202 TROPICAL NATURE, AND OTHER ESSAYS. 



far as we can see, be ornamented to no purpose " (Lc., 

 p. 316). I am not aware that any one has ever main- 

 tained that the brilliant colours of butterflies have 

 " commonly been acquired for the sake of protection/' 

 yet Mr. Darwin has himself referred to cases in which 

 the brilliant colour is so placed as to serve for protec- 

 tion ; as for example, the eye-spots on the hind wings 

 of moths, which are pierced by birds and so save the 

 vital parts of the insect ; while the bright patch on the 

 orange-tip butterflies which Mr. Darwin denies are pro- 

 tective, may serve the same purpose. It is in fact 

 somewhat remarkable how very generally the black 

 spots, ocelli, or bright patches of colour are on the 

 tips, margins, or discs of the wings ; and as the insects 

 are necessarily visible while flying, and this is the time 

 when they are most subject to attacks by insectivorous 

 birds, the position of the more conspicuous parts at some 

 distance from the body may be a real protection to them. 

 Again, Mr. Darwin admits that the white colour of the 

 male ghost-moth may render it more easily seen by the 

 female while flying about in the dusk ; and if to this we 

 add that it will be also more readily distinguished from 

 allied species, we have a reason for diverse ornamentation 

 in these insects quite sufficient to account for most of the 

 facts, without believing in the selection of brilliant males 

 by the females, for which there is not a particle of 

 evidence. 1 



Probable use of the Horns of Beetles. A somewhat 

 analogous case is furnished by the immense horns of 

 some beetles of the families Copridse and Dynastidae, 

 which Mr. Darwin admits are not used for fighting, and 



1 See M. Fabre's testimony on this point, Descent of Man, p. 291. 



