PREHISTORIC HIPPOPOTAMUS
Drawn by Christman. (American Museum of Natural History)

The swine occupy a somewhat intermediate place between the solid-hoofed and the split-hoofed sections of the Herbivora; and the stomach is simple except in the peccaries, where it takes a complicated form that approaches that of the ruminants. This simplicity, with the correlated fact that swine do not chew the cud, enabled the leaders of the ancient Hebrews to set pigs apart, as unclean, by a more general definition than a mere name could give, thus leaving no way of escape for those who might be inclined to dodge the prohibition by quibbling. All other Herbivora are ruminants, that is, chewers of the "cud"—those that gather and swallow their food in haste, and then at leisure recover it and thoroughly rechew it in small quantities (cuds).

Photos, Elwin R. Sanborn, N. Y. Zoological Society
AT THE LEFT, THE KUDU, OR STRIPED ANTELOPE OF AFRICA; AT THE RIGHT, HEAD OF THE GREATER SABLE ANTELOPE

Photo, American Museum of Natural History
HEAD OF AN ALASKAN MOOSE

This strange operation, like the carrying away of food by pocket mice, monkeys, etc., enabled these comparatively defenseless animals to gather nutriment in a short time and then retreat to a safe place to prepare it for digestion. Associated with this practice is a large, complicated stomach, normally consisting of four chambers, into the first and largest of which the hastily swallowed forage is first received. Then, when swallowed a second time, it passes on into the second or true stomach, where real digestion begins.