The Red-deer, maddened with desire, scours the country, calling as he travels with a loud musical roar, ever and anon impatiently listening for the tremulous response of females hardly less anxious to mate than himself. One after another is speedily added to his harem, but not without conflict. For sooner or later he catches the call of another stag in like case. A jealous fury at once takes possession of him, and the call, intended as a message to mateless hinds, becomes translated into a challenge to fight for the mates possessed. Each of the now infuriated challengers makes all haste to come to blows, and speedily they are rushing headlong on one another to meet in a crash of antlers. Then follows a test of strength, a sort of tug-of-war reversed, for each strives to push the other to his knees, and succeeding, to deal a deadly sideways thrust at the kneeling adversary’s heart with the spike-shaped brow-tines. This attempt, however, is rarely achieved. Yet not seldom such encounters become a duel to the death, and one in which both die, for in the remorseless tilt at one another the antlers of one may spring apart, and then close in on those of the other. Once this happens, it seems to be rare indeed that they can be extricated from this close embrace. With heads thus locked, they sway, and twist, and tug, not now for the mastery, but for life itself. But as the hours run they become more and more exhausted by their efforts, weaker and weaker from loss of food and rest, till finally death releases both.

A male having once succeeded in forming a harem, will commonly contrive to repeat his success year after year, withstanding all comers. But sooner or later his vigour wanes and he is ousted by another and younger male. Not else would the stamina of the race be preserved. It is considered a moot point, however, whether physical strength and sexual potency run at the same pace; for it is believed by some that a stag will often contrive to hold a harem against all rivals after his fertility has declined. This, however, is extremely improbable. A lowering of fertility means a decline in the potency of the hormones, and in the development of the secondary sexual characters, among which are the antlers, which are by no means negligible factors. That they are not all-important, however, seems to be shown by the fact that, occasionally, stags appear in a herd which are congenitally unable to produce antlers—a reversion to the ancestral condition—and such are said, occasionally at any rate, to be able to oust their formidably armed rivals. This may be so, but the fact that “hummel” stags, as they are called, are so rare is surely to be regarded as eloquent testimony of the disadvantages of their unarmoured state. They become speedily eliminated, in short, by “Sexual Selection.”

After this outburst of sexual activity has spent itself, the various harems, with their lords, amalgamate; all living in peace through the winter. The stags retain their antlers at this season, partly as a protection against predatory enemies, such as wolves, and other large carnivores, which would otherwise play havoc in their ranks, and partly because the cold of winter and scanty fodder would inhibit the growth of new antlers or reduce their size. With the return of spring the dangers of attack are lessened, temperature rises, and food becomes once more plentiful. Then the inevitable disarmament takes place.

The Red-deer, though mature at six, does not reach his prime till his eleventh year, and from thence till his fifteenth or sixteenth year is at his best. The hinds mature earlier, and appear to be fertile for a much longer period. At any rate, a wild hind in Jura, known by certain peculiarities of its ears, during twenty-one years produced twenty calves. She was killed at last with a calf at her side, but was thin and haggard-looking. She was, therefore, not less than six-and-twenty at her death. The calves, it may be mentioned, are born in May and June.

Old stags shed their antlers, it is remarked, earlier than young ones. And this is an advantage to the species, since it prevents premature breeding on the part of sexually precocious but immature males, and limits competition to the adults.

What obtains in the case of the Red-deer obtains also with minor variations due to environment, climate, and so on, in the case of all other deer. The life-history of the Wapiti, as might be supposed, differs only in detail from that of the Red-deer. But during the winter they form vast herds, numbering thousands. It may be that in primitive times the Red-deer was no less numerous. But in this country, at any rate, conditions favourable to the maximum development, either in bodily size, or in the massiveness of the antlers, have long since passed away. Even in the Highlands of Scotland the conditions of existence have entirely changed owing to disafforestation. Deer are essentially forest dwellers. But the “deer forests” are such only in name, and for the most part the wild stags of to-day must get what shelter they can from rocks and inequalities of the ground. From this cause, and from the very natural desire of the owners of such “forests” to secure the finest heads in each year, the whole race has deteriorated. How great a change has come over it may be seen by comparing the heads of British Stags with those from German forests, where the conditions of existence are more favourable. If we turn to the records of the past we find that the antlers found in the fens, turbaries, and caverns of our islands are vastly larger, heavier, and carry a greater number of points on the sur-royals, than do those of the existing Scotch stags.

Having regard to the fact that hundreds, and in the distant past thousands, of antlers were shed annually, the comparative rarity of these weapons in the haunts of deer excites comment. This is accounted for by the fact that they are greedily eaten by their late owners, apparently, though unconsciously, for the sake of their bone-producing qualities.

