OBJECTIONS TO THE THEORY 301 



result wbich we thus arrive at; namely, that characters 

 of slight vital importance to the species are the most 

 important to the systematist; but, as we shall hereafter 

 see when we treat of the genetic principle of classifica- 

 tion, this is by no means so paradoxical as it may at 

 first appear. 



Although we have no good evidence of the existence 

 in organic beings of an innate tendencj?^ toward progres- 

 sive development, yet this necessarily follows, as I have 

 attempted to show in the fourth chapter, through the 

 continued action of natural selection. For the best 

 definition which has ever been given of a high standard 

 of organization is the degree to which the parts have 

 been specialized or differentiated; and natural selection 

 tends toward this end, inasmuch as the parts are thus 

 enabled to perform their functions more efficiently. 



A distinguished zoologist, Mr. St. George Mivart, has 

 recently collected all the objections which have ever been 

 advanced by myself and others against the theory of 

 natural selection, as propounded by Mr. Wallace and 

 myself, and has illustrated them with admirable art 

 and force. When thus marshalled, they make a for- 

 midable array; and as it forms no part of Mr. Mivart's 

 plan to give the various facts and considerations opposed 

 to his conclusions, no slight effort of reason and memory 

 is left to the reader, who may wish to weigh the evidence 

 on both sides. When discussing special cases, Mr. Mivart 

 passes over the effects of the increased use and disuse of 

 parts, which I have always maintained to be highly im- 

 portant, and have treated in my "Variation under Domes- 

 tication" at greater length than, as I believe, any other 



