272 Darwin, and after Darwin. 



peacocks. But to say that it is due to correlation 

 with general "vitality," is merely to discharge the 

 doctrine of correlation of any assignable meaning. 

 Vitality, or " perfect adaptation to the conditions of 

 existence," is obviously a prime condition to the 

 occurrence of a peacock's tail, as it is to the occur- 

 rence of a peacock itself ; but this is quite a different 

 thing from saying that the specific characters which 

 are presented by a peacock's tail, although useless 

 in themselves, are correlated with some other and 

 useful specific characters of the same bird — as we saw 

 in a previous chapter with reference to secondary 

 sexual characters in general. Therefore, when Mr. 

 Wallace 'comes to the obvious question why it is that 

 even in " allied species," which must be in equally 

 " perfect adaptation to the conditions of existence," 

 there are no such " wonderful superfluities of plumage," 

 he falls back — as he previously fell back — on what- 

 ever unknown causes it may have been which pro- 

 duced the peacock's tail, when the primary condition 

 to their operation has been furnished by '' complete 

 success in the battle for life." 



I have quoted the above passages, not so much for 

 the sake of exposing fundamental inconsistencies on 

 the part of an adversary, as for the sake of observing 

 that they constitute a much truer exposition of 

 " Darwinism " than do the contradictory views ex- 

 pressed in some other parts of the work bearing that 

 title. For even if characters of so much size and elabo- 

 ration as the tail of a peacock, the plumes of a bird of 

 paradise &c., are admitted to be due to non-utilitarian 

 causes, much more must innumerable other characters 

 of incomparably less size and elaboration be mere 