By way of contrast with the Red-deer and Wapiti, we may take the Moose (Alces machlis), which at no time, and nowhere, attains to large herds. This is explained by the relatively restricted food supply which obtains in the haunts of these creatures. For they frequent the margins of streams, feeding largely on willows and birch. From the shortness of their necks, and the great length of their legs, they cannot crop grass and other short herbage, for unless they kneel they cannot reach the ground. Hence it is obvious that though their geographical range may be wide, their numbers are kept rigidly in check. They would be fewer still but for the fact that, unlike other deer, they glean no small amount of food from the water, wading out to feed upon aquatic vegetation. The roots of water-lilies are especially sought for, and to obtain these the animal will often disappear entirely under water.

As a consequence of the limited food supply the Moose lead solitary lives. On the Eastern side of America, where the winter is severe, a few individuals, generally a family party, will “yard up,” or make a fortress for their mutual protection by trampling down the snow over a restricted area. But in the Yukon district, my friend Mr. F. C. Selous tells me this is never done.

The rutting season of the bulls begins as soon as the antlers begin to “peel.” What follows is practically a repetition of what has already been related in regard to the Red-deer and Wapiti. And in this connection it is interesting to note that the natives take advantage of the period of desire in the bull to entice him to his death. Generally this is done by imitating the call of the cow in response to the bull’s anxious bellowing. But in Southern Alaska the opposite side of his nature is played upon. This is done by scraping or beating the bushes with the shoulder-blade of a Moose in such a way as to reproduce the sound of a bull cleaning his horns. The very suspicion of a rival enrages him, and, rushing in a blind fury in the direction of the tell-tale sounds, he speedily falls a victim to the trick which has been played him.

That the mating period is the most critical, and most searching in the whole life-history there can be no doubt. Every faculty during this time is put to the test, and from the time of sexual maturity until old age is at last attained it is an annual test. Alertness is all important. Other things being equal, success falls most certainly to those individuals with the keenest perception, and quickest interpretation of sight, sound and smell.

One is puzzled at what seems a concession of Darwin’s to the Lamarckian theory of the inherited effects of use in this connection. For in discussing the bellowing of the stag in “The Descent of Man,” he remarks that it “does not seem to be of any special service to him, either during courtship or battles, or in any other way. But may we not believe that the frequent use of the voice, under the strong excitement of love, jealousy and rage, continued during many generations, may at last have produced an inherited effect on the vocal organs of the stag, as well as of other male animals?” All the evidence goes to show that the production of sound, and the instant interpretation of its significance, is a matter of the highest importance. In the case of the Moose, for example, the noise occasioned by the cleaning of antlers provokes the same frenzy as at another time is aroused by the voice. Dullness of perception not only in these matters, but at all times, is fatal.

As touching the less conspicuous secondary sexual characters of Deer more must be said presently. For the moment the antlers must retain our attention. Time was when the Deer lacked these appendages. When they first appeared, in the now extinct species of the Middle Miocene period, they were no more than short prongs. Later, one of the prongs became elongated, and developed short branches or “tines,” which, in succeeding species, became more numerous, while at the same time, with the gradual evolution of more and more species, these antlers assumed new features both in the matter of size and in the character and number of the “tines,” a development which has reached its maximum to-day. But apart from these specific variations, which have given us such types as those of the Roe-deer, Red-deer, Wapiti, Caribou, Moose, Fallow-deer, Sambar, Schombergk’s deer, the strange Milou-deer, Elds-deer and Mule-deer, each species displays a quite remarkable range of variation in regard to its particular type of antler. Nowhere, perhaps, is this more strikingly marked than in the case of the Caribou and Moose. No doubt this feature is due largely to the fact that the horns are shed annually, and that the variations are due, in part at any rate, to temporary environmental conditions, such as food and weather. But these apart, individual peculiarities are constant, reappearing with more or less exactness each year.

In contemplating these facts one asks: What are the underlying factors of this variability? What is the significance of the branching? What end is attained by the annual shedding? That the antlers constitute very effective weapons of offence there can be no doubt, and one is inclined to regard the branching as the outcome of natural selection, on the assumption that branched antlers would be less deadly than lance-like weapons. It would perhaps be tempting to accept this interpretation as all sufficient were it not for the evidence afforded by the hollow-horned ruminants. The Oryx and the Kudu, for example, are lance-bearers, and therefore show conclusively that stags similarly armed might well have continued to survive in spite of the foils which the “tines” provide. Darwin, long since, guardedly suggested that while these weapons primarily served for offensive purposes, their elaborate systems of branching might have been brought about by sexual selection. That is to say, the extreme beauty of the weapons may excite the admiration of the females as well as our own. Granting this, he inferred they might have played an important part in elaborating the branching by constantly displaying a preference to mate with those males possessed of the largest and most branched antlers. But there are many and serious objections to this suggestion, and the most important of all is the fact that the female is allowed no choice in the selection of her lord and master. We can, then, only regard the antlers of deer as another instance of the survival of a “fortuitous” but inherent variation, which survived because, whatever the defects thereof, they proved advantageous in the struggle for existence.

