THE METHOD OF EVOLUTION 17 



provement in many directions, in size, in strength, 

 in speed, in endurance and hardiness, in beauty of 

 colour and form, in sight, in scent, in hearing, and 

 so forth, so few animals would be excellent at once 

 in all these particulars that if he attempted selection 

 in all, he would exterminate rather than improve his 

 stock. He, therefore, deals with a few characters 

 only, and as regards all other characters eliminates 

 only such animals as are plainly inferior to the 

 average. If the Neo-Darwinian doctrine be true, 

 the same thing must occur in Nature. In that case 

 wild plants and animals could not undergo evolution 

 in many directions at the same time. It may be 

 argued that the higher plants and animals are very 

 complex, and that all their thousand parts must all 

 have undergone evolution. This is true ; they have 

 certainly all undergone evolution, but not all at the 

 same time. For thousands of years the eyes, the 

 ears, the hands, the feet, and very many of the 

 other characters of man, for instance, have under- 

 gone no appreciable evolution. They were evolved 

 during different but overlapping periods of a long 

 extended past. It follows, then, that the Darwinian 

 scheme of evolution presents us with problems of com- 

 parative simplicity. According to it, evolution results 

 from the selective elimination of inferior individuals, 

 and then only when the selective elimination 

 is considerable in volume. And, since considerable 



B 



