in singularly ill-adapted situations, as on the leaves of a large thistle. They must, however, as far as Mr. Hudson has ascer- tained, complete a nest for themselves. They often lay so many eggs, from fifteen to twenty, in the same foster-nest, that few or none can possibly be hatched. They have, moreover, the exti-a- ordinary habit of pecking holes in the eggs, whether of their own species or of their foster-parents, which they find in the appropriated nests. They drop also many eggs on the bare 310 ANIMAL INTELLIGENCE. ground, which are thus wasted. A third species, the M. precius of North America, has acquired instincts as perfect as those of the cuckoo, for it never lays more than an egg in a foster-nest, so that the young bird is securely reared. Mr. Hudson is a strong disbeliever in evolution, but he appears to have been so much struck by the imperfect instincts of the Melothrus Ganari- erisis that he quotes my words, and asks, ' Must we consider these habits not as especially endowed or created instincts, but as small consequences of one general law, namely transition ? ' ^ Such are all the facts and considerations which I have to present with reference to the curious instinct in ques- tion. It will be seen that — with one doubtful or not suffi- ciently investigated exception, viz., that of cuckoos adapt- ing the colour of their eggs to that of the eggs of the foster-parents — there is nothing connected with these instincts that presents any difficulty to the theory of evo- lution. We may, perhaps, at first sight wonder why some counteracting instinct should not have been developed by the same agency in the birds which are liable to be thus duped ; but here we must remember that the deposition of a parasitic egg is, comparatively speaking, an exceed- ingly rare event, and therefore not one that is likely to lead to the development of a special instinct to meet it. General Intelligence, Under this heading I shall here, as in the case of this heading elsewhere, string together all the instances which I have met with, and which I deem trustworthy, of the display of unusually high intelligence in the class, family, order, or species of animals under consideration — the ob- ject of this heading in all cases being that of supplying, by the facts mentioned beneath it, a general idea of the upper limit of intelligence which is distinctive of each group of animals. That birds recognise their own images in mirrors as birds there can be no question. Houzeau, who records observations of his own in this connection with parrots,^ adds that dogs are more difficult to deceive by mirrors in > Origin of Species, p. 215. 2 Tom. i., p. 130. BIKDS — GENEKAL INTELLIGENCE. 311 this way than birds, on account of their depending so much upon smell for their information. No doubt indi- vidual differences are to be met with in animals of both classes, and much depends on previous experience. Young dogs, or dogs which have never seen a mirror before, are not, as a rule, difficult to deceive, even though they have good noses. I myself had a setter with an excellent nose, who on many repeated occasions tried to fight his own image, till he found by experience that it was of no use. As to birds, I have seen canaries suppose their own images to be other canary birds, and also the reflection of a room to be another room — the birds flying against a large mirror and falling half stunned. I mention the latter circumstance because it afforded evidence of the superior intelligence of a linnet, which on the same occasion dashed itself against the mirror once, but never a second time, while the canaries did so repeatedly. Mrs. Frankland, in ' Nature '(xxi., p. 82), gives the fol- lowing account of a bullfinch paying more attention to a portrait of a bullfinch than to his own image in a mirror, which is certainly remarkable ; and as the fact seems to have been observed repeatedly, it can scarcely be discredited : The following is a curious instance of discrimination which I have observed in my bullfinch. He is in the habit of coming out of his cage in my room in the morning. In this room there is a mirror with a marble slab before it, and also a very cleverly executed water-colour drawing of a hen bullfinch, life size. The fii'st thing that my bullfinch does on leaving his cage is to fly to the picture (perching on a vase just below it) and pipe his tune in the most insinuating manner, accompanied with much bow- ing to the portrait of the hen bullfinch. After having duly paid his addresses to it, he generally spends some time on the marble slab in front of the looking-glass, but without showing the slightest emotion at the sight of his own reflection, or courting it with a song. Whether this perfect coolness is due to the fact of the reflection being that of a cock bird, or whether (since he shows no desire to fight the reflected image) he is per- fectly well aware that he only sees himself, it is difficult to say. That birds possess considerable powers of imagination, or forming mental pictures of absent objects, may be in- 312 ANIMAL INTELLIGENCE. ferred from the fact of their pining for absent mates, parrots calling for absent friends, &c. The same fact is further proved by birds dreaming, a faculty which has been noticed by Cuvier, Jerdon, Thompson, Bennet, Houzeau, Bechstein, Lindsay, and Darwin.' The facility with which birds lend themselves to the education of the show-man is certain evidence of consider- able docility, or the power of forming novel associations of ideas. Thus, according to Bingley, — Some years ago the Sieur E-oman exhibited in this country the wonderful performances of his birds. These were gold- finches, linnets, and canary birds. One appeared dead, and was held up by the tail or claw without exhibiting any signs of life. A second stood on its head, with its claws in the air, &c., &c.