30 SEXUAL DIMORPHISM 



only to each other but to hawks and other enemies ; their 

 long plumes diminish their powers of escape ; their constant 

 fights tend to diminish their numbers, while their dances and 

 rival singing are merely distractions which protect the 

 females against their too constant attentions. 



A very little reflection is enough to show that these curious 

 and ingenious suggestions are of no real assistance towards 

 the solution of the problem. As far as individual selection 

 within the species is concerned, the males with the special 

 peculiarities most highly developed must according to the 

 theory be the first to be exterminated, and therefore it is 

 impossible to understand how such peculiarities could ever 

 make much progress in evolution. The theory is founded on 

 the argument that the decimation of the males is for the 

 good of the' species, which merely means that those species 

 in which the males are most conspicuous, and exposed to the 

 most numerous perils, will flourish most. But how are we 

 to conceive of the evolution of a species which is at the same 

 time characterised by the greatest development of peculiarities 

 in the males and the greatest destruction of males on account 

 of those very peculiarities. The two processes supposed are 

 in direct opposition, and logically the result would be nothing. 

 There is no variation of species apart from individuals, and 

 according to the assumptions made by Stolzmann, the in- 

 dividuals in the species with the greatest development of the 

 required characters would not transmit their peculiarities. 



The fundamental objection to Darwin's theory of sexual 

 selection, or to any other selection theory, is that it does not 

 account for the origin of the variations which it assumes. 

 Those who consider the process of selection as the most im- 

 portant factor, maintain, and rightly maintain, that in- 

 dividual variations do actually occur, and they are either not 

 inclined to analyse the problem further, or they support 

 some theory which professes to explain the indefinite varia- 



