84 



HUMAN BIOLOGY 



Apparently the orang-utan was the first to branch off 

 from the common stock. It rapidly attained great size, 

 especially the old males, and became excessively speciaHzed 



Fig. 15. Structural stages in rise from fish to man. 

 Starting from upper right-hand corner, "living fossils" form a series that 

 gradually approaches man in general structural plan. Each "living fossil" 

 is also a surviving witness of a corresponding stage in past ages. 



for arboreal life, using chiefly the suspension grasp of both 

 the hands and feet, which are now extremely long and hook- 



