1 c e. cm . urgh,&c. T. BLIZARD CURLING, Esq. Lect. on Surg. and Assist. Surg. to the Lond. Hospital. G. P. DESHAYES, M.D. Paris. A. T. S. DODD, ESQ. H. DUTROCHET, M.D. W.F.EDWARDS, M.D. F.R.S. H. MILNE EDWARDS, M.D. Prof.ofNat. History to the College of Henry IV., and to the Central School of Arts and Manufactures, Paris. ARTHUR FARRE, M.D. F.R.S. Professor of Midwifery in King's College and Physician Accoucheur to King's College Hospital. R. D. GRAINGER, F.R.S. Lect. on Anat. and Phys. at St. Thomas's Hospital. R. E. GRANT, M.D. F.R.S. L. & E. Fell, of the Roy. Coll. of Physicians, Edinb. and Prof.of Comp. Anatomy and Zoology in Univ. College, &c. &.c. W. A. GUY, M.D. Prof. For. Med. King's College, London, and Physician to King's College Hospital. M. HALL, M.D. F.R.S. L. & E. London. HENRY HANCOCK, ESQ. Lect. on Anat. and Physiology at, and Surgeon to the Charing-Cross Hospital. ROBERT HARRISON, M.D. M.R.I.A. Prof, of Anat. and Surg. in the Univ. of Dublin JOHN HART, M.D. M.R.I.A. Prof, of Anat. in the Royal Coll. of Surf. Dublin. A. HIGGINSON, ESQ. Liverpool." ARTHUR JACOB, M.D. M.R.I.A. Professor of Anatomy and Physiology to the Royal College of Surgeons in Ireland. ' GEORGE JOHNSON, M.D. Assistant Physician to King's College Hospital, and resident Medical Tutor in King's College, London. T.RYMER JONES, F.R.S. Prof.of Comp. Anat., in King's College, London. T. WHARTON JONES, F.R.S. London. T. WILKINSON KING, ESQ. SAMUEL LANE, ESQ. Lecturer on Anatomy, St. George's Hospital, London. F. T. MACDOUGALL, ESQ. JOHN MALYN, Esq. C. MATTEUCCI. Professor of Physics in the University of Pisa. ROBERT MAYNE, M.D. Lect. on Anat. & Phys. Richmond Hospital, Dublin. W. A. MILLER, M.D. F.R.S. Professor of Chemistry in King's College, London. W. F. MONTGOMERY, M.D. M.R.I.A. Fellow of and Professor of Midwifery to the King and Queen's College of Physicians in Ireland. GEORGE NEWPORT, F.R.S. Vice-Pros, of the Entomological Society of London. R. OWEN, F.R.S. F.G.S. Hunterian Professor of Comparative Anatomy and Physiology to the Royal College of Surgeons in London. JAMES PAGET, ESQ. Lect. on Anat. & Phys. St. Bartholomew's Hospital. RICHARD PARTRIDGE, F.R.S. Prof.of Descrip. and Surg. Anat. in King's Coll. Lond. BENJAMIN PHILLIPS, F.R.S. London. Surgeon to the Westminster Hospital. SIMON ROOD PITTARD, ESQ. London. W. H. PORTER, ESQ. Prof, of Surgery to the Royal Poll, of Surg. in Ireland. J. C. PRICHARD, M.D. F.R.S. Corresponding Member of the Institute of France, Member of the Royal Academy of Medicine of Paris. G. O. REES, M.D. F.R.S. Assistant Physician to Guv's Hospital. J. REID, M.D. Prof, of Medicine in the University of St. Andrews. EDWARD RIGBY, M.D. F.L.S. Lect. on Midwifery at St. Bartholomew's Hospital. J. FORBES ROYLE, M.D. F.R.S. F.G.S. Professor of Materia Medicain King'sCollege, London. HENRY SEARLE, ESQ. London. W. SHARPEY, M.D. F.R.S. Prof, of Anat. and Physiol. in Univ. Coll. London. JOHN SIMON, F.R.S. Lecturer on Pathology, St. Thomas's Hospital. J. Y. SIMPSON, M.D. Fellow of the Royal College of Physicians, and Pro- fessor of Midwifery in the University of Edinburgh. SAMUEL SOLLY, F.R.S. Assistant Surgeon to St. Thomas's Hospital. GABRIEL STOKES, M.D. J. A. SYMONDS, M.D. Physician to the Bristol General Hospital, and Lectu- rer on the Theory and Practice of Medicine at the Bristol Medical School. ALLEN THOMSON, M.D. Fellow of the Royal College of Surgeons, and Professor of the Institutes of Medicine in the University of Edinburgh. JOHN TOMES, ESQ. Surgeon- Dentist to the Middlesex Hospital. WM. TREW, ESQ. W. VROLIK, Prof. Anat. and Phys. at the Athenaeum of Amsterdam. RUDOLPH WAGNER, M.D. Prof.of Med. & of Comp. Anat. in theRoy.Uni.Eilangen. W. H. WALSHE, M.D. Physician to University College Hospital. R. WILLIS, M.D. W. J. ERASMUS WILSON, F.R.S. Consulting Surgeon to the St. Pancnis Infirmary. CONTENTS OF THE THIRD VOLUME. nal ) Instinct Irritability Knee-Joint, Normal Anatomy Knee-Joint, Abnormal Anatomy of the Lacrymal Organs .... Larynx, Normal Ana- ) tomy ' Larynx, Abnormal ) Anatomy $ Leg, Regions of Leg, Muscles of .... Life Liver Luminousness, Animal Lymphatic & Lacteal ) System $ Lymphatic System, > Abnormal Anatomy ) Mammalia , Mammary Glands .... Marsupialia Membrane Meninges Microscope Milk Mollusca Monotremata Motion, Animal, in- } eluding Locomotion S Mucus Mucous Membrane . . Muscle Muscular Motion .... Page Dr. Alison 1 Dr. Marshall Hall 29 A. Higginson, Esq. 44 R. Adams, Esq. . . 48 T. W. Jones, Esq. 78 J. Bishop, Esq. .. 100 W.H. Porter, Esq. 114 A.T.S.Dodd.Esq. 126 A.T.S.Dodd, Esq. 137 Dr. Carpenter... . 141 E. Wilson, Esq... 160 Dr. Coldstream . . 197 S. Lane, Esq 205 Dr. Todd.. . 232 Professor Owen . . S. Solly, Esq. Professor Owen . , Dr. Todd Dr. Todd Dr. Carpenter. . . , Dr. G. O. Rees . . Professor Owen . . Professor Owen . , 234 245 331 331 331 358 363 366 J. Bishop, Esq. . . 407 Dr. G. O. Rees . . 481 W. Bowman, Esq. 484 W. Bowman, Esq. 506 W. Botcman, Esq. 519 Muscular System, Comp. Anatomy Myriapoda Neck, Muscles and Regions of the. . Nervous System . . Nerve Nervous System, Comp. Anatomy Nervous Centres, Normal Anatomy Nervous Centres, Abnormal Anat. Nervous System, } Physiology of the $ N inth Pair of N erves Nose Nutrition OZsophagus Optic Nerves Orbit Organic Analysis .. Osseous System, } Comp. Anatomy S Osseous Tissue .... Pachydermata . Pacinian Bodies . . Par Vagum. Parotid Region .... Parturition Penis Perineum Peritoneum Pharynx Pisces Professor R. Jones. Professor R. Jones. J. Simon, Esq. . . . Dr. Todd. Dr. Todd. J. Anderson, Esq. Dr. Todd.. Page 530 545 561 585 591 601 626 Dr. Todd 712 Dr. Todd.. 720c G. Stokes, Esq. . . , J. Paget, Esq. .. . Dr. Carpenter Dr. G. Johnson . . , Dr. Mayne , Dr. G. Johnson . . , Dr. Miller . 721 723 741 758 762 782 792 Professor R. Jones . . 820 J. Tomes, Esq 847 Professor R. Jonr s . . 858 W. Bowman, Esq... 876 Dr. J. Reid 881 Dr. G. Johnson .... 902 Dr. Rigby 904 E. Wilson, Esq 909 Dr. Mayne 919 S. R. Pittard, Esq. . . 935 W. Trew, Esq 945 Professor R. Jones.. 955 ERRATA IN VOLUME THE THIRD. Page 684, col. 2, line 44, after " medulla oblongata," insert " and the cerebrum."' 700, col. 2, line 1 9, for " testes," read " nates." line 20, for " nates," read " testes." line 36, for "thalami," read "thalamus." 708, col. 1, line 10, for "distend," read "exist." 711, col. 1, line 59,Jbr " optic thalami," read " hemispheres." 712, col. 2, line 40, for " Seinruch," read " Steinruch." line 41, Jor " Hermann, Nasse," read "Hermann Nasse." At page 902, see a list of Errata in the article PAR VAGUM. , THE ADDITIONAL ERRATA IN VOLUME THE THIRD. " six times," read " six lines.' 01- Page 71, col. 1, line 1 and 2,. /or 287, col. 1, line I, for " Peophagous," read " Poephagous. 351, col. 1, line 7, /or " made be made," read " may be made. ^ 361, col. 2, line 28 from bottom, for " analysis," read " analyses. 409, col. 1, fig. 207, Jraser* " B" at the angle which is not lettered. 41?' col' 2' Imes land's, for quadratus femoris," mid quadriceps extensor femoris 418* col l! line 26 from bottom, /or " separated," read " adapted." 433 col 1 line .5, /or" or d cd, in the second movement; the tail being, read u dcd ; in the second movement, the tail being." line 10, for " 6," read " ad." 441, col. 1, line 7, de/e " Sect. IV." 610, col. l.line 5, for " molar," read " motor. G67, col. 1, line 19, for " foramen," read " fore-arm. 715, col. 1, line 39, for " in membranous," read " in a membranous. 716' col. l! line 33 from bottom, /or " his," rend " this." 720x, col. 2, line 2 from bottom, > posterior and posterior," read " anterior and po terior." 722s col. 1, line 8 from bottom, for " cerebri," read " cerebelli." 751, col. 1, line 19, for " had," read " have." 83o' col. 1, line 10 from bottom, for " resemble,' read resembling. ' col. 2, line 6, /or " it," read " them." 849, col. 2, in description of cut, for " animal," read" earthy. may be inferred, with perfect confidence, to take place throughout the whole range of the animal kingdom, and even that some of them must be performed with greater energy and precision in some of the lower tribes than in man. The different external senses attain their highest perfection in different animals ; that of smell, for example, probably in the predaceous mammalia, that of touch in the antennae of insects, and that of sight in the predaceous birds ; it is not likely that any one is enjoyed in its highest perfection by man ; and what have been accurately distinguished from mere VOL. in. the emotions of fear, of joy, of affection, of anger, even of jealousy, are as distinctly indi- cated by their actions as by those of man ; that under the influence of these emotions their mental operations are excited or depressed, and their attention fixed or distracted, and their volition excited, as in our own case ; and that their actions are habitually guided by a clear perception, or rather, we should say, by conti- nual correct applications, of a first principle of belief, which is generally admitted to be an ultimate fact in the constitution of the human rnind, and on which much stress has been B THE C Y CLOP.EDI A OF ANATOMY AND PHYSIOLOGY. INSTINCT. This word is often applied to the mental acts of the lower animals, as if it were truly applicable to the whole of these acts ; but a little consideration will shew, jirst, that this word, in its more approved and correct acceptation, is applicable only to a part of the mental operations, which may be inferred from the observation of the actions and habits of animals ; and secondly, that in this restricted sense, the term is applicable to a part of the operations of the human mind itself; and that the subject of instinct cannot be tho- roughly understood, unless information regard- ing it is sought in the consciousness of our own minds, as well as in the observation of other living beings. The study of this subject is therefore equally important as a part of natural history, of mental philosophy, and of human physiology ; and is a good illustration of the necessity of this latter science being based on the observation and generalization of the laws and conditions of vital action through- out the whole extent of the animal creation. It is obvious, indeed, that various mental acts, of which we are conscious in ourselves, may be inferred, with perfect confidence, to take place throughout the whole range of the animal kingdom, and even that some of them must be performed with greater energy and precision in some of the lower tribes than in man. The different external senses attain their highest perfection in different animals ; that of smell, for example, probably in the predaceous mammalia, that of touch in the antennae of insects, and that of sight in the predaceous birds ; it is not likely that any one is enjoyed in its highest perfection by man ; and what have been accurately distinguished from mere VOL. III. sensations as the perceptions of external things, i. e. the notions as to the qualities of these, which naturally present themselves to our minds in consequence of sensations being felt, would seem in various instances to follow the sensa- tions more quickly and more surely in other animals than in us ; for it is generally allowed that what appear to be acquired perceptions of the eye to us, i. e. the notions of the distance, size, and form of visible objects, are instanta- neously made known to many of the lower animals the very first time that those objects make impressions on their retinae; the faculty of Intuition, which we must admit as part of the source of our own knowledge, appears to exist in greater perfection in other animals, and the notions of external things which they thus acquire are amply sufficient to regulate their muscular motions. It is equally plain that many of the strictly mental acts, of which our complex trains of thought are composed, are habitually performed by animals ; that they have a perfect recollec- tion of past sensations, implying the exercise of the powers of memory and of conception ; that the emotions of fear, of joy, of affection, of anger, even of jealousy, are as distinctly indi- cated by their actions as by those of man ; that under the influence of these emotions their mental operations are excited or depressed, and their attention fixed or distracted, and their volition excited, as in our own case ; and that their actions are habitually guided by a clear perception, or rather, we should say, by conti- nual correct applications, of a first principle of belief, which is generally admitted to be an ultimate fact in the constitution of the human mind, and on which much stress has been INSTINCT. tions, the sensations, the voluntary powers, the memory and instinct of the animals are all brought into play ; but we have no reason to believe that the animals performing them are capable of anticipating their ultimate result. In all cases, those actions which are en- titled to the appellation of Instinctive are ge- nerally xmderstood to be characterized by two marks, quite sufficient to distinguish them from the effects of voluntary power guided by rea- son : 1. That, although in many cases expe- rience is required to give the will command over the muscles concerned in them, yet the will, when under the influence of the instinc- tive determination, acts equally well the first time as the last ; no experience or education is required, in order that the different voluntary efforts requisite for these actions may follow one another with unerring precision; and 2. That they are always performed by the same species of animal nearly, if not exactly, in the same manner ; presenting no such variation of the means applied to the object in view, and admitting of no such improvements in the pro- gress of life or in the succession of ages, as we observe in the habits of individual men, or in the manners and customs of nations, adapted to the attainment of any particular ends by those voluntary efforts which are guided by Reason. " The manufactures of animals," says Dr. Reid, " differ from those of men in many striking particulars. No animal of the species can claim the invention. No animal ever in- troduced any new improvement, or variation from the former practice. Every one has equal skill from the beginning, without teaching, without experience or habits. Every one has its art by a kind of inspiration, i. e. the ability and inclination of working in it without any knowledge of its principles." A third distinc- tive mark, naturally resulting from the last, is at least equally characteristic, although much less generally observable, that these instinc- tive actions are seen to be performed in cir- cumstances which reason informs us to be such as to render them nugatory for the ends which are usually accomplished by them, and for which they are obviously designed. The efforts made by migratory birds, even when confined, at their usual period of migration, the mistake of the flesh-fly who deposits her eggs on the carrion-plant instead of a piece of meat,* or of the hen who sits on a pebble in- stead of an egg, or of the mule which remains immoveably fixed by terror instead of escaping from the flood which threatens to overwhelm it, (as exemplified in the inundation of the valley of Luisnes in Savoy in 1818,) or of the bee which gathers and stores up honey even in a climate where there is no winter, f are so many proofs, that an instinctive action is prompted by an impulse, which results merely from a particular sensation or emotion being felt, not by anticipation of the effect which the action will produce. * Kiiby. t See Kirby and Spcncr, Introduction to Ento- mology, vol. ii. p. 469. But, in order to have demonstrative proof of the essential difference between instinct and reason, and of the correctness of the view which we take of the nature of that mental impulse which prompts what we call the in- stinctive actions of animals, it is only neces- sary to reflect on what passes within ourselves on occasion of certain actions of the very same class being performed by us. It is dif- ficult, indeed, in adult age, to distinguish those actions which we perform instinctively from those which we have learnt by repeated efforts to perform habitually ; but in the case of infants we see complex actions, useful or necessary to the system, performed -with per- fect precision at a time when we are certain that the human intellect is quite incompetent to comprehend their importance or anticipate their effects ; yet we cannot doubt that it is by a mental impulse that they are excited, because we perform the same actions in the same cir- cumstances in adult age, and are then con- scious of the impulse which prompts them. " It is an instinct," says Bichat, " which I do not understand, and of which I cannot give the smallest account, which makes the infant, at the moment of birth, draw together its lips to commence the action of sucking," to be fol- lowed by the still more complex act of deglu- tition. " This cannot be ascribed to the mere novelty of the sensations which it experiences from external objects, for the general effect of such sensations is to determine various agita- tions or irregular movements indeed, but not an uniform movement, directed to a deter- minate end. If we examine different animals at the moment of birth, we shall see that the special instinct of each directs the execution of peculiar movements. Young quadrupeds seek the mammae of their mothers, birds of the order Gallinacese seize immediately the grain which is their appropriate nourishment, while the young of the Carnivorous