MANS RELATIVES: THE PRIMATES 



479 



The orangutan. Next above the gibbon in the scale of living primates 

 is the orangutan, or "man of the woods" of Borneo and Sumatra. It is a 

 bulky and powerful animal, though short-legged and standing only 4 

 to 5 feet tall. The arms are very long, with a span of over 7 feet, and the 

 hands and feet are long and narrow, with a short thumb and great toe. 

 The skull and brain are relatively larger than in the gibbon; the muzzle is 

 large and protruding, the brow ridges scarcely prominent, and the nasal 

 region deeply concave. The canine teeth are large, tusklike, and inter- 



Fig. 29.9. A group of gibbons, genus Hylobates. There are a number of kinds differing in 

 coloration, but all are probably varieties or subspecies of one or two species. (Courtesy 

 Chicago Natural History Museum.) 



locking. The body is sparsely covered with long, reddish-brown hair. This 

 ape is almost exclusively arboreal, but on account of its weight (up to 

 160 pounds) is not an expert brachiator; it climbs deliberately and tests 

 the strength of branches before venturing upon them. Orangutans build 

 nests on which to sleep and on rainy nights are said to cover themselves 

 with leaves. They feed on fruits and foliage. One young is produced at a 

 birth, and the life span is about 45 years. The orangutan, while more 

 advanced than the gibbon, is probably far off the line leading to the two 

 higher manlike apes and man. 



The chimpanzee and the gorilla. These two apes, which inhabit 

 tropical Africa, are closely related and may be discussed together. Of all 



