Page:Encyclopædia Britannica, Ninth Edition, v. 8.djvu/133

Rh ELEPHANT 123 them the largest of living terrestrial mammals, by peculiari ties in their dentition, and by the possession of a lengthened proboscis or trunk. The latter organ is a huge prolonga tion of the nose and upper lip, measuring usually from 6 to 8 feet in length, and almost wholly composed of a mass of muscles, numbering, according to Cuvier, nearly 40,000, and curiously interlaced, so as to produce the greatest diversity of motion. Its extremity contains the two open ings of the nostrils by which the elephant breathes when swimming, as it sometimes does, with only the tip of its trunk above the surface, and through which it can fill the channels of its trunk with water, the flexibility of that organ enabling it to pour the liquid into its mouth or to squirt it over the surface of its body. By a peculiar valvular arrangement the water is prevented from penetrating into the bony nostrils. The extremity of the trunk 13 produced on the upper surface into a finger-like process, and ends beneath in a thick tubercle which acts the part of thumb to the prolongation above, while the whole is exquisitely en dowed with the sense of touch, and so forms an organ of prehension comparable in many respects to the human hand. With it the elephant collects its food and drink, discovers the snares that are often set in its path, strikes its antago nist to the ground, and gives vent to its rage in a shrill trumpet-like sound, hence the French name of trompe for the proboscis, corrupted in our language into trunk. With out it the animal is helpless, being unable even to feed itself ; and, as if conscious of the vital importance of this organ, the elephant is exceedingly cautious in using it, pre ferring when in combat with the tiger to fight with its trunk carried aloft, out of reach of its antagonist s claws. When the trunk is injured the elephant becomes furious with rage and pain, and can no longer be controlled by its rider. The teeth of the elephant consist of two incisors, or tusks, as they are called, in the upper jaw, and six molars on each side of either jaw. The permanent tusks are preceded by small milk teeth, which, however, give place to their successors before the end of the second year. The tusks, proceeding from a permanent pulp, continue to grow during the elephant s lifetime, and sometimes attain enormous size, examples having been known to weigh from 150 to upwards of 200 Ib each. They consist almost entirely of ivory a remarkably fine and elastic form of dentine and are hollow for a considerable part of their length. They are also deeply imbedded in the skull; thus a tusk, about 8 feet long and 22 inches in girth, was found by Sir Samuel Baker to be imbedded to a depth of 31 inches. The tusks are invariably best developed in the male sex, and are regarded by Darwin as sexual weapons. Their almost vertical posi tion, however, and the inability of the elephant to raise its head above the shoulder, render their use as offensive weapons somewhat difficult; nevertheless they are certainly employed as such in fighting with the tiger, the mode of using them depending, says Darwin, &quot;on their direction and curvature&quot; thus the elephant has been known to toss a tiger to a distance of 30 feet with its tusks, when these were turned upward and outward, while it seeks to pin its foe to the ground when these organs have the usual down ward direction. The tusks are largest in the African species, which feeds principally on the foliage and the succulent roots of trees, and in this species they are often used as levers in uprooting mimosa trees, whose crown of foliage is beyond the reach of the upturned trunk. In Ceylon, on the other hand, where the elephant lives chiefly on grass and herbage, tusks are generally absent in botli sexes. The bullets occasionally found imbedded in the solid ivory have evidently been shot into the upper part of the tusk, and, getting lodged in the pulp cavity, have been carried down by the growth of successive layers of ivory into the solid part of the tooth. The molar teeth consist of a series of transverse plates, composed of dentine, and coated with a layer of enamel, the whole bound together by the substance known as crusta petrosa, or cement. Each of these materials, possessing a different degree of hardness, wears away at a different rate from the others, and the uneven surface necessary for the proper trituration of the food is thus produced. Although the elephant may be said to have altogether six molars on each side of either jaw, at no time can more than one and a portion of a second be seen. These molars are not deciduous in the ordinary sense, but they grow from behind forward, and as the anterior part of the front molar gets worn away by degrees, its successor is gradually cutting its way through the gum, from which, however, it does not wholly emerge until the tooth in front has almost disappeared. This progression of the molar teeth continues throughout the greater part of the elephant s life, so that it may be said to be always teething. Six of such molars, each composed of a greater number of plates than its predecessor, are said to suffice it for life. The massiveness of the skull, and its height in front, to which the elephant owes something of its sagacious aspect, is due not to the great size of the brain which is relatively small but to the enormous development of the bones of the cranium, rendered necessary in order to give attachment to the powerful muscles of the head and trunk. The presence of large air cells, however, in the cranial bones, renders the skull light in proportion to its enormous bulk. The eyes in the elephant are small, and its range of vision, owing to the shortness and slight flexibility of its neck, is somewhat circumscribed; this, however, is of secondary importance to an animal living generally in dense forests, where the prospect is necessarily limited, and in the elephant is compensated for by exceeding keenness in the senses of hearing and smell. Its stomach resembles that of the camel in having a chamber which can be cut off from the proper digestive cavity for the storing of water; this is capable of holding 10 gallons. The con tents of this chamber it is able to convey into its trunk, should it wish to indulge its body in the luxury of a shower bath. The elephant is an unwieldy creature, weighing fully 3 tons, and supported on colossal limbs, which from their straightness and apparent want of flexibility an effect pro duced by the greater nearness of the knee and elbow to the ground than in most animals were for centuries supposed either to be jointless, or to have such joints as could not be used. Such evidently was Shakespeare s belief when he wrote &quot;The elephant hath joint?, but not for courtesy ; His legs are for necessity, not flexure.&quot; This delusion was further supported by the fact that the elephant often sleeps standing, its huge body leaning against a tree or rock. In lying down it does not place the hind legs beneath it, as is generally the case, but extends them backwards after the manner of a person kneeling. By this method the elephant can raise its huge weight with little perceptible effort. The feet are furnished with five toes, completely enveloped in a tegumentnry cushion, and with four or five nails on each of the front feet, and three or four on the hind ones, according to the species. The skin of the elephant is thick and soft, and of a dark brown colour. With the exception of a few hairs on certain parts of its body, it is naked, although individuals found in the elevated districts of Northern India are said to be more hairy than those inhabiting warmer regions, while the young everywhere, according to Tennent, are at first covered with a woolly fleece, especially about the head and shoulders, approximating in this respect to the mammoth which inhabited the alfoarctic region during Pleistocene times. From such facts Darwin regards it as