birds merely open their mouths to receive the food which their parents bring to their nests. In general, it is very important to distinguish the irregular or varied movements which, at the moment of birth, are produced simply by the new sensations and excitements which the body receives, from those definite actions which are the effect of instinct, a cause of which we can give no further explanation." In fact, when we attend to the simple action of deglutition,* as performed in our mature years, we may be conscious that it results from the same instinctive impulse which guided it with unerring precision in the new-born infant, long before the voluntary power of simply raising the hand to the mouth had been ac- quired. If we were to consult only the grati- fication of our sensations, we should keep any grateful food in the mouth ; for when it is swal- lowed the gratification immediately resulting from it is at an end, and there is no peculiar pleasure attached, in other circumstances, to the mere act of deglutition; but all we can * [I. e. that part of the act which is dependent on the voluntary movement of the tongue to pass on the food to the isthmus faucium. ED.] INSTINCT. observe by attention to our own feelings on such occasions is, that while we feel the sen- sations of hunger and thirst, we feel also a pro- pensity, all but irresistible, to swallow what- ever grateful food or drink is in the mouth. This propensity is not only prior to reason, but stronger than reason, and prompts us to action more surely and more energetically than the mere recollection of the effects previously resulting from food or drink taken into the sto- mach could have done. If we reflect further, we shall find that there are various other sensations, with which we can feel, in our own persons, that an instinctive impulse is naturally linked. The term Appe- tite does not express the whole of these, although it is only by referring to the action which it uniformly prompts that an appetite can be distinguished from another sensation. Sympathetic movements, such as breathing, coughing, sneezing, vomiting, &c. are ascribed by VVhytt and others to sensations ; and laugh- ter, weeping, the expression of feeling in the countenance and features, &c. are strictly refer- able to emotions of mind, and in the perform- ance of all these actions, a propensity which may be called strictly instmotive, because prior to experience, and independent of reason- ing, may be frequently and distinctly felt, and is from the first equally effectual in exciting very complex muscular movements, as the impulse to swallow food in the mouth. We may specify several other kinds or modes of action, which we are all conscious of frequently per- forming, and which we perform on many oc- casions in obedience, not to any effort of reason, but to a truly instinctive impulse, natu- rally consequent on certain sensations or emotions, and felt even in adult age to be inde- pendent of, as they are in the infant prior to, any anticipation of remote consequences, viz. 1. those which are prompted by the instinct of self-preservation, (as the winking of the eye- lids when the eyes are threatened with injury, the shrinking of any limb or part of the body which is struck, the projection of the arms when we ate about to fall forwards on the face,* the act of crying from pain or from fear); 2. those which are prompted by the instinct of shame, as when the saliva escapes from the mouth, when the sphincters fail in their office, or the sense of modesty is out- raged ; 3. those which are prompted by the instinct of imitation, existing more or less in the early stage of all human existence, and whereby we are all led to fashion our language, manners, and habits, on the model of those around us, and particularly of those persons with whom we have either the most frequent inter- course, or the intercourse which is most fitted to make an impression on our minds ; 4. those which are prompted by the emotions of affec- * Let any one try the experiment of attempting to fall forward on his face, with his arms extended at his sides, and he will be immediately conscious of the instinctive impulse which urges him to throw forward his arms ; and which he feels dis- tinctly and resists with difficulty, even when he knows that he is about to fall only on soi't matter which cannot injure him. tion and pity, or still more decidedly by the impulse of maternal love, on witnessing the helpless condition of young infants.* We do not enter into details on these subjects at pre- sent, but merely mention them as examples, in which we may safely and legitimately avail ourselves of the evidence of consciousness to assure ourselves of the essential peculiarity, and of the paramount authority, of the in- stinctive impulse, as distinguished from the voluntary effort, which results from a train of reasoning. It has been often said that the nature of instinct is absolutely mysterious and inscru- table; but if what has now been stated be correct, this can be said of instinct only in the same sense in which it may be said of all mental acts without exception ; the essence of mind, like that of matter, being wholly in- scrutable. The characters of the instinctive impulse may be distinguished as clearly as those of any other mental act, in the only way in which any such act can be distin- guished, viz. by attention to our own conscious- ness ; although we never could have antici- pated a priori that this kind of mental impulse could have extended to so long continued and complex actions, and to the concerted ope- rations of so many individuals, as the operations of some animals indicate. Having satisfied ourselves of the existence of certain instinctive impulses, both in the lower animals and in ourselves, essentially dis- tinct from those voluntary efforts which are guided by reason, we need not be perplexed at finding that there is much difficulty in some individual instances, in determining to which class of mental acts particular actions ought to be referred. However difficult it may be in any in- dividual instance, to decide whether an action, of man or of animals, is the effect of a blind in- stinct, or of reason, anticipating and desiring its consequences, there can be no doubt or difficulty as to the fact, that these two distinct kinds of mental determination to the perform- ance of actions exist. Neither do we consider it of any import- ance to enter on the metaphysical speculations which ingenious men have hazarded at different times as to the nature of the agent, by which the instinctive actions may be supposed to be immediately excited. Some philosophers have been so strongly impressed with the admirable adaptation of means to ends which these phe- nomena present, in animals manifestly devoid of reason, that they have believed them to be in all cases the immediate offspring of the divine intelligence, and have expressed their theory in the form of an axiom, " Deus anima brutorum," which, it is humbly conceived, is admissible only in the same sense in which we assent to the more general assertion, " Deus anima mundi." Mr. Kirby, in his very learned and elaborate Bridgewater Treatise on the History, Habits, and Instincts of Animals, seems to favour the [* The greater number of the actions enumerated may, however, be accounted for on the principle of reflux nervous artion, now so generally admitted by physiologists, ED.] INSTINCT. idea which other philosophers have maintained, of intermediate agents between the Divine will and the living beings on earth, by which the actions of the latter are guided ;* but in pro- secuting this idea he is disposed to regard the proximate cause of instinct, as he expresses it, not as metaphysical, but merely as physical, and to suppose that "light, heat, and air, or any modification of them " may be the inter- mediate agents " employed by the Deity to excite and direct animals, when their intellect cannot, in their instinctive operations;" and that " the organization of the brain and nervous system may be so varied and formed by the Creator as to respond in the way that he wills, to pulses upon them from the physical powers of nature."f On this it may be observed that this last sentence expresses no more than the truth, whatever opinion we may form as to the mode, in which the response of the nervous system of an animal to the impressions made on it by physical agents takes place; but if it be meant by the expression, that the proximate cause of instinct is probably not metaphysical but physical, to exclude all mental operation, and all consciousness of effort, from the instinctive actions of animals, we can regard the theory only as a denial of all mental acts or affections in any of the lower animals, and as easily con- tradicted by the whole analogies of their struc- ture, by observation of their habits, and by the evidence of our own consciousness in the performance of those precisely similar instinc- tive actions which have been noticed above. It seems quite unreasonable to doubt that the immediate cause of all the actions that we call instinctive, is a strictly mtntnl effort, but the occurrence of that effort in every case when it is required must in all probability be always held as an ultimate Juft in the animal ceconomy ; and all speculations as to its inti- mate nature or proximate cause may be re- garded as mere conjectures, on a subject which is beyond the reach of the human faculties. Nor would any thing be gained, in the infer- ence as to final causes, from establishing any one of these conjectures ; for the mental constitution of man himself, and of the whole lower ani- mals, is equally a part of the contrivance of the Divine Artificer of the world, as the laws of motion or the properties of light. He who could make man after his own image could assuredly impart such mental propensities to other beings, as well as to man, as were ne- cessary for the ends for which the creation was designed. And when we attempt, in all hu- mility, but at the same time in confident re- liance on the mental powers which He has vouchsafed to us, to draw inferences as to His existence and attributes from the study of created things, we do so, not by vainly attempt- ing to comprehend the nature of the energy by which any of the changes (physical or mental) occurring around us are effected, but simply by observing the adaptation of means to ends in those regular and uniform laws which we are * Sec vol. ii. p. 243-4. t Vol. ii. p. 255-6. enabled to infer from the observation of such changes, which we ascribe to His authority, and beyond which we feel that it is not yet given us, by any exercise of our minds, to ascend. In enabling us to draw those in- ferences, the instincts of animals, as we shall afterwards state, are of peculiar importance ; but the inferences are the same, whatever opi- nion we may adopt as to the mode in which the Divine Intelligence so indicated rules the wills of the animal creation. Having said so much of the characteristics of this class of phenomena, and endeavoured to set them in the proper point of view, we shall next offer a very rapid sketch of the varied instincts exhibited in the different tribes of animals, arranging them simply according to the purposes which they seem destined to serve, and shall conclude with a few general reflections. It may be premised that it certainly seems reasonable a priori to suppose, that the struc- ture of the nervous system, and 1 especially of the brain, of different animals, will bear some relation to the kind of instinctive propensities which they exhibit. In the size of the sen- sitive and motor nerves, and portions of the cerebro-spinal axis whence these originate, par- ticularly the spinal tord, medulla oblongata, and optic lobes (or corpora quadrigemina), in the higher animals, this relation may be distinctly perceived; and it has been further confidently stated by some phrenologists, that strong evi- dence of certain of their peculiar doctrines may be deduced from observation of the size and form of the brains of animals, as compared with their instincts ; but this last speculation certainly cannot be carried further than the vertebrated animals, which form but a small part of the living beings that are continually guided and ruled by the laws of instinct; and even in them no such relation of the size and form of the brain, or of any part of the brain, to the general intelligence of an animal, or to any par- ticular instinct, has been fully ascertained. In- deed, until some such essential difference shall be observed between the habits and instincts of the dolphin, or other cetaceous animals, and the predaceous fishes, as may correspond to the extraordinary difference of the size and struc- ture of their brains, (that of the former being much larger in proportion to the spinal cord than the human brain, and of complex struc- ture, while that of the latter is not larger than the optic lobes or corpora quadrigemina of the same animal, and of very simple structure,) such speculations may be safely distrusted.* Mr. Kirby has stated that the principal in- stincts of animals may be referred to three heads; those relating to their food, those re- lating to their propagation and the care of their offspring, and those relating to their hybernation. But this enumeration is certainly defective, and indeed will hardly include several which * We cannot suppose this difference to be con- nected with the difference in the mode of respi- ration of these animals, because we know that the only part of the central masses of the nervous system of either, concerned in that function, is the medulla oblonguta. INSTINCT. he has himself accurately described. The fol- lowing appears a more comprehensive enume- ration. Three great classes of instinctive ac- tions may be distinguished ; the first designed for the preservation of individuals ; the second for the propagation and support of their off- spring; and the third for various purposes im- portant either to the race of animals exhibiting them, or to other animals, but not distinctly referable to either of the formei heads. Each of these classes admits of obvious sub- divisions. I. Of instincts designed for the preservation of the individuals exhibiting the>, we may enumerate the following : 1. All animals are endowed with instincts prompting them to some means of escaping or repelling injury or violence, but these are ex- ceedingly various, both as to the kind and as to the degree of complexity of the actions which they excite; from the simple retraction of the tentacula of the infusory Vorticella, or of the Medusa, Polype, or Actinia, up to the active and formidable resistance of the ele- phant or the tiger. The most common instinct of self-preservation excited by the emotion of fear, is that which prompts to flight, an in- stinct so obviously existing in the human species, that the effort by which it is resisted has in all ages been regarded with respect; and another very common propensity in animals is that which prompts to concealment. This is often combined with flight, as in most of the Carnivorous Mammalia, the Rodentia, the Ce- tacea, the diving birds, reptiles, insects, &c. ; but some of the higher animals, and many of the Mollusca and insects, and others of the lower tribes, remain quite motionless and counterfeit death when under the influence of fear ;* and it is remarkable that when the cir- cumstances of the animals render this mode of defence the most effectual, it is that adopted, in preference to flight, even by single species of families, the other members of which shew no such instinct, as in the case of the ptarmi- gan, which so frequently cowers among the grey lichen, or the snow on the mountain- tops, instead of taking wing like the moor fowl, or in that of the hedge-hog, which on occasion of any imminent danger makes no effort but that of coiling itself into a ball. In many instances the instinct either of flight or concealment is aided by very various special contrivances, equally instinctive, fitted either to deceive, or to alarm, or injure an assailant. Some even of the Mollusca, and some of the reptiles, as the toad, squirt water on him ; many reptiles and some lower animals, as the scorpion, bee, wasp, &c., even some of the gelatinous radiata,f have the power of emit- * " In this situation, spiders will suffer them- selves to be pierced with pins and torn to pieces, without discovering the smallest sign of pain. This simulation of death has been ascribed to a strong convulsion or stupor occasioned by terror ; but this solution of the phenomenon is erroneous. If the object of terror is removed, in a few se- conds the animal runs off with great rapidity." Duncan on Instinct. t Kirby, vol. i. p. 198. ting irritating matter of greater or less inten- sity ; the electrical animals, as the gymnotus and torpedo, use their appointed weapons ; the hedge-hog and porcupine oppose their sharp thorns to any one who attempts to molest them; many insects and some reptiles protect them- selves by emitting peculiarly fetid effluvia; the cuttle-fish tribe have the remarkable power of emitting an inky fluid which darkens the wa- ter and hides them ; and on the other hand there is reason to believe that the phosphores- cent light which so many marine animals ex- hibit, may be suddenly augmented on occa- sion of any threatening of injury, and serve as a means of defence.