Chapter XXI

General Summary and Conclusion.

Main conclusion that man is descended from some lower form—Manner of development—Genealogy of man—Intellectual and moral faculties—Sexual selection—Concluding remarks.

A brief summary will here be sufficient to recall to the reader’s mind the more salient points in this work. Many of the views which have been advanced are highly speculative, and some no doubt will prove erroneous; but I have in every case given the reasons which have led me to one view rather than to another. It seemed worth while to try how far the principle of evolution would throw light on some of the more complex problems in the natural history of man. False facts are highly injurious to the progress of science, for they often long endure; but false views, if supported by some evidence, do little harm, as every one takes a salutary pleasure in proving their falseness; and when this is done, one path towards error is closed and the road to truth is often at the same time opened.

The main conclusion arrived at in this work, and now held by many naturalists who are well competent to form a sound judgment, is that man is descended from some less highly organised form. The grounds upon which this conclusion rests will never be shaken, for the close similarity between man and the lower animals in embryonic development, as well as in innumerable points of structure and constitution, both of high and of the most trifling importance,—the rudiments which he retains, and the abnormal reversions to which he is occasionally liable,—are facts which cannot be disputed. They have long been known, but until recently they told us nothing with respect to the origin of man. Now when viewed by the light of our knowledge of the whole organic world, their meaning is unmistakeable. The great principle of evolution stands up clear and firm, when these groups of facts are considered in connection with others, such as the mutual affinities of the members of the same group, their geographical distribution in past and present times, and their geological succession. It is incredible that all these facts should speak falsely. He who is not content to look, like a savage, at the phenomena of nature as disconnected, cannot any longer believe that man is the work of a separate act of creation. He will be forced to admit that the close resemblance of the embryo of man to that, for instance, of a dog—the construction of his skull, limbs, and whole frame, independently of the uses to which the parts may be put, on the same plan with that of other mammals—the occasional reappearance of various structures, for instance of several distinct muscles, which man does not normally possess, but which are common to the Quadrumana—and a crowd of analogous facts—all point in the plainest manner to the conclusion that man is the co-descendant with other mammals of a common progenitor.

We have seen that man incessantly presents individual differences in all parts of his body and in his mental faculties. These differences or variations seem to be induced by the same general causes, and to obey the same laws as with the lower animals. In both cases similar laws of inheritance prevail. Man tends to increase at a greater rate than his means of subsistence; consequently he is occasionally subjected to a severe struggle for existence, and natural selection will have effected whatever lies within its scope. A succession of strongly-marked variations of a similar nature are by no means requisite; slight fluctuating differences in the individual suffice for the work of natural selection. We may feel assured that the inherited effects of the long-continued use or disuse of parts will have done much in the same direction with natural selection. Modifications formerly of importance, though no longer of any special use, will be long inherited. When one part is modified, other parts will change through the principle of correlation, of which we have instances in many curious cases of correlated monstrosities. Something may be attributed to the direct and definite action of the surrounding conditions of life, such as abundant food, heat, or moisture; and lastly, many characters of slight physiological importance, some indeed of considerable importance, have been gained through sexual selection.

No doubt man, as well as every other animal, presents structures, which as far as we can judge with our little knowledge, are not now of any service to him, nor have been so during any former period of his existence, either in relation to his general conditions of life, or of one sex to the other. Such structures cannot be accounted for by any form of selection, or by the inherited effects of the use and disuse of parts. We know, however, that many strange and strongly-marked peculiarities of structure occasionally appear in our domesticated productions, and if the unknown causes which produce them were to act more uniformly, they would probably become common to all the individuals of the species. We may hope hereafter to understand something about the causes of such occasional modifications, especially through the study of monstrosities: hence the labours of experimentalists, such as those of M. Camille Dareste, are full of promise for the future. In the greater number of cases we can only say that the cause of each slight variation and of each monstrosity lies much more in the nature or constitution of the organism, than in the nature of the surrounding conditions; though new and changed conditions certainly play an important part in exciting organic changes of all kinds.

Through the means just specified, aided perhaps by others as yet undiscovered, man has been raised to his present state. But since he attained to the rank of manhood, he has diverged into distinct races, or as they may be more appropriately called sub-species. Some of these, for instance the Negro and European, are so distinct that, if specimens had been brought to a naturalist without any further information, they would undoubtedly have been considered by him as good and true species. Nevertheless all the races agree in so many unimportant details of structure and in so many mental peculiarities, that these can be accounted for only through inheritance from a common progenitor; and a progenitor thus characterised would probably have deserved to rank as man.

It must not be supposed that the divergence of each race from the other races, and of all the races from a common stock, can be traced back to any one pair of progenitors. On the contrary, at every stage in the process of modification, all the individuals which were in any way best fitted for their conditions of life, though in different degrees, would have survived in greater numbers than the less well fitted. The process would have been like that followed by man, when he does not intentionally select particular individuals, but breeds from all the superior and neglects all the inferior individuals. He thus slowly but surely modifies his stock, and unconsciously forms a new strain. So with respect to modifications, acquired independently of selection, and due to variations arising from the nature of the organism and the action of the surrounding conditions, or from changed habits of life, no single pair will have been modified in a much greater degree than the other pairs which inhabit the same country, for all will have been continually blended through free intercrossing.

By considering the embryological structure of man,—the homologies which he presents with the lower animals,—the rudiments which he retains,—and the reversions to which he is liable, we can partly recall in imagination the former condition of our early progenitors; and can approximately place them in their proper position in the zoological series. We thus learn that man is descended from a hairy quadruped, furnished with a tail and pointed ears, probably arboreal in its habits, and an inhabitant of the Old World. This creature, if its whole structure had been examined by a naturalist, would have been classed amongst the Quadrumana, as surely as would the common and still more ancient progenitor of the Old and New World monkeys. The Quadrumana and all the higher mammals are probably derived from an ancient marsupial animal, and this through a long line of diversified forms, either from some reptile-like or some amphibian-like creature, and this again from some fish-like animal. In the dim obscurity of the past we can see that the early progenitor of all the Vertebrata must have been an aquatic animal, provided with branchiæ, with the two sexes united in the same individual, and with the most important organs of the body (such as the brain and heart) imperfectly developed. This animal seems to have been more like the larvæ of our existing marine Ascidians than any other known form.

The greatest difficulty which presents itself, when we are driven to the above conclusion on the origin of man, is the high standard of intellectual power and of moral disposition which he has attained. But every one who admits the general principle of evolution, must see that the mental powers of the higher animals, which are the same in kind with those of mankind, though so different in degree, are capable of advancement. Thus the interval between the mental powers of one of the higher apes and of a fish, or between those of an ant and scale-insect, is immense. The development of these powers in animals does not offer any special difficulty; for with our domesticated animals, the mental faculties are certainly variable, and the variations are inherited. No one doubts that these faculties are of the utmost importance to animals in a state of nature. Therefore the conditions are favourable for their development through natural selection. The same conclusion may be extended to man; the intellect must have been all-important to him, even at a very remote period, enabling him to use language, to invent and make weapons, tools, traps, &c.; by which means, in combination with his social habits, he long ago became the most dominant of all living creatures.

A great stride in the development of the intellect will have followed, as soon as, through a previous considerable advance, the half-art and half-instinct of language came into use; for the continued use of language will have reacted on the brain, and produced an inherited effect; and this again will have reacted on the improvement of language. The large size of the brain in man, in comparison with that of the lower animals, relatively to the size of their bodies, may be attributed in chief part, as Mr. Chauncey Wright has well remarked,472 to the early use of some simple form of language,—that wonderful engine which affixes signs to all sorts of objects and qualities, and excites trains of thought which would never arise from the mere impression of the senses, and if they did arise could not be followed out. The higher intellectual powers of man, such as those of ratiocination, abstraction, self-consciousness, &c., will have followed from the continued improvement of other mental faculties; but without considerable culture of the mind, both in the race and in the individual, it is doubtful whether these high powers would be exercised, and thus fully attained.

The development of the moral qualities is a more interesting and difficult problem. Their foundation lies in the social instincts, including in this term the family ties. These instincts are of a highly complex nature, and in the case of the lower animals give special tendencies towards certain definite actions; but the more important elements for us are love, and the distinct emotion of sympathy. Animals endowed with the social instincts take pleasure in each other’s company, warn each other of danger, defend and aid each other in many ways. These instincts are not extended to all the individuals of the species, but only to those of the same community. As they are highly beneficial to the species, they have in all probability been acquired through natural selection.

A moral being is one who is capable of comparing his past and future actions and motives,—of approving of some and disapproving of others; and the fact that man is the one being who with certainty can be thus designated makes the greatest of all distinctions between him and the lower animals. But in our third chapter I have endeavoured to shew that the moral sense follows, firstly, from the enduring and always present nature of the social instincts, in which respect man agrees with the lower animals; and secondly, from his mental faculties being highly active and his impressions of past events extremely vivid, in which respects he differs from the lower animals. Owing to this condition of mind, man cannot avoid looking backwards and comparing the impressions of past events and actions. He also continually looks forward. Hence after some temporary desire or passion has mastered his social instincts, he will reflect and compare the now weakened impression of such past impulses, with the ever present social instinct; and he will then feel that sense of dissatisfaction which all unsatisfied instincts leave behind them. Consequently he resolves to act differently for the future—and this is conscience. Any instinct which is permanently stronger or more enduring than another, gives rise to a feeling which we express by saying that it ought to be obeyed. A pointer dog, if able to reflect on his past conduct, would say to himself, I ought (as indeed we say of him) to have pointed at that hare and not have yielded to the passing temptation of hunting it.

Social animals are partly impelled by a wish to aid the members of the same community in a general manner, but more commonly to perform certain definite actions. Man is impelled by the same general wish to aid his fellows, but has few or no special instincts. He differs also from the lower animals in being able to express his desires by words, which thus become the guide to the aid required and bestowed. The motive to give aid is likewise somewhat modified in man: it no longer consists solely of a blind instinctive impulse, but is largely influenced by the praise or blame of his fellow men. Both the appreciation and the bestowal of praise and blame rest on sympathy; and this emotion, as we have seen, is one of the most important elements of the social instincts. Sympathy, though gained as an instinct, is also much strengthened by exercise or habit. As all men desire their own happiness, praise or blame is bestowed on actions and motives, according as they lead to this end; and as happiness is an essential part of the general good, the greatest-happiness principle indirectly serves as a nearly safe standard of right and wrong. As the reasoning powers advance and experience is gained, the more remote effects of certain lines of conduct on the character of the individual, and on the general good, are perceived; and then the self-regarding virtues, from coming within the scope of public opinion, receive praise, and their opposites receive blame. But with the less civilised nations reason often errs, and many bad customs and base superstitions come within the same scope, and consequently are esteemed as high virtues, and their breach as heavy crimes.

