SELECTION 167 



touching each other, and driven inward by 

 incessant blows." ... "It may be meta- 

 phorically said that natural selection is 

 daily and hourly scrutinizing throughout 

 the world the slightest variations." . . . 

 "Battle within battle must be continually 

 recurring with varying success; and yet in 

 the long run the forces are so nicely balanced 

 that the merest trifle would give the victory 

 to one organic being over another." 



What we wish to suggest is, that Darwin's 

 characteristic fundamental idea of the in- 

 tricacy of interrelations in the web of life, 

 lies below the idea of the struggle for exist- 

 ence, and therefore below the idea of natural 

 selection. Unless we appreciate the funda- 

 mental natural history fact of the web of life, 

 we cannot rightly understand how slight 

 differences can be of critical moment in 

 determining survival. The entanglements 

 are so intricate that a slight variation may be 

 of survival-value to its possessor. 



There is another consideration which 

 Darwin had certainly in mind, and which, 

 like that just explained, has often been lost 

 sight of since. It is illustrated, for instance, 

 by the researches of Bumpus and of Cramp- 

 ton on the survival of sparrows and pupae 

 respectively. The point was, that the sur- 

 vivors seemed to survive, not because of 



