THE COURTSHIP OF INSECTS 257 



and agility — qualities which are indubitably associated 

 with his superior sense-organs and well-balanced physique 

 — are thought to offset any special dangers which his 

 bright colours may entail. Moreover, it is noteworthy 

 that those Colours which are believed to play a part in 

 courtship are generally concealed at other times. The 

 male orange-tip butterfly, when at rest with folded wings, 

 is not less perfectly disguised than his mate. 



The theory of sexual selection, as opposed to that of 

 exuberant vitality on the part of the male, is certainly 

 the more romantic ; while the two are not necessarily 

 Irreconcilable. The essential natures of the sexes must 

 always obtain, and might well constitute the foundation 

 upon which specialised characters, due either directly or 

 indirectly to the choice of the female, could be based. 

 The supposed inadequacy of the insect's aesthetic sense is 

 often urged as a weighty objection. But on this point 

 we can judge only by analogy. If, as we are justified 

 in believing, the chirping of crickets, and the other 

 sounds produced by insects at the period of courtship, 

 are the outcome of sexual selection, why should we 

 assume that decorative colours were evoked in some other 

 manner ? " Why " (writes Professor Weismann) " should 

 the eye be less sensitive to specifically male colours and 

 other visible signs enticing to the female than the olfac- 

 tory sense to specifically male odours, or the sense of 

 hearing to specifically male sounds ? . . . decorative 

 colouring and sweet-scentedness may replace one another 

 in Lepidoptera as well as in flowers, for just as some 

 modestly coloured flowers (mignonette and violet) have 

 often a strong perfume, while strikingly coloured ones are 

 sometimes quite devoid of fragrance, so we find that the 

 most beautifully and gaily coloured of our native Lepidop- 

 tera, the species of Vanessa (the ' tortoiseshells ' and their 