The moral faculties are generally esteemed, and with justice, as of higher value than the intellectual powers. But we should always bear in mind that the activity of the mind in vividly recalling past impressions is one of the fundamental though secondary bases of conscience. This fact affords the strongest argument for educating and stimulating in all possible ways the intellectual faculties of every human being. No doubt a man with a torpid mind, if his social affections and sympathies are well developed, will be led to good actions, and may have a fairly sensitive conscience. But whatever renders the imagination of men more vivid and strengthens the habit of recalling and comparing past impressions, will make the conscience more sensitive, and may even compensate to a certain extent for weak social affections and sympathies.

The moral nature of man has reached the highest standard as yet attained, partly through the advancement of the reasoning powers and consequently of a just public opinion, but especially through the sympathies being rendered more tender and widely diffused through the effects of habit, example, instruction, and reflection. It is not improbable that virtuous tendencies may through long practice be inherited. With the more civilised races, the conviction of the existence of an all-seeing Deity has had a potent influence on the advancement of morality. Ultimately man no longer accepts the praise or blame of his fellows as his chief guide, though few escape this influence, but his habitual convictions controlled by reason afford him the safest rule. His conscience then becomes his supreme judge and monitor. Nevertheless the first foundation or origin of the moral sense lies in the social instincts, including sympathy; and these instincts no doubt were primarily gained, as in the case of the lower animals, through natural selection.

The belief in God has often been advanced as not only the greatest, but the most complete of all the distinctions between man and the lower animals. It is however impossible, as we have seen, to maintain that this belief is innate or instinctive in man. On the other hand a belief in all-pervading spiritual agencies seems to be universal; and apparently follows from a considerable advance in the reasoning powers of man, and from a still greater advance in his faculties of imagination, curiosity and wonder. I am aware that the assumed instinctive belief in God has been used by many persons as an argument for His existence. But this is a rash argument, as we should thus be compelled to believe in the existence of many cruel and malignant spirits, possessing only a little more power than man; for the belief in them is far more general than of a beneficent Deity. The idea of a universal and beneficent Creator of the universe does not seem to arise in the mind of man, until he has been elevated by long-continued culture.

He who believes in the advancement of man from some lowly-organised form, will naturally ask how does this bear on the belief in the immortality of the soul. The barbarous races of man, as Sir J. Lubbock has shewn, possess no clear belief of this kind; but arguments derived from the primeval beliefs of savages are, as we have just seen, of little or no avail. Few persons feel any anxiety from the impossibility of determining at what precise period in the development of the individual, from the first trace of the minute germinal vesicle to the child either before or after birth, man becomes an immortal being; and there is no greater cause for anxiety because the period in the gradually ascending organic scale cannot possibly be determined.473

I am aware that the conclusions arrived at in this work will be denounced by some as highly irreligious; but he who thus denounces them is bound to shew why it is more irreligious to explain the origin of man as a distinct species by descent from some lower form, through the laws of variation and natural selection, than to explain the birth of the individual through the laws of ordinary reproduction. The birth both of the species and of the individual are equally parts of that grand sequence of events, which our minds refuse to accept as the result of blind chance. The understanding revolts at such a conclusion, whether or not we are able to believe that every slight variation of structure,—the union of each pair in marriage,—the dissemination of each seed,—and other such events, have all been ordained for some special purpose.

Sexual selection has been treated at great length in these volumes; for, as I have attempted to shew, it has played an important part in the history of the organic world. As summaries have been given to each chapter, it would be superfluous here to add a detailed summary. I am aware that much remains doubtful, but I have endeavoured to give a fair view of the whole case. In the lower divisions of the animal kingdom, sexual selection seems to have done nothing: such animals are often affixed for life to the same spot, or have the two sexes combined in the same individual, or what is still more important, their perceptive and intellectual faculties are not sufficiently advanced to allow of the feelings of love and jealousy, or of the exertion of choice. When, however, we come to the Arthropoda and Vertebrata, even to the lowest classes in these two great Sub-Kingdoms, sexual selection has effected much; and it deserves notice that we here find the intellectual faculties developed, but in two very distinct lines, to the highest standard, namely in the Hymenoptera (ants, bees, &c.) amongst the Arthropoda, and in the Mammalia, including man, amongst the Vertebrata.

In the most distinct classes of the animal kingdom, with mammals, birds, reptiles, fishes, insects, and even crustaceans, the differences between the sexes follow almost exactly the same rules. The males are almost always the wooers; and they alone are armed with special weapons for fighting with their rivals. They are generally stronger and larger than the females, and are endowed with the requisite qualities of courage and pugnacity. They are provided, either exclusively or in a much higher degree than the females, with organs for producing vocal or instrumental music, and with odoriferous glands. They are ornamented with infinitely diversified appendages, and with the most brilliant or conspicuous colours, often arranged in elegant patterns, whilst the females are left unadorned. When the sexes differ in more important structures, it is the male which is provided with special sense-organs for discovering the female, with locomotive organs for reaching her, and often with prehensile organs for holding her. These various structures for securing or charming the female are often developed in the male during only part of the year, namely the breeding season. They have in many cases been transferred in a greater or less degree to the females; and in the latter case they appear in her as mere rudiments. They are lost by the males after emasculation. Generally they are not developed in the male during early youth, but appear a short time before the age for reproduction. Hence in most cases the young of both sexes resemble each other; and the female resembles her young offspring throughout life. In almost every great class a few anomalous cases occur in which there has been an almost complete transposition of the characters proper to the two sexes; the females assuming characters which properly belong to the males. This surprising uniformity in the laws regulating the differences between the sexes in so many and such widely separated classes, is intelligible if we admit the action throughout all the higher divisions of the animal kingdom of one common cause, namely sexual selection.

Sexual selection depends on the success of certain individuals over others of the same sex in relation to the propagation of the species; whilst natural selection depends on the success of both sexes, at all ages, in relation to the general conditions of life. The sexual struggle is of two kinds; in the one it is between the individuals of the same sex, generally the male sex, in order to drive away or kill their rivals, the females remaining passive; whilst in the other, the struggle is likewise between the individuals of the same sex, in order to excite or charm those of the opposite sex, generally the females, which no longer remain passive, but select the more agreeable partners. This latter kind of selection is closely analogous to that which man unintentionally, yet effectually, brings to bear on his domesticated productions, when he continues for a long time choosing the most pleasing or useful individuals, without any wish to modify the breed.

The laws of inheritance determine whether characters gained through sexual selection by either sex shall be transmitted to the same sex, or to both sexes; as well as the age at which they shall be developed. It appears that variations which arise late in life are commonly transmitted to one and the same sex. Variability is the necessary basis for the action of selection, and is wholly independent of it. It follows from this, that variations of the same general nature have often been taken advantage of and accumulated through sexual selection in relation to the propagation of the species, and through natural selection in relation to the general purposes of life. Hence secondary sexual characters, when equally transmitted to both sexes can be distinguished from ordinary specific characters only by the light of analogy. The modifications acquired through sexual selection are often so strongly pronounced that the two sexes have frequently been ranked as distinct species, or even as distinct genera. Such strongly-marked differences must be in some manner highly important; and we know that they have been acquired in some instances at the cost not only of inconvenience, but of exposure to actual danger.

The belief in the power of sexual selection rests chiefly on the following considerations. The characters which we have the best reason for supposing to have been thus acquired are confined to one sex; and this alone renders it probable that they are in some way connected with the act of reproduction. These characters in innumerable instances are fully developed only at maturity; and often during only a part of the year, which is always the breeding-season. The males (passing over a few exceptional cases) are the most active in courtship; they are the best armed, and are rendered the most attractive in various ways. It is to be especially observed that the males display their attractions with elaborate care in the presence of the females; and that they rarely or never display them excepting during the season of love. It is incredible that all this display should be purposeless. Lastly we have distinct evidence with some quadrupeds and birds that the individuals of the one sex are capable of feeling a strong antipathy or preference for certain individuals of the opposite sex.

Bearing these facts in mind, and not forgetting the marked results of man’s unconscious selection, it seems to me almost certain that if the individuals of one sex were during a long series of generations to prefer pairing with certain individuals of the other sex, characterised in some peculiar manner, the offspring would slowly but surely become modified in this same manner. I have not attempted to conceal that, excepting when the males are more numerous than the females, or when polygamy prevails, it is doubtful how the more attractive males succeed in leaving a larger number of offspring to inherit their superiority in ornaments or other charms than the less attractive males; but I have shewn that this would probably follow from the females,—especially the more vigorous females which would be the first to breed, preferring not only the more attractive but at the same time the more vigorous and victorious males.

Although we have some positive evidence that birds appreciate bright and beautiful objects, as with the Bower-birds of Australia, and although they certainly appreciate the power of song, yet I fully admit that it is an astonishing fact that the females of many birds and some mammals should be endowed with sufficient taste for what has apparently been effected through sexual selection; and this is even more astonishing in the case of reptiles, fish, and insects. But we really know very little about the minds of the lower animals. It cannot be supposed that male Birds of Paradise or Peacocks, for instance, should take so much pains in erecting, spreading, and vibrating their beautiful plumes before the females for no purpose. We should remember the fact given on excellent authority in a former chapter, namely that several peahens, when debarred from an admired male, remained widows during a whole season rather than pair with another bird.

Nevertheless I know of no fact in natural history more wonderful than that the female Argus pheasant should be able to appreciate the exquisite shading of the ball-and-socket ornaments and the elegant patterns on the wing-feathers of the male. He who thinks that the male was created as he now exists must admit that the great plumes, which prevent the wings from being used for flight, and which, as well as the primary feathers, are displayed in a manner quite peculiar to this one species during the act of courtship, and at no other time, were given to him as an ornament. If so, he must likewise admit that the female was created and endowed with the capacity of appreciating such ornaments. I differ only in the conviction that the male Argus pheasant acquired his beauty gradually, through the females having preferred during many generations the more highly ornamented males; the æsthetic capacity of the females having been advanced through exercise or habit in the same manner as our own taste is gradually improved. In the male, through the fortunate chance of a few feathers not having been modified, we can distinctly see how simple spots with a little fulvous shading on one side might have been developed by small and graduated steps into the wonderful ball-and-socket ornaments; and it is probable that they were actually thus developed.

Everyone who admits the principle of evolution, and yet feels great difficulty in admitting that female mammals, birds, reptiles, and fish, could have acquired the high standard of taste which is implied by the beauty of the males, and which generally coincides with our own standard, should reflect that in each member of the vertebrate series the nerve-cells of the brain are the direct offshoots of those possessed by the common progenitor of the whole group. It thus becomes intelligible that the brain and mental faculties should be capable under similar conditions of nearly the same course of development, and consequently of performing nearly the same functions.

The reader who has taken the trouble to go through the several chapters devoted to sexual selection, will be able to judge how far the conclusions at which I have arrived are supported by sufficient evidence. If he accepts these conclusions, he may, I think, safely extend them to mankind; but it would be superfluous here to repeat what I have so lately said on the manner in which sexual selection has apparently acted on both the male and female side, causing the two sexes of man to differ in body and mind, and the several races to differ from each other in various characters, as well as from their ancient and lowly-organised progenitors.

