THE SKELETyVL SYSTEM 



165 



base of the nasal septum. Apes and fossil species of men, however, help 

 to bridge this contrast. See Fig. 158. 



The heavy superciliary crests characteristic of the chimpanzee and 

 gorilla, but lacking in modern species of men, are present in fossil Neander- 

 thal and Rhodesian man. Furthermore, the usual contrast between apes 

 and man disappears in the orang-utan which, like modern man, has rudi- 

 mentary superciliary ridges. Furthermore the contrast between the 



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Fig. 157. — A series of fossil skulls (A-G) which are believed to represent fairly well 

 the phylogenetic changes of the human skull. (Redrawn after Romer's " Man and the 

 Vertebrates," University of Chicago Press.) 



skulls of apes and man holds for the adult only, not for the young, the 

 differences increasing with age. 



Against the evolution theory as appUed to the human species it used 

 to be urged that there are no connecting hnks between man and apes, 

 contrary to expectation if man and apes have evolved from a common 

 ancestry. The contrast in brain size between man and apes is especially 

 striking. The brain of the gorilla is never larger than 600 cc, while the 

 smallest human brain is not less than 1000 cc. and the normal male brain is 