^ And many years ago there was exhibited a very puzzling automaton, which, although of very small size and quite isolated from any possibly mechanical connection with its designer, performed certain movements in any order that the fancy of the observers might dictate. The explana- tion turned out to be that within the mechanism of the figure there was a canary bird which had been taught to run in different directions at different words or tones of command, so by its weight starting the mechanism to perform the particular movement required. The rapidity with which birds learn not to fly against newly erected telegraph wires, displays a large amount of observation and intelligence. The fact has been repeatedly observed. For instance, Mr. Holden says : — About twelve years ago I was residing on the coast of county Antrim, at the time the telegraph wires were set up along that charming road wbich skirts the sea between Larne and Cushendall. During the winter months large flocks of starlings always migrated over from Scotland, arriving in the early morn- ing. The first winter after the wires were stretched along the coast I frequently found numbers of starlings lying dead or wounded on the road-side, they having evidently in their flight in the dusky morn struck against the telegraph wires, not ^ See Birds of India, i., p. 21 ; Passions of Animals, p. 60 ; Mbo. Men. des Ani., torn, ii., p. 183 ; Mind in Lower AnimalSy vol. ii., p. 96 ; and Descent of Man, p. 74. 2 Animal Biography, vol. ii., p. 173 BIRDS — GENERAL INTELLIGENCE. 313- blown against them, as these accidents often occurred when there was but little wind. I found that the peasantry had come to the conclusion that these unusual deaths were due to the flash of the telegraph messages killing any starlings that happened to be perched on the wires when working. Strange to say that throughout the following and succeeding winters hardly a death occurred among the starlings on their arrival. It would thus appear that the birds were deeply impressed, and understood the cause of the fatal accidents among their fellow-travellers the previous year, and hence carefully avoided the telegraph wires ; not only so, but the young birds must also have acquired this knowledge and perpetuated it, a knowledge which they could not have acquired by experience or even instinct, unless the instinct was really inherited memory derived from the parents whose brains were first impressed by it.^ Similar facts are given in Buckland's ' Curiosities of Natural History,' ^ and I have myself known of a case in Scotland where a telegraph was erected across a piece of moorland. During the first season some of the grouse were injured by flying against the wires, but never in any succeeding season. Why the young birds should avoid them without having had individual experience may, I think, be explained by the consideration that in birds which fly in flocks or coveys, it is the older ones that lead the way. This explanation would not, of course, apply to birds which fly singly ; but I am not aware that any ob- servations have gone to show that the young of such birds avoid the wires. I quote the following exhibition of intelligence in an eagle from Menault : — The following account of the patience with which a golden eagle submitted to surgical treatment, and the care which it showed in the gradual use of the healing limb, must suggest the idea that something very near to prudence and reason existed in the bird. This eagle was caught in a fox-trap set in the forest of Fontainebleau, and its claw had been terribly torn. An operation was performed on the limb by the conservators of the Zoological Gardens at Paris, which the noble bird bore with a rational patience. Though his head was left loose, he made no attempts to interfere with the agonising extraction of the » Nature, xx.,p. 266. ^ Vol. i., p. 216. See also Descent of Man, p. 80. .314 ANIMAL INTELLiaENCE. splinters, or to disturb the arrangements of the annoying band- age«!. He seemed really to understand the nature of the services rendered, and that they were for his good.^ Speaking of the Urubu vultures, Mr. Bates says : — They assemble in great numbers in the villages about the end of the wet season, and are then ravenous with hunger. My cook could not leave the open kitchen at the back of the house for a moment whilst the dinner was cooking, on account of their thievish propensities. Some of them were always loitering about, watching their opportunity, and the instant the kitchen was left unguarded, the bold marauders marched in and lifted the lids of the saucepans with their beaks to rob them of their contents. The boys of the village lie in wait, and shoot them with bow and arrow ; and vultures have consequently acquired such a dread of these weapons, that they may be often kept off by hanging a bow from the rafters of the kitchen. ^ Mrs. Lee, in her 'Anecdotes,' says that one day her gardener was struck by the strange conduct of a robin, which the man had often fed. The bird fluttered about him in so strange a manner — now coming close, then hurrying away, always in the same direction — that the gardener followed its retreating move- ments. The robin stopped near a flower-pot, and fluttered over it in great agitation. It was soon found that a nest had been formed in the pot, and contained several young. Close by was a snake, intent, doubtless, upon making a meal of the brood. The following appeared in the * Gardeners Chronicle ' for Aug. 3, 1878, under the initials ' T. Gr.' I wrote to the editor requesting him to supply me with the name of his correspondent, and also to state whether he knew him to be a trustworthy man. In reply the editor said that he knew his correspondent to be trustworthy, and that his name is Thomas Gruring : — About thirty years ago the small market town in which I reside was skirted by an open common, upon which a number of geese were kept by cottagers. The number of the birds was very great. . . . Our corn market at that time was held in the street in front of the principal inn, and on the market day a good deal of coi-n was scattered from sample bags by millers. Somehow the geese found out about the spilling of corn, and they appear to have held a consultation upon the subject. . . . • Menault, Wonders of Instinct, -p. 132. 2 Nat. on Amazons, p. 177; Anecdotes, p. 135. BIRDS- -GENERAL INTELLiaENUE. 