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 (Pzerzs 
brassice, 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 Animatls):—‘‘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, 
