144 THE COMING [CH. 



human race, Darwin was led to propound his views 

 concerning Sexual selection, the results of the pre- 

 ferences shown by males and females, respectively, 

 not only among mankind, but in various other animals. 

 It was with respect to some of the conclusions con- 

 tained in this work that Wallace found himself unable 

 to follow Darwin. Wallace maintained that while 

 man's body could have been developed by Natural 

 Selection, his intellectual and moral nature must 

 have had a different origin. He also declined to 

 adopt the theory of sexual selection, so far as it 

 depends on preferences exhibited by females for 

 beauty in the males. Wallace, however, in some 

 respects has always been disposed to attach more 

 importance to Natural Selection, as the greatest, if 

 not the only factor in evolution, than Darwin himself. 



It will be seen that although Darwin had in all 

 probability thought out all his important theoretical 

 conclusions before 1869, when he reached the 'fatal 

 age,' yet, owing to various delays, the books, in 

 which he embodied his views, had not all appeared 

 till more than four years later. 



Lyell, who was a convinced evolutionist before the 

 publication of the Principles of Geology, as is shown 

 by his letters, and the fact is strongly insisted on 

 both by Huxley and Haeckel 141 , was slow in coming 

 into complete agreement with Darwin concerning the 

 theory of Natural Selection. While he followed his 