315 From this time they never missed their opportunity, and the •entry of the geese was always looked for and invariably took place. On the morning after the market, early, and always on the proper morning, fortnightly, in they came cackling and gobbling in merry mood, and they never came on the wrong day. The corn, of course, was the attraction, but in what manner did they mark the time 1 One might have supposed that their perceptions were awakened on the market day by the smell of corn, or perhaps by the noise of the market traffic; but my story is not yet finished, and its sequel is against this view. It happened one year that a day of national humiliation was kept, and the day appointed was that on which our market should have been held. The market was postponed, and the geese for once were baffled. There was no corn to tickle their olfactory organs from afar, no traffic to appeal to their sense of hearing. I think our little town was as still as it usually is on Sundays. . . . The geese should have stopped away ; but they knew their day, and came as usual. ... I do not pretend to remember under what precise circumstances the habit of coming into the street was acquired. It may have been formed by degrees, and continued from year to year; but how the old birds, who must have led the way, marked the time so as to come in regularly and fortnightly, on a particular day of the week, I am at a loss to conceive. Livingstone's 'Expedition to the Zambesi, 1865,' p. 209, gives a conclusive account of the bird called the honey-guide, which leads persons to bees' nests. ' They are quite as anxious to lure the stranger to the bees' hive as other birds are to draw him away from their own nests.' The object of the bird is to obtain the pupae of the bees which are laid bare by the ravaging of the nest. The habits of this bird have long been known and described in books on popular natural history ; but it is well that the facts have been observed by so trustworthy a man as Livingstone. He adds, ' How is it that members of this family have learned that all men, white and black, are fond of honey ? ' We can only answer, by intelligent observa- tion in the first instance, passing into individual and hereditary habit, and so eventually into a fixed instinct. Brehm relates an instance of cautious sagacity in a pewit. He had placed some horsehair snares over its nest, but the bird seeing them, pushed them aside with 316 ANIMAL INTELLIGENCE. her bill. Next day he set them thickly round the nest ; but now the bird, instead of running as usual to the nest along the ground, alighted directly upon it. This shows a considerable appreciation of mechanical appliances, as does also the following. Mrs. Gr. M. E. Campbell writes to me : — At Ardglass, co. Down, Ireland, is a long tract of turf coming to the edge of the rocks overhanging the sea, where cattle and geese feed ; at a barn on this tract there was a low enclosure, with a door fastening by a hook and staple to the side- post : when the hook was out of the staple, the door fell open by its own weight. 1 one day saw a goose with a large troop of goslings coming off the turf to this door, which was secured by the hook being in the staple. The goose waited for a minute or two, as if for the door to be opened, and then turned round as if to go away, but what she did was to make a rush at the door, and making a dart with her beak at the point of the hook nearly threw it out of the staple ; she repeated this manoeuvre, and succeeded at the third attempt, the door fell open, and the goose led her troop in with a sound of triumphant chuckling. How had the goose learned that the force of the rush was need- ful to give the hook a sufficient toss 1 Mrs. K. Addison sends me the following instance of the use of signs on the part of an intelligent jackdaw. The bird was eighteen months old, and lived in some bushes in Mrs. Addison's garden. She writes : — I generally made a practice of filling a large basin which stands under the trees every morning for Jack's bath. A few days ago I forgot this duty, and was reminded of the fact in a very singular manner. Another of my daily occupations is to open my dressing-room shutters about eleven o'clock of a morning. Now these said shunters open almost on to the trees where Jack lives. The day I forgot his bath, when I opened the shutters I found my Httle friend waiting just outside them, as though he knew that he should see me there ; and when he did he placed himself immediately in front of me, and then shook himself and spread out his wings just as he always does in his bath. The action was so suggestive and so unmistakable, that I spoke just as I would have done to a child — ' Oh yes, Jack, of course you shall have some water.' Mr. W. W. Nichols writes to * Nature : ' — BIRDS— GENERAL INTELLIGENCE. 317 The Central Prison at Agra is the roosting-place of great numbers of the common blue pigeon ; they fly out to the neigh- bouring country for food every morning, and return in the evening, when they drink at a tank just outside the prison walls. In this tank are a large number of fresh-water turtles, which lie in wait for the pigeons just under the surface of the water and at the edge of it. Any bird alighting to drink near one of these turtles has a good chance of having its head bitten off and eaten ; and the headless bodies of pigeons have been picked up near the water, showing the fate which has sometimes befallen the birds. The pigeons, however, are aware of the danger, and have hit on the following plan to escape it. A pigeon comes in from its long flight, and, as it nears the tank, instead of flying down at once to the water's edge, will cross the tank at about twenty feet above its surface, and then fly back to the side from which it came, apparently selecting for alighting a safe spot which it had remarked as it flew over the bank ; but even when such a spot has been selected the bird will not alight at the edge of the water, but on the bank about a };ard from the water, and will then run down quickly to the water, take two or three hurried gulps of it, and then fly off to repeat the same process at another part of the tank till its thirst is satisfied. I had often watched the birds doing this, and could not account for their