* (See LUMINOUSNESS.) The means of defence, and the instincts guid- ing them, in the case, not only of the higher Carnivorous animals, but many of the stronger of the Herbivorous classes, the elephant, the hog, the horse, the buffalo, the deer, &c. re- quire no illustration. The instinct which prompts many animals to utter cries when injured or threatened, (as well as on other occasions and for other purposes,) deserves notice as a means of protection, parti- cularly on this account, that as it is one of the instincts which most clearly extends to the human race, so we may perceive in man, as well as in some of the lower animals, that its use is not merely to frighten assailants, but especially to procure assistance and protection for the young animal from its parents. 2. The most conspicuous and most remark- ably varied of the instincts under this head are those by which the food of different ani- mals is procured. With the exception of the sponges, and some others of the lowest Zoo- phyta, in which the nourishment is supplied by currents, all animals have organs corresponding to a mouth and stomach, into which aliments are taken by a process of deglutition, imply- ing sensations and instinctive efforts conse- quent on these; and in the Articulata and Mollusca, the most important central organ of the nervous system seems to be the nervous collar surrounding the oesophagus, which in the vertebrated animals seems to be developed and subdivided into the first, fifth, and part of the eighth pairs of nerves, with the corres- ponding portions of the cerebro-spinal axis, by which the sensation of hunger is felt, the suitable nourishment discriminated, and the instinctive effort, whether of deglutition only, or of mastication more or less powerful ac- cording to the food, is excited. In some instances subsidiary instincts are also implanted in certain animals, which are essential to their digestion and nutrition. The art of cookery, as universally practised by the human race, may be said to be the result of experience; but this cannot be said of the pro- pensity of many animals to swallow salt, still less of the swallowing of gravel or pebbles by the graminivorous birds, or of the copious draughts of water, sufficient to store the nu- merous and peculiar cells of their first and second stomachs, which are taken by the camel * Ibid, vol. i. p. 178. INSTINCT. or llama before they enter on the deserts, and which enable them subsequently to subsist without water for many days. But the instincts by which animals are en- abled to search for and obtain food may be easily supposed to be much more numerous and varied than those by which they merely seize and swallow it, and in fact furnish the conditions by which the varieties of the whole structure of animals are chiefly determined. Probably the greatest number of animals are nourished by the vegetable world in the living or dead state, and are continually guided by sensations, to which instinctive efforts are at- tached, i. e. by appetites, in the selection of food, which may in general be found and seized without much difficulty. But through- out the whole animal kingdom, from the mi- croscopic animalcules up to the largest of the Mammalia, a very great number of carni- vorous animals are found, who subsist on, and continually repress the numbers of, the herbi- vorous tribes; and it may easily be supposed that the instincts implanted in these animals, which oppose and counteract the varying efforts at self-preservation already mentioned, will be more varied, and bear more marks of contri- vance and ingenuity. Accordingly, from the numerous Vorticellae, or other animalcules, of the order Rotatoria, which excite currents in the water around them, and so attract into their stomachs many of the smaller ani- malcules, up to the lion, the whale, or the eagle, we find an infinite number of con- trivances and instinctive propensities, served by organs, by which the predaceous animals, of all the orders, are enabled to prey on the others. The Polype, Echinus, and Actinia, for example, among the Zoophyta, seize their prey, as it is brought to them by the waves, with their numerous tentacula ; the Entozoa, and the leech and other of the Annelides, have the faculty and the necessary instinct of attach- ing themselves to the larger animals in the situations which suit them, as the Cirrhipedes or barnacles do to vegetable substances. The cuttle-fish and other predaceous Mollusca have legs furnished with admirably constructed suckers and powerful jaws, and most of the Crustacea have claws and mandibles, suf- ficient to enable them to seize and destroy ma- rine animals of very considerable size ; and it is unnecessary to enlarge on the powerful means of destruction, or on the instincts guid- ing their use, which are seen in many genera of each of the classes of vertebrated animals. There is often a peculiar instinct guiding each of the Carnivorous Mammalia to the part of the body of its victim where it can most easily inflict a mortal wound, to the throat in the case of a large animal, to the head in that of a small one, of which the cranium may be pierced. In the greater number of them, however, the instinctive actions by which their prey is obtained are distinguished only by power and violence ; and although much con- trivance is employed for adapting the different parts of the structure to the habits and des- tination of the animals, there is little apparent ingenuity in the modes in which the animals perform their office in creation. The attitude and gesture of the cat, the pointer, or the tiger, " slow stealing with crouched shoulders on his prey," is an example of instinctive con- trivance preliminary to the act of violence. The aspect and expression of many carnivo- rous animals, not only of the Mammalia and birds, but of the shark, the cuttle-fish, the scorpion, the tiger-beetle, &c., are so adapted to the feelings and instincts of the animals on which they feed, as often to deprive them of the power of flight or resistance; and it is maintained by many, that some of the predace- ous animals have the power of fascinating their prey by merely fixing their eyes on them. Many have ascribed this power to the serpent ; and Mr. Kirby asserts it with confidence of the fox.* A few only of the predaceous ani- mals, as the dog and wolf, have the instinct of associating together for procuring their prey. It has been stated that the pelican and the dog-fish have a similar instinct.f But the more striking indications of con- trivance in the actions prompted by this in- stinct are to be found in some of the less pow- erful of the carnivorous tribes. The Lophius Piscatorius or fishing-frog, although a large fish, having no strength or speed, obtains its prey by stratagem, plunging itself in mud, or covering itself with sea-weed: " it lets no part of it be perceived except the extremity of the filaments that fringe its body, which it agitates in different directions, so as to make them ap- pear like worms. The fishes, attracted by this apparent prey, approach and are seized by a single movement of the fishing-frog, and swal- lowed by his enormous throat, and retained by the innumerable teeth by which it is armed." J A still more singular art is practised by the Choetodon rostratus, which feeds on flies, and, as Sir Charles Bell states, actually takes aim at them, and shoots them with a drop of water. The instinct of the myrmecophaga or ant-eater, which protrudes the tongue to allure flies to settle on it, and then suddenly retracts it to devour them, also deserves notice. A more complex art is practised by the ant-lion, which digs a pitfall in the track usually followed by ants, and conceals itself in the bottom of it, waiting for its prey. But of all contrivances in the animal creation for procuring food, the most complex and artificial are those of the different genera of spiders, equally curious on account of the peculiar organs by which they spin their webs, as of the peculiar and varied instincts by which they are guided in using them. || For example, " any common black and white spider (Salticus Scenicus), which may always be seen in summer on sunny rails, &c., when it spies a fly at a distance, ap- proaches softly, step by step, and seems to measure his distance from it by the eye; then if he judges that he is within reach, first fixing * Vol. ii. p. 2fi9. t See Darwin's Zoon. vol. i. p. 229, 249. J See Kirby, vol. ii. p. 406, and pi. xiii. $ Bridirewater Treatise, p. 200. || See Kirby, vol. ii. p. 184 and 286. INSTINCT. a thread to the spot on which he is stationed, by means of his fore feet, which are much larger and longer than the others, he darts on his victim with such rapidity, and so true an aim, that he seldom misses it. He 13 pre- vented from falling by the thread just men- tioned, which acts as a kind of anchor, and enables him to recover his station.' 1 * Again, the kind of spider that has received the name of Geometric, " having laid the foundation of her net, and drawn the skeleton of it, by spinning a number of rays, converging to a centre, next proceeds, setting out from that point, to spin a spiral line of unadhesive web, like that of the rays, which it intersects, and after numerous circumvolutions finishes this at the circumference. This line, in conjunction with the rays, serves as a scaffolding for her to walk over, and also keeps the rays properly stretched. Her next labour is to spin a spiral or labyrinthiform line from the circumference towards the centre, but which stops somewhat short of it ; this line is the most important part of the snare. It consists of a fine thread, stud- ded with minute viscid globules, like dew,which by their viscid quality retain the insects which fly into the net. The snare being thus finished, the little geometrician selects a concealed spot in the vicinity, where she constructs a cell, in which she may hide herself and watch for game; of the capture of which she is informed by the vibrations of a line of communication, drawn between her cell and the centre of her snare."f 3. Many animals are guided by instinct to form habitations for themselves, of very various kinds, for protection against injury and against cold, from the simple contrivance of the earth- worm, which closes the orifice of its hole with leaves or straw, up to the elaborate structures of the bee, the ant, or the beaver. Here we observe a singular but easily understood diffe- rence between the inhabitants of water and air. The greater number of the more delicate animals that inhabit the sea, chiefly of the Mollusca and Crustacea, are provided by nature with shells, or very firm integuments, evidently for protec- tion against the violence of the waves, in the formation of which instinct has little or no share ; but there are some of the Annelides inhabiting water, as the Sabella and Terebella, and the larvae of some moths, which have a sin- gular instinct enabling them to form habitations sufficient for their own protection, " by collect- ing grains of sand and fragments ot decayed shells, &c. which they agglutinate together by means of a viscid exudation, so as to form a firm defensive covering, like a coat of mail." This may be stated as the intermediate link be- tween the habitations given to the Mollusca and Crustacea by nature, and those which many land animals have organs and instincts enabling them to form for themselves. " The manoeuvres of the terebella are best observed by taking it out of its tube and placing * Kirby. vol. ii. p . 298. t Ibid. p. 295. See also Darwin's Zoon. vol. i. p. 253. it under water upon sand. It is then seen to unfold all the coils of its body, to extend its tentacula in every direction, often to a length exceeding an inch and a half, and to catch, by their means, small fragments of shells and the larger particles of sand. These it drags to- wards its head, carrying them behind the scales which project from the anterior and lower part of the head, where they are immediately ce- mented by the glutinous matter which exudes from that part of the surface. Bending the head alternately from side to side, while it con- tinues to apply the materials of its tube, the terebella has very soon formed a complete collar, which it sedulously employs itself to lengthen at every part of the circumference with an activity and perseverance highly inte- resting. For the purpose of fixing the different fragments compactly, it presses them into their places with the erected scales, at the same time retracting the body. Hence the fragments, being raised by the scales, are generally fixed by their posterior edges, and thus, overlaying each other, often give the tube an imbricated appearance. " Having formed a tube of half an inch or an inch in length, the terebella proceeds to burrow ; for which purpose it directs its head against the sand, and contracting some of the posterior rings, effects a slight extension of the head, which thus slowly makes its way through the mass before it, availing itself of the materials which it meets with in its course, and so con- tinues to advance till the whole tube is com- pleted. After this has been accomplished, the animal turns itself within the tube, so that its head is next the surface, ready to receive the water which brings it food, and is instrumental in its respiration. In summer the whole task is completed in four or five hours ; but in cold weather, when the worm is more sluggish, and the gluten is secreted more scantily, its progress is considerably slower."* The habitation formed by the water-spider, which is not exposed to the violence of the sea, shews much greater delicacy of workmanship, as well as greater variety of instinct. " The insects that frequent the waters," says Kirby, " require, as well as those that inhabit the earth, predaceous animals to keep them within due limits, and the water-spider is one of the most remarkable on whom that office is imposed by the Creator. To this end her in- stinct instructs her to fabricate a kind of diving- bell, for which purpose she usually selects still waters. Her house is an oval cocoon filled with air, and lined with silk, from which threads issue in every direction, and are fast- ened to the surrounding plants ; >n this cocoon, which is open below, she watches for her prey, and even appears to pass the winter, when she closes the opening. It is most commonly en- tirely under water, but its inhabitant has filled it with air for respiration, by which she is ena- bled to live in it. She conveys the air in the following manner : she usually swims upon her back, when her abdomen is enveloped in a * Roget's Bridge-water Treatise, vol. i. p. 279. 10 INSTINCT. bubble of air, and appears like a globe of quick- silver; with this she enters her cocoon, and displacing an equal mass of water, again ascends for a second lading, till she has suffi- ciently filled her house with it, so as to expel all the water. The males construct similar habitations by the same manoeuvres. How these little animals can envelope their abdomen with an air-bubble, and retain it till they enter their cells, is still one of Nature's mysteries that have not been explained.'' We need say nothing of the habitations formed by solitary animals of the higher tribes, chiefly by burrowing under ground, for their own protection and comfort; but the most curi- ous of such solitary habitations on the earth's surface are also furnished by the tribe of spiders. " Some species of spiders, M. Audouin re- marks, are gifted with a particular talent for building : they hollow out dens ; they bore galleries ; they elevate vaults ; they build, as it were, subterranean bridges; they construct also entrances to their habitations, and adapt doors to them, which want nothing but bolts, for without any exaggeration, they work upon a hinge and are fitted to a frame. The interior of these habitations is not less remarkable lor the extreme neatness which reigns there; whatever be the humidity of the soil in which they are constructed, water never penetrates them ; the walls are nicely covered with a tapestry of silk, having usually the lustre of satin, and almost always of a dazzling white- ness. " The habitations of the species in question are found in an argillaceous kind of red earth, in which they bore tubes about three inches in depth and ten lines in width. The walls of these tubes are not left just as they are bored, but are covered with a kind of mortar, suffi- ciently solid to be easily separated from the mass that surrounds it." " The door that closes the apartment is still more remarkable in its structure. If the well were always open, the spider would sometimes be subject to the intru- sion of dangerous guests. Providence has there- fore instructed her to fabricate a very secure trap-door which closes the mouth of it. To judge of this door by its outward appearance, it appears to be formed of a mass of earth coarsely worked, and covered internally by a solid web, which would be sufficiently wonder- ful for an animal that seems to have no special organ for constructing it ; but when divided vertically, it is found to be a much more com- plicated fabric than its outward appearance in- dicates, it being formed of more than thirty alternate layers of earth and web emboxed, as it were, in each other, like a set of weights for small scales. "If these layers of web are examined, it will be seen that they all terminate in the hinge, so that the greater the volume of the door the more powerful is the hinge. The frame in which the tube terminates above, and to which the door is adapted, is thick, arising from the number of layers of which it consists, and which seem to correspond with those of the door; hence the formation of the door, the hinge, and the frame, seem to be a simultaneous operation ; except that in fabricating the first, the animal has to knead the earth as well as to spin the layers of web. By this admirable arrangement these parts always correspond with each other, and the strength of the hinge and the thickness of the frame will always be proportioned to the weight of the door. " The interior surface of the cover to the tube is not rough and uneven like its exterior, but perfectly smooth and even like the walls of the tube, being covered with a coating of white silk, but more firm, and resembling parchment, and remarkable for a series of minute orifioes placed in the side opposite the hinge, and ar- ranged in a semicircle ; there are about thirty of these orifices, the object of which, M. Au- douin conjectures, is to enable the animal to hold her door down in any case of emergency against external force, by the insertion of her claws into some of them."