Having regard to the fact that so many of the females among the hollow-horned ruminants have acquired horns, it is somewhat remarkable that in the Reindeer alone among the deer are these weapons normally possessed by the female. The gradual transference to the female of features which were originally secondary sexual characters in the male is an occurrence which is met with in every group of animals. In writing “The Infancy of Animals” I gave a number of instances of this kind. But the case of the Reindeer affords a more than usually striking illustration of this curious sequence; and this because rudiments of antlers are to be met with among the females in several different species of Deer to-day. They have been found in the females of both Roe- and Red-deer, though such cases are rarely met with. As a rule this assumption of the male secondary sexual characters by the female occurs only in very aged animals, or as one of the sequelæ of diseased ovaries and consequent sterility. But at least one instance is on record of a doe Roe-deer which possessed small antlers while pregnant. Thus, then, we gain a further insight into the process by which the female slowly assumes the outward attributes of the male; that is to say, the secondary sexual characters appear first in the male, and as seasonal characters. Sooner or later they become permanently established. By the time they have become firmly fixed in the male, and apparently not till then, they appear in a dilute form during senility, or in consequence of ovarian disease, in the female. Having once started, however, they appear earlier and earlier in the life-history of succeeding generations of females, and at last in the juvenile stages of both sexes.

The hollow-horned ruminants, which must now be considered, afford some very striking facts in regard to these “secondary sexual characters,” more especially in so far as horns are concerned. In the first place these weapons are permanent structures, taking the form of a bony core ensheathed in horn, with which we may compare the temporary covering of velvet in the deer: in the second, they are unbranched. The only exception to this rule is furnished by the Prong-horned Antelope, wherein the sheath is both annually shed, and branched. The branching, however, is very slight, taking the form of a short forwardly directed prong about half-way up the sheath, which is borne on a long bony pedicle recalling that of the Muntjac. The shedding is due to the formation of new horn material at the base of the old sheath, which is gradually forced off by the growth of the new tissue. Structurally the horn of this remarkable Antelope differs somewhat from that of its relatives.

As may be seen in Plate 4, in the form of the horns the typical hollow-horned ruminants present an exceedingly varied range, and one often of great beauty in the matter of curvature. That they serve as formidable weapons of offence was demonstrated during 1912, when, according to the Annual Report of the Government Game Reserves, published by the Pretoria Government, the game warden, Major Stevenson Hamilton, reported of the Antelopes that “many carcases of males of almost all species, killed in single combat with rivals, were found during the mating season, untouched by anything except vultures.” As a rule, however, these animals, like the Sheep and Goats, and their larger relatives the Cattle, seem to avoid a duel to the death. One or two instances as to the general character of these combats for the possession of mates must suffice. Thus the late A. H. Neumann, a hunter of experience, remarks that he once or twice saw conflicts between the Topi (Damaliscus jimela), an ally of the Hartebeestes. The two rivals would stand a little apart, affecting, apparently, to be unaware of one another’s presence. Suddenly they would rush headlong at one another, bringing their heads together with a clash, each, at the same moment, falling on his knees.

Major Powell Cotton, again, once witnessed an affray between two Beisa Oryx. Here the master bull of the herd was infuriated by the advent of an intruder in his harem. Time after time they dashed at each other, their foreheads meeting with a thud; then, with horns interlocked, they wrestled fiercely; then, separating, they charged again. Yet neither, he remarks, tried to use his lance-points, as they do when cornered by man or beasts of prey. Nevertheless, encounters of a more sanguinary character appear to be by no means rare, for it is no uncommon experience of hunters to kill bulls of this species in which one eye has been burst by a horn-thrust. Another peculiarity of these animals is the extreme thickness of the hide of the neck and withers, which seems to afford a shield against such spear-thrusts during these battles. How powerful is the thrust of these weapons, and how efficiently they can be used, is shown by the fact that lions in making an attack on an old bull are often severely wounded, or even killed. And there are many instances on record of cases where both the lion and his intended victim have died together, the Antelope having been unable to withdraw his horns from his adversary’s body. The beautiful Pala Antelope fights furiously with rival rams, and the vanquished, as with so many of the Antelopes, form herds by themselves, till one by one they gather strength and skill enough to establish their right to mate.

The Elands present some puzzling features, for both sexes bear large horns, and they are very massive in the bulls. Yet these animals are generally described as the most inoffensive of all the horned ruminants. That the horns are used to any extent in conflicts between rival males seems doubtful, inasmuch as this species is remarkable for the development of an enormous “dewlap,” a thin pendulous fold of skin which runs from the throat to the chest. Such a form of “ornament”—for in this light we must regard it—would be dangerous, indeed, when much fighting was to be done. Nevertheless, it would be contrary to all our experience to conclude that weapons so well developed as are the horns of the bull Eland were entirely useless. This is a matter which decidedly calls for further investigation.