strange mode of drinking till told by my friend the super- intendent of the prison, of the turtles which lay in ambush for the pigeons. As a still more remarkable instance of the display of intelligence by a bird of this species, I shall quote the following observation of Commander E. H. Napier, also published in ' Nature ' (viii., p. 324) : — A number of them (pouters) were feeding on a few oats that had been accidentally let fall while fixing the nose-bag on a horse standing at bait. Having finished all the grain at hand, a large ' pouter ' rose, and flapping its wings furiously, flew directly at the horse's eyes, causing the animal to toss his head, and in doing so, of course shake out more corn. I saw this several times repeated — in fact, whenever the supply on hand had been exhausted. . . . Was not this something more than instinct '? The following display of intelligence on the part of swallows is communicated to me by Mr. Charles Wilson. 318 ANIMAL INTELLIGENCE, It can scarcely be attributed to accident, and does not admit of mal-observation. My informant says : — Two swallows^ were building a nest in the verandah of a house in Yictoria, but as their nest was resting partly on a bell- wire, it was by this means twice pulled down. They then began afresh, making a tunnel through the lower part of the nest, through which the wii-e was able to act without doing damage. Another gentleman writes me of another use to which he has observed swallows put the artifice of building tunnels. Being molested by sparrows which desired to take forcible possession of their nest, a pair of swallows modified the entrance of the latter, so that instead of opening by a simple hole under the eaves of a house, it was carried on in the form of a tunnel. Linnaeus says that the martin, when it builds under the eaves of houses, sometimes is molested by sparrows taking possession of the nest. The pair of martins to which the nest belongs are not strong enough to dislodge the in- vaders ; but they convoke their companions, some of whom guard the captives, whilst others bring clay, close up the entrance of the nest, and leave the sparrows to die miser- ably. This account has been to a large extent indepen- dently confirmed by Jesse, who seems not to have been acquainted with the statement of Linnaeus. He writes : — Swallows seem to entertain the recollection of injury, and to resent it when an opportunity offers. A pair of swallows built their nest under the ledge of a house at Hampton Court. It was no sooner completed than a couple of sparrows drove them from it, notwithstanding the swallows kept up a good re- sistance, and even brought others to assist them. The intruders were left in peaceable possession of the nest, till the two old birds were obliged to quit it to provide food for their young. They had no sooner departed than several swallows came and broke down the nest ; and I saw the young sparrows lying dead on the ground. As soon as the nest was demolished, the swallows began to rebuild it.^ The same author gives the following and somewhat similar case : — ' Gleanings^ vol. ii., p. 96. BIRDS — GENERAL INTELLIGENCE. SlO* A pair of swallows built their nest against one of the first- floor windows of an uninhabited house in Merrion Square, Dublin. A sparrow, however, took possession of it, and the swallows were repeatedly seen clinging to the nest, and en- deavouring to gain an entrance to the abode they had erected with so much labour. All their ejBTorts, however, were defeated by the sparrow, who never once quitted the nest. The perse- verance of the swallows was at length exhausted : they took flight, but shortly afterwards returned, accompanied by a number of their congeners, each of them having a piece of dirt in its bill. By this means they succeeded in stopping up the hole, and the intruder was immured in total darkness. Soon afterwards the nest was taken down and exhibited to several persons, with the dead sparrow in it. In this case there ap- peal's to have been not only a reasoning faculty, but the birds must have been possessed of the power of communicating their resentment and their wishes to their friends, without whose aid they could not thus have avenged the injury they had sus- tained.^ That birds sometimes act in conceit may also be gathered from the following observations recorded by Mr. Buck :— I have constantly seen a flock of pelicans, when on the feed, form a line across a lake, and drive the fish before them up its whole length, just as fishermen would with a net.^ The following is extracted from Sir E. Tennent's ' Natural History of Ceylon,' and displays remarkable in- telligence on the part of the crows in that island : — One of these ingenious marauders, after vainly attitudi- nising in front of a chained watch-dog, that was lazily gnawing a bone, and after fruitlessly endeavouring to divert his attention by dancing before him, with head awry and eye askance, at length flew away for a moment, and returned bringing a com- panion which perched itself on a branch a few yards in the rear. The crow's grimaces were now actively renewed, but with no better success, till its confederate, poising itself on its wings, descended with the utmost velocity, striking the dog upon the spine with all the force of its strong beak. The ruse was successful; the dog started with surprise and pain, but not quickly enough to seize his assailant, whilst the bone he had been gnawing was snatched away by the first crow the » Ibid., p. 99. "" Nature, vol. xiii., p. 303. 