Page:Encyclopædia Britannica, Ninth Edition, v. 15.djvu/447

Rh UNGULATA.J functions of the lips of other animals are performed. By its means the Elephant is enabled to drink without bend ing the head or limbs ; the end of the trunk being dipped into the stream or pool, a forcible inspiration fills the two capacious air-passages in its interior with water, which, on the tip of the trunk being turned upwards and inserted into the mouth, is ejected by a blowing action, and swallowed ; or if the animal wishes to refresh and cool its skin, it can throw the water in a copious stream over any part of its surface. Elephants can also throw dust and Band over their bodies by the same means and for the same purpose, and wild animals have been frequently observed fanning themselves with leafy boughs held in the trunk. The species are at present limited in their geographical distri bution to the Ethiopian and Oriental regions, but they formerly had a far more extensive range. Elephas. Dentition : i, c $, in f = 26. The incisors variable, but usually of very large size, especially in the male sex, directed some what outwards, and curved upwards, without enamel except on the apex before it is worn; preceded by small milk incisors. The molars succeed each other by horizontal replacement from before back wards, never more than one or part of two being in use on each side of each jaw at the same time ; each composed of numerous flattened enamel-covered plates or ridges of dentine, projecting from a common many-rooted base, surrounded and united together by cementum. The number of plates increases from the anterior to the posterior molar in regular succession, varying in the different species, but the third and fourth (or the last milk molar and the first true molar), and these only, have the same number of ridges, which always exceeds five. Skull of adult very high and globular. Mandible ending in front in a prolonged deflected and spout-like symphysis. Vertebra;: C 7, D 19-21, L 3-4, S 4, C 26-33. The existing species of the genus differ so much that they must be placed in two distinct sections, considered by some zoologists as distinct genera. 1. Elephas proper. Elasmodon, F. Cuv. ; Euelephas, Falc. Average number of plates of the six successive molar teeth expressed by the &quot;ridge formula&quot; 4, 8, 12, 12, 16, 24. The plates com pressed from before backwards, the anterior and posterior surfaces (as seen in the worn grinding face of the tooth) being nearly parallel. Ears of moderate size. Upper margin of the end of the proboscis developed into a distinct finger-like process, much longer than the lower margin. Five nails on the fore feet, and four (occasionally five) on the hind feet. The well-known Asiatic Elephant, E. indicus, inhabits in a wild state the forest lands of India, Burmah, the Malay Peninsula, Cochin China, Ceylon, and Sumatra. Those from the last-named islands, presenting some variations from those of the mainland, have been separated under the name of E. sumatranus, but the distinction has not been satisfactorily established. The appearance of the Asiatic Elephant is familiar to all. Though rarely breeding in captivity, it has been domesticated from the most remote antiquity, and is still extensively used in the East as a beast of burden. In the wild state it is gregarious, associating in herds of ten, twenty, or more individuals, and, though it may under certain circumstances become dangerous, it is generally inoffensive and even timid, fond of shade and solitude and the neighbourhood of water. The height of the male at the shoulder when full grown is usually from 8 to 10 feet, occasionally as much as 11. The female is somewhat smaller. See ELEPHANT. 2. Loxodon. Molar teeth of coarse construction, with fewer and larger plates and thicker enamel. Ridge formula: 3, 6, 7, 7, 8, 10. The plates not flattened, but thicker in the middle than at the edges, so that their worn grinding surfaces are lozenge-shaped. Ears very large. The upper and lower margins of the end of the trunk forming two nearly equal prehensile lips. But three hoofs on the hind foot. The one species, E. africanus, now inhabits the wooded districts of the whole of Africa south of the Sahara, except where it has been driven away by human settlements. Fossil remains of Pleistocene age, undistinguishable specifically, have been found in Algeria, Spain, and Sicily. It was trained for war and show by the ancient Carthaginians and Romans, and recent experi ence of the species in captivity in England shows that it is as intelligent as its Asiatic relative, if not more so, while surpass ing it in courage, activity, and obstinacy. Nevertheless, in modern times, no people in Africa have been sufficiently civilized or enter prising to care to train it for domestic purposes. It is hunted chiefly for the sake of the ivory of its immense tusks, of which it yields the principal source of supply to the European market, nnd the desire to obtain which is rapidly leading to the extermination of the species. In size the male African elephant often surpasses that of Asia, but the female is usually smaller. The circumference of the forefoot is half the height at the shoulder, a circumstance 425 which enables the hunters to judge from