* But the most extraordinary habitations formed by the instincts of animals are those which are the joint result of the labours of communities; and here we observe the same difference as has been already noticed, between the inhabitants of the air and of the ocean. Many of the ani- mals that inhabit the latter are formed by na- ture, as Mr. Kirby expresses it, (and evidently with a view to the rude shocks to which they are exposed,) " into a body politic, consisting of many individuals, separate and distinct as inhabiting different cells, but still possessing a body in common, and many of them receiving benefit from the systole and diastole of a com- mon organ ; thus by a natural union is symbo- lized what in terrestrial animal communities re- sults from numerous wills uniting to effect a common object. The land, as far as I recol- lect, exhibits no instance of an aggregate animal, nor the ocean of one which, like the beaver, lemming, bee, wasp, &c. forms associations to build and inhabit a common house. "f And there is a curious family, named Salpa, in which the individuals are attached to each other almost like bees in their cells at birth, and are afterwards separated when they have acquired strength; thus forming the link be- tween the aggregated sea animals (such as Co- rals, Madrepores, Sertularia, Flustra, &c.) and the associated land animals. The habitations that are formed by animals of the latter description, although in very diffe- rent parts of the scale of beings, afford equally curious evidence of skill and contrivance, and of the wills of numerous individuals, bound together by a common instinct, as surely as the materials of which the aggregate animals are composed. Take, for example, the houses of beavers. " Beavers set about building some time in the month of August: those that erect their habitations in small rivers or creeks in which the water is liable to be drained off, with won- derful sagacity provide against that evil by * Kirby, vol. ii. p. 287, et scq. t Kubj, vol. i. p. 222. INSTINCT. 11 forming a dike across the stream, almost straight where the current is weak, but where it is more rapid, curving more or less, with the convex side opposed to the stream. They construct these dikes or dams of the same materials as they do their lodges, viz. of pieces of wood of any kind, of stones, mud, and sand. These causeways oppose a sufficient barrier to the force both of water and ice ; and as the willows, poplars, &c. &c. employed in constructing them often strike root in it, it becomes in time a green hedge in which the birds build their nests. " By means of these erections the water is kept at a sufficient height, for it is absolutely necessary that there should be at least three feet of water above the extremity of the entry into their lodges, without which, in the hard frosts, it would be entirely closed. This entry is not on the land side, because such an open- ing might let in wild animals, but towards the water. " They begin to excavate under water at the base of the bank, which they enlarge upwards gradually, and so as to form a declivity, till they reach the surface ; and of the earth which comes out of this cavity they form a hillock, with which they mix small pieces of wood and even stones ; they give this hillock the form of a dome from four to seven feet high, from ten to twelve long, and from eight to nine wide. As they proceed in heightening, they hollow it out below, so as to form the lodtre which is to receive the family. At the anterior part of this dwelling, they form a gentle declivity termina- ting at the water, so that they enter and go out under water. " The interior forms only a single chamber resembling an oven. At a little distance is the magazine for provisions. Here they keep in store the roots of the yellow water-lily, and the branches of the black spruce, the aspin, and the birch, which they are careful to plant in the mud. These form their subsistence. Their magazines sometimes contain a cart-load of these articles, and the beavers are so industrious that they are always adding to their store."' The nests so admirably constructed by what have been called the perfect societies of insects, the white ants or termites, the ants or formicae, the bees, wasps, and humble bees, are well known, and have been often described. The materials used by the two first genera are chiefly clay, with bits of straw or wood, cemented by animal secretions ; the bees manufacture wax for the purpose. " The wasps and hoi-nets are remarkable for the well-known curious papier-mache edifices, in the construction of which they employ fila- ments of wood, scraped from posts and rails witli their own jaws, mixed with saliva, of which the hexagonal cells in which they rear their young are formed, and often their combs are separated and supported by pillars of the same material ; and the external walls of their nests are formed by foliaceous layers of their ligneous paper." f * Kirby, vol. ii. p. 510. t Kirby, loc. cit. p. 335. " The tree-ants, again, are remarkable for forming their nests on the boughs of trees of different kinds; and their construction is sin- gular, both for the material and the architec- ture, and is indicative of admirable foresight and contrivance ; in shape they vary from glo- bular to oblong, the longest diameter being about ten inches, and the shortest eight. The nests consist of a multitude of thin leaves of cow-dung, imbricated like tiles upon a house, the upper leaf formed of one unbroken sheet covering the summit like a skull-cap. The leaves are placed one upon another in a wavy or scalloped manner, so that numerous little arched entrances are left, and yet the interior is perfectly secured from rain. They are usually attached near the extremity of a branch, and some of the twigs pass through the nest. A vertical section presents a number of irregular cells, formed by the same process as the exte- rior. Towards the interior the cells are more capacious than those removed from the centre, and an occasional dried leaf is taken advantage of to assist in their formation. The nurseries for the young broods in different stages of developement are in different parts of the nest."* What is most peculiar in the habitations of all these " perfect societies of insects," is the formation, by the same working members of these societies, of cells of different size and form, suited for the different classes or ranks of indi- viduals which, as we shall afterwards state, each of these associations comprises ; and the occasional alteration of the size and form of the cells, when circumstances occur, which will be afterwards mentioned, to make an alteration of their destination advisable. There are other examples among insects, of imperfect societies or associations, found tempo- rarily and during the larva state only, which unite in forming tents under which they feed, and which shelter them from sun and rain. This is done by the larvae of several species of butterfly and moth.-)~ 4. The next instincts which may be noticed under this head are those connected with the hi/ber-nation of animals ; for in almost every case in which this faculty (which is found so gene- rally in the lower tribes, particularly reptiles and insects, as well as in the order Cheiroptera and several others of the higher animals,) exists, there is attached to it some instinctive propensity, prompting the animal, even although it be not one of those which form houses for themselves, at least to search for some suitable residence in which it may be sheltered during the winter, whether under ground, under stones or timber, under the bark of trees, &c. ; and it is very re- markable that their hiding places are often found, or formed, long before the weather has become very cold. " I am led to believe from my own observation," says Mr. Spence, " that the days which the majority of coleopterous insects select for retiring to their hybernacula are some of the warmest days of autumn, when * Ibid. p. 340. t Spence and Kirby, vol. ii. p. 21. 12 INSTINCT. they may be seen in great numbers alighting on walls, rails, path-ways, &c."* Some insects, and many larvae (as the silk-worm) approaching to the 'state of pupse, form a covering for them- selves by exudations from their own bodies, likewise at some distance of time before the frosts set in. Many hybernating animals ex- hibit so little of any vital action as to require little or no nourishment during the winter, ex- cepting the product of absorption of their own fat; but it is also well known that many of different orders (as the beaver, the hedgehog, the squirrel, the dormouse, the bee, which are seldom or never quite torpid,) are guided by instinct to lay up stores of provisions, on which they subsist during the winter. Some of these, as the lemming, have been observed to spread out their stores to dry in fine weather. Some of the most curious of the provisions of this kind are the following : " There is an animal, the rat-hare, which is gifted by its Creator with a very singular in- stinct, on account of which it ought rather to be called the hay-maker, since man may or might have learned that part of the business of the agriculturist, which consists in providing a store of winter provender for his cattle, from this industrious animal. Professor Pallas was the first who described the quadruped exercising this remarkable function, and gave an account of it. The Tungusians, who inhabit the country beyond the lake of Baikal, call it Pika, which has been adopted as its trivial name. " About the middle of the month of August these little animals collect their winter's pro- vender, formed of select herbs, which they bring near their habitations and spread out to dry like hay. In September they form heaps or stacks of the fodder they have collected under places sheltered from rain or snow. Where many of them have laboured together, their stacks are sometimes as high as a man, and more than eight feet in diameter. A subterranean gallery leads from the burrow below the mass of hay, so that neither frost nor snow can intercept their communication with it. Pallas had the pa- tience to examine their provision of hay piece by piece, and found it to consist chiefly of the choicest grasses and the sweetest herbs, all cut when most vigorous, and dried so slowly as to form a green and succulent fodder; he found in it scarcely any ears or blossoms, or hard and woody stems, but some mixture of bitter herbs, probably useful to render the rest more whole- some."-t " Although," says Kirby, " ants during the cold winters in this country remain in a state of torpidity, and have no need of food, yet in warmer regions during the rainy seasons, when they are probably confined to their nests, a store of provisions may be necessary for them. Now although the rainy season, at least in America, is a season in which insects are full of life, yet the observation that ants may store up provi- sions in warm countries is confirmed by an account sent me by Colonel Sykes, with respect * Introduction to Entomology, vol. ii. p. 438. t Ib. p. 507. to another species which appears to belong to the same genus as the celebrated ants of visi- tation, by which the houses of the inhabitants of Surinam were said to be cleared periodically of their cock-roaches, mice, and even rats. The present species has been named by Mr. Hope the provident ant. These ants, after long-con- tinued rains during the monsoon, were found to bring up and lay upon the earth on a fine day, their stores of grass seeds and grains of Guinea corn, for the purpose of drying them. Many scores of these hoards were frequently observable on the extensive parade at Poona."* The great and important instinct of migration is another means by which the lives of many animals are preserved during winter. The number of species of birds, which pass the summer to bring forth their young in this country, but disappear from it in autumn, and are known to spend the winter in the south of Europe or Africa, has been stated at not less than five-sixths of the whole number resident here during the summer, and these are replaced by many other species, chiefly aquatic birds and waders, but likewise the fieldfares, redwings, starlings, &c. which have brought forth their young in the colder climates, and return here for the winter. There are others, as the crane and stork, which perform similar migrations, but are rarely seen in this country. The migra- tions of the larger birds from the northern regions are chiefly performed in large bodies, forming angular lines, very high in the air; those of the smaller birds of passage, swallows, singing birds, &c. that go southwards from hence, seem to take place less regularly, and have been less accurately observed. There are also many annual migrations from one part of this country to another, in spring and autumn, as of the plovers and lapwings, curlews, ring ouzels, &c. It is still doubtful with what sensations the propensity to perform these peri- odical migrations is chiefly connected, whether with changes of temperature, or deficiency of food, or with the changes of the sexual desire, (as maintained by Jenner.f) But it is certain that the migrations take place while the tem- perature is still such as is well borne by the animals ; indeed of most of the species of birds of passage some individuals are frequently observed not to migrate ; J and it is equally certain that most of the birds of passage do not gradually withdraw, as if following the gradual changes of the food on which they live, but go oft' suddenly, and perform their voyages, par- ticularly in autumn, so rapidly, as to be much exhausted and emaciated at the end of them ; so that it is certainly not under the influence of sensations gradually changing and tending to partial and successive changes of place, but under that of a strong determination, overcom- ing the motives to action which are usually predominant, and commanding strenuous and painful exertion at a time when no great incon- venience is felt, that these voyages are per- * Vol. ii. p. 344. i Phil. Trans. 1824. $ Sec Darwin, Zoouomia, sect. xvi. 12. INSTINCT. 13 formed. And if, with Darwin and some others, we doubt of the existence of a blind instinctive propensity as the cause of these movements, we have no resource but to ascribe them to a very high decree of intelligence, combined with much mental resolution, and extending to all or almost all the individuals of the species, enabling them to foresee evils that are still remote, and determining them to undergo labour, fatigue, and danger in order to avoid them. It has also been repeatedly ascertained that the same indi- viduals return after their six months of absence and long voyages, to the very spots where they had been brought forth, implying a power of discernment and recollection which appear to us quite inconceivable. Of such high qua- lities of mind we see no indications in the other actions of these birds, excepting only in their preparations for the nurture of their young ; and if they really possessed these qualities, we might expect with perfect confidence to see them devise many contrivances for their comfort and convenience, and to witness variations and im- provements in habits, which we know from the writings of the ancient naturalists to have been perfectly uniform and stationary at least since the time of Aristotle. There are some of the Mammalia, chiefly of the order Ruminantia, which likewise perform periodical migrations in the natural state, as has been particularly noticed in America, of the bison, the musk-ox, and rein-deer. A similar instinct has been observed in the quaggas in Africa ; and a singular observation, as shewing a variation of instinct according to varying cir- cumstances, was made by Dr. Richardson, that the American black bear, when lean, and from that cause unfitted for hybernation, migrates in severe winters from the northward into the United States. The periodical migrations of fishes appear to be designed for the benefit of their offspring, not for their own preservation; and there are other migrations, in immense numbers, of various kinds of animals which are not periodical, and of which the object is still obscure, but which do not fall under the present head. II. Of instincts Jo?'' the propagation and support of offspring. Of the very curiously varied instincts of animals connected with the propagation and support of their off- spring, we need not dwell on those which must necessarily attend the very various kinds of organs (so well arranged and de- scribed by Cuvier), by which the impreg- nation of the ova in the different tribes of animals is effected the instincts, e. g. which prompt most male fishes to impregnate eggs already laid, and many reptiles to impregnate them at the moment of their emission from the body of the female, or which guide the different warm-blooded animals in the different modes of their sexual intercourse. The in- stincts which enable animals to anticipate and provide for the wants of their young are still more varied, and imply mental processes of greater complexity. The most important of these may be referred to the following heads. 