222 



ANIMAL BIOLOGY 



monkeys of the New World, which have a thicker par- 

 tition and have a broader nose. (Figs. 403, 404.) The 

 monkeys of America all have six molar teeth in each half 

 jaw (Fig. 352); the monkeys and apes of the Old World 

 have thirty-two teeth which agree both in number and 

 arrangement with those of man. 



Which of the primates figured in this book appear to 

 have the arm longer than the leg? Which have the 



eyes directed forward instead of 

 sideways, as with cats or dogs ? 

 Nearly all the primates are 

 forest dwellers ', and inhabit warm 

 countries, where the boughs of 

 trees are never covered with ice 

 or snow. Their ability in climb- 

 ing serves greatly to protect 

 them from beasts of prey. 

 Many apes and monkeys are 

 able to assume the upright posi- 

 tion in walking, but they touch 

 the ground with their knuckles 

 every few steps to aid in preserving the balance. 



The Simians are the highest family of primates below 

 man, and include the gorilla, chimpanzee, orang, and gib- 

 bon. Some of the simians weave together branches in the 

 treetops to form a rude nest, and all are very affectionate 

 and devoted to their young. How are apes most readily 

 distinguished from monkeys? (Figs. 401, 406.) 



The study of man as related to his environment will be 

 taken up in detail in the part called Human Biology. We 

 will there examine the effect upon man's body of the rapid 

 changes since emerging from savagery that he has made 

 in food eaten, air breathed, clothing, and habits of life. 



FIG. 406. CHIMPANZEE. 