That our knowledge of that most important period of life of the larger mammals, the period of sexual exaltation, is lamentably incomplete will be realized by anyone who seeks enlightenment on this subject. Most of the meagre information we possess has been collected by travellers and sportsmen, neither of whom have the time to devote to the long and laborious watches that a fuller history demands. Every now and then a glimpse is afforded of this period of the life-history which brings home in a very convincing fashion, how little is really known. It seems certain that the fighting hitherto described is to be regarded as but a phase of a cycle of events which takes place at this time. Thus, for example, the old naturalist and traveller Schweinfurth tells how he once encountered a herd of Hartebeest which were apparently effervescing with animal spirits, for they kept running around in couples, like horses in a circus, using a clump of trees as a pivot. Others, in groups of three or four, stood by, interested spectators. After a time these, in turn, took their places and ran round, two at a time, in their own circuit, and in the same fashion. Their evolutions, he says, were so regular as to suggest the guidance of some invisible ring-master. These gyrations may be regarded as an erotic dance. The Sambar, under like excitement, will stalk about with erected tail, outstretched muzzle and everted face glands, and the Black-buck, among the antelopes, behaves in like fashion.

It cannot be supposed that these quaint performances are peculiar to the species in which they have been observed, but rather it may be inferred that similar antics, besides others yet to be discovered, are performed by all. Their purpose seems plain enough, for they must be regarded surely as aphrodisiacs, excitants to pairing. They recall the erotic dances of savages, or the ceremonial orgies of ancient civilizations. Such performances, on an even more elaborate scale, are to be met with among the birds.

So far, in describing the horned ruminants, the horns only have been considered; but these animals display yet other secondary sexual characters, which, while less conspicuous, are yet no less important during this critical period of life. Some, as for instance the canine teeth possessed by some of the deer, are decidedly puzzling. While absent, or vestigial, in most, in a few they are greatly developed, and this, too, in species which possess relatively large horns, as in the Muntjac. It seems difficult to believe that the co-existence of these very different kinds of weapons can be of vital importance to their possessors; yet unless this be so, one or other would surely have degenerated. It is significant that in the hornless Musk-deer these teeth attain to a very considerable length, at their maximum as much as three inches. That they are used by rival males, and with effect, is shown by the fact that the hides of these animals are often found scored by deep lines cut by these tusks. In those aberrant ruminants, the Camels, quite formidable tusks are present both in the upper and lower jaws, and these are used with effect whenever occasion demands, and often when it does not.

The armoury necessary for successful love-making contains yet other weapons, evolved to supplement physical force, and more subtle in their effect. Such are certain skin glands which, at the rutting season, secrete a copious flow of a creamy, or semi-fluid matter, and pungent odour. In the deer the more important of these are found in the deep pit, or “larmier,” which opens in front of the eye. In the Musk-deer, however, this secretion has a most powerful odour of musk, and is formed in a pouch, or “pod,” of about the size of a small orange, under the skin of the abdomen. The secretion, which is formed by the male only, is of a chocolate colour, and of about the consistence of moist gingerbread. It has a most pungent scent, and when diluted forms the basis of many of our most powerful and most highly-prized perfumes, on which account, it may be mentioned, this animal has for generations been submitted to a most unrelenting persecution. But that is another story.

In most of the antelopes the principal scent gland is seated in a pit in front of the eye, as in the deer. In some, as in the Gnu, it forms instead a swollen, tumid area, oblong in shape, instead of lying in a pit. In the Reedbuck it is placed around the bases of the horns; and in the Rocky-Mountain Goat it forms a great bare cushion behind the horns. All have more or less well-developed glands seated in the skin between the toes. But, wherever placed, the secretions thereof are more or less completely suspended save during the breeding season, when they are poured forth abundantly. The precise rôle they play is by no means certainly known. It seems reasonable to suppose that, in the first place, the odour they disperse enables the males to announce their whereabouts to the females seeking mates, should they fail to hear their bellowing. But the antelopes, for the most part, unlike deer, do not, the year round, lose touch with one another; so that it must be concluded that these odours serve as excitants to the act of pairing, and we know that the sense of smell plays a very important part at this time, which, so far as these animals are concerned, is the only period which comes more or less exactly within the meaning of the term “courtship.”

That scent among the antelopes holds a really important place is shown by the fact that the bull of the common Eland intensifies his natural odours by micturating upon the mass of long hair which grows upon the forehead. To do this the head is bent down and turned tailwards, in order that the tuft should receive its due urinary spray! And goats in captivity exhibit the same curious habit. In them, indeed, it is often pushed to such an excess that blindness results, so that the animal has to be slaughtered.