320 ANIMAL INTELLiaENCE. instant his head was turned. Two well-authenticated instances of the recurrence of this device came within my knowledge at Colombo, and attest the sagacity and powers of communication and combination possessed by these astute and courageous birds. This account, which would be difficult of credence if narrated by a less competent author, is strikingly confirmed by an independent observation on the crows of Japan, which has recently been published by Miss Bird, in whose words I shall render it. She writes : — In the inn garden I saw a dog eating a piece of carrion in the presence of several of these covetous bii'ds. They evidently said a great deal to each other on the subject, and now and then one or two of them tried to pull the meat away from him, which he resented. At last a big strong crow succeeded in tearing off a piece, with which he returned to the pine where the others were congregated, and after much earnest speech they all surrounded the dog, and the leading bird dexterously dropped the small piece of meat within reach of his mouth, when he immediately snapped at it, letting go the big piece unwisely for a second, on which two of the crows flew away with it to the pine, and with much fluttering and hilarity they all ate, or rather gorged it, the deceived dog looking vacant and bewildered for a moment, after which he sat under the tree and barked at them inanely. A gentleman told me that he saw a dog holding a piece of meat in like manner in the presence of three crows, which also vainly tried to tear it from him, and after a consultation they separated, two going as near as they dared to the meat, while the third gave the tail a bite sharp enough to make the dog turn round with a squeak, on which the other villains seized the meat, and the three fed triumphantly upon it on the top of a wall.^ These two independent statements by competent ob- servers of such similar exhibitions of intelligence by crows, justifies us in accepting the fact, remarkaole though it be. As further corroboration, however, I shall quote still another independent and closely similar observation, which I find in a letter to me from Sir J. Clarke Jervoise, who says, while writing of rooks which he has observed in England : — * Unbeaten Tracks in Japan, vol. ii., pp. 149-50, BIRDS — GENERAL INTELLIGENCE. 321 A pheasant used to come very boldly and run off with large pieces of food, which he could only divide by shaking, and he was closely watched by the rooks for the pieces that flew out of his reach. He learned to run off into the shrubs, followed by the rooks, who pulled his tail to make him drop his food. I shall next quote a highly interesting observation -which seems to have been well made, and which displays remarkable intelligence on the part of the birds described. These are Turnstones, which, as their name implies, turn over stones, &c., in order to obtain as food the sundry small creatures concealed beneath. In this case the ob- server was Edward. Being concealed in a hollow, and unnoticed by the birds, he saw a pair trying to turn over the body of a stranded cod-fish, three and a half feet long, and buried in the sand to a depth of several inches. He thus describes what he saw : — Having got fairly settled down in my pebbly observatory, I turned my undivided attention to the birds before me. They were boldly pushing at the fish with their bills, and then with their breasts. Their endeavours, however, were in vain : the object remained immovable. On this they both went round to the opposite side, and began to scrape away the sand from iDeneath the fish. After removing a considerable quantity, they again came back to the spot which they had left, and went once more to work with their hills and breasts, but with as little apparent success as formerly. Nothing daunted, however, they ran round a second time to the other side, and recommenced their trenching operations with a seeming determination not to he baffled in their object, which evidently was to undermine the dead animal before them, in order that it might be the more easily overturned. While they were thus employed, and after they had laboured in this manner at both sides alternately for nearly half an hour, they were joined by another of their own species, which came flying with rapidity from the neighbouring rocks. Its timely arrival was hailed with evident signs of joy, I was led to this conclusion from the gestures which they exhibited, and from a low but pleasant murmuring noise to which they gave utterance so soon as the new-comer made his appearance. Of their feelings he seemed to be perfectly aware, and he made his reply bo them in a similar strain. Their mutual congratulations being over, they all three set to work; and after labouring Y 322 ANIMAL INTELLIGENCE. vigorously for a few minutes in removing the sand, they came round to the other side, and putting their breasts simultaneously to the fish, they succeeded in raising it some inches from the sand, but were unable to turn it over. It went down again into its sandy bed, to the manifest disappointment of the three^ Resting, however, for a space, and without leaving their respective positions, which were a little apart the one from the other, they resolved, it appears, to give the work another trial. Lowering themselves, with their breasts pressed close to the sand, they managed to push their bills underneath the fish, which they made to rise about the same height as before. Afterwards, withdrawing their bills, but without losing tho advantage which they had gained, they applied their breasts ta the object. This they did with such force, and to such purpose, that at length it went over, and rolled several yards down a slight declivity. It was followed to some distance by the birds themselves before they could recover their bearing.^ I shall now bring this chapter to a close by presenting all the evidence that I have been able to collect with, regard to the punishment of malefactors among rooks. Groldsmith, who used constantly to observe a rookery from his window, says that the selection of a site for the building of a nest is a matter of much anxious delibera- tion on the part of a young crow couple ; the male and female ' examining all the trees of a grove very atten- tively, and when they have fixed upon a branch that seems fit for their purpose, they continue to sit upon it, and observe it very sedulously for two or three days longer : ' — It often happens that the young couple have made choice of a place too near the mansion of an older pair, who do not choose to be incommoded by such troublesome neighbours ; a quarrel, therefore, instantly ensues, in which the old ones are always victorious. The young couple, thus expelled, are obliged again to go through their fatigues— dehberating, examining, and choosing ; and, having taken care to keep their due distance, the nest begins again, and their industry deserves commen- dation. But their activity is often too great in the beginning ; they soon grow weary of bringing the materials of their nests from distant places, and they very early perceive that sticks may be provided nearer home, with less honesty indeed, but some degree of address. Away they go, therefore, to pilfer as. fast as they can, and, whenever they see a nest unguarded, they 1 Smiles, Life of Edward, pp. 244-6. BIKDS — GENERAL INTELLIGENCE. 