The feet of all these animals terminate in two toes which are joined together in a bone called the shank. Sometimes also there exists at the back of the foot two small spurs or toes. In all these animals except the Camels and Llamas—the hoofs, which entirely cover the last joint of the two toes on each foot, act side by side on a smooth surface, and resemble one single but cloven hoof. Thus the origin of the word cloven-hoofed. The Ruminants are divided in various ways by different Naturalists. Some are satisfied with the division simply into Horned and Hornless Ruminants. But the best classification is into the two large families of the Camels and Common Ruminants. The Camel family includes the Camels and Dromedaries—the beasts of burden in dessert lands, and the Llama, etc., the beast of burden among the mountains. The Common Ruminants are divided into three tribes—those with hairy and permanent horns, those with hollow-horns, and those that shed their horns. THE CAMEL FAMILY. [Illustration: CAMEL.] Most of the modern Naturalists admit two distinct species of the Camel genus; the Camel proper, which has two humps on its back, and the Dromedary, which has only one. The individuals of the Camel genus have a small and strongly-arched head. Their ears are slightly developed, still their sense of hearing is excellent. Their eyes, which have oblong and horizontal pupils, are projecting and gentle in expression, and are protected by a double eyelid. Their power of sight is very great. Their nostrils are situated at some distance from the extremity of the upper lip, and, externally, appear only two simple slits in the skin, which the animal can open or shut at will. Their upper lip is split down the centre, and the two halves are susceptible of various and separate movements. These constitute a very delicate organ of feeling. They are also possessed of an extremely acute sense of smell. This remarkable head is carried with a certain degree of nobility and dignity on a somewhat long neck, which, when the animal moves slowly, describes a graceful arched curve. Their peculiar body, made more remarkable by the one or two humps on its back, is supported on four long legs, which appear slender in comparison with the mass they bear. In the Camel proper the color of the coat is chestnut-brown. The hair grows to a considerable length, and becomes rather curly on the humps and about the neck. Below the neck it forms a fringe, which descends over the fore-legs. THE DROMEDARY. [Illustration: DROMEDARY.] The Dromedary, which is less massive in form and smaller in size than the Camel, has a coat of brownish-grey. Its hair is soft, woolly, and moderately long, more especially about its hump and neck.