While in many cases these odours are imperceptible to human nostrils, in others this is far from being the case. Among the ruminants the goat is particularly odorous. So also are the giraffe and the water-buck, both of which may be detected by their smell at considerable distances. And these emanations are most noticeable in the males and at the breeding season. The bull elephant, both in the Indian and African species, during the breeding season produces a copious flow of aromatic matter from a gland which opens above the eye in the form of a tubular aperture large enough to admit a pencil. This aperture in the African elephant is remarkable for the fact that it is invariably found to be “plugged” with numerous spines of the acacia, which have from time to time found their way in as the animal was forcing its way through the dense undergrowth. This extraordinary fact was first noticed by Mr. F. C. Selous, and has since been confirmed by Dr. Einar Lonnberg.

It is probable that the “bloody sweat,” which at times covers the hide of the Hippopotamus just after leaving the water, is associated with the period of rut. This mysterious exudation is accompanied by small crystals; but though red in colour, it contains no blood. So far no reasonable explanation for this remarkable phenomenon has ever been given, but probably it will be found to be associated with the sexual activities and is possibly odoriferous. A precisely similar exudation occurs in the neck of the male of the Red Kangaroo.

That these secretions play an important and perhaps variable part in the selection of mates seems demonstrated in the case of an incident related to me by my friend Mr. John Cooke, who some time ago was watching a flock of some three hundred sheep while it was being driven by the shepherd and his dogs into a field. As soon as they were securely shut in, and the shepherd had gone, three rams who were included in the flock at once began a three-cornered fight. One, presumably the youngest, was soon vanquished. The other two soon settled their differences, and the clashing of horns was at once followed by a very different performance. The master ram began to run in and out among the ewes, sniffing at each, and driving out those whose odour most pleased him. Having at last satisfied himself with a harem of about one hundred, the second ram was allowed to make a like choice, and behaved in a like manner, leaving the remainder to the ram which was first vanquished. May we take it that the strongest and oldest rams selected the youngest ewes, and the oldest were left to the youngest, and first conquered ram? By some such rough and ready method of selection Nature may contrive that the immature male shall do as little harm to the race as possible by mating with the oldest, and in many cases barren females.

Our survey of the “hoofed” animals has so far been confined to the ruminants. Space must now be found for a brief review of what obtains under like circumstances in the case of the great pachyderms—the Elephant, Rhinoceros and Hippopotamus; the Pig and the Camel.

As to actual “courtship” among these animals practically nothing is known; but the varied and formidable weapons which they possess are enough to show that the secondary sexual characters play a very important part in the preliminary capture of mates. That they may also be used for the more prosaic purpose of securing food is nothing to the point. In the Elephant, for example, the tusks are sometimes of enormous size and weight, specimens of eleven feet in length and weighing as much as two hundred and fifty pounds are on record. They are used for cutting through the bark of machabel trees, which is then seized by the trunk and torn off, for elephants are extremely fond of this bark; and they are also turned to account in breaking up roots which have been exposed by digging with the fore-feet. But this is certainly not the main purpose of such weapons. On the contrary, their use is primarily as weapons of offence between rival bulls. As one would expect, they never attain to a very large size in the female, but that they are large enough to serve her at need is shown by the fact that a portion of a tusk, evidently of a cow-elephant, was once found embedded in the jaw of a bull. There can be little doubt but that this was broken off in an endeavour to repel the advances of a too amorous male, for, as with all animals, pairing is impossible without the consent of the female, and this is never accorded until she is desirous that it should take place. As a preliminary to this, an amorous dalliance is perhaps the invariable rule among animals, and this takes many and often strange forms. The Elephant affords a case in point. For the late A. H. Neumann once came upon a pair which were evidently, as he says, “love-making.” Creeping upon them noiselessly, he found the male fondling his mate with his trunk, and then, standing side by side, they crossed their trunks, and put the tips thereof into each other’s mouths, the elephantine form of kissing. Deer, cattle and horses, cats and dogs, constantly lick one another under like circumstances.

Superficial secondary sexual characters are wanting both in the Hippopotamus and the Camel. Both, however, possess a formidable armature of teeth which are capable of inflicting very severe wounds. In the Hippopotamus the canines are of enormous size, and their punishing power is further strengthened by the fact that they work in opposition to a pair of similar teeth in the lower jaw; they cut like a pair of shears, the upper closing upon the lower pair with the precision of scissors-blades. In addition, the lower jaw develops two long, blunt-pointed, ivory spikes, which are scarcely less to be dreaded. With these weapons the bulls fight furiously, and it is no uncommon thing to find vanquished males frightfully mauled, the hide being lacerated from head to tail. Protection, in a measure, is afforded by its enormous thickness, but the great folds and pleats of skin seen in the Rhinoceros are never developed. The females, however, are similarly armed, and the teeth are nearly as large as in the males, which is a rather unusual occurrence.