the footprints the exact size of the animals of which they are in pursuit. Extinct Species of Elephant. Abundant remains of Elephants are found embedded in alluvial gravels, or secreted in the recesses of caves, into which they have been washed by streams and floods, or dragged as food by Hyaenas and other carnivorous inhabitants of these subterranean dens. Such remains belonging to the Pleistocene and Pliocene periods have been found in many parts of Europe, in cluding the British Isles, in North Africa, throughout the North American continent from Alaska to Mexico, and extensively dis tributed in Asia, where the deposits of the sub-Himalayan or Sivalik hills, belonging to the earliest Pliocene, are rich in the remains of Elephants of varied form. These species are chiefly known and characterized at present by the teeth, some of which resemble the existing Indian and some the African type, but the majority are between the two, and make the distinction between Elephas and Loxodon as different genera quite impracticable. Others again approach so closely in the breadth and coarseness of the ridges and paucity of cementum to Mastodon as to have been placed by some zoologists in that genus. These form the group or subgenus called Slegodon by Falconer. Among the best known extinct Elephants are E. primigenius, the Mammoth, very closely resembling the existing Indian species, and one of the most recently extinct and extensively distributed (see MAMMOTH); E. anliquus and E. meridional-is, also found in Britain, as well as in Europe generally, of rather earlier date, and inclining more to the Loxodon type, as also do two species found in ihe island of Malta, E. mnaidicnsis and E. mditcnsis, the latter the smallest known species of the suborder, sometimes not exceeding 3 feet in height when adult. The Stegodon forms, E. clifti, bombifrons, insig- nis, and gancsa, are 11 from India, which locality would appear, from the abundance of remains and variety of forms, as well as the generalized character of some and the geological horizon (Plio- Miocene) in which the remains are found, to be the earliest habi tation of the true Elephants yet discovered. Remains of Elephants of the last-named group have also lately been found in China and Japan. A tusk the dentine of which presents the characters hither to considered peculiar to the Proboscidca, from Australia, has been lately described by Professor Owen under the name of Notelephas. Mastodon. Dentition: i j-^,, c %, p and m. Upper incisors very large, as in Elephas ; sometimes with longitudinal bands of enamel, more or less spirally disposed. Lower incisors vari able : when present comparatively small and straight, sometimes persistent, sometimes early deciduous, and in some species never present. Grinding surface of molars with transverse ridges, the summits of which arc divided more or less into conical or mam- millary cusps, and often with secondary or additional cusps between and clustering against the principal ridges ; enamel thick ; cemen tum very scanty, never filling up the interspaces between the ridges. The third, fourth, and fifth molars having the same num ber of ridges, 1 which never exceeds five. In some species (M. ohioticus] no vertical succession has been observed, but in others, as M. angustidcns, the two posterior premolars, and in the American M. prodtidus apparently all three, are preceded by milk molars. There is also a horizontal succession as in Elephants, the anterior teeth being lost before the posterior ones are fully developed, but not so complete as in the former genus, for as many as three teeth may be in place in one jaw at one time. The skull generally is less elevated and less cellular than in Elephas ; otherwise the remainder of the skeleton is similar. All known Mastodons are gigantic animals, equalling or exceed ing the recent Elephants in size. Their remains have been found in Europe and southern Asia and America, from the Miocene to the Pleistocene epochs. Dinothcrium. Dentition of adult: i~, c , p , m f = 22; all present at the same time, there being no horizontal succession, but the premolars replace milk teeth in the ordinary manner. The presence or absence of upper incisors has not yet been clearly ascer tained. Lower incisors, large, conical, descending and slightly curved backwards, implanted in a greatly thickened and deflected beak or prolongation of the symphysis. In section they do not show the decussating stria? characteristic of Mastodons and Elephants. Crowns of molars with strong, transverse, crenulated ridges, with deep valleys between, much resembling those of the Tapirs. Ridge formula of the permanent molar series : 2, 2, 3, 2, 2. The three ridges of the first true molar appear to be constant in both upper and lower jaws, although it is quite an anomalous character among 1 This, and the larger number of ridges in the latter, are the only absolute distinctions which Falconer could find between Mastodon and Elephas (Palicont. Memoirs, ii. p. 9), and it is clear that they are somewhat arbitrary. The line between the two genera is drawn at this point more as a matter of convenience for descriptive purposes than as indicating any great natural break in the sequence of modifications of the same type.