370 TROPICAL NATURE 



turkey, and the pea-fowl go on feeding while the male is dis- 

 playing his finery ; and there is reason to believe that it is 

 his persistency and energy rather than his beauty which 

 wins the day. Again, evidence collected by Mr. Darwin 

 himself, proves that each bird finds a mate under any 

 circumstances. He gives a number of cases of one of a 

 pair of birds being shot, and the survivor being always 

 found paired again almost immediately. This is sufficiently 

 explained on the assumption that the destruction of birds by 

 various causes is continually leaving widows and widowers in 

 nearly equal proportions, and thus each one finds a fresh 

 mate; and it leads to the conclusion that permanently 

 unpaired birds are very scarce, so that, speaking broadly, 

 every bird finds a mate and breeds. But this would almost 

 or quite neutralise any effect of sexual selection of colour or 

 ornament, since the less highly-coloured birds would be at 

 little or no disadvantage as regards leaving healthy offspring. 

 If, however, heightened colour is correlated with health and 

 vigour ; and if these healthy and vigorous birds provide best 

 for their young, and leave offspring which, being equally 

 healthy and vigorous, can best provide for themselves which 

 cannot be denied then natural selection becomes a preserver 

 and intensifier of colour. 



Another most important consideration is, that male butter- 

 flies rival or even excel the most gorgeous male birds in 

 bright colours and elegant patterns ; and among these there is 

 literally not one particle of evidence that the female is influ- 

 enced by colour, or even that she has any power of choice, 

 while there is much direct evidence to the contrary (Descent 

 of Man, p. 318). The weakness of the evidence for conscious 

 sexual selection among these insects is so palpable that Mr. 

 Darwin is obliged to supplement it by the singularly incon- 

 clusive argument that, " Unless the female prefer one male to 

 another, the pairing must be left to mere chance, and this 

 does not appear probable" (Ic. p. 317). But he has just 

 said : " The males sometimes fight together in rivalry, and 

 many may be seen pursuing or crowding round the same 

 female;" while in the case of the silk-moths, "the females 

 appear not to evince the least choice in regard to their part- 

 ners." Surely the plain inference from all this is, that males 