1. This is probably one object of the migra- tions of birds above-mentioned, and certainly the main object of the migrations of great swarms of fishes, both in the sea, and of those which ascend the rivers ; to which the same observations, as to the return to the same spot whence they had formerly departed, and as to the labours and hazard which the instinct im- pels them to incur, are in many instances appli- cable. " The cod-fah makes for the coast at spawn- ing time, going northward ; this takes place towards the end of winter, or the beginning of spring. " The mackarel hybernates in the Arctic, Antarctic, and Mediterranean Seas, where it is stated to select certain depths of the sea called by the natives Barachouas, which are so land- locked, that the water is as calm at all times as in the most sheltered pools. " It is in these that the mackarel, directed by instinct, pass the winter. In the spring they emerge in infinite shoals from their hiding places, and proceed southward for the purposes of depositing their eggs in more genial seas. " What the mackarel is' to the north of Europe, the thunny is to the south. It de- posits its esgs in May and June, when it enters the Mediterranean, seeking the shores in shoals arranged in the form of a parallelogram, or as some say, a triangle, and making a great noise and stir. " The herring may be said to inhabit the arctic seas of Europe, Asia, and America, from whence they annually migrate at different times in search of food, and to deposit their spawn. Their shoals consist of millions of myriads, and are many leagues in width, many fathoms in thickness, and so dense that the fishes touch each other." " The largest and strongest are said to lead the shoals, which seem to move in a certain order, and to divide into bands as they proceed, visiting the shores of various islands and countries, and enriching their in- habitants." " They seek places for spawning where stones and marine plants abound, against which they rub themselves alternately on each side, all the while moving their fins with great rapidity." " In temperate climates the salmon quits the sea early in the spring, when the waves are driven by a strong wind against the river currents." " They leave the sea in numerous bands formed with great regularity. The largest individual, which is usually a female, takes the lead, and is followed by others of the same sex, two and two, each pair being at the distance of from three to six feet from the preceding one ; next come the old, and after them the young males in the same order." " They employ only three months in ascending to the sources of the Maraguon, the current of which is remarkably rapid, which is at the rate of nearly forty miles a day ; in a smooth stream or lake their progress would increase in a four-fold ratio. Their tail is a very powerful organ, and its muscles have wonderful energy ; by placing it in their mouth, they make of it a very elastic spring, for, letting it go with violence, they raise themselves in the air to the 14 INSTINCT. 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 efforts till they have accomplished it. The female is stated to hollow out a long and deep excavation in the gravelly bed of the river to receive her spawn."* A similar periodical emigration has been ob- served in other animals, particularly in some of the Crustacea. " Several of the crabs forsake the waters for a time, and return to them to cast their spawn ; but the most celebrated of all is that known by the name of land-crab, and alluded to by Dr. Paley as the violet-crab, and which is called by the French the tourlounm. They are natives of the West Indies and South Ame- rica. In the rainy season, in May and June, their instinct impels them to seek the sea, that they may fulfil the great law of their Creator, and cast their spawn. They descend the moun- tains, which are their usual abode, in such numbers that the roads and woods are covered witli them." " They are said to halt twice every day, and to travel chiefly in the night. Arrived at the sea-shore, they are there reported to bathe three or four times, when retiring to the neighbouring plains or woods, they repose for some time, and then the females return to the water, and commit their eggs to the waves. This business dispatched, they endeavour to regain, in the same order, the country they had left, and by the same route, but only the most vigorous can reach the mountains. "f The object of all these migrations is, that the female animals may have an opportunity of de- positing their eggs where they will be in circum- stances suited to their development, particularly as to the essential requisites, exposure to heat and to air. 2. The same object, the choice of a suitable place for depositing their eggs, is accomplished in other instances by very different instincts im- planted in female animals. " Repiiles," says Kirby, " and Fishes do not feel the instinctive love for their young, after birth, which is ex- hibited by quadrupeds and birds, but are in- variably instructed by the Creator to select a place in which their eggs can be hatched either by artificial or solar heat." Many of them likewise, as the salmon, dig holes before depositing them, for their protection. Those of the serpents which are not ovo-viviparous, bury their eggs in sand, or in heaps of fer- menting matter. The Saurians also select a proper place for their eggs, the crocodile, e.g. the sands beside rivers ; " one species of sala- mander commits a single egg to a leaf of Persicaria, protects it by carefully doubling the leaf, and then proceeding to another, repeats the manoeuvre till her oviposition is finished. Toads and frogs lay their eggs in water, sur- rounded by a gelatinous envelope which forms the first nourishment of the embryo," corres- ponding to the albumen of the bird's egg. In like manner every insect is directed by nature to place its eggs in situations where its Kirby, vol. i. t Ibid. young, when disclosed, will find its appro- priate nourishment ; some burrowing in the earth for this purpose ; many flies in dead animal matter about to putrefy ; many in dif- ferent parts of living vegetables;* bees and ants in the cells where they are to be fed by the working members of their hives, &c. A spe- cies of the ichneumon fly and some of the wasps have been observed to bury caterpillars along with their eggs, on which their larvae are to feed, and another fly to deposit its eggs on the back of a caterpillar, when the larvae feed on the secretion by which the covering of the pupa is to be formed.f 3. The instincts called into action in the nidification, particularly of birds, are so nume- rous, varied, and admirably adapted to their purpose, as to have called forth admiration in all ages. The pairing of the parent birds at the beginning of spring, when the labour is to begin ; the choice of a place suited to the habits of the species, on the ground, under ground, in rocks, on the edge of lakes or of the sea, in marshes, in bushes, on trees, on buildings of all descriptions ; the choice of the materials, and the labour exerted for com- pleting the work ; some using clay, some sand, some moss, some leaves, some straw or twigs, some moss or lichen ; many forming a rough outside of materials hardly to be distinguished from the surrounding objects, while the inside is warm and smooth ; some building in very pe- culiar forms to impede the access to their young ; the tailor-bird sewing leaves together with distinct stitches, and the Java swallows forming their gelatinous nests, as the bees manufacture their waxen cells, from the contents and secre- tions of their own stomachs ; all furnish proofs of contrivance too obvious and too nearly ad- justed to varying circumstances, to have es- caped the attention even of careless observers. Many of the Mammalia make some kind of provision, although less artificial, for the re- ception of their progeny. " Cats search about inquisitively for a concealed situation ; bur- rowing animals retire to the bottom of their burrows, and several of the Rodentia make beds of their own hair to receive their young ; " all beasts of prey, whose progeny come into the world blind and helpless, have some kind of retreat in which they supply them at once with warmth and nourishment. Many insects, also, besides those which associate in hives, use various precautions for the covering and pro- tection of their eggs. 4. The instinct of incubation, which forms the next part of the provisions for the repro- duction of birds, the extraordinary change then effected in the habits of the female bird, par- ticularly when attended and cheered, as hap- pens in so many cases, by the equally temporary instinct of song of the male bird, is another natural phenomenon too striking and interesting to have escaped observation ; and the object of * In this choice insects seem to be guided by the sense of smell, at least in the case where the food of the larvae to be brought forth is different from that of the parent. t Darwin. INSTINCT. 15 this provision of nature has been fully elucidated by the observations of Reaumur and many others as to the efficacy of artificial heat in procuring the development of the chick. 5. The instincts of many parent animals are likewise the means adopted by nature for pro- curing nourishment for the young. This is observed as to those of the lower orders whose young are brought forth in circumstances ren- dering it impossible for them to procure their own food (as the bee and wasp), and also as to the carnivorous tribes, both of birds and quad- rupeds ; the exertion requisite for procuring their prey being beyond the power of the young- animal, the instinct of the parent supplies the defect. In most cases fresh supplies of food are daily or even hourly brought to the young animals, but in some instances stores of nou- rishment are provided for the young of the higher animals, equally as for those of the bee or ant; the pelican brings a large supply in his pouch from a single fishing; and according to the observations of an author in the Magazine of Natural History, some of the carnivorous animals have the curious instinct of storing up with this view animals not dead, but stupified by injury of the brain. " I dug out," says he, " five young pole-cats, comfortably imbedded in dry withered grass ; and in a side hole, of proper dimensions for such a larder, I poked out forty large frogs and two toads, all alive, but merely capable of sprawling a little. On examination 1 found that the whole number, toads and all, had been purposely and dex- trously bitten through the brain."* Lastly, the young of all warm-blooded animals being unable for some time after they come into the world to maintain their own temperature, would soon perish of cold, even if capable of procuring their own food, but for the protection they receive from their parents. This seems to be the most general final cause of the crrogyjj or maternal affection so strongly implanted in all these animals, and to which so much of the first period of the existence of their offspring is intrusted, but of which there is little trace in the lower tribes. As, however, the dangers to which these young animals are exposed are numerous and varied, so nature has provided against them, not by a propensity to the performance of one kind of action only, but by a vigilant and permanent feeling which controls all the habits of the parent animal, and prompts many actions, some of which are strictly instinctive, while others ought rather to be called voluntary, but are quite at variance with the ordinary habits of the animals. Every one must be aware of the increased ferocity given to the female carnivo- rous animals during the time that they are occupied with the care of their young, and of the resolution with which birds, at other seasons pacific and even timid, will resent any intrusion on their nests or young broods ; of the provi- dent care of the cat or the lioness, which carries her young in her mouth, and of almost all fe- male warm-blooded animals, which gather them * Magazine, &c. vol. vi. p. 206. close to their bodies for protection from cold ; of the anxiety of the hen which has sat on duck's eggs, when the ducklings take to the water; of the resolution and ingenuity with which the lapwing fixes on herself the attention of passengers who may come near her nest, See. But what most distinctly indicates that all this care and anxiety are unconnected with any such anticipation of the results as would be acquired by a process of reasoning, is the absolute indif- ference which succeeds, when the parent animal at length sees her offspring independent of her assistance " And once rejoicing, never knows them more." III. Various instinctive propensities may be observed in animals, the object of which is the advantage of the race or of the animal creation generally, rather than of the individual or his progeny, and some the object of which is still obscure. Some of these are, like the maternal affection last mentioned, obviously partaken by the human race, or even chiefly perceptible in those animals which have much con- nexion with man. The instinctive attachments not only of dogs but various domestic animals to their masters or attendants, of cats to houses, of sheep to particular hills or pastures, might be illustrated by many curious anecdotes, and seem to be very similar to the feelings which, after being fully developed in the human race, and strengthened and extended by the reflective powers of the human mind, obtain the names of family affection, of local attachment, of patriotism, &c. If the instinct of modesty exists in hardly any animals, the desire of clean- liness may be observed in many. The instinct of imitation, formerly noticed, and which is of so essential importance to all human enterprises in which the cooperation of numbers is re- quired, is perhaps more distinctly observable in individual monkeys than in any other ani- mals, although it is probable that a similar feeling may be part of the bond of association by which many animals are congregated toge- ther in the mode to be presently noticed. The intuitive perception of the signs of emotion or passion in the countenance and gestures which precedes and excites the tendency to imitation in man, is obviously common to us with many other animals. In fact, although we rigidly maintain the essential superiority of the intellect of man over that of all other animals, we have already stated that the greater number of the active powers of the human mind which furnish the chief motives to action are on the same footing with those which operate on the lower animals. Not only are our appetites similar to theirs, but the greater number of the desires of which we are conscious are either shared with us by them, or at least would seem to belong to the same class as their instincts. Thus the desire of approbation is quite obvious at least in some of the domestic animals, and the desire of society, as observed by Stewart, seems to act very generally, although variously, in the ani- mal creation. The desire of power may be thought to be more peculiar to man, and we 16 INSTINCT. have every reason to believe that no other ani- mal can reflect on the possession of power in the abstract, or indulge in the imagination of scenes in which it is to be exerted, or rejoice in the acquisition of wealth of any kind, as the means of exercising power and procuring pleasure, independently of the actual enjoy- ment of them ; but many of the practical exemplifications of this desire come into direct comparison with, and probably involve feelings very similar to, the instincts of animals. Thus the pleasure which men feel in exerting power over the elements around them may be seen, in the case of children, to be prior to the expe- rience of any practical advantage from the arts of architecture, of mechanics, or of navigation ; and it may be confidently asserted, that but for this pleasure attending the exercise of those arts (and which may be supposed to be very similar to that which animates the beaver, the bird, or the ant in their respective labours,) they could never have been prosecuted with success. So also the pleasure which man in all ages has felt both in hunting and destroying animals, and also in acquiring dominion over them and sub- jecting them to his power, is clearly quite different from the anticipation of the useful purposes to which, whether dead or living, they may be applied, and appears precisely similar, both in its nature and in its object or final cause, to some of the instincts of animals. Indeed, in conformity to what has been already said of the essential peculiarities of the human intellect, it is only those motives to action which imply the previous formation of general notions or abstract ideas, that we can regard as peculiar to man ; and we may accord- ingly state that the