PDF - Wallace Online

370 TROPICAL NATUREturkey, and the pea-fowl go on feeding while the male is displayinghis finery and there is reason to believe that it is;his persistency and energy rather than his beauty whichwins the day. Again, evidence collected by Mr. Darwinhimself, proves that each bird finds a mate under anycircumstances. He gives a number of cases of one of apair of birds being shot, and the survivor being alwaysfound paired again almost immediately. This is sufficientlyexplained on the assumption that the destruction of birds byvarious causes is continually leaving widows and widowers innearly equal proportions, and thus each one finds a freshmate; and it leads to the conclusion that permanentlyunpaired birds are very scarce, so that, speaking broadly,every bird finds a mate and breeds. But this would almostor quite neutralise any effect of sexual selection of colour orornament, since the less highly-coloured birds would be atlittle or no disadvantage as regards leaving healthy offspring.If, however, heightened colour is correlated with health andvigour and if these ; healthy and vigorous birds provide bestfor their young, and leave offspring which, being equallyhealthy and vigorous, can best provide for themselves whichcannot be denied then natural selection becomes a preserverand intensifier of colour.Another most important consideration is, that male butterfliesrival or even excel the most gorgeous male birds inbright colours and elegant patterns and ; among these there isliterally not one particle of evidence that the female is influencedby colour, or even that she has any power of choice,while there is much direct evidence to the contrary (Descentof Man, p. 318). The weakness of the evidence for conscioussexual selection among these insects is so palpable that Mr.Darwin is obliged to supplement it by the singularly inconclusiveargument " that, Unless the female prefer one male toanother, the pairing must be left to mere chance, and thisdoes not appear probable" (Ic. p. 317). But he has justsaid " : The males sometimes fight together in rivalry, andmany may be seen pursuing or crowding round the samefemale;" while in the case of the silk-moths, "the femalesappear not to evince the least choice in regard to their partners."Surely the plain inference from all this is, that males