He who admits the principle of sexual selection will be led to the remarkable conclusion that the cerebral system not only regulates most of the existing functions of the body, but has indirectly influenced the progressive development of various bodily structures and of certain mental qualities. Courage, pugnacity, perseverance, strength and size of body, weapons of all kinds, musical organs, both vocal and instrumental, bright colours, stripes and marks, and ornamental appendages, have all been indirectly gained by the one sex or the other, through the influence of love and jealousy, through the appreciation of the beautiful in sound, colour or form, and through the exertion of a choice; and these powers of the mind manifestly depend on the development of the cerebral system.

Man scans with scrupulous care the character and pedigree of his horses, cattle, and dogs before he matches them; but when he comes to his own marriage he rarely, or never, takes any such care. He is impelled by nearly the same motives as are the lower animals when left to their own free choice, though he is in so far superior to them that he highly values mental charms and virtues. On the other hand he is strongly attracted by mere wealth or rank. Yet he might by selection do something not only for the bodily constitution and frame of his offspring, but for their intellectual and moral qualities. Both sexes ought to refrain from marriage if in any marked degree inferior in body or mind; but such hopes are Utopian and will never be even partially realised until the laws of inheritance are thoroughly known. All do good service who aid towards this end. When the principles of breeding and of inheritance are better understood, we shall not hear ignorant members of our legislature rejecting with scorn a plan for ascertaining by an easy method whether or not consanguineous marriages are injurious to man.

The advancement of the welfare of mankind is a most intricate problem: all ought to refrain from marriage who cannot avoid abject poverty for their children; for poverty is not only a great evil, but tends to its own increase by leading to recklessness in marriage. On the other hand, as Mr. Galton has remarked, if the prudent avoid marriage, whilst the reckless marry, the inferior members will tend to supplant the better members of society. Man, like every other animal, has no doubt advanced to his present high condition through a struggle for existence consequent on his rapid multiplication; and if he is to advance still higher he must remain subject to a severe struggle. Otherwise he would soon sink into indolence, and the more highly-gifted men would not be more successful in the battle of life than the less gifted. Hence our natural rate of increase, though leading to many and obvious evils, must not be greatly diminished by any means. There should be open competition for all men; and the most able should not be prevented by laws or customs from succeeding best and rearing the largest number of offspring. Important as the struggle for existence has been and even still is, yet as far as the highest part of man’s nature is concerned there are other agencies more important. For the moral qualities are advanced, either directly or indirectly, much more through the effects of habit, the reasoning powers, instruction, religion, &c., than through natural selection; though to this latter agency the social instincts, which afforded the basis for the development of the moral sense, may be safely attributed.

The main conclusion arrived at in this work, namely that man is descended from some lowly-organised form, will, I regret to think, be highly distasteful to many persons. But there can hardly be a doubt that we are descended from barbarians. The astonishment which I felt on first seeing a party of Fuegians on a wild and broken shore will never be forgotten by me, for the reflection at once rushed into my mind—such were our ancestors. These men were absolutely naked and bedaubed with paint, their long hair was tangled, their mouths frothed with excitement, and their expression was wild, startled, and distrustful. They possessed hardly any arts, and like wild animals lived on what they could catch; they had no government, and were merciless to every one not of their own small tribe. He who has seen a savage in his native land will not feel much shame, if forced to acknowledge that the blood of some more humble creature flows in his veins. For my own part I would as soon be descended from that heroic little monkey, who braved his dreaded enemy in order to save the life of his keeper; or from that old baboon, who, descending from the mountains, carried away in triumph his young comrade from a crowd of astonished dogs—as from a savage who delights to torture his enemies, offers up bloody sacrifices, practises infanticide without remorse, treats his wives like slaves, knows no decency, and is haunted by the grossest superstitions.

Man may be excused for feeling some pride at having risen, though not through his own exertions, to the very summit of the organic scale; and the fact of his having thus risen, instead of having been aboriginally placed there, may give him hopes for a still higher destiny in the distant future. But we are not here concerned with hopes or fears, only with the truth as far as our reason allows us to discover it. I have given the evidence to the best of my ability; and we must acknowledge, as it seems to me, that man with all his noble qualities, with sympathy which feels for the most debased, with benevolence which extends not only to other men but to the humblest living creature, with his god-like intellect which has penetrated into the movements and constitution of the solar system—with all these exalted powers—Man still bears in his bodily frame the indelible stamp of his lowly origin.

INDEX.

A.

Abbott, C., on the battles of seals, ii. 240.

Abductor of the fifth metatarsal, presence of, in man, i. 128.

Abercrombie, Dr., on disease of the brain affecting speech, i. 58.

Abipones, marriage-customs of the, ii. 373.

Abou-Simbel, caves of, i. 217.

Abortion, prevalence of the practice of, i. 134.

Abstraction, i. 62.

Acalles, stridulation of, i. 384.

Acanthodactylus capensis, sexual differences of colour in, ii. 36.

Accentor modularis, ii. 198.

Acclimatisation, difference of, in different races of men, i. 216.

Achetidæ, stridulation of the, i. 352, 353, 355; rudimentary stridulating organs in female, i. 359.

Acilius sulcatus, elytra of the female, i. 343.

Acomus, development of spurs in the female of, ii. 162.

Acridiidæ, stridulation of the, i. 352, 356; rudimentary stridulating organs in female, i. 359.

Acting, i. 232.

Actiniæ, bright colours of, i. 322.

Admiral butterfly, i. 392.

Adoption of the young of other animals by female monkeys, i. 41.

Advancement in the organic scale, Von Baer’s definition of, i. 211.

Aeby, on the difference between the skulls of man and the quadrumana, i. 190.

Æsthetic faculty, not highly developed in savages, i. 64.

Affection, maternal, i. 40; manifestation of, by animals, i. 40; parental and filial, partly the result of natural selection, i. 81; shown by birds in confinement, for certain persons, ii. 110; mutual, of birds, ii. 108.

Africa, probably the birthplace of man, i. 199; South, crossed population of, i. 225; South, retention of colour by the Dutch in, i. 242; South, proportion of the sexes in the butterflies of, i. 310; tattooing practised in, ii. 339; Northern, coiffure of natives of, ii. 340.

Agassiz, L., on conscience in dogs, i. 78; on the coincidence of the races of man with zoological provinces, i. 218; on the number of species of man, i. 226; on the courtship of the land-snails, i. 324; on the brightness of the colours of male fishes during the breeding season, ii. 13; on the frontal protuberance of the males of Geophagus and Cichla, ii. 13, 20; on the slight sexual differences of the South Americans, ii. 323; on the tattooing of the Amazonian Indians, ii. 342.

Age, in relation to the transmission of characters in birds, ii. 183; variation in accordance with, in birds, ii. 213.

Agelæus phœniceus, ii. 116.

Ageronia feronia, noise produced by, i. 387.

Agrion, dimorphism in, i. 363.

Agrion Ramburii, sexes of, i. 362.

Agrionidæ, difference in the sexes of, i. 362.

Agrotis exclamationis, i. 369.

Ague, tertian, dog suffering from, i. 13.

Aïthurus polytmus, young of, ii. 220.

Ainos, hairiness of the, ii. 321.

Alca torda, young of, ii. 217. Alces palmata, ii. 259.

Alder and Hancock, MM., on the nudibranch mollusca, i. 326.

Algen, Mr., on the stridulation of Scolytus, i. 379.

Allen, J. A., on the relative size of the sexes of Callorhinus ursinus, ii. 260; on the mane of Otaria jubata, ii. 267; on the pairing of seals, ii. 279; on sexual differences in the colour of bats, ii. 286.

Allen, S., on the habits of Hoplopterus, ii. 48; on the plumes of herons, ii. 82; on the vernal moult of Herodias bubulcus, ii. 84.

Alligator, courtship of the male, i. 272, ii. 29; roaring of the male, i. 331.

Amadavat, pugnacity of male, ii. 49.

Amadina Lathami, display of plumage by the male, ii. 95.

Amadina castanotis, display of plumage by the male, ii. 95.

Amazons, butterflies of the, i. 309; fishes of the, ii. 17.

America, variation in the skulls of aborigines of, i. 108; wide range of aborigines of, i. 218; lice of the natives of, i. 220; general beardlessness of the natives of, ii. 322.

America, North, butterflies of, i. 309; Indians of, women a cause of strife among the, ii. 324; Indians of, their notions of female beauty, ii. 344, 347.

America, South, character of the natives of, i. 216; population of parts of, i. 225; piles of stones in, i. 233; extinction of the fossil horse of, i. 239; desert-birds of, ii. 224; slight sexual difference of the aborigines of, ii. 323; prevalence of infanticide in, ii. 361.

American languages, often highly artificial, i. 112.

Americans, wide geographical range of, i. 112; and negroes, difference of, i. 247; aversion of, to hair on the face, ii. 348; native, variability of, i. 226.

Ammophila, on the jaws of, i. 342.

Ammotragus tragelaphus, hairy forelegs of, ii. 282, 285.

Amphibia, affinity of, to the ganoid fishes, i. 204;

vocal organs of the, ii. 331.

Amphibians, i. 213, ii. 24;

breeding whilst immature, ii. 215.

Amphioxus, i. 204.

Amphipoda, males sexually mature while young, ii. 215.

Amunoph III., negro character of features of, i. 217.

Anal appendages of insects, i. 342.

Analogous variation in the plumage of birds, ii. 74.

Anas, ii. 180.

Anas acuta, male plumage of, ii. 84.

Anas boschas, male plumage of, ii. 84.

Anas histrionica, ii. 214.

Anastomus oscitans, sexes and young of, ii. 217; white nuptial plumage of, ii. 228.

Anatidæ, voices of, ii. 60.

Anax junius, difference in the sexes of, i. 362.

Anglo-Saxons, estimation of the beard among the, ii. 349.

Animals, cruelty of savages to, i. 94; domesticated, more fertile than wild, i. 132; characters common to man and, i. 185; domestic, change of breeds of, ii. 369.

Annelida, i. 327.

Annulosa, i. 327.

Anolis cristatellus, male, crest of, ii. 32; pugnacity of the male, ii. 32; throat-pouch of, ii. 33.

Anobium tessellatum, sounds produced by, i. 384.

Anser canadensis, ii. 116.

Anser cygnoides, ii. 114; knob at the base of the beak of, ii. 129.

Anser hyperboreus, whiteness of, ii. 228.

Antelope, prong-horned, horns of, i. 289.

Antelopes, generally polygamous, i. 267; horns of, i. 289, ii. 245; canine teeth of some male, ii. 241; use of horns of, ii. 251; dorsal crests in, ii. 282; dewlaps of, ii. 284; winter change of two species of, ii. 299; peculiar markings of, ii. 299.

Antennæ, furnished with cushions in the male of Penthe, i. 343.

Anthidium manicatum, large male of, i. 347.

Anthocharis cardamines, i. 388, 393, 394; sexual difference of colour in, i. 409.

Anthocharis genutia, i. 393.

Anthocharis sara, i. 393.

Anthophora acervorum, large male of, i. 347.

Anthophora retusa, difference of the sexes in, i. 366.

Anthus, moulting of, ii. 83.

Anthropidæ, i. 195.

Antigua, Dr. Nicholson’s observations on yellow fever in, i. 245.

Antics of birds, ii. 68.