desire of knowledge (we may even say more specifically, of scientific knowledge, ' rerum cognoscere causas ) and the sense of obligation religious and moral, are the motives to action which we believe to be truly peculiar to the human race. The most important instinct of animals refer- able to this head, clearly and strongly felt like- wise by man, (although combined in his case with many other feelings,) is the instinct of congregation. More or less of the desire of society is seen in a greafl majority of animals; but we may refer to this head many actions of animals, wherein many individuals of the same species cooperate, of which the object is in many instances still obscure, but to which the animals are impelled with an energy, and fre quently a self-devotion, attesting the strength of the mental feeling, and completely super- seding their usual habits. Messrs. Spence and Kirby enumerate not less than five kinds of association of insects to form what they term imperfect societies. " The first of these associations (for the sake of company only) consists chiefly of insects in their perfect state. The little beetles called whirlwigs, which may be seen clustering in groups under warm banks in every river and every pool, wheeling round and round with great velocity, at your approach dispersing and diving under water, but as soon as you retire resuming their accustomed movements, seem to be under the influence of the social principle, and to form their assemblies for no other purpose than to enjoy together in the sun- beam the mazy dance. Impelled by the same feeling, in the very depth of winter, even when the earth is covered with snow, the tribes of Tipulidtf (usually but improperly called gnats) assemble in sheltered situations at mid-day where the sun shines, and form themselves into choirs that alternately rise and fall with rapid evolutions. " Another association is that of males during the season of pairing. Of this nature seems to be that of the cockchafer and fernchafer, which, at certain periods of the year and hours of the day, hover over the summits of the trees and hedges like swarms of bees. " The males of another root-devouring beetle (Hoplia argentea, F.) assemble by myriads before noon in the meadows, when in these infinite hosts you will not find a single female. " The next description of insect associations is of those that congregate for the purpose of travelling or emigrating together. De Geer has given an account of the larvae of certain gnats (Tipulte, L.) which assemble in considerable numbers for this purpose, so as to form a band of a finger's breadth, and of one or two yards in length. And what is remarkable, while upon their march, which is very slow, they adhere to each other by a kind of glutinous secretion. " Kuhn mentions another of the Tipulida, the larvas of which live in society and emigrate in files. " But of insect emigrants none are more celebrated than the locusts, which, when arrived at their perfect state, assemble in such numbers as in their flight to intercept the sun-beams and to darken whole countries, passing from one region to another, and laying waste kingdom after kingdom. " The same tendency to shift their quarters has been observed in our little indigenous devourers, the Aphides. " It is the general opinion in Norfolk, Mr. Marshall informs us, that the saw-fly ( Tenthredo) comes from over sea. A farmer declared he saw them arrive in clouds so as to darken the air; the fishermen asserted that they had repeatedly seen flights of them pass over their heads when they were at a distance from land, and on the beach and cliffs they were in such quantities that they might have been taken up by shovels full. Three miles in- land they were described as resembling swarms of bees. " It is remarkable that of the emigrating insects here enumerated, the majority, for in- stance the Libellulae, the Coccinellee, Carabi, Cicadoe, &c. are not usually social insects, but seem to congregate, like swallows, merely for the purpose of emigration. " The next order of imperfect associations is that of those insects which feed together. " Two populous tribes, the great devastators of the vegetable world, the one in warm and the other in cold climates, to which 1 have already alluded under the head of emigrations, INSTINCT. 17 I mean Aphides and Locusts, are the best examples of this order. " So much as the world has suffered from these animals, it is extraordinary that so few observations have been made upon their history, economy, and mode of proceeding. " The eggs of the locusts were no sooner hatched in June," says Dr. Shaw, " than each of the broods collected itself into a compact body, of a furlong or more in square, and then marching directly forwards towards the sea, they let nothing escape them ; they kept their ranks like men iifwar, climbing over as they advanced every tree or wall that was in their way ; nay, they entered into our very houses and bed- chambers like so many thieves. A day or two after one of these hordes was in motion, others were already hatched to march and glean after them. Having lived near a month in this manner they arrived at their full growth, and threw off their ni/mpha state by casting their outward skin." " The transformation was per- formed in seven or eight minutes, after which they lay for a short time in a torpid and seem- ingly languishing condition; but as soon as the sun and the air had hardened their wings by dry- ing up the moisture that remained on them after casting their sloughs, they re-assumed their former voracity with an addition of strength and agility." " According to Jackson they have a govern- ment amongst themselves similar to that of the bees and ants; and when the king of the locusts rises, the whole body follow him, not one soli- tary straggler being left behind. But that locusts have leaders like the bees or ants, dis- tinguished from the rest by the size and splen- dour of their wings, is a circumstance that has not yet been established by any satisfactory evidence; indeed, very strong reasons maybe urged against it." " The last order of imperfect associations approaches nearer to perfect societies, and is that of those insects which the social principle urges to unite in some common work for the benefit of the community. " Many larvae of Lepidoptera associate with this view, some of which are social only during part of their existence, and others during the whole of it. " A still more singular and pleasing spectacle when their regiments march out to forage, is exhibited by the Processionary Bombyx. This moth, which is a native of France and has not yet been found in this country, inhabits the oak. Each family consists of from 600 to 800 individuals. When young, they have no fixed habitation, 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 sun-set the regiment leaves its quarters; or, to make the metaphor harmonize with the trivial name of the animal, the monks their coenobium. At their head is a chief, by whose movements their procession is regulated. When he stops all stop, and pro- ceed when he proceeds ; three or four of his immediate followers succeed in the same line, VOL. III. 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 on the steps of those that precede it. If the leader, arriving at a particular point, pursues a different direc- tion, all march to that point before they turn."* Examples of occasional associations, more or less resembling all these, and of which the object is in many instances still obscure, may be found in all the classes of the higher ani- mals, as is obvious, when we consider to how many tribes of animals the term gregarious is usually applied, e. g. to almost all the Rumi- nantia, some of the Pachydermata, and a few of the Rodentia. Some of the genus Muridse (rats and mice) have been long known to migrate, occasionally, in a manner resembling the locusts. " The general residence of the lem- ming," says Pallas, " is in the mountainous parts of Lapland and Norway, from which tracts at uncertain periods it descends in im- mense troops, and by its incredible numbers becomes a temporary scourge to the country, devouring the grain and herbage, and com- muting devastations equal to those of an army of locusts." " It is observable that their chief emigrations are made in the autumns of such years as are followed by severe winters." " The ground over which they have passed appears at a distance as if it had been ploughed, the grass being devoured to the roots in numerous stripes or parallel paths, of one or two spans broad, and at the distance of some yards from each other." " The army moves chiefly at night, or early in the morning. No obstacles that they meet in their way have any effect in altering their route, neither fires, nor deep ravines, nor torrents, nor marshes, nor lakes ; they proceed obstinately in a straight line, and hence many thousands perish in the waters." " If disturbed, in swimming over a lake, by oars or poles, they will not recede, but keep swim- ming directly on, and soon get into regular order again." " In their passage over land, if attacked by men, they will raise themselves up, uttering a kind of barking sound, and fly at the legs of their invaders, and will fasten so fiercely on the end of a stick, as to suffer them- selves to be swung about without quitting their hold, and are with great difficulty put to flight." " The major part of these hosts is destroyed by various enemies, as owls, hawks, weasels, ex- clusively of the number that perish in the waters, so that but a small part survive to return, as they are sometimes observed to do, to their native mountains." The campagnol, or short-tailed rat, has been known to com- mit similar ravages in France. It is obvious here, that under the influence of this instinct, and of the excitement of numbers (in which, as in our own race, the principle of imitation is probably much concerned) the usual motives to action of these animals are superseded, and their usual habits changed. We are still uncertain as to the use, or final * Introduction to Entomology, letter xvi. c 18 INSTINCT. cause, of the various congregations of birds that we daily witness, and of the varying" habits which they then exhibit crows, e. g. herons, and many water birds, roosting and bringing forth their young in large irregular societies ; the crows, besides, assembling at particular hours of the day, at all seasons ; some of the genus Parus, particularly the great and long-tailed titmouse, feeding in small flocks at all seasons ; plovers and lapwings keeping separate during the season of hatching and rearing their offspring, but assembling in flocks after their young have attained matu- rity; most of the birds of this country in the depth of winter associating in flocks much greater than can be necessary for the sake of warmth ; the hen chaffinches, and perhaps the females of other birds, congregating separately; many of these flocks consisting of multi- tudes moving quite irregularly, but all of them having apparently some means of intercom- munication or agreement ; some of them, as the starlings, performing very singular evo- lutions in concert; and many, as wild geese and other water-birds, always showing the dis- position to fly in regular lines. The greatest of all the congregations of birds are those of the migrating pigeons in America, described by Audubon, as forming clouds which pass over the whole extent of a town for several hours together, and as settling on ex- tensive districts of the woods in such multi- tudes as to cause much devastation among the branches. But the most extraordinary of all the asso- ciations of animals are those which have re- ceived the title of the perfect societies of in- sects, the bees, wasps, hornets and ants in the order of Hymenoptera, and the white ants or termites, in that of Neuroptera. The most important facts as to them seem to have been ascertained, partly by numerous former ob- servers, but chiefly by the Ilubers, Latreille, and others in the present age. The essential peculiarity of these associations of insects appears to be the complete sepa- ration of the males and females, on whom the propagation of the species depends, from the working members of the communities, by whom the habitations are constructed, and who pro- cure food both for the young and for the more perfect insects. In the case of the bees, the only prolific female is the queen-bee; the males are the drones; the working bees, constituting the mass of the community, are sterile females, and the larvae and pupae are confined to the cells and helpless ; the ants appear to differ from these only in the perfect females being much more numerous (only a few, however, being retained in each ant-hill); but the termites difier, in the larvae and even the pupae being working members, the males and females, when brought to perfection, always wandering abroad, and one of each sex in the perfect state only existing in each nest, being in fact forcibly detained there. Among these animals there is also a separate class, believed to be analogous to the working bees, i. e. to be sttrile females, larger than the labourers, and which are thought to act exclu- sively as the soldiers of the community, the smaller working ants (larvae) always disap- pearing, and these larger and fiercer animals shewing -themselves, when any of the works are attacked.* These associations differ from all others existing among animals, in the extraordinary instinct of respect and devotion shewn by the working members to the impregnated female, single in each swarm of bees, and in each nest of termites, and few in number in each nest of ants, and with this instinct most of their other peculiarities seem to be connected. But it is justly observed by Mr. Spence, that if we suppose all the labours of the bees and the ants to be guided by instincts, we must ne- cessarily attribute to these animals a much greater number and variety of instinctive pro- pensities, and more extraordinary modifications of them to suit varying circumstancts of their condition, than to any of what are usually called the higher animals. " In the common duck, one instinct leads it at its birth from the egg to rush to the water ; another to seek its proper food ; a third to pair witli its mate; a fourth to form a nest; a fifth to sit upon its eggs till hatched ; a sixth to assist the young ducklings in extricating them- selves from the shell ; and a seventh to defend them when in danger until able to provide for themselves : and it would not be easy as far as my knowledge extends, to add many more instinctive actions to the enumeration, or to adduce many specimens of the superior classes of animals endowed with a greater number. " But how vastly more manifold are the instincts of the majority of insects! " As the most striking example of the whole, I shall select the hive-bee, begging you to bear in mind that I do not mean to include those exhibited by the queen, the drones, or even those of the workers, termed by Huber cirieres (wax- makers) ; but only to enumerate those presented by that portion of the workers, termed by Huber nourrices or petites abeilles, upon whom, with the exception of making wax, laying the foundation of the cells, and col- lecting honey for being stored, the principal labours of the hive devolve. " By one instinct bees are directed to send out scouts previously to their swarming in search of a suitable abode ; and by another to rush out of the hive after the queen that leads forth the swarm, and follow wherever she bends her course. Having taken possession of their new abode, whether of their own selection or prepared for them by the hand of man, a third instinct teaches them to cleanse it from all im- purities ; a fourth to collect propolis, and with it to stop up every crevice except the entrance : a fifth to ventilate the hive for preserving the purity of the air ; and a sixth to keep a con- stant guard at the door. " In constructing the houses and streets of their new city, or the cells and combs, there are probably several distinct instincts exercised ; * See Spence and Kirby, vol. ii. p. 39. INSTINCT. 