258 Darwin, and after Darwin. 



and still more all higher, characters must be useful. 

 Buti as we have seen, this is not maintained by our 

 opponents. On the contrary, they draw the sharpest 

 distinction between specific and all other characters in 

 this respect, freely conceding that both those below 

 and those above them need not and very often do 

 not present any utilitarian significance. 



Although it appears to me that this doctrine is self- 

 contradictory, and on this ground alone might be 

 summarily dismissed, as it is now held in one or 

 other of its forms by many naturalists, I will give it 

 a more detailed consideration in both its parts 

 namely, first with respect to the distinction between 

 varieties and species, and next with respect to the 

 distinction between species and genera. 



Until it can be shown that species are something 

 more than merely arbitrary divisions, due to the 

 disappearance of intermediate varietal links ; that in 

 some way or another they are "definite entities," 

 which admit of being delineated by the application of 

 some uniform or general principles of definition ; 

 that, in short, species have only then been classified 

 as such when it has been shown that the origin of 

 each has been due to the operation of causes which 

 have not been concerned in the production of varieties ; 

 until these things are shown, it clearly remains 

 a gratuitous dogma to maintain that forms which 

 have been called species differ from forms which have 

 been called varieties in the important respect, that 

 they (let alone each of all their distinctive characters) 

 must necessarily have been due to the principle of 

 utility. Yet, as we have seen, even Mr. Wallace 



