892 



PHYLUM CHORDATA : CLASS MAMMALIA 



contain bone, but in no case adequately known is there any increase in 

 the number of vertebras which normally fuse to form the terminal 

 portion of the human vertebral column, known as the coccyx. 



The arguments by which Darwin and others have sought 

 to show that man arose from an ancestral type common to 



Fig. 526. — Restoration of head of Pithecanthropus erectus. — 



After MacGregor. 



him and to the higher apes, are the same as those used to 

 substantiate the general doctrine of descent. The Descent 

 of Man is the expansion of a chapter in the Origin of 

 Species. The arguments may be briefly summarised : — 

 (i) Physiological. The bodily life of man is like that 

 of monkeys ; men and monkeys are subject to similar 

 diseases ; various human traits of gesture, expression, etc.. 