The Swine, which are near relations of the Hippopotamus, in like manner develop huge pointed canines, and these reach their maximum in the great Wart-hogs of Africa. But in the swine the mechanism differs, for although the canines are closely opposed, the shaft of the upper teeth curves upwards, and the lower teeth are much smaller than the upper. In fighting, these animals do not bite, like the Hippopotamus, but use the upper canines to rip up their antagonist with a sudden, swift upward and sideways movement of the head. How dangerous is the wound thus inflicted those who have hunted the wild-boar know well. A curious exaggeration of this arrangement of the teeth is seen in the Babiroussa. Herein the upper canines grow directly upwards, actually piercing the upper lip as in the case of the downwardly growing tusks of the elephant. That these teeth, however, are of any service in fighting is doubtful, for the upper tooth curves upwards and backwards in a semicircle so that the points are harmless. The tusks of the lower jaw, however, are extremely long and pointed, though their wounding power is limited by reason of the upper teeth. This may account for the fact that the head, the part mostly attacked by enraged boars, presents no sort of armature designed for defence; while in the Wart-hog, on the other hand, great solid bucklers of hide stand out on either side of the head below the eyes, giving the animal a most repulsive appearance, but affording him a very present help in time of trouble. In the wild-boar, where the tusks are shorter, no such protective armature is needed.

While the ungulates, or hoofed animals, are peculiar in the development of horns as weapons of offence, they are by no means singular in the use of teeth for this purpose. In some cases, as in the Muntjac, both forms of armature are present. The only other instances where teeth in this group of animals are used for offensive purposes are those furnished by the Camel and the Horse. But here they do not exhibit that excessive size which is met with in the Elephant, and some of the Swine. In both the Camel and the Horse it is the canine which is used, and both jaws are similarly armed. Since the camel has no upper incisors, the part played by the teeth is beyond dispute; but it has been contended that the horse uses his incisor or “front-teeth” alone when fighting. But this is not so; the canines can, and do, inflict ugly wounds, as is shown by the necks of zebras.

A further method of defence among the larger Ungulates, at any rate, is resorted to when hard pressed: and this is the use of the hoof in kicking. Giraffes kick both after the usual fashion and in striking downwards with the fore-foot. And an interesting demonstration of this has been furnished by Mr. F. C. Selous in his delightful “African Nature Notes.” He relates that on one occasion he came across a calf only a day or two old, with its back broken. From scratches on the calf, and the footprints on the ground in its vicinity, he was at once enabled to gather the cause of its terrible plight. In a word, it had been attacked by two leopards, and the mother, in an endeavour to beat off the assailants with a blow of her fore-foot had accidentally struck her offspring. Horses, Cattle, Antelopes, Camels and Elephants can all kick with precision and effect. So far as the evidence goes, however, this is a method of defence used against beasts of prey, and is rarely, if ever, employed in conflicts between rival males. Females persecuted by the undesired attentions of amorous males, however, do, as we know from the case of domesticated animals, use this device to defend themselves.

It is not difficult to account for the origin of such secondary sexual characters as manes, beards, tusks, and brightly-coloured areas of skin, though whether our interpretations are really correct is another matter. But no attempt to explain the origin of horns has yet achieved a like degree of persuasiveness. These weapons appear only in the Ungulates, a group which has, in past times, given birth to some very extraordinary types of head armature of this kind. These must be excluded from the present discussion; suffice it to say that, as usual, they were the adjuncts of the males. According to current theories it is supposed that these weapons arose as the result of the action of sexual selection. It is assumed that the hornless ancestors of now horned ruminants fought for their mates by “butting” with the forehead. Naturally, other things being equal, the thickest skulled combatants obtained the mastery. Any tendency to develop frontal “bosses” of bone would further enhance the chances of success, and would, indeed, soon become necessary for survival. And from such “bosses” the passage to horns and antlers forms an easy transition. Just such incipient horns or “bosses” actually make their appearance in the domesticated horse: but these animals never butt at one another. If, however, we regard horn-production as an inherent diathesis of the ungulate somatoplasm, we have an intelligible basis for the explanation of horn development.

The formidable horns of the Rhinoceros are of a totally different character, being solid structures formed by hairlike agglomerations, firmly fixed upon a roughened area of the nasal region. These weapons play a very important part in settling disputes between rival males, but on other occasions demanding offensive tactics the Indian Rhinoceros at any rate seems to depend rather on his power of wounding by means of the chisel-shaped lower incisors. These, by means of a swift lateral movement of the head can be made to inflict most terrible gashes, as those who hunt with elephants well know. It is quite possible, however, that the teeth are also thus used during struggles for supremacy. And this may perhaps account for the enormous bucklers of skin developed by the Indian Rhinoceros, but only indicated in the case of the African species.

