60 MIMICRY, AND OTHER PROTECTIVE 



every one of them will be of some shade of ash or 

 brown or ochre, such as are found among dead, dry, 

 or decaying leaves. The apex of the upper wings 

 is produced into an acute point, a very common form 

 in the leaves of tropical shrubs and trees, and the 

 lower wings are also produced into a short narrow 

 tail. Between these two points runs a dark curved 

 line exactly representing the midrib of a leaf, and 

 from this radiate on each side a few oblique lines, 

 which serve to indicate the lateral veins of a leaf. 

 These marks are more clearly seen on the outer por- 

 tion of the base of the wings, and on the inner side 

 towards the middle and apex, and it is very curious 

 to observe how the usual marginal and transverse 

 stria? of the group are here modified and strengthened 

 so as to become adapted for an imitation of the 

 venation of a leaf. We come now to a still more 

 extraordinary part of the imitation, for we find re- 

 presentations of leaves in every stage of decay, 

 variously blotched and mildewed and pierced with 

 holes, and in many cases irregularly covered with 

 powdery black dots gathered into patches and spots, 

 so closely resembling the various kinds of minute 

 fungi that grow on dead leaves that it is impossible 

 to avoid thinking at first sight that the butterflies 

 themselves have been attacked by real fungi. 



But this resemblance, close as it is, would be of little 

 use if the habits of the insect did not accord with it. 

 If the butterfly sat upon leaves or upon flowers, or 

 opened its wings so as to expose the upper surface, or 