Antilocapra americana, horns of, i. 289, ii. 245.

Antilope bezoartica, horned females of, ii. 246, 248; sexual difference in the colour of, ii. 288.

Antilope Dorcas and euchore, ii. 245.

Antilope euchore, horns of, ii. 251.

Antilope montana, rudimentary canines in the young male of, ii. 258.

Antilope niger, sing-sing, caama, and gorgon, sexual differences in the colours of, ii. 289.

Antilope oreas, horns of, i. 289.

Antilope saiga, polygamous habits of, i. 267.

Antilope strepsiceros, horns of, i. 289.

Antilope subgutturosa, absence of suborbital pits in, ii. 280.

Antipathy, shown by birds in confinement, to certain persons, ii. 110.

Ants, i. 186; playing together, i. 39; memory in, i. 45; intercommunication of, by means of the antennæ, i. 58; large size of the cerebral ganglia in, i. 145; soldier-, large jaws of, i. 155; difference of the sexes in, i. 365; recognition of each other by, after separation, i. 365.

Ants, White, habits of, i. 364.

Anura, ii. 25.

Apatania muliebris, male unknown, i. 314.

Apathus, difference of the sexes in, i. 366.

Apatura Iris, i. 386, 388.

Apes, anthropomorphous, i. 196; difference of the young, from the adult, i. 13; building platforms, i. 53; probable speedy extermination of the, i. 201; Gratiolet on the evolution of, i. 230; semi-erect attitude of some, i. 142; mastoid processes of, i. 143; influence of the jaw-muscles on the physiognomy of, i. 144; female, destitute of large canines, i. 156; imitative faculties of, i. 161; canine teeth of male, ii. 241; females of some, less hairy beneath than the males, ii. 377.

Apes, long-armed, their mode of progression, i. 143.

Apis mellifica, large male of, i. 347.

Apollo, Greek statues of, ii. 350.

Apoplexy in Cebus Azaræ, i. 12.

Approbation, influence of the love of, i. 86, 92, 164, 165.

Appendages, anal, of insects, i. 342.

Aprosmictus scapulatus, ii. 174.

Aquatic birds, frequency of white plumage in, ii. 229.

Aquila chrysaëtos, ii. 105.

Arab women, elaborate and peculiar coiffure of, ii. 353.

Arabs, gashing of cheeks and temples among the, ii. 339.

Arachnida, i. 337.

Arakhan, artificial widening of the forehead by the natives of, ii. 351.

Arboricola, young of, ii. 190.

Archeopteryx, i. 204.

Arctiidæ,, coloration of the, i. 396.

Ardea asha, rufescens, and cærulea, change of colour in, ii. 231, 232.

Ardea cærulea, breeding in immature plumage, ii. 214.

Ardea gularis, change of plumage in, ii. 232.

Ardea herodias, love-gestures of the male, ii. 68.

Ardea ludoviciana, age of mature plumage in, ii. 213; continued growth of crest and plumes in the male of, ii. 216.

Ardea nycticorax, cries of, ii. 51.

Ardeola, young of, ii. 190.

Ardetta, changes of plumage in, ii. 179.

Argenteuil, i. 29.

Argus pheasant, ii. 72, 97, 181; display of plumage by the male, ii. 91; ocellated spots of the, ii. 134, 141; gradation of characters in the, ii. 141.

Argyll, Duke of, the fashioning of implements peculiar to man, i. 52; on the contest in man between right and wrong, i. 104; on the physical weakness of man, i. 156; on the primitive civilisation of man, i. 181; on the plumage of the male Argus pheasant, ii. 91; on Urosticte Benjamini, ii. 151; on the nests of birds, ii. 167; on variety as an object in nature, ii. 230.

Argynnis aglaia, colouring of the lower surface of, i. 396.

Aricoris epitus, sexual differences in the wings of, i. 345.

Aristocracy, increased beauty of the, ii. 356.

Arms, proportions of, in soldiers and sailors, i. 116; direction of the hair on the, i. 192.

Arms and hands, free use of, indirectly correlated with diminution of canines, i. 144.

Arrest of development, i. 121, 122.

Arrow-heads, stone, general resemblance of, i. 233.

Arrows, use of, i. 232.

Arteries, variations in the course of the, i. 108.

Artery, effect of tying, upon the lateral channels, i. 116.

Arthropoda, i. 328.

Arts practised by savages, i. 234.

Ascension, coloured incrustation on the rocks of, i. 326.

Ascidia, affinity of the lancelet to, i. 205;

tadpole-like larvæ of, i. 205.

Ascidians, i. 324; bright colours of some, i. 322.

Asinus, Asiatic and African species of, ii. 306.

Asinus tæniopus, ii. 306.

Ass, colour-variations of the, ii. 305.

Ateles, effects of brandy on an, i. 12;

absence of the thumb in, i. 140.

Ateles beelzebuth, ears of, i. 23.

Ateles marginatus, colour of the ruff of, ii. 291; hair on the head of, ii. 109; on the recognition of a dog by a turkey, ii. 110; on the selection of a mate by female birds, ii. 307.

Ateuchus, stridulation of, i. 384.

Ateuchus cicatricosus, habits of, i. 376.

Athalia, proportions of the sexes in, i. 314.

Attention, manifestations of, in animals, i. 44.

Audouin, V., on a hymenopterous parasite with a sedentary male, i. 273.

Audubon, J. J., on the pugnacity of male birds, ii. 43, 48; on Tetrao cupido, ii. 50; on Ardea nycticorax, ii. 51; on Sturnella ludoviciana, ii. 51; on the vocal organs of Tetrao cupido, ii. 56; on the drumming of the male Tetrao umbellus, ii. 61; on sounds produced by the nightjar, ii. 63; on Ardea herodias and Cathartes jota, ii. 68; on the spring change of colour in some finches, ii. 86; on Mimus polyglottus, ii. 116; on the turkey, ii. 119, 121; on variation in the male scarlet tanager, ii. 126; on the habits of Pyranga æstiva, ii. 167; on local differences in the nests of the same species of birds, ii. 171; on the habits of woodpeckers, ii. 175; on Bombycilla carolinensis, ii. 180; on young females of Tanagra æstiva acquiring male characters, ii. 180; on the immature plumage of thrushes, ii. 185; on the immature plumage of birds, ii. 186 et seq.; on birds breeding in immature plumage, ii. 214; on the growth of the crest and plumes in the male Ardea ludoviciana, ii. 216; on the change of colour in some species of Ardea, ii. 231; on the speculum of Mergus cucullatus, ii. 291; on the musk-rat, ii. 298.

Audubon and Bachman, MM., on squirrels fighting, ii. 239; on the Canadian lynx, ii. 267.

Austen, N. L., on Anolis cristatellus, ii. 32, 33.

Australia, half-castes killed by the natives of, i. 220; lice of the natives of, i. 220; not the birthplace of man, i. 199; prevalence of female infanticide in, ii. 364.

Australia, South, variation in the skulls of aborigines of, i. 108.

Australians, colour of newborn children of, ii. 318; height of the sexes of, ii. 320; women a cause of war among the, ii. 323.

Axis deer, sexual difference in the colour of the, ii. 290.

Aymaras, measurements of the, i. 119; no grey hair among the, ii. 320; hairlessness of the face in the, ii. 322; long hair of the, ii. 348.

Azara, on the proportion of men and women among the Guaranys, i. 302; on Palamedea cornuta, ii. 48; on the beards of the Guaranys, ii. 322; on strife for women among the Guanas, ii. 324; on infanticide, ii. 344, 364; on the eradication of the eyebrows and eyelashes by the Indians of Paraguay, ii. 348; on polyandry among the Guanas, ii. 366; celibacy unknown among the savages of South America, ii. 367; on the freedom of divorce among the Charruas, ii. 372.

B.

Babbage, C., on the greater proportion of illegitimate female births, i. 302.

Babirusa, tusks of the, ii. 264.

Baboon, employing a mat for shelter against the sun, i. 53; manifestation of memory by a, i. 45; protected from punishment by its companions, i. 78; rage excited in, by reading, i. 42.

Baboon, Cape, mane of the male, ii. 267; Hamadryas, mane of the male, ii. 267.

Baboons, effects of intoxicating liquors on, i. 12; ears of, i. 23; manifestation of maternal affection by, i. 41; using stones and sticks as weapons, i. 51; co-operation of, i. 75; silence of, on plundering expeditions, i. 79; diversity of the mental faculties in, i. 110; hands of, i. 139; habits of, i. 141; variability of the tail in, i. 150; apparent polygamy of, i. 266; polygamous and social habits of, ii. 362.

Bachman, Dr., on the fertility of mulattoes, i. 221.

Baer, K. E. von, on embryonic development, i. 14.

Bagehot, W., on the social virtues among primitive men, i. 93; on the value of obedience, i. 162; on human progress, i. 166; on the persistence of savage tribes in classical times, i. 239.

Bailly, E. M., on the fighting of stags, ii. 252; on the mode of fighting of the Italian buffalo, ii. 250.

Bain, A., on the sense of duty, i. 71; aid springing from sympathy, i. 77; on the basis of sympathy, i. 82; on love of approbation, &c., i. 86; on the idea of beauty, ii. 354.

Baird, W., on a difference in colour between the males and females of some Entozoa, i. 321.

Baker, Mr., observation on the proportion of the sexes in pheasant-chicks, i. 306.

Baker, Sir S., on the fondness of the Arabs for discordant music, ii. 67; on sexual difference in the colours of an antelope, ii. 289; on the elephant and rhinoceros attacking white or grey horses, ii. 295; on the disfigurements practised by the negroes, ii. 296; on the gashing of the cheeks and temples practised in Arab countries, ii. 339; on the coiffure of the North Africans, ii. 340; on the perforation of the lower lip by the women of Latooka, ii. 341; on the distinctive characters of the coiffure of central African tribes, ii. 342; on the coiffure of Arab women, ii. 353.

“Balz” of the Black-cock, ii. 45, 100.

Bantam, Sebright, i. 259, 294.

Banteng, horns of, ii. 247; sexual differences in the colours of the, ii. 289.

Banyai, colour of the, ii. 346.

Barbarism, primitive, of civilised nations, i. 181.

Barbs, filamentous, of the feathers, in certain birds, ii. 74.

Barr, Mr., on sexual preference in dogs, ii. 272.

Barrington, Daines, on the language of birds, i. 55; on the clucking of the hen, ii. 51; on the object of the song of birds, ii. 52; on the singing of female birds, ii. 54; on birds acquiring the songs of other birds, ii. 55; on the muscles of the larynx in song-birds, ii. 55; on the want of the power of song by female birds, ii. 163.

Barrow, on the widow-bird, ii. 98.

