296 DARWINISM chap. 



The term " sexual selection " must, therefoi'e, be restricted 

 to the direct results of male struggle and combat. This is 

 really a form of natural selection, and is a matter of direct 

 observation ; while its results are as cleai'ly deducible as those 

 of any of the other modes in which selection acts. And if 

 this restriction of the term is needful in the case of the higher 

 animals it is much more so with the lower. In butterflies the 

 weeding out by natural selection takes place to an enormous 

 extent in the egg, larva, and pupa states ; and perhaps not 

 more than one in a hundred of the eggs laid produces a perfect 

 insect which lives to breed. Here, then, the impotence of 

 female selection, if it exist, must be complete ; for, unless the 

 most brilliantly coloiu'ed males are those which produce the 

 best protected eggs, larvae, and pupre, and unless the particular 

 eggs, larvae, and pupae, which are able to survive, are those 

 which produce the most brilliantly coloured butterflies, any 

 choice the female might make must be completely swamped. 

 If, on the other hand, there is this correlation l)etween colour 

 development and perfect adaptation to conditions in all stages, 

 then this development will necessarily proceed l)y the agency 

 of natural selection and the general laws which determine 

 the production of colour and of ornamental appendages.^ 



General Lcnvs of Animal Coloration. 

 The condensed account which has now been given of the 

 phenomena of colour in the animal world will sufficiently show 

 the wonderful complexity and extreme interest of the subject ; 

 while it aff"ords an admirable illustration of the importance of 

 the great principle of utility, and of the eftect of the theories 

 of natural selection and development in giving a new interest 



^ Tlie Rev. 0. Pickard-Caml)ridge, who has devoted himself to the study 

 of spiders, has kindly seut me the following extract from a letter, written 

 in 1869, in which he states his views on this question : — 



" I myself doubt that particular application of the Darwinian theorj' 

 which attributes male peculiarities of form, structure, colour, and ornament 

 to female appetency or predilection. There is, it seems to me, undoubtedly 

 something in the male organisation of a special, and sexual nature, which, 

 of its own vital force, develops the remarkable male jieculiarities so 

 commonly seen, and of no imaginable use to that sex. In as far as 

 these peculiarities show a great vital power, tliey point out to us the finest 

 and strongest individuals of the sex, and show us which of them would 

 most certainly appropriate to themselves the best and gi-eatust number of 

 females, and leave behind them the strongest and greatest number of 



