2O De Vi Physica 



this way ? What are, if any, the limits of the 

 power of accumulated increment ? Is there, 

 in organic parts and systems of parts, any 

 element irreducible to the principle : any- 

 thing which, from the nature of the case, 

 accumulated increment cannot possibly ex- 

 plain ? 



But Darwin never did anything of the 

 kind. To question the power of Natural 

 Selection ; to doubt, whether organic parts 

 could be produced by continuous accumu- 

 lation, never entered his head. There is not, 

 in all his writings, a single line even be- 

 traying a suspicion, that such a preliminary 

 consideration was even necessary. So far 

 from doubting that accumulated increments 

 could produce the parts of animals, there 

 never even seemed to him to be any question 

 about it. Had any one told him, that accu- 

 mulated increments could not possibly have 

 produced the parts of animals, it would have 