Bartlett, A. D., on the tragopan, i. 270; on the development of the spurs in Crossoptilon auritum, i. 290; on the fighting of the males of Plectropterus gambensis, ii. 46; on the knot, ii. 82; on display in male birds, ii. 87; on the display of plumage by the male Polyplectron, ii. 89; on Crossoptilon auritum and Phasianus Wallichii, ii. 93; on the habits of Lophophorus, ii. 121; on the colour of the mouth in Buceros bicornis, ii. 129; on the incubation of the cassowary, ii. 204; on the Cape Buffalo, ii. 250; on the use of the horns of antelopes, ii. 251; on the fighting of male wart-hogs, ii. 266; on Ammotragus tragelaphus, ii. 282; on the colours of Cercopithecus cephus, ii. 291; on the colours of the faces of monkeys, ii. 310; on the naked surfaces of monkeys, ii. 377.

Bartram, on the courtship of the male alligator, ii. 29.

Basque language, highly artificial, i. 61.

Bate, C. S., on the superior activity of male crustacea, i. 272; on the proportions of the sexes in crabs, i. 315; on the chelæ of crustacea, i. 330; on the relative size of the sexes in crustacea, i. 332; on the colours of crustacea, i. 335.

Bates, H. W., on variation in the form of the head of Amazonian Indians, i. 111; on the proportion of the sexes among Amazonian butterflies, i. 309; on sexual differences in the wings of butterflies, i. 345; on the field-cricket, i. 353; on Pyrodes pulcherrimus, i. 367; on the horns of Lamellicorn beetles, i. 370, 371; on the colours of Epicaliæ, &c., i. 388; on the coloration of tropical butterflies, i. 391; on the variability of Papilio Sesostris and Childrenæ, i. 402; on male and female butterflies inhabiting different stations, i. 403; on mimickry, i. 411; on the caterpillar of a Sphinx, i. 416; on the vocal organs of the umbrella-bird, ii. 58; on the toucans, ii. 227; on Brachyurus calvus, ii. 309.

Batokas, knocking out two upper incisors, ii. 340.

Batrachia, ii. 25; eagerness of male, i. 272.

Bats, sexual differences in the colour of, ii. 286.

Battle, law of, i. 182; among beetles, i. 375; among birds, ii. 40; among mammals, ii. 239 et seq.; in man, ii. 323.

Beak, sexual difference in the forms of the, ii. 39; in the colour of the, ii. 72.

Beaks, of birds, bright colours of, ii. 227.

Beard, development of, in man, ii. 317; analogy of the, in man and the quadrumana, ii. 319; variation of the development of the, in different races of men, ii. 321; estimation of, among bearded nations, ii. 349; probable origin of the, ii. 379.

Beards, in monkeys, i. 192; of mammals, ii. 282.

Beautiful, taste for the, in birds, ii. 108; in the quadrumana, ii. 296.

Beauty, sense of, in animals, i. 63; appreciation of, by birds, ii. 111; influence of, ii. 338, 343; variability of the standard of, ii. 370.

Beavan, Lieut., on the development of the horns in Cervus Eldi, i. 288.

Beaver, instinct and intelligence of the, i. 37, 38; voice of the, ii. 277; castoreum of the, ii. 279.

Beavers, battles of male, ii. 239.

Bechstein, on female birds choosing the best singers among the males, ii. 52; on rivalry in song-birds, ii. 53; on the singing of female birds, ii. 54; on birds acquiring the songs of other birds, ii. 55; on pairing the canary and siskin, ii. 115; on a sub-variety of the monk pigeon, ii. 132; on spurred hens, ii. 162.

Beddoe, Dr., on causes of difference in stature, i. 115.

Bee-eater, ii. 56.

Bees, i. 73; destruction of drones and queens by, i. 82; pollen-baskets and stings of, i. 155; female, secondary sexual characters of, i. 254; difference of the sexes in, i. 365.

Beetle, luminous larva of a, i. 345.

Beetles, i. 366; size of the cerebral ganglia in, i. 145; dilatation of the fore tarsi in male, i. 343; blind, i. 367; stridulation of, i. 378.

Belgium, ancient inhabitants of, i. 237.

Bell, Sir C, on emotional muscles in man, i. 5; “snarling muscles,” i. 127; on the hand, i. 141.

Bell, T., on the numerical proportion of the sexes in moles, i. 305; on the newts, ii. 24; on the croaking of the frog, ii. 27; on the difference in the coloration of the sexes in Zootoca vivipara, ii. 36; on moles fighting, ii. 239.

Bell-bird, sexual difference in the colour of the, ii. 79.

Bell-birds, colours of, ii. 228.

Benevolence, manifested by birds, ii. 109.

Bennett, A. W., on the habits of Dromœus irroratus, ii. 205.

Bennett, Dr., on birds of paradise, ii. 89.

Bernicla antarctica, colours of, ii. 228.

Bernicle gander pairing with a Canada goose, ii. 114.

Bettoni, E., on local differences in the nests of Italian birds, ii. 171.

Bhoteas, colour of the beard in, ii. 319.

Bhringa, disciform tail-feathers of, ii. 83.

Bibio, sexual differences in the genus, i. 349.

Bichat, on beauty, ii. 354.

Bile, coloured, in many animals, i. 323.

Bimana, i. 190.

Birds, imitations of the songs of other birds by, i. 44; dreaming, i. 46; language of, i. 55; sense of beauty in, i. 63; pleasure of, in incubation, i. 79; male, incubation by, i. 210; and reptiles, alliance of, i. 213; sexual differences in the beak of some, i. 255; migratory, arrival of the male before the female, i. 259; apparent relation between polygamy and marked sexual differences in, i. 270; monogamous, becoming polygamous under domestication, i. 270; eagerness of male in pursuit of the female, i. 272; wild, numerical proportion of the sexes in, i. 306; secondary sexual characters of, ii. 38; difference of size in the sexes of, ii. 43; fights of male, witnessed by females, ii. 49; display of male, to captivate the females, ii. 50; close attention of, to the songs of others, ii. 52; acquiring the song of their foster-parents, ii. 55; brilliant, rarely good songsters, ii. 56; love-antics and dances of, ii. 68; coloration of, ii. 74 et seqq.; moulting of, ii. 80 et seqq.; unpaired, ii. 103; male, singing out of season, ii. 106; mutual affection of, ii. 108; in confinement, distinguish persons, ii. 110; hybrid, production of, ii. 113; European, number of species of, ii. 124; variability of, ii. 124; gradation of secondary sexual characters in, ii. 135; obscurely coloured, building concealed nests, ii. 169; young female, acquiring male characters, ii. 180; breeding in immature plumage, ii. 214; moulting of, ii. 214; aquatic, frequency of white plumage in, ii. 229; vocal courtship of, ii. 331; naked skin of the head and neck in, ii. 377.

Birgus latro, habits of, i. 334.

Birkbeck, Mr. on the finding of new mates by Golden Eagles, ii. 105.

Birthplace of man, i. 199.

Births, numerical proportions of the sexes in, in animals and man, i. 263, 265; male and female, numerical proportion of, in England, i. 300.

Bischoff, Prof., on the agreement between the brains of man and of the Orang, i. 11; figure of the embryo of the dog, i. 15; on the convolutions of the brain in the human fœtus, i. 16; on the difference between the skulls of man and the quadrumana, i. 190.

Bishop, J., on the vocal organs of frogs, ii. 28; on the vocal organs of corvine birds, ii. 55; on the trachea of the Merganser, ii. 60.

Bison, American, mane of the male, ii. 267.

Bitterns, dwarf, coloration of the sexes of, ii. 179.

Biziura lobata, musky odour of the male, ii. 38; large size of male, ii. 43.

Blackbird, sexual differences in the, i. 268; proportion of the sexes in the, i. 307; acquisition of a song by a, ii. 55; colour of the beak in the sexes of the, ii. 72, 227; pairing with a thrush, ii. 113; colours and nidification of the, ii. 170; young of the, ii. 219; sexual difference in coloration of the, ii. 226.

Black-buck, Indian, sexual difference in the colour of the, ii. 288.

Blackcap, arrival of the male, before the female, i. 259; young of the, ii. 219.

Black-cock, polygamous, i. 269; proportion of the sexes in the, i. 306; pugnacity and love-dance of the, ii. 45; call of the, ii. 60; moulting of the, ii. 83; duration of the courtship of the, ii. 100; sexual difference in coloration of the, ii. 226; crimson eye-cere of the, ii. 227; and pheasant, hybrids of, ii. 113.

Black-grouse, characters of young, ii. 185, 194.

Blackwall, J., on the speaking of the magpie, i. 59; on the desertion of their young by swallows, i. 84; on the superior activity of male spiders, i. 272; on the proportion of the sexes in spiders, i. 314; on sexual variation of colour in spiders, i. 337; on male spiders, i. 338.

Bladder-nose Seal, hood of the, ii. 278.

Blaine, on the affections of dogs, ii. 270.

Blair, Dr., on the relative liability of Europeans to yellow fever, i. 243.

Blake, C. C., on the jaw from La Naulette, i. 126.

Blakiston, Capt., on the American snipe, ii. 64; on the dances of Tetrao phasianellus, ii. 69.

Blasius, Dr., on the species of European birds, ii. 124.

Bledius taurus, hornlike processes of male, i. 374.

Bleeding, tendency to profuse, i. 292.

Blenkiron, Mr., on sexual preference in horses, ii. 272.

Blennies, crest developed on the head of male, during the breeding season, ii. 12.

Blethisa multipunctata, stridulation of, i. 379.

Bloch, on the proportions of the sexes in Fishes, i. 308.

Blood, arterial, red colour of, i. 323.

Blood-pheasant, number of spurs in, ii. 46.

Bluebreast, red-throated, sexual differences of the, ii. 195.

Blumenbach, on Man, i. 111; on the large size of the nasal cavities in American aborigines, i. 119; on the position of man, i. 190; on the number of species of man, i. 226.

Blyth, E., observations on Indian crows, i. 77; on the structure of the hand in species of Hylobates, i. 140; on the ascertainment of the sex of nestling bullfinches by pulling out breast-feathers, ii. 24; on the pugnacity of the males of Gallinula cristata, ii. 41; on the presence of spurs in the female Euplocamus erythropthalmus, ii. 46; on the pugnacity of the amadavat, ii. 49; on the spoonbill, ii. 60; on the moulting of Anthus, ii. 83; on the moulting of bustards, plovers, and Gallus bankiva, ii. 84; on the Indian honey-buzzard, ii. 126; on sexual differences in the colour or the eyes of hornbills, ii. 129; on Oriolus melanocephalus, ii. 178; on Palæornis javanicus, ii. 179; on the genus Ardetta, ii. 179; on the peregrine falcon, ii. 180; on young female birds acquiring male characters, ii. 180; on the immature plumage of birds, ii. 185; on representative species of birds, ii. 190; on the young of Turnix, ii. 202; on anomalous young of Lanius rufus and Colymbus glacialis, ii. 211; on the sexes and young of the sparrows, ii. 212; on dimorphism in some herons, ii. 214; on orioles breeding in immature plumage, ii. 214; on the sexes and young of Buphus and Anastomus, ii. 217; on the young of the blackcap and blackbird, ii. 219; on the young of the stonechat, ii. 220; on the white plumage of Anastomus, ii. 229; on the horns of Antilope bezoartica, ii. 246; on the horns of Bovine animals, ii. 247; on the mode of fighting of Ovis cycloceros, ii. 249; on the voice of the Gibbons, ii. 276; on the crest of the male wild goat, ii. 282; on the colours of Portax picta, ii. 287; on the colours of Antilope bezoartica, ii. 288; on the development of the horns in the Koodoo and Eland antelopes, i. 289; on the colour of the Axis deer, ii. 290; on sexual difference of colour in Hylobates hoolock, ii. 291; on the hog-deer, ii. 303; on the beard and whiskers in a monkey becoming white with age, ii. 319.