19 but not to leave room for objection, 1 shall regard them as the result of one only: yet the operations of polishing the interior of the cells, and soldering their angles and orifices with propolis, which are sometimes not under- taken for weeks after the cells are built; and the obscure but still more curious one of var- nishing them with the yellow tinge observable in old combs, seem clearly referable to at least two distinct instincts. " In their out-of-door operations several dis- tinct instincts are concerned. By one they are led to extract honey from the nectaries of flowers ; by another to collect pollen after a process involving very complicated manipu- lations, and requiring a singular apparatus of brushes and baskets ; and that must surely be considered a third which so remarkably and beneficially restricts each gathering to the same plant. It is clearly a distinct instinct which inspires bees with such dread of rain, that even if a cloud pass before the sun, they return to the hive in the greatest haste. " Several distinct instincts, again, are called into action in the important business of feeding the young brood. One teaches them to swal- low pollen, not to satisfy the calls of hunger, but that it may undergo in their stomach an elaboration fitting it for the food of the grubs ; and another to regurgitate it when duly con- cocted, and to administer it to their charge, proportioning the supply to the a?e and con- dition of the recipients. A third informs them when the young grubs have attained their full growth, and directs them to cover their cells with a waxen lid, convex in the male cells, but nearly flat in those of workers, and by a fourth, as soon as the young bees have burst into day, they are impelled to clean out the deserted tenements and make them ready for new oc- cupants. " Numerous as are the instincts already mentioned, the list must yet include those connected with that mysterious principle which binds the working bees of a hive to their queen : the singular imprisonment in which they retain the young queens that are to lead off a swarm, until their wings be sufficiently expanded to enable them to fly the moment they are at liberty, gradually paring away the waxen wall that confines them to an extreme thinness, and only suffering it to be broken down at the precise moment required ; the attention with which in these circumstances they feed the imprisoned queen by frequently putting honey on her proboscis, protruded from a small orifice in the lid of her cell ; the watchfulness with which, when at the period of swarming more queens than one are re- quired, they place a guard over the cells of those undisclosed, to preserve them from the jealous fury of their excluded rivals ; the exquisite calculation with which they inva- riably release the oldest queens the first from their confinement ; the singular love of mo- narchical dominion, by which, when two queens in other circumstances are produced, they are led to impel them to combat until one is de- stroyed ; the ardent devotion which binds them to the fate and fortune of the survivor; the distraction which they manifest at her loss, and their resolute determination not to accept of any stranger until an interval has elapsed sufficiently long to allow of no chance of the return of their rightful sovereign ; and (to omit a further enumeration) the obedience which in the utmost noise and confusion they shew to her well-known hum. " I have now instanced at least thirty dis- tinct instincts with which every individual of the nurses amongst the working-bees is en- dowed ; and if to the account be added their care to carry from the hive the dead bodies of any of the community ; their pertinacity in their battles, in directing their sting at those parts only of the bodies of their adversaries which are penetrable by it; their annual autum- nal murder of the drones, &c. Sec.- it is cer- tain that this number might be very consider- ably increased, perhaps doubled."* To these instincts, in the case of some species of ants we shall certainly have to add those by which they are guided in carrying on a regular system of warfare, either with other hives of the same species or with other species, in subjuga- ting and bringing up as workers or slaves those that they have subdued, and likewise in sub- jecting to their dominion tribes of Aphides.f But all this becomes still more surprising, because more at variance with the usual in- stincts of animals, when we consider the power of adapting their operations to changes in their circumstances, which such associations of in- sects possess. " It is," says Mr. Spence, " in the deviations of the instincts of insects and their accommoda- tion to circumstances, that the exquisiteness of these faculties is most decidedly manifested. The instincts of the larger animals seem capable of but slight modification. They are either ex- ercised in their full extent or not at all. A bird, when its nest is pulled out of a bush, though it should be laid uninjured close by, never attempts to replace it in its situation ; it contents itself with building another. But in- sects in similar contingencies often exhibit the most ingenious resources, their instincts surpri- singly accommodating themselves to the new circumstances in which they are placed, in a manner more wonderful and incomprehensible than the existence of the faculties themselves." This observation we support by various in- stances taken from the history of different in- sects ; but the most extraordinary are from the societies of insects of which we now speak ; and of these the following are only a specimen. " The combs of bees are always at an uniform distance from each other, namely, about one- third of an inch, which is just wide enough to allow them to pass easily, and have access to the young brood. On the approach of winter, when their honey-cells are not sufficient in number to contain all the stock, they elongate them considerably, and thus increase their capa- * Introduction to Entomology, vol. ii. p. 498 et seq. f Introd. to Entomology, letter xvii. c 2 20 INSTINCT. city. By this extension the intervals between the combs are unavoidably contracted ; but in winter well-stored magazines are essential, while from their state ot comparative inactivity spa- cious communications are less necessary. On the return of spring, however, when the cells are wanted for the reception of eggs, the bees contract the elongated cells to their former dimensions, and thus re-establish the just dis- tances between the combs which the care of their brood requires. But this is not all. Not only do they elongate the cells of the old combs when there is an extraordinary harvest of honey, but they actually give to the new cells which they construct on this emergency, a much greater diameter as well as a greater depth. " The queen-bee, in ordinary circumstances, places each egg in the centre of the pyramidal bottom of the cell, where it remains fixed by its natural gluten : but in an experiment of Huber, one whose fecundation had been re- tarded, had the first segments of her abdomen so swelled that she was unable to reach the bottom of the cells. She therefore attached her eggs (which were those of males) to their lower side, two lines from the mouth. As the larvae always pass that state in the place where they are deposited, those hatched from the eggs in question remained in the situation assigned them. But the working bees, as if aware that in these circumstances the cells would be too short to contain the larvae when fully grown, extended t/ieir length, even before the eggs were hatched. " The working bees, in closing up the cells containing larva?, invariably give a convex lid to the large cells of drones, and one nearly flat to the smaller cells of workers; but in an ex- periment instituted by Huber to ascertain the influence of the size of the cells on that of the included larva, he transferred the larvae of workers to the cells of drones. What was the result ? Did the bees still continue blindly to exercise their ordinary instinct ? On the con- trary, they now placed a nearly flat lid upon these large cells, as if well aware of their being occupied by a different race of inhabitants." But the most extraordinary of all these varia- tions of the operations of bees are seen in two cases which have been often produced for the sake of experiment, and of which the result appears to have been repeatedly and carefully observed. ' If a hive be in possession of a queen duly fertilized, and consequently sure, the next sea- son, of a succession of males, all the drones, towards the approach of winter, are massacred by the workers with the most unrelenting fero- city. This would seem to be an impulse as naturally connected with the organization and very existence of the workers, as that which leads them to build cells or store up honey. But however certain the doom of the drones if the hive be furnished with a duly fertilized queen, their undisturbed existence through the winter is equally certain if the hive has lost its sovereign, or if her impregnation has been so retarded as to make a succession of males in the spring doubtful ; in such a hive the workers do not destroy a single drone, though the hot- test persecution rages in all the hives around them." Again, " in a hive which no untoward event has deprived of its queen, the workers take no other active steps in the education of her suc- cessors, those of which one is to occupy her place when she has flown oft' at the head of a new swarm in spring, than to prepare a certain number of cells of extraordinary capacity for their reception while in the egg, and to feed them when become grubs with a peculiar food until they have attained maturity. This, there- fore, is their ordinary instinct ; and it may hap- pen that the workers of a hive may have no neces- sity, for a long series of successive generations, to exercise any other. But suppose them to lose their queen. Far from sinking into that inac- tive despair which was formerly attributed to them, after the commotion which the rapidly- circulated news of their calamity gave birth to has subsided, they betake themselves with an alacrity from which man, when under misfor- tune, might deign to take a lesson, to the repa- ration of their loss. Several ordinary cells are without delay pulled down and converted into a variable number of royal cells, capacious enough for the education of one or more queen- grubs selected out of the unhoused working grubs which in this pressing emergency are mercilessly sacrificed and fed with the appro- priate royal food to maturity. Thus sure of once more acquiring a head, the hive return to their ordinary labours, and in about sixteen days one or more queens are produced, one of which steps into day and assumes the reins of state." There can be no doubt that the perfect order and regularity seen in all the operations of these societies of insects could not be main- tained without some mode of communication among the different individuals concerned in these operations ; and it appears distinctly that such means of communication exist, and that it is in consequence of their being exercised, for example, that a swarm of bees, when it leaves a hive, takes the direction to a spot pre- viously fixed on, and carefully examined, by a small number of scouts, as observed by Mr. Knight.* When such facts are duly considered, we cannot be surprised to find so intelligent a na- turalist as Mr. Spence acknowledging that he had at one time arranged them as indications of reason in these animals. But on further consideration, we shall probably see cause to acquiesce in his later and more matured judg- ment, which ascribes them to strictly instinc- tive, although singularly varying propensities ; chiefly on two grounds, which exactly corre- spond to what was stated in the beginning of this paper as the most distinctive characters of instinct : 1 . that although various contrivances are fallen on by all bees to enable them to con- tinue their usual operations under varying ex- ternal circumstances, yet there is no such variety observed either in the conduct of individuals * Phil. Trans. 1807. INSTINCT. 21 of the species or in the conduct of different communities, as we cannot doubt must occur if the inhabitants of every hive were guided, on such unusual occasions, by processes of reason- ing, by observation of the laws of nature, by experience, and anticipation of the effects of their actions. If such mental processes were their guide, we should certainly observe a diffe- rence in the conduct of experienced workers, and of those just emerged from their pupae ; and we should observe some variety in the ex- pedients adopted in different hives for meeting such accidents or difficulties. 2. While the varying operations of these animals for one particular end, the preservation of their own lives and the perpetuation of their species, are planned and combined in such a manner as to indicate consummate intelligence as to what is essential for that purpose, all these indications of instinct are limited to that object, and we see no evidence of the exercise of their senses suggesting to them any other trains of thought, or exciting them to the prosecution of other objects, such as a number of human intellects capable of planning and executing such works would certainly, sooner or later, attempt to accomplish. The degree of uniformity seen in their operations, and the limitation of the ob- jects on which their faculties are exerted, are therefore our reason for thinking (although we do not wish to express ourselves with absolute confidence on the subject) that the mental pro- cesses concerned, even in those the most elabo- rate and artificial of the works of animals, be- long to the same class as those notions of man which are prompted by his instinctive propen- sities as distinguished from his reason. At the same time it ought to be stated, that there are many acts of individual animals, or of particular communities, in which we must admit that, although instinct is concerned, it must be guided by mental operations, in which short processes of reasoning, involving certain general ideas, must have been concerned. Several instances, quoted by Mr. Spence, seem hardly to admit of any other interpretation, e. g. the following from Huber. The bees of some of his neighbours protected themselves against the attacks of the death's-head moth, (Sphinx atropos,) by so closing the entrance of the hive with walls, arcades, &c. built of a mixture of wax and propolis, that these ma- rauders could no longer intrude themselves. Pure instinct would have taught " the bees to fortify themselves on the Jirst attack ; if the occupants of a hive had been taken unawares by these gigantic aggressors one night, on the second at least the entrance should have been barricadoed. But it appears clear, from the statement of Huber, that it was not until the hives had been repeatedly attacked, and robbed of nearly their whole slock of honey, that the bees betook themselves to the plan so success- fully adopted for the security of their remaining treasures ; so that reason, taught by experience, seems to have called into action their dormant instinct.'' Again, " a German artist, a man of strict vera- city, states that in his journey through Italy he was an eye-witness to the following occurrence. He observed a species of Scarabaeus busily en- gaged in making, for the reception of its egg, a pellet of dung, which when finished it rolled to the summit of a small hillock, and repeatedly suffered to tumble down its side, apparently for the sake of consolidating it by the earth which each time adhered to it. During this process the pellet unluckily fell into an adjoin- ing hole, out of which all the efforts of the beetle to extricate it were in vain. After several ineffectual trials, the insect repaired to an ad- joining heap of dung, and soon returned with three of his companions. All four now applied their united strength to the pellet, and at length succeeded in pushing it out ; which being done, the three assistant beetles left the spot and returned to their own quarters."* A number of other instances have been col- lected by Mr. Duncan. " Professor Fischer has published an account of a hen, which hen made use of the artificial heat of a hotbed to hatch her eggs." " A fact is stated by Reaumur of some ants, which, finding they could derive heat from a bee-hive, contrived to avail themselves of it by placing their larvae between the hive and an exterior covering." " Dr. Darwin observed a wasp with a large fly nearly as big as itself; finding it too heavy, it cut off the head and the abdomen, and then carried off the remainder, with the wings at- tached to it, into the air : but again finding the breeze act on the wings, and impede its pro- gress, it descended, and deliberately cut off the wings. Instinct might have taught it to cut off the wings of all insects previous to flying away with them ; but here it attempted to fly with the wings on, was impeded by a certain cause, discovered what that cause was, and alighted to remove it. Is not this a comparison of ideas, and deducing consequences from pre- mises ?" " M. de la Loubiere, in his relation of Siam, says, that in a part of that kingdom which lies open to great inundations, all the ants make their settlements on trees ; no ants' nests are to be seen any where else. Whereas in our country the ground is their only habitation." " We sometimes kill a cockroach," says Ligon in his history of Barbadoes, quoted by Spence, " and throw him on the ground, and mark what the ants will do with him ; his body is bigger than a hundred of them, and yet they will find the means to lay hold of him and lift him up; and having him above ground, away they carry him ; and some go by as ready assistants if any be weary, and some are officers that lead and shew the way ; and if the van-couriers perceive that the body of the cockroach lies across, and will not pass through the hole or arch through which they mean to carry him, order is given, and the body turned endways, and this is done a foot before they come to the hole, and without stop or stay/'f * Introd. to Entomology, vol. ii. j). 525. t History of Barbadoes, p. 63. 