RUMINANTS, herbivorous split-hoofed animals, characterized especially by chewing the cud; they include the camels and llamas, giraffes, deer, pronghorns, antelopes, sheep, goats and ox-tribe and thus nearly all the mammals most economically important to man. All these, except the camels and giraffes, are represented on the continent of North America, and two — the pronghorns and musk ox — are peculiar •to it In most, no incisor or canine teeth exist in the upperjaw, the place of these being supplied by a hardened or callous pad of awn, against which the lower incisors bite. Six incisors exist in the lower jaw. Canines are always present there, and are usually inclined forward and toward the incisiors, which they nearly resemble in form. The general number of lower canine teeth is two. The molar and premolar teeth number six on each side of each jaw and are selenodont, that is possess flat tened crowns topped by two double folds of enamel of an irregular crescentic shape. The stomach is divided into four compartments. (See DIGESTION). In feeding, the herbage is rapidly cropped off by the lower incisors press mg against the hardened gum of the upper jaw. The food mixed with saliva is swallowed into the paunch, where it is simply moistened and then passes into the reticulum or second com partment The aperture of the gullet now closes, and the mass of food contained therein is propelled upward into the mouth by a mus cular action similar to that of vomiting. Mas tication of the food is then effected by a kind of rotary motion, the lower jaw thus giving a first stroke, for example, from left to right, and the rotary motion continuing persistently afterward from right to left, or in the opposite direction to the first movement of the jaws. This is °chewing the cud.* In the camels the motion of 'the •yaws is said to be simply one from side to side. After it has been thus thoroughly masticated and remixed with saliva, the food is again swallowed, and passes on at once into the third stomach and is assimilated.
Two distinct divisions of the ruminants may be recognized according to the nature of the horns, and ate known respectively as the °solid borne& and the The first Section includes the giraffe (al though no external antlers arise), the deer and pronghorns; and the other the antelopes and the sheep, goat and ox tribes. The antlers of deer consist of nearly homogeneous bony tissue, lighter and more porous in structure than ordi nary bone; they are generally much branched or forked, and are shed and renewed every year. (See ANTLERS; DEER ) .
The horns of the hollow-horned ruminants are entirely different from the antlers of deer, in structure as well as in manner of growth. They are usually common to both as in our domestic cattle, are simple and not branched and grow continuously throughout the life of the animal, though very slowly after it has reached maturity, and are never shed. They consist of a bony core—an elongated process from the frontal bone—covered with a sheath of horn. (See Hoax).
Technically speaking, the ruminant game animals of North America consist of three dis tinct families, two of which are represented by several genera, and some of the genera by nu merous species. These families are the prong
horns (Antilocaprider) ; the deer (Cervidor) ; and the sheep, goat and ox tribes (Bovider). They are all °game animals,* and some of them are rapidly approaching extermination. The pronghorn, though usually called the American antelope, is not a true antelope, but is of a dis tinct family type, found only in North Amer ica, and peculiar in the fact that• its horns .are branched, and shed annually. (See max). The deer tribe in America consists of five genera, namely, the wapiti (Germs) ; the small deer of the United States and Mexico (Damn, or Odoeoileus) ; a Central American brocket (Mamma) ; the moose (Ake:), and the caribou (Rungsler). These are separately scribed under their names. Altogether between 25 and 30 species of deer exist in North ica, including Mexico. Of the ox and sheep tribes or horned ruminants, the most prominent native member is the almost extinct bison (q.v.). The mountain sheep (see BIGHORN) number five species, and the Rocky Mountain goat (q.v.) number two species; but of most of these species so few examples are known and their ra.e is so limited that it may well be drubbed whether they will ultimately be garded as distinct. The goats and sheep are mountain dwellers, their favorite haunts are the more inaccessible parts of the higher ranges and they are exceedingly watchful and cious. They have been exterminated in the more accessible parts of their ranges and vive in comparatively small numbers and greatly restricted areas. The musk-oxen, or musk-sheep, are a very distinct type, entitled to a distinctive name free from the Implication of such alliance; but the term musk-ox (q.v.) is not likely soon to be displaced. There are two species, the barren-ground and the Greenland. The ancestors of the higher ruminants are mainly of Old World origin, and are tively scarce and late in appearance in the fossil beds of our own continent. The oldest forms definitely known were those of the family ihracothernde, pig-like animals, with teeth proaching the selenodont shape and a complete dentition; all the bones of the five-toed feet were free. The type-genus Anthracotherium (q.v.) begins in the Oligocene and continues down to the Pliocene, and is known from all parts of the world. Another early group was more like in its characteristics and forms, the family Camotheriida, represented by Consotherison, which flourished in the Eocene and Miocene eras. They were small-sized, more delicate than modern sheep, the dentition was complete and four toes reached the ground. Another large group was the family Oreodontidw, which was limited to North America, and whose mains have been found plentifully and usually in excellent condition in the Tertiary rocks of the eastern Rocky Mountain region. The donts were ancestors of deer and antelopes and some were horned, while all had five functional toes in front and four behind. Prominent genera are .0 radon, of the size of a small and stouter; Casoryx, A Mesoreodon, larger ocklerus and most primitive of all on. Another primitive family wholly European was AnoPlotheriide, represented by the long-known Anoplotheriuns.