Boar, wild, polygamous in India, i. 267; use of the tusks by the, ii. 256; fighting of, ii. 263.

Boitard and Corbié, MM., on the transmission of sexual peculiarities in pigeons, i. 283; on the antipathy shown by some female pigeons to certain males, ii. 118.

Bold, Mr., on the singing of a sterile hybrid canary, ii. 53.

Bombet, on the variability of the standard of beauty in Europe, ii. 370.

Bombus, difference of the sexes in, i. 366.

Bombycidæ, coloration of, i. 394; pairing of the, i. 401.

Bombycilla carolinensis, red appendages of, ii. 179.

Bombyx cynthia, i. 346; proportion of the sexes in, i. 309, 313; pairing of, i. 401.

Bombyx mori, difference of size of the male and female cocoons of, i. 346; pairing of, i. 401.

Bombyx Pernyi, proportion of sexes of, i. 313.

Bombyx Yamamai, i. 346; M. Personnat on, i. 310; proportion of sexes of, i. 313.

Bonaparte, C. L., on the call-notes of the wild turkey, ii. 60.

Bond, F., on the finding of new mates by crows, ii. 104.

Bone, implements of, skill displayed in making, i. 138.

Boner, C., on the transfer of male characters to an old female chamois, ii. 245; on the antlers of the red deer, ii. 252; on the habits of stags, ii. 259; on the pairing of red deer, ii. 269.

Bones, increase of, in length and thickness, when carrying a greater weight, i. 116.

Bonnet monkey, i. 192.

Boomerang, i. 183.

Boreus hyemalis, scarcity of the male, i. 314.

Bory St. Vincent, on the number of species of man, i. 226; on the colours of Labrus pavo, ii. 16.

Bos gaurus, horns of, ii. 247.

Bos primigenius, ii. 240.

Bos sondaicus, horns of, ii. 247; colours of, ii. 289.

Botocudos, i. 181; mode of life of, i. 247; disfigurement of the ears and lower lip of the, ii. 341.

Boucher de Perthes, J. C. de, on the antiquity of man, i. 3.

Bourbon, proportion of the sexes in a species of Papilio from, i. 310.

Bourien, on the marriage-customs of the savages of the Malay Archipelago, ii. 373.

Bovidæ, dewlaps of, ii. 284.

Bower-birds, ii. 102; habits of the, ii. 69; ornamented playing-places of, i. 63, ii. 112.

Bows, use of, i. 232.

Brachiopoda, i. 329.

Brachycephalic structure, possible explanation of, i. 148.

Brachyscelus, second pair of antennæ in the male, i. 337.

Brachyura, i. 332.

Brachyurus calvus, scarlet face of, ii. 309.

Brain, of man, agreement of the, with that of lower animals, i. 10; convolutions of, in the human fœtus, i. 16; larger in some existing mammals than in their tertiary prototypes, i. 51; relation of the development of the, to the progress of language, i. 57; disease of the, affecting speech, i. 58; influence of development of mental faculties upon the size of the, i. 145; influence of the development of, on the spinal column and skull, i. 146; difference in the convolutions of, in different races of men, i. 216.

Brakenridge, Dr., on the influence of climate, i. 115.

Braubach, Prof., on the quasi-religious feeling of a dog towards his master, i. 68; on the self-restraint of dogs, i. 78.

Brauer, F., on dimorphism in Neurothemis, i. 363.

Brazil, skulls found in caves of, i. 218; population of, i. 225; compression of the nose by the natives of, ii. 352.

Break between man and the apes, i. 200.

Bream, proportion of the sexes in the, i. 308.

Breeding, age of, in birds, ii. 214.

Breeding season, sexual characters making their appearance in the, in birds, ii. 80.

Brehm, on the effects of intoxicating liquors on monkeys, i. 12; on the recognition of women by male Cynocephali, i. 13; on revenge taken by monkeys, i. 40; on manifestations of maternal affection by monkeys and baboons, i. 41; on the instinctive dread of monkeys for serpents, i. 42; on a baboon using a mat for shelter from the sun, i. 53; on the use of stones as missiles by baboons, i. 51; on the signal-cries of monkeys, i. 57; on sentinels posted by monkeys, i. 74; on co-operation of animals, i. 75; on an eagle attacking a young Cercopithecus, i. 76; on baboons in confinement protecting one of their number from punishment, i. 78; on the habits of baboons when plundering, i. 79; on the diversity of the mental faculties of monkeys, i. 110; on the habits of baboons, i. 141; on polygamy in Cynocephalus and Cebus, i. 266; on the numerical proportion of the sexes in birds, i. 306; on the love-dance of the Black-cock, ii. 45; on Palamedea cornuta, ii. 48; on the habits of the Black-grouse, ii. 49; on sound produced by Birds of Paradise, ii. 63; on assemblages of grouse, ii. 101; on the finding of new mates by birds, ii. 106; on the fighting of wild boars, ii. 263; on the habits of Cynocephalus hamadryas, ii. 362.

Brent, Mr., on the courtship of fowls, ii. 117.

Breslau, numerical proportion of male and female births in, i. 301.

Bridgman, Laura, i. 57.

Brimstone butterfly, i. 393; sexual difference of colour in the, i. 409.

British, ancient, tattooing practised by, ii. 339.

Broca, Prof., on the occurrence of the supra-condyloid foramen in the human humerus, i. 28; on the capacity of Parisian skulls at different periods, i. 146; on the influence of natural selection, i. 152; on hybridity in man, i. 220; on human remains from Les Eyzies, i. 237; on the cause of the difference between Europeans and Hindoos, i. 240.

Brodie, Sir B., on the origin of the moral sense in man, i. 71.

Bronn, H. G., on the copulation of insects of distinct species, i. 342.

Bronze period, men of, in Europe, i. 160.

Brown, R., sentinels of seals generally females, i. 74; on the battles of seals, ii. 240; on the narwhal, ii. 242; on the occasional absence of the tusks in the female walrus, ii. 242; on the bladder-nose seal, ii. 278; on the colours of the sexes in Phoca grœnlandica, ii. 287; on the appreciation of music by seals, ii. 333; on plants used as love-philters, by North American women, ii. 344.

Brown-Séquard, Dr., on the inheritance of the effects of operations by guinea pigs, ii. 380.

Bruce, on the use of the elephant’s tusks, ii. 249.

Brulerie, P. de la, on the habits of Ateuchus cicatricosus, i. 376; on the stridulation of Ateuchus, i. 384.

Brünnich, on the pied ravens of the Feroe islands, ii. 126.

Bryant, Capt., on the courtship of Callorhinus ursinus, ii. 269.

Bubas bison, thoracic projection of, i. 372.

Bucephalus capensis, difference of the sexes of, in colour, ii. 29.

Buceros, nidification and incubation of, ii. 169.

Buceros bicornis, sexual differences in the colouring of the casque, beak, and mouth in, ii. 129.

Buceros corrugatus, sexual difference in the beak of, ii. 72.

Büchner, L., on the origin of man, i. 4; on the want of self-consciousness, &c., in low savages, i. 62; on the use of the human foot as a prehensile organ, i. 142; on the mode of progression of the apes, i. 142.

Buckland, F., on the numerical proportion of the sexes in rats, i. 305; on the proportion of the sexes in the trout, i. 308; on Chimæra monstrosa, ii. 12.

Buckland, W., on the complexity of crinoids, i. 61.

Buckler, W., proportion of sexes of Lepidoptera reared by, i. 313.

Buckinghamshire, numerical proportion of male and female births in, i. 300.

Bucorax abyssinicus, inflation of the neck-wattle of the male, during courtship, ii. 72.

Budytes Raii, i. 260.

Buffalo, Cape, ii. 250.

Buffalo, Indian, horns of the, ii. 247.

Buffalo, Italian, mode of fighting of the, ii. 250.

Buffon, on the number of species of man, i. 226.

Bugs, i. 349.

Buist, R., on the proportion of the sexes in salmon, i. 308; on the pugnacity of the male salmon, ii. 3.

Bulbul, pugnacity of the male, ii. 41; display of under tail-coverts by the male, ii. 96.

Bull, mode of fighting of the, ii. 250; curled frontal hair of the, ii. 282.

Bullfinch, sexual differences in the, i. 269; piping, ii. 52; female, singing of the, ii. 54; courtship of the, ii. 94; widowed, finding a new mate, ii. 105; attacking a reed-bunting, ii. 111; nestling, sex ascertained by pulling out breast-feathers, ii. 214.

Bullfinches distinguishing persons, ii. 110; rivalry of female, ii. 121.

Bulls, two young, attacking an old one, i. 75; wild, battles of, ii. 240.

Bull-trout, male, colouring of, during the breeding season, ii. 14.

Bunting, reed, head feathers of the male, ii. 95; attacked by a bullfinch, ii. 111.

Buntings, characters of young, ii. 184.

Buphus coromandus, sexes and young of, ii. 217; change of colour in, ii. 231, 232.

Burchell, Dr., on the zebra, ii. 302; on the extravagance of a Bushwoman in adorning herself, ii. 344; celibacy unknown among the savages of South Africa, ii. 367; on the marriage-customs of the Bushwomen, ii. 374.

Burke, on the number of species of man, i. 226.

Burmese, colour of the beard in, ii. 319.

Burton, Capt., on negro ideas of female beauty, ii. 346; on a universal ideal of beauty, ii. 351.

Bushmen, i. 157.

Bushwoman, extravagant ornamentation of a, ii. 344.

Bushwomen, hair of, i. 216; marriage-customs of, ii. 374.

Busk, Prof. G., on the occurrence of the supra-condyloid foramen in the human humerus, i. 28.

Bustard, throat-pouch of the male, ii. 58; humming noise produced by a male, ii. 65; Indian, ear-tufts of a, ii. 73.

Bustards, occurrence of sexual differences and of polygamy among the, i. 269; love-gestures of the male, ii. 68; double moult in, ii. 81, 83.

Butler, A. G., on sexual differences in the wings of Aricoris epitus, i. 345; >on the colouring of the sexes in species of Thecla, i. 389; on the resemblance of Iphias glaucippe to a leaf, i. 394; on the rejection of certain moths and caterpillars by lizards and frogs, i. 417.

Butterfly, noise produced by a, i. 387; Emperor, i. 386, 388; meadow brown, instability of the ocellated spots of, ii. 132.

Butterflies, proportion of the sexes in, i. 309; forelegs atrophied in some male, i. 344; sexual difference in the neuration of the wings of, i. 345; pugnacity of male, i. 386; protective resemblances of the lower surface of, i. 392; display of the wings by, i. 396; white, alighting upon bits of paper, i. 400; attracted by a dead specimen of the same species, i. 400; courtship of, i. 400; male and female, inhabiting different stations, i. 403.