323 take care to rob it of the very choicest sticks of which it is composed. But these thefts never go unpunished, and probably, upon complaint being made, there is a general punishment inflicted. I have seen eight or ten rooks come upon such occasions, and, setting upon the new nest of the young couple, all at once tear it to pieces in a moment. At length, however, the young pair find the necessity of going more regularly to work. While one flies to fetch the materials, the other sits upon the tree to guard it ; and thus in the space of three or four days, with a skirmish now and then between, the pair have filled up a commodious nest, composed of sticks without, and of fibrous roots and long grass within. From the instant the female begins to lay, all hostilities are at an end ; not one of the whole grove, that a little before treated her so rudely, will now venture to molest her, so that she brings forth her brood with perfect tranquillity. Such is the severity with which even native rooks are treated by each other ; but if a foreign rook should attempt to make himself a denizen of their society, he would meet with no favour, the whole grove would at once be up in arms against him, and expel him with- out mercy. Couch says {' Illustrations of Instinct,' p. 334 et seq,) : — The wrong- doers being discovered, the punishment is ap- propriate to the oflfence ; by the destruction of their dishonest work they are taught that they who build must find their own bricks or sticks, and not their neighbours', and that if they wish to live in the enjoyment of the advantages of the social con- dition, they must endeavour to conform their actions to the principles of the rookery of which they have been made members. It is not known what enormities led to the institution of another tribunal of the same kind, called the Crow Court, but ac- cording to Dr. Edmonson, in his ' Yiew of the Shetland Islands,' its proceedings are as authoritative and regular, audit is remark- able as occurring in a species (Corvus Cornice) so near akin to the rook. The Crow Court is a sort of general assembling of birds who, in their usual habits, are accustomed to live in pairs, scattered at great distances from each other ; when they visit the south or west of England, as they do in severe winters, they are commonly solitary. In their summer haunts in the Shetland Islands, numbers meet together from different points on a particular hill or field ; and on these occasions the assem- bly is not complete, and does not begin its business for a day or two, till, all the deputies having arrived, a general clamour Y 2 324 ANIMAL INTELLIGENCE. or croaking ensues, and the whole of the court, judges, barristers, ushers, audience, and all, fall upon the two or three prisoners at the bar, and beat them till they kill them. When this is accomplished the court breaks up and quietly disperses. In the northern parts of Scotland (says Dr. Edmonson), and in the Faroe Islands, extraordinary meetings of crows are occasionally known to occur. They collect in great numbers, as if they had all been summoned for the occasion ; a few of the flock sit with drooping heads, and others seem as grave as judges, while others again are exceedingly active and noisy ; in the course of about one hour they disperse, and it is not un- common, after they have flown away, to find one or two left dead on the spot. These meetings will sometimes continue for a day or two before the object, whatever it may be, is completed. Crows continue to arrive from all quarters during the session. As soon as they have all arrived, a very general noise ensues ; and, shortly after, the whole fall upon one or two individuals, and put them to death. When the execution has been per- formed, they quietly disperse. Similarly, the Bishop of Carlisle writes in the ' Nine- teenth Century' for July 1881 : — I have seen also a jackdaw in the midst of a congregation of rooks, apparently being tried for some misdemeanour. First Jack made a speech, which was answered by a general cawing of the rooks ; this subsiding. Jack again took up his parable, and the rooks in their turn replied in chorus. After a time the business, whatever it was, appeared to be settled satisfac- torily : if Jack was on his trial, as he seemed to be, he was honourably acquitted by acclamation ; for he went to his home in the towers of Ely Cathedral, and the rooks also went their way. Lastly, Major-G-eneral Sir Greorge Le Grrand Jacob, K.C.S.I., C.B., writes to me that while sitting in a ve- randah in India, he saw three or four crows come and perch on a neighbouring house. They then cawed continuously with such peculiar sound and vigour as to attract his at- tention. His account proceeds : — Soon a gathering of crows from all quarters took place, until the roof of the guard-house was blackened by them. Thereupon a prodigious clatter ensued ; it was plain that a ' palaver ' was going forward. Some of its members, more eager than others, skipping about, I became much interested, and narrowly watched the proceedings, all withia a dozen yards of me. After much cawing and clamour, the whole group suddenly rose into the air. BIRDS — GENERAL INTELLIGENCE. 