the birth of weapons—all flesh is grass—utility and ornament—the fever of love—the “challenge” of the deer—what it means—more about “hormones”—“hummel” stags—the age of deer—the “courtship” of the moose—types of antlers—antlered females—fighting topi—the lance of the oryx in the lion’s flanks—happiness and hartebeestes—odoriferous suitors—the bloody sweat of the hippopotamus—the elephant in love—concerning tusks—polygamy.
from apes to antelopes is a far cry, but contrasts are always helpful. antelopes and deer, zebras and elephants, rhinoceroses and swine, are types, taken at random, of that great and important group of animals known as the “ungulates,” or “hoofed” animals. these illustrate in a very striking manner what is meant by the term “secondary sexual characters.” they demonstrate no less forcibly what is meant by the term “sexual selection.” they are valuable in this connection, because of the often formidable weapons, in the shape of horns and tusks, which so many species have developed during the struggle for mates.
but “sexual selection” will not explain their origin, and it is difficult, in the present state of our knowledge, to discover any clues which will reveal this. in seeking these there are certain broad aspects of the problem which 50are not to be lost sight of. in the first place, horns, at any rate, are confined to the hoofed animals. that the various types of hoofed animals, living and extinct, have had a common ancestry, no one at the present day will probably call in question. the relationship, however, of the various living types, one to another, is by no means always apparent: the missing links are to be sought in the records of the rocks.
when the whole of the evidence comes to be surveyed, and not till then, it becomes apparent that this wonderful diversity is the result of complex factors. that the conditions of existence have controlled the results is beyond question; but it is equally certain that these conditions have been merely controlling and not causative. in other words, we must regard each of these different groups or types—deer, antelopes, horses, elephants, swine, and so on—as witnesses of what we call “heredity.” they are so many “diathetic types.” that is to say, the forms, or individuals, belonging to each type have inherited certain peculiarities in common; they display a “diathesis” as the doctors call it: an inherent, inborn tendency, or habit of growth, in a definite direction: a tendency which, ever and anon, develops new qualities, takes new directions. and thus it is that we get oxen—using this term in its widest sense and not in its special sense—antelopes, goats and sheep, for example. these have, among other things, a “diathesis” in the direction of horn production, and each, too, of a different type. what is meant by this apparently mystifying term “diathesis” will perhaps be made clear by taking the case of the ox and the sheep. while very different in appearance, these live on precisely similar food; yet no one has any difficulty in 51discriminating between the taste of beef and mutton. in the marvellous chemical laboratory of the body the grass gathered in the same field is converted into flesh which even in its uncooked state is easily distinguishable. though for the purposes of this illustration domesticated animals have been used, the same is true of their wild relations. sportsmen tell us that the various types of antelopes and the zebra, which may be seen feeding together, have yet flesh of very different qualities. these qualities are to be attributed neither to “natural” nor to “sexual” selection; they are “accidents.” similarly, their horns are the witness of a horn-producing “diathesis”: the various divergencies in curvature, and in the form of their spirals, or the number of their encircling rings—as in the horns of antelopes—are to be interpreted in like fashion. these twists and turns vary in the same way that the taste of the flesh varies, and for the same reason; that is to say, they are not the outcome of “sexual selection,” nor have they been brought about by “natural selection” to serve the purpose of “recognition marks,” as wallace would have us believe.
but horns, as horns, apart from their “accidents” of curvature and ornament, must certainly be regarded as the product of sexual selection, for having once started into being those individuals had the best chance of leaving descendants which were best armed. the possession of horns was not necessary to the maintenance of the species; but such armature was essential among the males in securing possession of the females. other things being equal, the male with the biggest horns wins the prize. since these are also used as weapons of offence, or rather of defence, in warding off the attacks of beasts of prey, it might be contended that they are as much the product of natural selection as of sexual selection.
52it soon becomes apparent that this interpretation must fail. in the first place, if it were true, the females should be similarly armed. in the second, in the presence of many of their enemies they are useless. the cape hunting-dog, for example, is more than a match for any antelope. this ferocious animal kills his victim by running it down, persistently tearing at its flanks, until at last the entrails protrude and the horrid chase is ended. furthermore, the horns are a comparatively late acquirement of the species, as is shown in the case of the deer; for the earliest known fossil species were hornless. that the females among the oxen and many of the antelopes possess horns is an interesting fact, but it can only be regarded as another instance of a character first acquired by the male and later, in successive generations, transferred to the female. and it is to be noticed that this transference is never found save in the cases where the character in question has attained its maximum in the male. the transference of weapons to the female is the more remarkable because there is no evidence that they play any part in the struggle for existence, either in securing mates or in warding off the attacks of enemies. moreover, these weapons in the female may exceed those of the male, in length, though they are never so massive. they are to be regarded solely in the light of ornaments. there are few more striking instances indeed where the purely ornamental and the strictly utilitarian are so closely associated.
plate 4.
by the courtesy of rowland, ward, ltd.
weapons of offence.
horns of various types furnish the most conspicuous of the “secondary sexual characters” of the ruminants. in the deer only are these branched. in the “hollow-horned” ruminants they are either lance-like or more or less spirally curved, or they may form more or less open loops.
