THE CAMEL. 513 



family are cushions developed more or less on the soles of the feet, the 

 absence of horns, and a cleft upper lip. North Africa, Central Asia, and 

 Southwestern America are the original homes of these animals. The two 

 species found in the Old World are entirely domestic animals, no longer 

 occurring in a state of nature ; in the New World two of the four 

 species are domesticated, but two still retain their independence. 



GENUS CAMELUS. 



The two species of this genus are both natives of the Old World ; they 

 are remarkable for their size, and for the possession of one or two 

 humps. They have a small, strongly arched head ; their ears are slightly 

 developed, but their sense of hearing is excellent. The eyes have oblong 

 horizontal pupils, are gentle in expression, and protected by a double 

 eyelid ; their power of sight is vcy great. The nostrils are situated at 

 some distance from the extremity of the upper lip, and externally appear 

 like two small slits which the animal can open or close at will. The lips 

 constitute a very delicate organ of touch, and the camel has an extremely 

 acute sense of smell. The head, which is as a whole exceedingly repul- 

 sive in appearance, is carried on a long neck, which, when the animal 

 moves slowly, describes a graceful arched curve. The Camel possesses 

 callosities on the breast, knees, and insteps, as well as on the patella and 

 heels. The feet are bifurcated. The two toes on each foot are not 

 enveloped in horn, and have only on the last joint a somewhat short and 

 hooked nail. A hard and callous sole covers the bottom of the toes — a 

 characteristic which enables them to walk with ease on loose sand, 

 where the elephant would be useless, and the horse soon exhaust its 

 strength. The hump of the camel is a very curious part of its structure. 

 The Arabs say that it feeds upon its hump, for when it suffers from 

 privation and fatigue the protuberance diminishes, and will often nearly 

 vanish at the end of a long and painful journey. As the animal is in- 

 tended to traverse the parched sand-plains, and to pass several con- 

 secutive days without the possibility of obtaining liquid nourishment, 

 there is an internal structure which permits it to store up a considerable 

 amount of water for future use. For this purpose, the honeycomb cells 

 of the " reticulum " are largely developed, and are enabled to receive 

 and to retain the water which is received into the stomach after the 

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