22 INSTINCT. Colonel Sykes communicated to Mr. Kirby a singular anecdote of some of the black ants in India, which had been prevented, for some time, from getting to some sweatmeats, by having the legs of the table on which they stood immersed in basins filled with water, and besides painted with turpentine. After a time, however, the ants again reached the sweatmeats ; and it was found that they did so by letting themselves drop from the wall, above the table, on the cloth which covered it* " In Senegal, where the heat is great, the ostrich neglects her eggs during the day, but sits on them at night. At the Cape of Good Hope, however, where the degree of heat is less, the ostrich, like other birds, sits upon her eggs both day and night." " Rabbits dig holes in the ground for warmth and protection ; but after continuing long in a domestic state, that resource being unnecessary, they seldom burrow." "A dog in a monastery, perceiving that the monks received their meals by rapping at a buttery-door, contrived to do so likewise, and when the allowance was pushed through, and the door shut, ran off with it. This was re- peated till the theft was detected." " A dog belonging to Mr. Taylor, a clergy- man, who lived at Colton, near Wolseley Bridge, was accused of killing many sheep. Complaints were made to his master, who as- serted that the thing was impossible, because he was muzzled every night. The neighbours persisting in the charge, the dog one night was watched, and he was seen to draw his neck out of the muzzle, then to go into a field, and eat as much of a sheep as satisfied his appetite. He next went into the river to wash his mouth, and returned afterwards to his kennel, put his head into the muzzle again, and lay very qui- etly down to sleep." " I observed," says the Rev. J. Hall in his Travels in Scotland, " two magpies hopping round a gooseberry bush, in a small garden near a poor-looking house, in a peculiar manner, and flying in and out of the bush. I stepped aside to see what they were doing, and found from the poor man and his wife, that as there are no trees all around, these magpies several succeeding years had built their nest, and brought up their young, in this bush ; and that foxes, cats, hawks, &c. might not interrupt them, they had barricadoed not only their nest, but had encircled the bush with briers and thorns in a formidable manner ; nay, so com- pletely, that it would have cost even a fox, cunning as he is, some days' labour to get into that nest. " The materials in the inside of the nest were soft, warm, and comfortable ; but all on the outside, so rough, so strong, and firmly en- twined with the bush, that without a hedge- knife, hatch-bill, or something of the kind, even a man could not, without much pain and trouble, get at their young; as from the outside to the inside of the nest extended as long as my arm. * Bridgewater Treatise, vol. ii. p. 342. " These magpies had been faithful to one another for several summers, and drove off their young, as well as every one else who at- tempted to take possession of their nest. This they carefully repaired and fortified in the spring with strong rough prickly sticks, that they sometimes brought to it by uniting their force, one at each end, pulling it along, when they were not able to lift it from the ground."* Such examples leave no reasonable ground for doubt, that on certain subjects at least some animals are capable of short and simple processes of reasoning or of imagination, which appear to imply the perception of general truths, and the formation of certain general ideas, and that the difference, formerly stated between the operations of their minds and ours, in that respect, is one of degree only, not absolutely of kind. But this admission, it must be remembered, does by no means di- minish the force of the considerations formerly adduced to establish the essential distinction between the instinctive determinations prompt- ing the usual actions of animals, and some of those of men, and those volitions, whether in animals or men, which are consequent on the exercise of reason, and on such anticipation of their consequences as a process of reasoning only can afford. It is worth while to mention that in some instances animals have been thought to be pos- sessed of a faculty resembling reason, on ac- count of actions, very wonderful indeed, but which the possession of reason would not have enabled them to perform. Thus there are many instances of animals finding their way to their usual place of residence, after being re- moved from it in such a way as to prevent the mere act of recollection guiding them back. Mr. Duncan^ mentions having seen a pigeon, which had been brought from London, let loose on Magdalen Bridge, in Oxford. " It flew first towards the north, but after several gyrations in the air, it flew directly east, and reached London within the appointed time, which was, I believe, three hours." And Mr. Spence gives an anecdote, well authenticated, of an ass from Gibraltar, thrown overboard from a vessel at a distance of 200 miles, which swam ashore, and in a few days afterwards pre- sented himself for admission when the gate of the fortress was opened in the morning. Two instances, equally extraordinary, have been stated on unexceptionable authority to the pre- sent writer ; one of a pointer which had been sent from Durham to the neighbourhood of Edinburgh by sea, and made his way back in a few days by land, to his master's house in the former county ; the other of a kitten, which had been brought in a carriage a distance of above forty miles, to Edinburgh, and made its way back in a few days to its place of nativity in Stirlingshire, in doing which it must have crossed several bridges. Similar facts have been ascertained in several instances as to sheep ; and the cases of the swallow and of the Duncan's Lectures on Instinct, Ibid. INSTINCT. 23 salmon, returning to the spots where they were bred after their long migrations, are clearly analogous. But in such cases it is obvious that the pos- session of reason could not have enabled these animals, alone and unassisted, to find their way ; neither was the result properly referable to instinct, this term being properly applicable only to the feeling of attachment which prompted the return home, not to the know- ledge which the animals somehow acquired where their home was to be found. The only term properly applicable to the acquisition of this knowledge is intuition, and they should be added to other facts, which shew that in va- rious instances animals acquire, by the exercise of their senses, information as to external things, more obviously distinct from the sensa- tions themselves, than those perceptions which Dr. Reid has so clearly shewn to be strictly intuitive inferences, drawn by the human in- tellect from the intimations of the senses. There is yet another fact well ascertained of late years regarding the instincts of animals, which we must not omit to state, because it is the only one which gives plausibility to the notion of Darwin, that sensations and experi- ence would explain the whole phenomena of instinct. This is the fact, which seems well ascertained as to certain animals at least, which is very probably true of man, and sus- ceptible of important practical application in his case, that the acquired habits of one gene- ration may become instinctive propensities in the next. Thus it has been often observed that the progeny of well-trained pointers learn to point with very little instruction. It is stated by Darwin that dogs in the wild state, both in Africa and America, have been observed not to bark, that they gradually acquire that note from European dogs ; and that the latter, when turned loose, retain it for three or four generations, and gradually lose it ; and it has been ascertained that in South America, when horses which had been taught to amble had been allowed to run wild, their progeny for two or three generations continued to practice that pace, and then lost it.* Of the existence of such acquired instincts, therefore, there can be no doubt; but it need hardly be said that it is quite incompetent to explain the perfect uni- formity and the skilful contrivance observed in the instincts of animals ; both because its ope- ration seems too limited, and because that sup- position would only remove the difficulty as to the continuance of the instinctive operations from the present to the early generations of animals. In reviewing the varied phenomena of which we have given this hasty sketch, it is impos- sible not to be struck with the very important share which they occupy in the provisions by which the earth's surface is made a scene of continual activity and change. It is interest- ing to reflect on the different powers, to the This principle has been lately investigated and illustrated by Mr. Knight, in a paper read before the Royal Society of London. operation of which we can trace the unceasing changes continually taking place around us, and particularly on the gradation, and very gradual transition that may be observed, from those by which inanimate matter is continually moved and changed, up to those which ema- nate from the intellect of man. By the ori- ginal impulse given to the world, and by the laws of gravitation and of motion impressed on all matter, the greater and more striking movements of the inanimate world around us are continually determined ; and by the laws of chemistry, these movements are made sub- servient to constant changes in the composition of the inanimate world. Again, by the laws which were impressed on the lower class of living beings at the time of their introduction into the world, and by the consequently in- cessant reproduction of vital affinities, which it is in vain to attempt to resolve into the che- mistry of dead matter, a constant succession of living vegetable structures is determined, merely by the agency of air and water, heat and light, on those already existing. By the peculiar chemical operation of these living structures, the air, the water, and all the ma- terials of the earth's surface are subjected to peculiar and continual changes, implying slow but incessant movements, which seem clearly to indicate attractions and repulsions, peculiar to the state of vitality. It is still perhaps doubtful whether in the case of vegetables a property of vital contraction is to be added to the active powers of nature. In immediate but still obscure connection with the lowest of the vegetable creation are the lowest of the animals, where we see the first and slightest indications of sersations, and the feeblest mo- tions consequent on sensations, which we judge to be similar to those that we ourselves ex- perience and excite ; and here also the vital power of contraction, on which the whole life and activity of animals essentially depends, first clearly manifests itself. Then tracing the animal creation upwards, we find that the world contains an infinite number and variety of sentient beings, the provisions for whose enjoyment we may well believe to have been the main object of Providence in all the ar- rangements on the surface of the earth ; and to which are granted, in a pretty uniform grada- tion, more and more of the sensations and mental faculties by which nature is made known, and of the powers by which she may be controlled, until we arrive at the intellect and the capacity of Man. It appears farther that the maintenance, and reproduction, and the very existence of these animal structures are entrusted in part to the sensations of which they are made susceptible, and to the voluntary powers with which they are invested ; but that the introduction of these spontaneous powers into the regulation of their ceconomy is so very gradual, that it is hardly possible to say where the movements which result only from physical (although vital) causes terminate, and those which are excited by mental acts begin; hardly possible, for example, to say, at least as to many animals, 24 INSTINCT. whether the reflex function of Dr. Mar- shall Hall, on which respiration, degluti- tion, the evacuation of the bowels and blad- der, &c. depend, is to be regarded as the re- sult of a merely physical impression on the nerves and spinal cord, like the impression of blood on the heart; or whether the sensations which naturally accompany these actions are, in the natural state, part of the cause which excites them. But that even when the volun- tary powers of animals are certainly the means employed for the ends of their creation, they are still very generally guided by the superior intelligence which has framed both their phy- sical and mental constitution, and which rules the mental but instinctive efforts consequent on the sensations that are felt, as surely as the laws of muscular contraction rule the move- ments of the heart ; and it is into the hands of man alone that the reins of voluntary power are absolutely resigned. And when we thus pass in review the sen- sorial and voluntary powers of animals, we are naturally led to the question, whether there is really in our own case so great an exception to those laws of nature which regulate all the other members of the animal creation; whe- ther, admitting the essential superiority of the intellect or reason of man, the different desires and motives to action, which are implanted in him, are not equally subject to the control of the power that gives them, and whether their consequences are not as exactly ruled by laws and as fully anticipated, as those of the in- stincts of animals. Without entering fully on this abstruse ques- tion, we would take the liberty of remarking, in the view of placing it in its simplest form before our readers, that as the intimations of our own consciousness are the ultimate foun- dation of all the knowledge that we have or can have of our own minds, and as certain of the intuitive principles of belief which our minds naturally suggest to us must be trusted, if we are to inquire into the subject at all ; so the only question that can " be reasonably proposed on this point is, whether there is any good reason for suspecting that the belief of our own free-will, which naturally attends cer- tain of the operations of our minds, is a de- ception; and that the analogy of other ani- mals is only applicable to the subject in so far as it can throw light on that question. Now, we find that the works of man, which we ascribe to his reason, and in the execution of which the consciousness of his free-will intervenes, are essentially different from those which we ascribe to the blind instincts of ani- mals, in the total absence (already noticed) of that uniformity which is so leading a charac- teristic of the effects of the latter; and we may reasonably assert that this is just the difference to be expected between the works of man and of other animals, on the supposition that the power concerned in the former is not subject to the direct influence and control of that higher intellect, by which the laws and limits of that concerned in the latter are irrevocably set ; and therefore, that there exists no such analogy between the works of man and of other animals as need induce us to suspect, that the evidence of his consciousness on the point in question is not to be trusted. At the same time it ought to be observed, and perhaps has not been duly remarked, not only that the desires which are the principal motives to human action, are analogous to, sometimes identical with, the instincts of ani- mals, (many of them having been evidently given him with the same intention, and with a clear perception of their general result on his condition,) but also that the constitution of the human mind appears from the intimations of our own consciousness to be such, as to allow of interposition of a superior power, controlling in a certain degree the will of man, without making itself obvious to his mind. For it is admitted by the soundest metaphy- sicians, that the only truly voluntary power which we are conscious of possessing over the train of thought in our minds, and therefore ultimately over many of our actions, operates only indirectly.* We have no power of de- termining the thoughts that succeed one ano- ther or regulating the order of their succes- sion ; and although various laws of association have been laid down, by which many of the component parts of the train appear to be con- nected, yet it will hardly appear to any one who reflects on the operations of his mind, that all the thoughts which succeed one ano- ther can be ascertained to have such bonds of connection with one another. At all events, the only strictly voluntary power which we are conscious that we possess, is that of singling out and detaining any particular portion of the train, whereby it may be made to predominate in the mind, and to produce practical results which might not otherwise have followed ; and even this kind of influence over the train of thought is not exercised exclusively by volition, but is produced in a great measure also by other causes, physical and moral. Now if this be so, how can we deny the possibility of a superior intelligence retaining a power of con- trolling the acts of any individual human mind, or of any number of minds, either by suggest- ing particular thoughts, or by causing the mind to dwell upon particular thoughts in preference to others, without its sense of its own volun- tary power being interrupted or withdrawn, nay, without the spontaneous voluntary power being really suspended, the only difference beins in the degree of influence which it exerts over the train of thought and consequent vo- litions? It has been said that the expression in Pope's Universal Prayer * " So completely is the current of thoughts in the mind," says Stewart, " subjected to physical laws, that it has been justly observed by Lord Kames that we cannot, by an effort of our will, call up any one thought, and that the train of our ideas depends on causes which operate in a man- ner inexplicable by us. This observation, although it has been censured as paradoxical, is almost self- evident ; for to call up any particular thought sup- poses it to be already in the mind." Elements,