All the larger Ungulates, and many of the smaller species, are polygamous. The Rhinoceros, and all of the swine-group save the Hippopotamus, among the larger species are exceptions to the rule. The preponderance of females which this implies is generally supposed to be due to the losses sustained among the males by fighting during the struggle for mates. The case of horses, however, seems to militate against this view, for though they undoubtedly fight furiously, no evidence is forthcoming to show that such conflicts terminate fatally.

Were it possible to secure the necessary data it would probably be found that polygamy, and polyandry, are determined solely by the numerical proportions of the sexes: the excess of males or females being due neither to “Natural” nor “Sexual” Selection, but to inherent peculiarities of the germ-plasm tending to produce an excess of males, or females, as the case may be.

Finally, all the evidence goes to show that it is a mistake to suppose that polygamy is due to the excessive sexual avidness of the males, which impels them to first essay the overthrow of all possible rivals, and then to appropriate every female within their sphere of influence, holding them by force. On the contrary, this plurality of mates is thrust upon them. And this because the females, impelled by “mate-hunger,” attach themselves to the nearest male within call: the size of the harem depending on the number of available males. The battles which are fought between rival males are no more sanguinary than in the case of monogamous species. This contention is well illustrated by the African Wydah-birds (Vidua), which are markedly polygamous, though they have no special weapons of offence. In districts where males are numerous the harem will not exceed eight, or ten, females; where males are scarce this number may be increased to fifty. In like manner the varying number of hinds accompanying a stag are to be regarded, not as an index of his prowess, but of the scarcity or abundance of males in the neighbourhood.

CHAPTER V

THE LION AND HIS KIN

A Surprising Relationship—The Lion’s Mane—The Sabre-toothed Tiger—Some Theories about Origins—Sea-lions in Love—Some Strange Ornaments—Whales and Weapons.

That the Lion and the Lamb could possibly have been derived from the same stock seems incredible: yet such is the case, though the pedigree is now well-nigh lost in the mists of a hoary antiquity. It is not surprising, then, that in their present-day garb they should show so little in common. Nor is it strange that among their many points of divergence the one should differ so conspicuously from the other in the matter of secondary sexual characters. For when these are conspicuous among the Ungulates they usually take the form of horns, of which the Carnivores have no need, for the teeth and claws whereby they win their daily portion of meat make equally serviceable weapons of offence when turned against their own kind.

Among the larger Carnivora, the Lion alone displays any obvious distinction between the sexes in the matter of ornament, and this in the form of the well-known mane. Darwin, and later authorities, have regarded this as a shield to protect the great blood-vessels from injury during battles between rivals. But it is not very clear that this alone is sufficient to explain its presence, inasmuch as the Tiger in this respect is defenceless. Mr. F. C. Selous long ago pointed out that the varying abundance of the mane is due to climatic causes. Lions which live in districts where the nights are very cold, as in high table-lands, have large manes; those which occupy lower ground, where the nights are relatively warm, have but a scanty mane. It is clear, however, that the abundance of the mane is not determined by the need for warmth, otherwise it would have been as well developed in the female. Rather we must regard a low temperature as conducive to the growth of long hair when a natural tendency to produce this is present.

There are few men who can claim to have so great a first-hand acquaintance with Lions as Mr. Selous, and he has pointed out to me one significant fact which seems to show not only that the mane has not been developed to serve as a shield when fighting, but that fights between rival males must be rare. And this because of the absence of any evidence in the shape of scars on the skin. With claws so formidable as those of the lion, ugly wounds would certainly be made in any prolonged conflicts, for the skin of this animal is very thin.

In the now extinct Sabre-toothed Tiger the upper canines were of enormous length, and it is not improbable that they, on this account, exceeded the bounds of usefulness; that, while as weapons of offence they may have proved exceedingly effective, yet they hampered the animal when feeding. In many ways one is reminded by these weapons of the huge tusks of the Walrus. These are blunt-pointed, and are said to be used very largely for digging up the large clams and other burrowing shell-fish on which this animal mainly feeds. They are also used as levers to drag the huge body out of the water on to the ice. As fighting weapons they are formidable, and the wounds they inflict are sometimes serious. The polygamous habits of this huge creature may account for the fact that they are so much larger in the males, wherein they may attain a length of thirty inches, and a weight of eight pounds a-piece.

