34 Darwin, and after Darwin. 



Qiiittingr then the last, and in my opinion the 

 weakest chapter of Dnr^vinism, the most im[)ortant 

 points presented by other portions of this work are — 

 to qudte its author's own enumeration of them — an 

 attempted 'proof that all specific characters are (or 

 once have been) either useful in themselves or corre- 

 lated with useful characters": an attempted "proof 

 that natural selection can, in certain cases, increase 

 the sterility of crosses ": an attempted '" proof that 

 the effects of use and disuse, even if inherited, must be 

 overpowered by natural selection " : an attempted 

 proof that the facts of variation in nature are in them- 

 selves sufficient to meet the difficulty which arises 

 against the theory of natural selection, as held by him, 

 from the .swamping effects of free inter-crossing: and, 

 lastly, "a fuller discussion on the colour relations of 

 animals, with additional facts and arguments on the 

 origin of sexual differences of colour." As I intend to 

 deal with all these points hereafter, excepting the last, 

 it will be sufficient in this opening chapter to remark, 

 that in as far as I disagree with Mr. Wallace (and 

 agree with Darwin), on the subject of "sexual 

 differences of colour," my reasons for doing so have 

 been already sufficiently stated in Part 1. But there 

 is much else in his treatment of this subject which 

 appears to mc highly valuable, and therefore present- 

 ing an admirable contribution to the literature of 

 Darwinism. In particular, it appears to me that the 

 most important of his views in this connexion 



admiraltlc dwcussion on this subject, which has been published since the 

 above was wriilen. The same has to be said of Weismann's Essay on 

 Music, wliere much that I have here said is anticipated. With the views 

 and arj^uments which Mr. Mivart has forcibly set forth 1 have already 

 dealt to the best ol my ability in a work on Mental Evolution in Man. 



