114 MIMICRY, AND OTHER PROTECTIVE 



Heliconidse and Danaidse, protected by a disagree- 

 able flavour, have the females as bright and conspi- 

 cuous as the males, and very rarely differing at all 

 from them. The stinging Hymenoptera have the two 

 sexes equally well coloured. The Carabidaa, the Coc- 

 cinellidye, Chrysomelida3, and the Telephori have both 

 sexes equally conspicuous, and seldom differing in 

 colours. The brilliant Curculios, which are protected 

 by their hardness, are brilliant in both sexes. Lastly, 

 the glittering CetoniadaB and Buprestidas, which seem 

 to be protected by their hard and polished coats, their 

 rapid motions, and peculiar habits, present few sexual 

 differences of colour, while sexual selection has often 

 manifested itself by structural differences, such as- 

 horns, spines, or other processes. 



Cause of the dull Colours of Female Birds. 



The same law manifests itself in Birds. The female 

 while sitting on her eggs requires protection by con- 

 cealment to a much greater extent than the male ; and 

 we accordingly find that in a large majority of the 

 cases in which the male birds are distinguished by 

 unusual brilliancy of plumage, the females are much 

 more obscure, and often remarkably plain-coloured. 

 The exceptions are such as eminently to prove the 

 rule, for in most cases we can see a very good reason 

 for them. In particular, there are a few instances 

 among wading and gallinaceous birds in which the 

 female has decidedly more brilliant colours than the 

 male; but it is a most curious and interesting fact 



