CLASS MAMMALIA. MAMMALS 



489 



about the size of small squirrels; the body is 

 covered with soft fur. The great toe has a 

 flat nail, but the other digits bear claws. 



The typical South American monkey 

 (Fig. 36 3A) is of small or medium size; the 

 thumb, as well as the great toe, is opposable; 

 all digits possess nails; the tail is usually long 

 and prehensile, aiding in climbing; the space 

 between the nostril openings is wide; there is 

 no vermiform appendix. They are known as 

 night monkeys, titis, squirrel monkeys, sakis, 

 howlers, capuchins, and woolly and spider 

 monkeys. 



The Old World monkeys (Fig. 363B) 

 usually possess long tails, which are never 

 prehensile; their buttocks are provided with 

 thick patches of callous skin on which they 

 rest in a sitting posture; the nostrils are 



Figure 362. Gibbon. It is the smallest of the 

 apes and the only one that habitually walks erect 

 like man. It is a tree dweller with very long arms, 

 legs, hands, and feet; sometimes called the acrobat 

 of mammals. (Courtesy of N.Y. Zoological Society.) 



separated by a narrow space; and some have 

 cheek pouches. Many species live in Asia 

 and Africa, including the baboons, ma- 

 caques, and langurs. 



The anthropoid apes (Pongidae) are the 

 primates most nearly related to man. Like 



man they have a vermiform appendix. The 

 tail is absent; the forelimbs are longer than 

 the legs; locomotion is often bipedal, and 

 when the ape is walking, the feet tend to 

 turn in; and the knuckles help preserve 

 equilibrium. There are 4 genera in the fam- 

 ily: (1) Hylobates or gibbons (Fig. 362), 



(2) Simla (formerly Pongo) or orang-utans, 



(3) Gorilla or gorillas (Fig. 363C), and (4) 

 Pan or chimpanzees (Fig. 363D). 



Gibbons (Fig. 362) are arboreal; they 

 have slender bodies and limbs, are omnivo- 

 rous, reach a height of not over three feet, 

 and when walking, they are not assisted by 

 the hands. There are more than a dozen 

 species inhabiting southeastern Asia and the 

 East Indies. 



There is one or probably two species of 

 orang-utans confined to Borneo and Suma- 

 tra. They live principally in the treetops, 

 where they construct a sort of nest for them- 

 selves. Orang-utans are herbivorous. They 

 are about 4V2 feet in height; when walking, 

 they use their knuckles as well as their feet. 

 The brain of this species is more nearly like 

 that of man than of any other animal. 



The gorilla, Gorilla gorilla (Fig. 363C), 

 inhabits the forests of western Africa. It is 

 arboreal, feeds mainly on vegetation, has 

 large canine teeth, reaches a height of SVi 

 feet and a weight of about 500 pounds, 

 walks on the soles of its feet, aided by the 

 backs of the hands, and is ferocious and un- 

 tamable. The lowland gorilla is blackish- 

 brown in color; the mountain gorilla 

 [Gorilla gorilla beringeri) is black. 



The chimpanzee, Pan troglodytes (Fig. 

 363D), also lives in West Africa. It resem- 

 bles the gorilla, but has shorter arms and a 

 smoother, rounder skull. In many respects 

 the chimpanzee is more nearly like man 

 than any other living mammal. It is easily 

 tamed when young. 



The family Hominidae contains the single 

 living species Homo sapiens or man. Man 

 differs from the other primates in the size 

 of the brain, which is about twice as large 



