E Cavicomia. The last family of the Ruminants is that of the Cavicornia, comprising the Oxen, Sheep, Goats, and Antelopes. This family includes the most typical Ruminants, and those of most importance to man. The upper jaw in all the Cavicornia is wholly destitute of incisors and canines, the place of which is taken by the hardened gum, against which the lower incisors bite. There are six incisors and two canines in the lower jaw, placed in a continuous series, and the molars are separated by a wide gap from the canines. There are six grinders on each side of each jaw. Both sexes have horns, or the males only may be horned, but in either case these appendages are very different to the "antlers" of the Cervidae. The horns, namely, are persistent, instead of being deciduous, and each consists of a bony process of the frontal bone - or "horn-core"-covered by a sheath of horn (fig. 411). In the Prong-buck (Antilocapra), however, the sheath of the horn is shed annually. The feet are cleft, but are mostly furnished with accessory hoofs placed on the back of the foot.
Fig. 411. - Skull of the Cape Buffalo (Bubalus caffer), viewed from above, showing the horn-cores. (After Cuvier.)
The Cavicornia comprise the three families of the Antilopidae, Ovidae, and Bovidae. The Antelopes form an extremely large section, with very many species. They are characterised by their slender deer-like form, their long and slender legs, and their simple cylindrical annulated or twisted horns, which are sometimes confined to the males, but often occur in the females as well (fig. 412). Accessory hoofs are generally, but not always, present. The Antelopes must on no account be confounded with the true Deer, to which they present many points of similarity. The structure of the horns, however, is quite sufficient to distinguish them. The Antelopes are further distinguished by rarely having a beard or dew-lap, and by the general possession of "inguinal pores" and" lachrymal sinuses." The inguinal pores are the apertures of two involutions of the integument of the groin, secreting a viscous substance, the use of which is unknown. The lachrymal sinuses, or "tear-pits," have already been mentioned as occurring in the Cervidae, and are not found in any of the Cavicornia except the Antelopes.
Fig. 412. - Head of the Koodoo (Strepsiceros Koodoo).
Each consists of a sebaceous sac placed beneath the eye, and secreting a yellowish waxy substance. The function of these glands is uncertain, but it is probably sexual. The Antelopes are especially numerous, both in individuals and in species, in Africa, in which country they appear to take the place of the true Deer (only one species of Deer being indigenous to Africa). Amongst the better-known African species of Antelopes are the Springbok, Hartebeest, Gnu, Eland, and Gazelle. The only European Antelopes are the Chamois (Rupicapra tragus), which inhabits the Alps and other mountain - ranges of southern Europe, and the Saiga of eastern Europe. Amongst the more remarkable Antelopes may be mentioned the Prong-buck (Antilocapra Americana) of N. America, in which there are no accessory hoofs, lachrymal sinuses, or inguinal pores; the females have very small horns, and the horns of the male have a snag or branch in front. The horn-core, however, is conical, and does not extend above the snag. The horns are also very remarkable for the fact that their sheath is annually shed, and annually reproduced. Another curious form is the Chickara (A. quadricornis) of India, in which the females are hornless, but the males have four horns.
The Sheep and Goats (Ovidae) have mostly horns in both sexes, and the horns are generally curved, compressed, and turned more or less backwards. The body is heavier, and the legs shorter and stouter, than in the true Antelopes. In the true Goats (Capra) both sexes have horns, and there are no lachrymal sinuses. The throat is furnished with long hair, forming a beard; and this appendage is usually present in both sexes, though sometimes in the males only. The goats live in herds, usually in mountainous and rugged districts. The domestic Goat (Copra hircus) is generally believed to be a descendant of a species which occurs in a wild state in Persia and in the Caucasus (the "Paseng," or Capra aegagrus). The true Sheep (Ovis) are destitute of a beard, and the horns though triangular and transversely ridged, are more cylindrical than in the Goats, and are generally twisted into a spiral. Horns may be present in both sexes, or in the males only.* Lachrymal sinuses are invariably absent.
Numerous varieties of the domestic sheep (Ovis aries) are known, but it is not certainly known from what wild species these were originally derived. Some, at any rate, of the domesticated breeds, more especially the smaller short-tailed breeds, with crescent-shaped horns, appear to be descended from the wild species known as the "Moufflon," which is found in Corsica and Sardinia. The Merino Sheep (a Spanish breed) and the Thibet Sheep are particularly celebrated for their long and fine wool. With the exception of one species (the Big-horn, Ovis montana), all the Sheep appear to be originally natives of the Old World. The Big-horn, however, inhabits the Rocky Mountains from their termination in latitude 68° to 400.
The true Oxen (Bovidae) are distinguished by having simply rounded horns, which are not twisted in a spiral manner. There are no lachrymal sinuses. Most of the oxen admit of being more or less completely domesticated, and some of them are amongst the most useful of animals, both as beasts of burden and as supplying food.