In connection with the monstrous tusks of the Sabre-toothed Tiger there is a point which so far seems never to have attracted the attention it deserves. And this concerns two small flanges of bone which project from the lower border of the end of the lower jaw. In themselves they are unimportant: they lie, it is to be noticed, parallel with the points of the great upper teeth which descend on either side of them. Their full significance is not apparent till we turn to the skull of another extinct animal of quite another type—the huge Dinoceros, one of the Ungulates. This animal was also armed with an enormous pair of tusks, which also, when the mouth was closed, descended on either side of a flange. In this case, however, the flange was developed to such an extent that its free edge descended to the level of the point of the tusk, thus affording it protection against injury. The really striking feature of this curious down-growth is not apparent till an attempt is made to explain its presence. What determined its growth? It seems to furnish us with another of the many instances which are to be found of the correlation of growth between unrelated parts, for there is apparently no traceable connection between the growth of this pair of teeth in the upper jaw and the development of the flanges of the lower border of the jaw which are embraced by these teeth. In the Sabre-toothed Tiger the inciting cause to this flange growth, whatever it may have been, seems to have been much weaker than in the case of Dinoceros.

Naturally one asks, can the whole thing be explained by the theory of Kinetogenesis promulgated years ago by Cope? That is to say, are these curious down-growths the result of a response to a stimulus set up in the lower jaw by constant lateral blows dealt by the tusks against the side of the jaw during the lateral movements of the jaw when feeding or ruminating? Such movements in an Ungulate would be frequent and constant: hence perhaps the more striking result. On account of the scissor-like action of the jaws in the Sabre-tooth such lateral movements were far less extensive, and less powerful. But though this explanation sounds plausible, it presents many difficulties. In the first place it seems to commit one to the admission that the responses of the Somatoplasm during the life of the individual are transmitted to the germ-plasm: that, in short, the characters acquired by the individual during its lifetime are transmitted to its offspring. And there are insuperable difficulties in the way of such a theory. Yet, it must be admitted, it is no less difficult to believe that this correlation of growth is due solely to fortuitous variation, for one cannot really conceive of a variation of this kind taking place in two such different structures independently. Such a conception would have been less difficult if the case of Dinoceros alone were known to us. We could have supposed that, somehow, the lower jaw started to produce its flange just as the teeth began to develop an excess of growth which carried their points beyond the level of the jaw. But the Sabre-tooth shows that the tusks had assumed a growth relatively exaggerated as in Dinoceros, and yet the flange never attained to more than feeble development. We cannot rest content with the theory that the flange is due to the constant stimulus of blows struck against this region of the jaw during the lateral movements which take place when feeding. Were these animals alive to-day it could be tested by extracting the tusks during infancy, when, the stimulus being removed, the flanges should not appear.

There are yet other aspects of the skull of Dinoceros which may well be considered here. The first concerns the excessive armature of horns, there being no less than three pairs supported on massive bony cores; and the second the ridiculously small brain cavity which is proportionately smaller than that of any other known mammal, recent or fossil. This poverty of brain-power was probably one, if not the chief, factor among the causes which brought about the extinction of this strange beast. Even more formidable horns were borne by the extinct Arsinoetherium. But this animal did not display the double armature of horns and tusks.

Among the Carnivora monogamy is the rule, though the Lion is occasionally polygamous. But the Eared-seals (Otaria), or Sea-lions, and Sea-bears afford a striking example of polygamous species and of the ferocity they display when sexually excited. These animals, moreover, are capable of the most astonishing powers of endurance and vitality, exceeding indeed that of all other mammals. Since the habits of the Northern Fur-seal (Otaria ursina) have been more carefully studied than those of any others, it may serve as a sample of the rest.

Living for the greater part of the year in the open sea, the old bulls—animals of six or seven years old—are the first to seek the “rookeries,” or breeding grounds, taking up their territory a full month before the cows arrive. Later, the younger bulls appear, and the more daring endeavour to force their way through the ranks of those who have already taken up positions. This often leads to fighting, but more usually nothing further than “bluffing” is indulged in, though it is commonly supposed that very severe engagements take place. This seems, however, to be only occasionally true. In due course, generally about the second week in June, the cows begin to arrive, at first in straggling numbers, but soon the main body puts in an appearance, and before the end of the month many thousands of both sexes are crowded along the foreshore. But yet, contrary to the generally accepted belief, no serious fighting takes place. The bulls quietly seize the females as they arrive. It would seem that the first arrival serves as a focus of attraction for all later comers landing in the vicinity. The bull holding the most advantageous post—that is to say, that nearest the best landing-place—starts the collection and, unintentionally, the distribution of the cows. Having seized the first arrival, he places her by his side. As the later females arrive he gives each a most cordial welcome, and then proceeds to round up his harem. But soon he has more wives than he can continue to control. Do what he will, he cannot be in two places at once; and thus it is that in rushing off to chastise some covetous neighbour, one or more bulls on the opposite side of his harem proceed to make captures from his horde. And this system of abduction goes on over the whole rookery till all the cows have been appropriated, leaving a crowd of envious bachelors in the background who have not yet developed either courage or strength to secure mates for themselves.