480 



THE CHANGING GENERATIONS 



existing animals they are those most similar to man, and both show a 

 change from arboreal to terrestrial life, though far less complete than in 

 man. They are large, powerful, and heavily built animals. The male 

 chimpanzee may be 5 feet tall and weigh 175 pounds, while the male 

 gorilla attains a height of more than 6 feet and a weight up to 600 pounds. 

 Weight for weight both are several times as strong as the strongest man. 

 The chimpanzee is an expert climber but spends much time on the 



Fig. 29.10. The "man of the woods," or orangutan, Simia ( = Pongo). Left, a young indi- 

 vidual; right, the face of a five-year-old male. {Courtesy Zoological Society of Philadelphia 

 and American Museum of Natural History respectively.) 



ground, where it runs on all fours or walks semierect for short distances. 

 The gorilla is largely terrestrial, though it climbs trees for fruit and to 

 sleep; it also is normally a quadruped, but stands erect for attack or 

 defense. Both animals have a coat of coarse black hair which is thin on 

 the chest and absent on the face, hands, and feet. These apes are chiefly 

 herbivorous, though the chimpanzee, at least, sometimes eats animal 

 food. There is some degree of family organization. Young are produced 

 singly, maturity is reached at eight to twelve years of age, and the span 

 of life is comparable with that of man. 



Some of the original arboreal adaptations of these apes have been 

 modified in conformity with the changed mode of life. The arms have 



