MAMMALIA 



637 



The manlike, or anthropoid, apes are grouped in the family 

 Shniidae which includes the gibbons, Hylolates; the orangutan, Simia 

 satyrus; the chimpanzee, Anthropopitheais troglodytes; and the 

 gorilla. Gorilla gorilla. The gibbons are tailless apes with long arms. 

 They are arboreal and omnivorous. They can accomplish bipedal 

 locomotion. They are only three feet tall and strictly arboreal ; they 

 live on the Malay Peninsula and in the East Indies. The orangutan 

 builds nests in the trees and feeds principally on fruits. It is be- 

 tween four and five feet tall and has an arm spread of seven feet. 

 The chimpanzee is perhaps the most intelligent ape. It is easily 

 tamed and in many respects is more manlike than most of the others. 

 It lives in central and western Africa. The arms are somewhat 

 shorter and the skull rounder and smoother than are those of the 

 gorilla. The gorilla, which is the largest of the group and somewhat 

 more ferocious, is about five and one-half feet tall. It walks on the 

 soles of the feet and on the knuckles of the hands. It has prominent 

 canine teeth and feeds mainly on plants and foliage. 



Economic Relations 



Nearly all of the important beasts of burden, such as horses, asses, 

 mules, elephants, camels, llamas, reindeer, oxen, and dogs, are 

 mammals. The history of the origin of the domestication of most 

 of these has been lost to antiquity. Cattle, sheep, hogs, goats, rein- 

 deer, alpaca, and rabbits are the chief meat-producing mammals. A 

 few years ago it was estimated that more than 20,000,000 cattle, 

 15,000,000 sheep, and 80,000,000 swine are required to supply the 

 meat demand in the United States each year. Cattle and goats are 

 the most important commercial milk-producing animals. The milk 

 of camels, reindeer, and llama is also used in some parts of the world. 

 The leather produced by tanning the hides of meat-producing do- 

 mestic animals particularly is worth millions of dollars. It is used 

 for making shoes, saddles, harness, belts, and for ornamentation. 

 Wool is a very important animal fiber used in the manufacture of 

 fabrics which are resistant to dampness and cold. It is produced 

 principally by sheep and goats in this country. In some parts of the 

 world the alpaca and camel are important wool-producing animals. 

 The skins and furs of many wild mammals, the fur-bearers, are 

 exceedingly important commercially. They were used as clothing 

 and ornamentation even by primitive people. The modern people are 



