74 THE EVOLUTION OF MAN 



has become very much reduced in man and is represented only 

 by a small part of the nasal mucous membrane. In corre- 

 spondence with this the olfactory portion of the brain is also 

 very much reduced. 

 --"""Other structures showing signs of retrogression are the 



Cc 



k 



Fig. 26. The caecum and vermiform appendix in various 

 mammals. 1, Horse; 2, Kangaroo; 3, Cat; 4, Lemur; 5, 

 Orang; 6, Man, fetal; 7, Man, adult. Redrawn from Stratz, 

 Naturgeschichte des Menschen. By permission of Ferdinand 

 Ecke. 



teeth. This is indicated by the tendency for the teeth and 

 jaws to become smaller and is very evident when these struc- 

 tures in civilized man are compared with those of the primitive 

 races and with fossil man. Additional evidence is to be noted 

 in the occurrence of misplaced and irregular teeth which, in 



