270 LIFE AND HABIT. 



" Some insects which imitate leaves extend the imi- 

 tation even to the very injuries on those leaves made 

 by the attacks of insects or fungi. Thus speaking of 

 the walking-stick insects, Mr. Wallace says, ■ One of 

 these creatures obtained by myself in Borneo (ceroxylus 

 laceratus) was covered over with foliaceous excre- 

 scences of a clear olive green colour, so as exactly 

 to resemble a stick grown over by a creeping moss 

 or jungermannia. The Dyak who brought it me as- 

 sured me it was grown over with moss, though alive, 

 and it was only after a most minute examination that I 

 could convince myself it was not so.' Again, as to the 

 leaf butterfly, he says, * We come to a still more extra- 

 ordinary part of the imitation, for we find represen- 

 tations 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 resem- 

 bling 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.' " 



I can no more believe that these artificial fungi in 

 which the moth arrays itself are due to the accumulation 

 of minute, perfectly blind, and unintelligent variations, 

 than I can believe that the artificial flowers which a 

 woman wears in her hat can have got there without 

 design; or that a detective puts on plain clothes 

 without the slightest intention of making his victim 

 think that he is not a policeman. 



Again Mr. Mivart writes : — 