Buxton, C., observations on macaws, i. 76; on an instance of benevolence in a parrot, ii. 109.

Buzzard, Indian honey-, variation in the crest of, ii. 126.

C.

Cabbage butterflies, i. 393.

Cachalot, large head of the male, ii. 242.

Cadences, musical, perception of, by animals, ii. 333.

Cæcum, i. 27; large, in the early progenitors of man, i. 206.

Cairina moschata, pugnacity of the male, ii. 43.

Callianassa, chelæ of, figured, i. 330.

Callionymus lyra, characters of the male, ii. 7.

Callorhinus ursinus, relative size of the sexes of, ii. 260; courtship of, ii. 269.

Calotes nigrilabris, sexual difference in the colour of, ii. 36.

Cambridge, O. Pickard, on the sexes of spiders, i. 315.

Camel, canine teeth of male, ii. 241, 257.

Campbell, J., on the Indian elephant, i. 267, 268; on the proportion of male and female births in the harems of Siam, i. 303.

Campylopterus hemileucurus, i. 307.

Canaries distinguishing persons, ii. 110.

Canary, polygamy of the, i. 270; change of plumage in, after moulting, i. 294; female, selecting the best singing male, ii. 52; sterile hybrid, singing of a, ii. 53; female, singing of the, ii. 54; selecting a greenfinch, ii. 115; and siskin, pairing of, ii. 115.

Canestrini, G., on rudimentary characters and the origin of man, i. 4; on rudimentary characters, i. 17; on the movement of the ear in man, i. 20; on the variability of the vermiform appendage in man, i. 27; on the abnormal division of the malar bone in man, i. 124; on abnormal conditions of the human uterus, i. 124; on the persistence of the frontal suture in man, i. 125; on the proportion of the sexes in silk-moths, i. 309, 311.

Canine teeth in man, i. 126; diminution of, in man, i. 144; diminution of, in horses, i. 144; disappearance of, in male ruminants, i. 144; large, in the early progenitors of man, i. 206. Canines, and horns, inverse development of, ii. 257.

Canoes, use of, i. 137, 234.

Cantharis, difference of colour in the sexes of a species of, i. 367.

Capercailzie, proportion of the sexes in the, i. 306; pugnacity of the male, ii. 45; pairing of the, ii. 49; autumn meetings of the, ii. 54; call of the, ii. 61; duration of the courtship of, ii. 100; behaviour of the female, ii. 121; inconvenience of black colour to the female, ii. 154; sexual difference in coloration of the, ii. 226; crimson eye-cere of the male, ii. 227; polygamous, i. 269.

Capital, i. 169.

Capitonidæ, colours and nidification of the, ii. 171.

Capra ægagrus, ii. 249; crest of the male, ii. 282; sexual difference in the colour of, ii. 289.

Capreolus Sibiricus subecaudatus, ii. 298.

Caprice, common to man and animals, i. 65.

Caprimulgus, noise made by the males of some species of, with their wings, ii. 62.

Caprimulgus virginianus, pairing of, ii. 49.

Carabidæ, bright colours of, i. 367.

Carbonnier, on the natural history of the pike, i. 308; the relative size of the sexes in fishes, ii. 7.

Carcineutes, sexual difference of colour in, ii. 173.

Carcinus mænas, i. 331, 333.

Carduelis elegans, sexual differences of the beak in, ii. 39.

Carnivora, marine, polygamous habits of, i. 268; sexual differences in the colours of, ii. 286.

Carp, numerical proportion of the sexes in the, i. 308.

Carr, R., on the peewit, ii. 48.

Carrier pigeon, late development of the wattle in the, i. 293.

Carrion beetles, stridulation of, i. 378.

Carus, Prof. V., on the development of the horns in merino sheep, i. 289.

Cassowary, sexes and incubation of the, ii. 204.

Castoreum, ii. 279.

Casuarius galeatus, ii. 204.

Cat, convoluted body in the extremity of the tail of a, i. 30; sick, sympathy of a dog with a, i. 77.

Cataract in Cebus Azaræ, i. 12.

Catarrh, liability of Cebus Azaræ to, i. 11.

Catarrhine monkeys, i. 196.

Caterpillars, bright colours of, i. 415.

Cathartes aura, ii. 116.

Cathartes jota, love-gestures of the male, ii. 68.

Catlin, G., on the development of the beard among North American Indians, ii. 322; on the great length of the hair in some North American tribes, ii. 348.

Caton, J. D., on the development of the horns in Cervus virginianus and strongyloceros, i. 288; on the presence of traces of horns in the female wapiti, ii. 245; on the fighting of deer, ii. 252; on the crest of the male wapiti, ii. 282; on the colours of the Virginian deer, ii. 288; on sexual differences of colour in the wapiti, ii. 289; on the spots of the Virginian deer, ii. 303.

Cats, dreaming, i. 46; tortois-eshell, i. 283, 285, 293; enticed by valerian, ii. 281; colours of, ii. 299.

Cattle, domestic, sexual differences of, late developed, i. 293; rapid increase of, in South America, i. 135; domestic, lighter in winter in Siberia, i. 282; horns of, i. 289, ii. 247; numerical proportion of the sexes in, i. 305.

Caudal vertebræ, number of, in macaques and baboons, i. 150; basal, of monkeys, imbedded in the body, i. 151.

Cebus, maternal affection in a, i. 40; gradation of species of, i. 227.

Cebus Azaræ, liability of, to the same diseases as man, i. 11; distinct sounds produced by, i. 53; early maturity of the female, ii. 318.

Cebus capucinus, polygamous, i. 266; sexual differences of colour in, ii. 290; hair on the head of, ii. 307.

Cebus vellerosus, hair on the head of, ii. 307.

Cecidomyidæ, proportions of the sexes in, i. 314.

Celibacy, unknown among the savages of South Africa and South America, ii. 367.

Centipedes, i. 339.

Cephalopoda, absence of secondary sexual characters in, i. 325.

Cephalopterus ornatus, ii. 58, 59.

Cephalopterus penduliger, ii. 59.

Cerambyx heros, stridulant organ of, i. 380.

Ceratophora aspera, nasal appendages of, ii. 34.

Ceratophora Stoddartii, nasal horn of, ii. 34.

Cerceris, habits of, i. 364.

Cercocebus æthiops, whiskers, &c., of, ii. 308.

Cercopithecus, young, seized by an eagle and rescued by the troop, i. 76; definition of species of, i. 227.

Cercopithecus cephus, sexual difference of colour in, ii. 291, 311.

Cercopithecus cynosurus and griseo-viridis, colour of the scrotum in, ii. 291.

Cercopithecus Diana, sexual differences of colour in, ii. 291, 311, 312.

Cercopithecus griseo-viridis, i. 75.

Cercopithecus petaurista, whiskers, &c., of, ii. 308.

Ceres, of birds, bright colours of, ii. 227.

Ceriornis Temminckii, swelling of the wattles of the male during courtship, ii. 72.

Cervulus, weapons of, ii. 257.

Cervulus moschatus, rudimentary horns of the female, ii. 245.

Cervus alces, i. 288.

Cervus campestris, odour of, ii. 279.

Cervus canadensis, traces of horns in the female, ii. 245; attacking a man, ii. 253; sexual difference in the colour of, ii. 289.

Cervus elaphus, battles of male, ii. 240; horns of, with numerous points, ii. 252.

Cervus Eldi, i. 288.

Cervus mantchuricus, ii. 303.

Cervus paludosus, colours of, ii. 290.

Cervus strongyloceros, i. 288.

Cervus virginianus, i. 288; horns of, in course of modification, ii. 255.

Ceryle, male black-belted in some species of, ii. 173.

Cetacea, nakedness of, i. 148.

Ceylon, frequent absence of beard in the natives of, ii. 321.

Chaffinch, proportion of the sexes in the, i. 306, 307; courtship of the, ii. 94.

Chaffinches, ii. 53; new mates found by, ii. 105.

Chalcophaps indicus, characters of young, ii. 185.

Chalcosoma atlas, sexual differences of, i. 368.

Chamæleon, sexual differences in the genus, ii. 34.

Chamæleon bifurcus, ii. 34, 35.

Chamæleon Owenii, ii. 34, 36.

Chameleons, ii. 32.

Chamois, danger-signals of, i. 74; transfer of male characters to an old female, ii. 245.

Chamæpetes unicolor, modified wing-feather in the male, ii. 64.

Chapuis, Dr., on the transmission of sexual peculiarities in pigeons, i. 283; on streaked Belgian pigeons, i. 294, ii. 157.

Char, male, colouring of, during the breeding season, ii. 14.

Characters, male, developed in females, i. 280; natural, artificial exaggeration of, by man, ii. 351; secondary sexual, transmitted through both sexes, i. 279.

Charadrius hiaticula and pluvialis, sexes and young of, ii. 216.

Chardin on the Persians, ii. 356.

Charms, worn by women, ii. 344.

Charruas, freedom of divorce among the, ii. 372.

Chasmorhynchus, difference of colour in the sexes of, ii. 79; colours of, ii. 228.

Chastity, early estimation of, i. 96.

Chatterers, sexual differences in, i. 269.

Cheiroptera, absence of secondary sexual characters in, i. 268.

Chelæ of crustacea, i. 330, 336.

Chelonia, sexual differences in, ii. 28.

Chenalopex ægyptiacus, wing-knobs of, ii. 46.

Chera progne, ii. 84, 120.

Chest, proportions of, in soldiers and sailors, i. 117; large, of the Quechua and Aymara Indians, i. 119.

Chevrotains, canine teeth of, ii. 257.

Chiasognathus, stridulation of, i. 384.

Chiasognathus Grantii, mandibles of, i. 377.

Children, legitimate and illegitimate, proportion of the sexes in, i. 302.

Chiloe, lice of the natives of, i. 220; population of, i. 225.

Chimæra monstrosa, bony process on the head of the male, ii. 12.

Chimæroid fishes, prehensile organs of male, ii. 1.

Chimpanzee, ii. 323; ears of the, i. 21; representatives of the eyebrows in the, i. 25; platforms built by the, i. 36; cracking nuts with a stone, i. 51; hands of the, i. 139; absence of mastoid processes in the, i. 143; direction of the hair on the arms of the, i. 192; supposed evolution of the, i. 230; polygamous and social habits of the, ii. 362.

China, North, idea of female beauty in, ii. 344.

China, Southern, inhabitants of, i. 246.

Chinese, use of flint tools by the, i. 183; difficulty of distinguishing the races of the, i. 215; colour of the beard in, ii. 319; general beardlessness of the, ii. 321; opinions of the, on the appearance of Europeans and Cingalese, ii. 345, 347; compression of the feet of, ii. 352.

Chinsurdi, his opinion of beards, ii. 341, 349.

Chlamydera maculata, ii. 70.

Chloëon, pedunculated eyes of the male of, i. 341.

Chloephaga, coloration of the sexes in, ii. 178.

Chlorocœlus Tanana (figured), i. 355.

Chorda Dorsalis, i. 207.

