Recapitulation and Conclusion. 327 



large our insight into the hidden relations between the 

 phenomena of nature. 



Chapter XL is devoted to an examination of the law 

 of natural selection, as modified by the law of heredity, 

 and I have here attempted to show that the acceptance 

 of this secondary law will remove the most serious ob- 

 jections to the view that our present forms of life have 

 been brought into existence through the survival of the 

 fittest variations, and I have also called attention to the 

 fact that the law of heredity is itself a result of the law 

 of natural selection. 



No one can deny that there are grave objections to the 

 law of natural selection in its original form. Darwin 

 admits this in many places, and able but dissenting 

 critics have stated most of these objections with great 

 ability. The evidence for the law of natural selection is 

 so many sided, so extensive, and so satisfactory, that we 

 may fairly conclude that the difficulties will disappear 

 with greater knowledge, and as none of its hostile critics 

 have proposed anything whatever to take its place, the 

 difficulties which they have pointed out have hardly re- 

 ceived from naturalists the attention which they deserve. 



One of the most serious objections is that natural 

 selection cannot effect any permanent modification of a 

 race, unless great numbers of individuals vary in essen- 

 tially /he same way at nearly the same time, and that 

 the chances against this are great beyond computation if 

 variations are purely fortuitous in Darwin's sense of the 

 word. 



Darwin has acknowledged the weight of this objection, 

 and there is no escape from the conclusion that natural 

 selection fails to account for the origin of species, unless 

 we can show that many individuals tend to vary at the 

 same time. According to our view, the production of 



