272 THE EVOLUTION OF MAN. 



in our older Ape ancestors. Thus it is possible even here, 

 with the help of Comparative Anatomy, to trace this human 

 organ from the similar but more highly-developed organ of 

 the lower Mammals, with certainty. At the same time, Com- 

 parative Physiology shows us that this organ is of more 

 or less high physiological value to the latter, while in 

 Anthropoids and Man it is a useless rudimentary organ. 

 Men with their ears cut off can hear as well as they did 

 before. The conveyance of sound is not affected by the loss 

 of the ear-shell. This explains the great diversity in the 

 form and size of the ear-shell in different persons ; it shares 

 this high degree of variability with other rudimentary 

 organs. 175 