1. black-tailed deer. 2. hangul or kashmir barasingha deer. 3. greater kudu. 4. black-buck. 5. saiga antelope, remarkable also for its curiously swollen nose. 6. marco-polo’s sheep.
[face page 52.
attention may now profitably be turned to the behaviour of these interesting tribes when under the alluring influences of love.
tradition and the poets have contrived to persuade us 53that the fever of love becomes epidemic in the spring. this, however, is by no means true, at any rate in so far as what we are pleased to call the “lower animals” are concerned. for with many, as for example the deer and the bats, this fever is not aroused till the time of autumn plenty. with regard to the deer, we can find a reason for this. it is determined in part by the period of gestation, and in part by the peculiar character of the most conspicuous of the male secondary sexual characters—the antlers. the deer, at any rate of the northern hemisphere, carry their young about eight months. now it is important that they should make their entry into the world just as the food supply is increasing and the temperature is rising. with the summer before them the young have time to gather strength for the encounter with their first winter. we have a striking witness to the truth of this contention in the fact that when the indian spotted deer, or chital, was first introduced into europe, nearly all the fawns perished owing to having been born in winter; later, the females took to calving in spring, and from thence onwards the species has held its own among us.
as touching the stags. the antlers, as everybody knows, are shed annually, and their renewal entails a very considerable strain on the system. as a consequence, it is necessary that this period of stress should fall after the trial of winter is overpast, and with the genial summer before them. from the end of march, when the old weapons are shed, till july, the masterful males of the community wander at large, seeking seclusion and avoiding all occasion of quarrel; for they are not only defenceless, but threatened with disaster should any accident 54befall the growing horns, which, during their formation, are exceedingly sensitive. even a slight blow would not only spoil their shapely proportions, but, further, might render them useless in the warfare that is before them.
with some species this desire to go into retreat is more marked than in others. the red-deer, and the wapiti, on the one hand, and the moose on the other, well illustrate this. the two first-named pass the winter in herds, in the case of the wapiti numbering many thousand individuals; no other species, indeed, is so markedly gregarious. with the advance of the spring, however, all is changed, for the males withdraw from their companions to suffer humiliation in seclusion. as chill october arrives, a striking alteration in their demeanour becomes apparent, at any rate in the case of the older males. the new antlers are now hardened, and the blood supply, which has hitherto been building up the new weapons, is cut off. as a consequence, the “velvet,” which till now has been directly concerned with the growth of the antlers, dies, and peels off the underlying bone. to facilitate this work of cleaning, the animal rubs them, first against the stems of saplings, and, later, against larger trees, and even rocks, till at last they are ready for “battle, murder and sudden death.” the “rutting” season, in short, has commenced. and with the final completion of the antlers other signs of that approaching frenzy, which is soon to establish itself, become apparent. the most striking of these are the swelling of the neck, and a marked increase in the mane thereof; while the voice enlarges its compass enormously, whereby the females, so long neglected, are now feverishly sought for.
plate 5.
photo by g. if. wilson co. ltd., from “the living animals of the world.”
manchurian wapiti “calling.”
the “stags” do not begin to call for mate’s until the horns have more or less completely shed their velvet.
[face page 54.
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 55females 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; 56for 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 57period. 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 58conditions 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 59protection 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 60strong 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.
plate 6.
photo by lord delamere, from “the living animals of the world.”
group of beisa oryx.
the lance-like horns of these animals can be used with deadly effect, even against lions.
[face page 60.
61
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 62proved 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 sequel? 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.
63the 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 64character 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.
plate 7.
photo by courtesy of the duchess of bedford, woburn abbey.
eland cows.
among antelopes the females commonly bear horns, which may be even longer than in the males, though less massive.
[face page 64.
plate 8.
photo by courtesy of the duchess of bedford, woburn abbey.
american bison
the “secondary sexual characters” of the male are here conspicuously developed, and are seen in the massive fore-quarters and enormous head.
65
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 66couples, 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 67vital 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 68the 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 r?le 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, 69both 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 70fight. 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.
plate 9.
photo by lord delamere, from “the living animals of the world”
elephants.
the sexes differ but little in general appearance: and chiefly in the superior size of the male and his more massive tusks.
[face page 70.
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 71also 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 72jaw; 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 73the 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.
plate 10.
head of male wart-hog.
in the “swine” family the canine teeth are always greatly developed, but they attain to their maximum, relatively, in the wart-hog.
photos by scholastic photo co., from “the living animals of the world.”
male and female babirusa.
a characteristic of this pig is the peculiar development of the tusks in the male, the upper pair of which grow through the lips and curve upwards.
[face page 72.
plate 11.
photo by lord delamere, from “the living animals of the world.”
somali zebras.
the zebras, unlike their cloven-hoofed relations, have no weapons, save for inter-tribal conflicts. yet they have been as successful in holding their own against lions and other predatory animals as species provided with horns.
[face page 72
plate 12.
photo copyright by a. h. bishop.
giraffe.
the horns of this animal can prove formidable weapons of offence on occasion, though they are useless against predatory animals.
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. 74 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, 75soon 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 76to 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.
