162 ASSOCIATION OF ORGANISMS THE WEB OF LIFE 



fully. In both sexes the upper sides of the wings are whitish, 

 while the front ones are tipped with black and have a spot in the 

 centre. This can hardly be regarded as a protective arrangement, 

 for it renders the insects conspicuous, though it is not a case of 

 warning coloration; and in the male the effect is greatly height- 

 ened by the beautiful orange tips of the fore-wings, and since 

 these present this peculiarity on their under as well as on their 

 upper sides, the members of this sex are not so inconspicuous 

 when they settle as are their partners. We can only conclude 

 that the magnificent orange patches are courtship adornments. 



It is very interesting to find that there are certain Moths in 

 which the females are degenerate, their eyes, among other parts, 

 having undergone retrogressive changes. Attractive colours and 

 patterns in the male would be here superfluous, and, as a matter 

 of fact, the males of such species are commonly dull and plain in 

 appearance. 



In some insects the usual rule is reversed, and the female is 

 more beautiful than the male, as in the Cabbage Butterfly (Pieris 

 brassicce, fig. 1117) and other Whites, where there are black mark- 

 ings on the fore-wings of the former sex. Careful observations 

 have demonstrated that in these species the females are the active 

 wooers, while the males are coy (compare vol. iii, p. 465). 



A considerable number of male insects proclaim their feelings 

 in an audible manner, as in Grasshoppers and Crickets (see 

 p. 38). Many beetles too, and some other sorts of insects, such 

 as the Cicadas, are possessed of variously situated and constructed 

 sound-producing organs, of which one or the chief use appears 

 to be the production of love-calls (see vol. i, p. 352 and vol. iii, 

 p. 224). Some male insects are also known which emit a strong 

 musky odour. 



That some female insects show a preference for one particular 

 admirer seems to be pretty clearly demonstrated in the case of 

 certain Moths, where a large number of males " assemble" round 

 a female that has just come out of the chrysalis (fig. 1118). The 

 following first-hand evidence on this point is given by Poulton (in 

 The Colours of Animals)'. " In many species of moths the males 

 ' assemble ' round the freshly - emerged female, but no special 

 advantage appears to attend an early arrival. The female sits 

 apparently motionless while the little crowd of suitors buzz around 

 her for several minutes. Suddenly, and, as far as one can see, 