325 and kept circling round half a dozen of their fellows, one of whom had been clearly told off for punishment, for the five repeat- edly attacked it in quick succession, allowing no opportunity for their victim to escape, which he was trying to do, until they had cast him fluttering on the ground about thirty yards from my chair. Unfortunately I rushed forward to pick up the bird, prostrate but fluttering on the grass which was like a lawn before the building. I succeeded only in touching it, for it "wriggled away from my grasp, and flew greatly crippled and close to the ground into the neighbouring bushes, where I lost sight of it. All the others, after circling round me and chattering, angrily as I thought, flew away, on my resuming my seat, in the direction taken by their victim. [Since going to press I have seen, through the kindness of Mr. Seebohm, some specimens of cuckoo's eggs coloured in imitation of those belonging to the birds in the nests of which they are laid. There can be no question about the imitation, and I add this note to mitigate the criticism which I have passed upon Professor Newton's theory of the cause. For Mr. Seebohm has pointed out to me that the theory becomes more probable if we consider that a cuckoo reared in the nest of any particular bird is likely afterwaids to choose a similar nest for the deposition of its own eggs. Whether or not the memory of a bird would thus act could only, of course, be certainly proved by experiment ; but in view of the possibility that it may, Professor Newton's theory becomes more probable than it is if the selection of the appropriate nest is supposed to depend only on inheritance. I must also add that Dr. Sclater has been kind enough to draw my attention to a remarkable description of a species of Bower-bird, published by Dr. Beccari in the Oardener's Chronicle for March 16, 1879. This species is called the Gardener Bower-bird {Amhlyornis niornata), and inhabits New Guinea. The animal is about the size of a turtle-dove, and its bower — or rather hut — is built round the stem of a tree in the shape of a cone, with a space between the stem of the tree and the walls of the hut. The latter are composed of stems of an orchid with their leaves on — ^this particular plant being chosen by the birds apparently because its leaves remain long fresh. But the most extra- ordinary structure is the garden, which is thus described by Dr. Beccari : — ' Before the cottage there is a meadow of moss. This is brought to the spot and left free from grass, stones, or anything which would offend the eye. On this green turf flowers and fruits of prett}- colour are placed, so as to form an elegant little garden. The greater part of the decoration is collected round the entrance to the nest, and it would appear that the husband offers these his daily gifts to his wife. The objects are very various, but always of a vivid colour. There were some fruits of a Garcinia like a small-sized apple. Others were the fruits of Gardencias of a deep yellow colour in the interior. I saw als*. small rosy fruits, probably of a Scitamineous plant, and beautiful rosy flowers of a new Vaccinium. There were also fungi and mottled insects placed on the turf. As soon as the objects are faded they are moved to the back of the hut.' There is a fine-coloured plate of this bird in. its garden, published in the Birds of Xeiv Guinea, by Mr. Gould, Partix., 1879.] 326 ANIMAL INTELLIGENCE. CHAPTEK XI. MAMMALS. I SHALL devote this chapter to the psychology of all the Mammalia which present any features of psychological interest, with the exception of the rodents, the elephant, the dog and cat tribe among Carnivora, and the Primates — all of which I shall reserve for separate treatment. Marsupials, In the ' Transactions of the Linnean Society,' Major Mitchell gives an interesting account of the structure reared by a small Australian marsupial {Gonilurus con- structor) for the purposes of defence against the dingo dog. It consists of a large pile of dry sticks and brushwood, ' big enough to make two or three good cart-loads.' Each stick and fragment is closely intertwined or woven with the rest, so that the whole forms a solid, compact mass. In the middle of this large structure is the nest of the animal. The marsupials are as low in the scale of mammalian intelligence as they are in that of mammalian structure ; so that, except the above, I have met with no fact con- nected with the psychology of this group that is worth quoting, except, perhaps, the following, which appears to show deliberation and decision on the part of the kangaroo. Jesse writes : — A gentleman who had resided for several years in New South Wales related the following circumstance, which he assured me he had frequently witnessed while hunting the kan- garoo : it furnishes a strong proof of the affection of that animal for her young, even when her own life has been placed in the MAKSUPIALS AND CETACEANS. 327 most imminent danger. He informed me that, when a female kangaroo has been hard pressed by dogs, he has seen her, while she has been making her bounds, put her fore-paws into her pouch, take a young one from it, and then throw it as far on one side as she possibly could out of the way of the dogs. But for this manoeuvre her own life and that of her young one would have been sacrificed. By getting rid of the latter she iias frequently effected her escape, and probably returned after- wards to seek for her offspring. Cetaceans, The following is quoted from Thompson :— In 1811, says Mr. Scoresby, one of my harpooners struck a sucker, with the hope of leading to the capture of the mother. Presently she arose close to the 'fast boat,' and seizing the young one, dragged about 600 feet of line out of the boat with remarkable force and velocity. Again she rose to the surface, darted furiously to and fro, frequently stopped short or suddenly changed her direction, and gave every possible intimation of SKtreme agony. For a length of time she continued thus to act, though pursued closely by the boats ; and, inspired with courage and resolution by her concern for her young, seemed regardless of the dangers which surrounded her. At length one of the boats approached so near that a harpoon was hove at her; it hit, but did not attach itself. A second harpoon was struck, but this also failed to penetrate ; but a third was more successful, and held. Still she did not attempt to escape, but allowed other boats to approach ; so that in a few minutes three more harpoons were fastened, and in the course of an hour afterwards fihe was killed.