THE OXEN 75 r 



greater part of its length and tufted at the extremity, but in the yak it is thickly 

 haired throughout. The muzzle is broad, naked, and moist; and there are never 

 any ' ' tearpits ' ' or glands below the eye, which are so frequently present in the 

 antelopes; and in consequence of the absence of these tearpits there are no depres- 

 sions in the skull immediately below the eyes for their reception. The horns, which 

 are present in both sexes and of nearly equal dimensions in both, may be either 

 cylindrical or more or less markedly angulated; and are usually situated in the im- 

 mediate neighborhood of, or actually upon, the summit of the skull, whence they 

 generally sweep in a more or less outward direction, and then curve upward, and 

 sometimes inward, at their extremities. They are never spirally twisted, or orna- 

 mented with prominent transverse knots or wrinkles. If the horn cores be cut 

 through, they will be found to be completely honeycombed by a number of irregulai 

 cavities of large size. The upper molar teeth are very tall and broad, and are pro 

 vided with an additional column on the inner side, as shown in the figure of the 

 tooth of the nylghau on p. 745. 



With the exception of the American bison, the whole of the exist- 

 ing species of oxen are confined to the Old World, where by far the 

 greater number of species are continental. There is, however, one species, of 

 smaller size than any of the rest, confined to the island of Celebes; and another 

 which may, however, have been introduced, in the Philippines. Domesticated races 

 are spread over nearly all the globe. The wild species inhabit either open, grassy 

 plains or dense forests, while one of them is confined to the higher regions of the 

 Himalayas and Tibet. All of them live in herds of larger or smaller size, which are 

 protected by the bulls; the number of individuals in these herds being in some cases 

 reckoned by thousands, only the old bulls becoming solitary in their habits. 



All cattle can swim readily, and some species will cross rivers of 

 considerable breadth without the slightest hesitation. They are re- 

 markable for their strength and endurance; and as beasts of draught oxen are supe- 

 rior to horses for dragging heavy vehicles through soft and yielding ground. The 

 usual pace of these animals is a walk, but when excited they break into a heavy and 

 awkward gallop. Their senses of smell and hearing are acute, but their sight does 

 not appear to be particularly keen. Their food may consist either of leaves and the 

 tender shoots of trees, grass, mosses, or various kinds of marsh and water plants; 

 and all the species display a marked partiality for salt. 



Usually but one calf is produced at a birth, but there may be occasionally two. 

 As is the case with other Ruminants, the calf is born in a highly-developed state, 

 and is soon able to run by the side of its parent. 



., ..... In most of their structural peculiarities the oxen appear to be among 



Specialization 



the most highly specialized of all the hollow-horned Ruminants; and 



this is confirmed by the lateness of their appearance in the geological series, the 

 group being quite unknown before the Pliocene period and attaining its maximum 

 development in the Pleistocene and present epochs. Probably the origin of the 

 group may be traced to Ruminants more or less closely allied to the antelopes; 

 and it is noteworthy that in some of the extinct species horns were present only in 

 the male sex. 