Chough, red beak of the, ii. 227.

Chromidæ, frontal protuberance in male, ii. 13; sexual differences in colour of, ii. 20.

Chrysemys picta, long claws of the male, ii. 28.

Chrysococcyx, characters of young of, ii. 185.

Chrysomela cerealis, bright colours of, i. 367.

Chrysomelidæ, stridulation of, i. 379.

Cicada pruinosa, i. 351.

Cicada septendecim, i. 351.

Cicadæ, songs of the, i. 350; rudimentary sound-organs in females of, i. 359.

Cicatrix of a burn, causing modification of the facial bones, i. 147.

Cichla, frontal protuberance of male, ii. 13.

Cimetière du Sud, Paris, i. 28.

Cincloramphus cruralis, large size of male, ii. 43.

Cinclus aquaticus, ii. 170.

Cingalese, Chinese opinion of the appearance of the, ii. 345.

Cirripedes, complemental males of, i. 255.

Civilisation, effects of, upon natural selection, i. 170; influence of, in the competition of nations, i. 239.

Clanging of Geese, &c., ii. 51.

Claparède, E., on natural selection applied to man, i. 137.

Clarke, on the marriage-customs of the Kalmucks, ii. 373.

Classification, i. 188.

Claus, C., on the sexes of Saphirina, i. 336.

Cleft-palate, inherited, i. 121.

Climacteris erythrops, sexes of, ii. 206.

Climate, i. 115; cool, favourable to human progress, i. 167; power of supporting extremes of, by man, i. 237; want of connexion of, with colour, i. 241.

Cloaca, existence of a, in the early progenitors of man, i. 207.

Cloacal passage existing in the human embryo, i. 16.

Club, origin of the, i. 234.

Clucking of fowls, ii. 51.

Clythra 4-punctata, stridulation of, i. 379.

Cobra, ingenuity of a, ii. 31.

Coccus, i. 186.

Coccyx, i. 29, 30; in the human embryo, i. 16; convoluted body at the extremity of the, i. 30; imbedded in the body, i. 151.

Cochin-China, notions of beauty of the inhabitants of, ii. 345, 347.

Cock, game, killing a kite, ii. 44; blind, fed by its companions, i. 77; comb and wattles of the, ii. 98; preference shown by the, for young hens, ii. 121; game, transparent zone in the hackles of a, ii. 136.

Cock of the rock, ii. 100.

Cockatoos, ii. 226, 228, 230; nestling, ii. 109; black, immature plumage of, ii. 188.

Cœlenterata, absence of secondary sexual characters in, i. 321.

Coffee, fondness of monkeys for, i. 12.

Cold, supposed effects of, i. 116; power of supporting, by man, i. 237.

Coleoptera, i. 366; stridulant organs of, discussed, i. 381.

Collingwood, C., on the pugnacity of the butterflies of Borneo, i. 386; on butterflies being attracted by a dead specimen of the same species, i. 400.

Colombia, flattened heads of savages of, ii. 340.

Colonists, success of the English as, i. 179.

Coloration, protective, in birds, ii. 223.

Colour, supposed to be dependent on light and heat, i. 115; correlation of, with immunity from certain poisons and parasites, i. 242; purpose of, in lepidoptera, i. 399; relation of, to sexual functions, in fishes, ii. 14; difference of, in the sexes of snakes, ii. 29; sexual differences of, in lizards, ii. 36; influence of, in the pairing of birds of different species, ii. 115; relation of, to nidification, ii. 167, 172; sexual differences of, in mammals, ii. 286, 294; recognition of, by quadrupeds, ii. 295; of children, in different races of man, ii. 318; of the skin in man, ii. 381.

Colours, admired alike by man and animals, i. 64; bright, due to sexual selection, i. 322; bright, among the lower animals, i. 322, 323; bright, protective to butterflies and moths, i. 395; bright, in male fishes, ii. 7, 13; transmission of, in birds, ii. 159.

Colquhoun, example of reasoning in a retriever, i. 48.

Columba passerina, young of, ii. 188.

Colymbus glacialis, anomalous young of, ii. 211.

Comb, development of, in fowls, i. 295.

Combs and wattles in male birds, ii. 98.

Community, preservation of variations useful to the, by natural selection, i. 155.

Compositæ, gradation of species among the, i. 227.

Comte, C., on the expression of the ideal of beauty by sculpture, ii. 380.

Conditions of life, action of changed, upon man, i. 113; influence of, on plumage of birds, ii. 196.

Condor, eyes and comb of the, ii. 129.

Conjugations, origin of, i. 61.

Conscience, i. 91, 104;

absence of, in some criminals, i. 92.

Constitution, difference of, in different races of men, i. 216.

Consumption, liability of Cebus Azaræ to, i. 12; connexion between complexion and, i. 244.

Convergence, i. 230.

Cooing of pigeons and doves, ii. 60.

Cook, Capt., on the nobles of the Sandwich Islands, ii. 356.

Cope, E. D., on the dinosauria, i. 204; on the origin of genera, ii. 215.

Cophotis ceylanica, sexual differences of, ii. 32, 36.

Copris, i. 370.

Copris Isidis, sexual differences of, i. 369.

Copris lunaris, stridulation of, i. 380.

Corals, bright colours of, i. 322.

Coral-snakes, ii. 31.

Cordylus, sexual difference of colour in a species of, ii. 36.

Corfu, habits of the chaffinch in, i. 307.

Cornelius, on the proportions of the sexes in Lucanus Cervus, i. 313.

Corpora Wolffiana, i. 207; agreement of, with the kidneys of fishes, i. 16.

Correlated variation, i. 130.

Correlation, influence of, in the production of races, i. 247.

Corse, on the mode of fighting of the elephant, ii. 257.

Corvus corone, ii. 104.

Corvus graculus, red beak of, ii. 227.

Corvus pica, nuptial assembly of, ii. 102.

Corydalis cornutus, large jaws of the male, i. 342.

Cosmetornis, ii. 181.

Cosmetornis vexillarius, elongation of wing-feathers in, ii. 73, 97.

Cotingidæ, sexual differences in, i. 269; coloration of the sexes of, ii. 177; resemblance of the females of distinct species of, ii. 192.

Cottus scorpius, sexual differences in, ii. 9.

Counting, origin of, i. 181; limited power of, in primeval man, i. 234.

Courage, variability of, in the same species, i. 40; universal high appreciation of, i. 95; importance of, i. 162; a characteristic of men, ii. 328.

Courtship, greater eagerness of males in, i. 272; of fishes, ii. 2; of birds, ii. 50, 100.

Cow, winter change of the, ii. 299.

Crab, devil, i. 332.

Crab, shore, habits of, i. 331.

Crabro cribrarius, dilated tibiæ of the male, i. 343.

Crabs, proportions of the sexes in, i. 315.

Cranz, on the inheritance of dexterity in seal-catching, i. 117.

Crawfurd, on the number of species of man, i. 226.

Crenilabrus massa and C. melops, nests built by, ii. 19.

Crest, origin of, in Polish fowls, i. 284.

Crests, of birds, difference of, in the sexes, ii. 189; dorsal hairy, of mammals, ii. 282.

Cricket, field-, stridulation of the, i. 353; pugnacity of male, i. 360.

Cricket, house-, stridulation of the, i. 352, 354.

Crickets, sexual differences in, i. 361.

Crioceridæ, stridulation of the, i. 379.

Crinoids, complexity of, i. 61.

Croaking of frogs, ii. 27.

Crocodiles, musky odour of, during the breeding season, ii. 29.

Crocodilia, ii. 28.

Crossbills, characters of young, ii. 184.

Crosses in man, i. 225.

Crossing of races, effects of the, i. 241.

Crossoptilon auritum, ii. 93, 166, 196; adornment of both sexes of, i. 290; sexes alike in, ii. 178.

Crotch, G. R., on the stridulation of beetles, i. 379, 382; on the stridulation of Heliopathes, i. 383; on the stridulation of Acalles, i. 384.

Crow Indians, long hair of the, ii. 348.

Crow, young of the, ii. 209.

Crows, ii. 226; vocal organs of the, ii. 55; living in triplets, ii. 106.

Crows, carrion, new mates found by, ii. 104.

Crows, Indian, feeding their blind companions, i. 77.

Cruelty of savages to animals, i. 94.

Crustacea, amphipod, males sexually mature while young, ii. 215; parasitic, loss of limbs by female, i. 255; prehensile feet and antennæ of, i. 256; male, more active than female, i. 272; parthenogenesis in, i. 315; secondary sexual characters of, i. 328; auditory hairs of, ii. 333.

Crystal worn in the lower lip by some Central African women, ii. 341.

Cuckoo fowls, i. 294.

Culicidæ, i. 254, 349.

Cullen, Dr., on the throat-pouch of the male bustard, ii. 58.

Cultivation of plants, probable origin of, i. 167.

Cupples, Mr., on the numerical proportion of the sexes in dogs, sheep, and cattle, i. 304, 305; on the Scotch deerhound, ii. 261; on sexual preference in dogs, ii. 271, 272.

Curculionidæ, sexual difference in length of snout in some, i. 255; hornlike processes in male, i. 374; musical, i. 378, 379.

Curiosity, manifestations of, by animals, i. 42.

Curlews, double moult in, ii. 80.

Cursores, comparative absence of sexual differences among the, i. 269.

Curtis, J., on the proportion of the sexes in Athalia, i. 314.

Cuvier, F., on the recognition of women by male quadrumana, i. 13.

Cuvier, G., views of, as to the position of man, i. 190; on instinct and intelligence, i. 37; on the number of caudal vertebræ in the mandrill, i. 150; on the position of the seals, i. 190; on Hectocotyle, i. 325.

Cyanecula suecica, sexual differences of, ii. 195.

Cyanalcyon, sexual difference in colours of, ii. 173; immature plumage of, ii. 188.

Cychrus, sounds produced by, i. 382.

Cycnia mendica, sexual difference of colour in, i. 398.

Cygnus ferus, trachea of, ii. 59.

Cygnus olor, white young of, ii. 211.

Cyllo Leda, instability of the ocellated spots of, ii. 133.

Cynanthus, variation in the genus, ii. 125.

Cynipidæ, proportions of the sexes in, i. 314.

Cynocephalus, difference of the young, from the adult, i. 13; male, recognition of women by, i. 13; polygamous habits of species of, i. 266.

Cynocephalus chacma, i. 41.

Cynocephalus gelada, i. 51.

Cynocephalus hamadryas, i. 51; sexual difference of colour in, ii. 291.

Cynocephalus leucophœus, colours of the sexes of, ii. 292.

Cynocephalus mormon, colours of the male, ii. 292, 296, 310.

Cynocephalus porcarius, mane of the male, ii. 267.

Cypridina, proportions of the sexes in, i. 315.

Cyprinidæ, proportion of the sexes in the, i. 308.

Cyprinidæ, Indian, ii. 17.

Cyprinodontidæ, sexual differences in the, ii. 7, 9.

Cyprinus auratus, ii. 16.

Cyprinus phoxinus, spawning of, ii. 15.

Cypris, relations of the sexes in, i. 315.