^ Mr. Saville Kent communicates an article to 'Nature' (vol. viii., p. 229) on ' Intellect of Porpoises.' He says : — The keeper in charge of these interesting animals is now in the habit of summoning them to their meals by the call of a whistle ; his approaching footsteps, even, cause great excitement in their movements. . . . The curiosity attributed to these creatures, as illustrated by the experiences of Mr. Matthew Williams, receives ample confirmation from their habits and confinement. A new arrival is at once subjected to the most importunate attention, and, advancing from familiarity to con- ' Passions of Animals, p. 154. 328 ANIMAL INTELLIGENCE. tempt if disapproved of, soon becomes the object of attack and persecution. A few dog-fish (Acanthias and Mastelua), three or four feet long, now fell victims to their tyranny, the porpoises seizing them by their tails, and swimming off with and shaking them in a manner scarcely conducive to their comfort or dignified appearance, reminding the spectator of a large dog worrying a rat. . . . On one occasion I witnessed the two Cetacea acting evidently in concert against one of these unwieldy- fish (skates), the latter swimming close to the top of the water, and seeking momentary respite from its relentless enemies by lifting its unfortunate caudal appendage high above its surface — the pecuUar tail of the skate being the object of sport to the porpoises, which seized it in their mouths as a convenient handle whereby to pull the animal about, and worry it incessantly. In a subsequent number of ' Nature ' (vol. ix., p. 42) Mr. C. Fox writes : — Several years ago a herd of porpoises was scattered by a net which I had got made to enclose some of them. . . . The whole ' scuUe ' was much alarmed, and two were secured. I conclude that their companions retained a vivid remembrance of the sea-fight, as these Cetacea, although frequent visitants in this harbour (Falmouth) previously, and often watched for,, were not seen in it again for two years or more. Horse o/nd Ass. The horse is not so intelligent an animal as any of the larger Camivora, while among herbivorous quadrupeds his sagacity is greatly exceeded by that of the elephant, and in a lesser degree by that of his congener the ass. On the- other hand, his intelligence is a grade or two above that of perhaps any ruminant or other herbivorous quadruped. The emotional life of this animal is remarkable, in that it appears to admit of undergoing a sudden trans- formation in the hands of the ' horse-tamer.' The cele- brated results obtained by Rarey in this connection have since been repeated with more or less success by many persons in various parts of the world, and the ' method ' appears to be in all cases essentially the same. The un- tamed and apparently untamable animal has its fore- leg or legs strapped up, is cast on its side and allowed to HORSE. 32^ struggle for a while. It is then subjected to various manipulations, which, without necessarily causing pain, make the animal feel its helplessness and the mastery of the operator. The extraordinary fact is that, after having once felt this, the spirit or emotional life of the animal undergoes a complete and sudden change, so that from having been ' wild ' it becomes ' tame.' In some cases there are subsequent relapses, but these are easily checked. Even the truly 'wild' horse from the prairie admits of being completely subdued in a marvellously short time by the Grauchos, who employ an essentially similar method, although the struggle is here much more fierce and prolonged.^ The same may be said of the taming of wild elephants, although in this case the facts are not nearly so remarkable from a psycho- logical point of view, seeing that the process of taming is so much more slow. Another curious emotional feature in the horse is the liability of all the other mental faculties of the animal to become abandoned to that of terror. For I think I am right in saying that the horse is the only animal which, under the influence of fear, loses the possession of every other sense in one mad and mastering desire to run. With its entire mental life thus overwhelmed by the flood of a single emotion, the horse not only loses, as other animals lose, ' presence of mind,' or a due balance among the distinctively intellectual faculties, but even the avenues of special sense become stopped, so that the wholly demented animal may run headlong and at terrific speed against a stone wall. I have known a hare come to grief in a somewhat similar fashion when hotly pursued by a dog ; this, however, was clearly owing to the hare looking behind instead of before, in a manner not, under the cir- cumstances, unwise ; but, as I have said, there is no animal except the horse whose whole psychology is thus liable to be completely dominated by a single emotion. As for its other emotions, the horse is certainly an affectionate animal, pleased at being petted, jealous of » See Mr. Dans in's account in Naturalisfs Voyage rmind the World, pp. 151-2. 330 ANIMAL INTELLIGENCE. companions receiving favour, greatly enjoying play with •others of its kind, and also the sport of the hunting-field. Lastly, horses exhibit pride in a marked degree, as do also mules. Such animals, when well kept, are unmistakably pleased with gay trappings, so that ' in Spain, as a punish- ment for disobedience, it is usual to strip the animal of its gaudy coronal and bells, and to transfer them to another ' (Thompson). The memory of the horse is remarkably good, as almost every one must have had occasion to observe who has driven one over roads which the animal may have only once traversed a long time before. As showing the duration of memory I may quote the following letter to Mr. Darwin from the Kev. Kowland H. Wedgwood, which I find among the MSS. of the former : — I want to tell you of an instance of long memory in a horse. I have just driven my pony down from London here, and though she has not been here for eight years, she re- membered her way quite well, and made a bolt for the stables where I used to keep her. A few instances of the display of intelligence by members of the horse tribe may bring this section to a