322 MAMMALS 



foLU-th stoinaeli, where the gastric juice is mixed with it. 

 To tlie iiuniiuuits belong most of our valuable domesti- 

 cated animals. 



Although the camel is a ruminant, its stomach has only 

 three compartments, the psalterium not l.)eing i.)re.sent. 

 The dromedary has one huin|:) and its body is covered 

 with a fine wool hair, except on the breast and knees, the 

 latter being covered with thick pads of skin. This is the 

 beast of burden used in traveling across the deserts of 

 Africa and Arabia. It is expected to go from three to five 

 days without water during these journevs, Ijut ordinarily 

 demands water e\'ery other day. (_)n the under side of 

 each of its feet is a large spongy pad which enables the 

 animal to travel over the sand with com])arati\e ease. The 

 camel inhabiting central Asia has two humps. 



The llamas and aljmcas, found in the western parts of 

 South America, are members of the camel family. The 

 llama is still used as a beast of liui'den, while the alpacas 

 are reared for their wool wliich is used in the manufacture 

 of dress fabrics. 



The thirtl group of ungulates is represented by the ele- 

 phants. There are only two representatives of living ele- 

 phants, the African and tlie Asiatic The former is wild, 

 and valued for the ivory of its tusks. The latter is domes- 

 ticated and is usually docile and intelligcmt. The head of 

 tlie elephant is very large, and would f)e almost insupjiort- 

 able from its enormous weight werc^ it not for tlie fact that 

 the bones of the head contain cells hlled with air. 



The ui)p(>r incisoi' teeth are greatly (l('\el()p(Hl and form 

 the tusks. The neck is very sliort, but the snout is pro- 

 longed into a long flexible trunk, oi' proboscis. At the end 

 of the trunk are the openings of the nostrils, which are 



