56 THE THEORY OF NATURAL SELECTION 



Examples of this kind in which the shape of an 

 animal leads to its concealment are less numerous 

 than those in which protection is afforded by an obscure 

 pattern or inconspicuous colour. Indeed, some re- 

 semblance between the colour of an animal and its 

 surroundings is to be traced in the majority of the 

 members of many groups. Familiar examples are 

 afforded by the white colour of animals which live in 

 snow, the tawny grey colour of most desert species, 

 the green of grass-frequenting animals, and so on. It 

 is perhaps not quite certain that in some of these cases 

 the peculiar colour is not evoked by the direct action 

 of some cause which affects different species in the same 

 way ; but such a cause awaits discovery, and in the 

 meantime natural selection has certainly a strong 

 claim to be regarded as the proper explanation. 



A more strict use of the term mimicry, however, is 

 to restrict it to cases where one species apes the colour 

 pattern or other external character proper to another 

 species which inhabits the same region ; and the idea 

 of mimicry has been put forward as especially appro- 

 priate in cases where the mimicked species is common, 

 and can be thought to possess some special means of 

 protection. Numerous supposed examples of this 

 phenomenon have been described among insects, espe- 

 cially in the case of various butterflies from Africa, 

 Malaya, and South America. It would be beyond the 

 scope of this work to do more than call attention to the 

 fascinating subject, the literature of which includes a 

 large number of papers to be found in the Proceedings 

 of the Linnaean Society and elsewhere. For a general 



