154 LEPIDOPTERA. 



on oak has stirred up our friends, Messrs. Doubleday and 

 Butler. The latter considering that it is within the 

 bounds of possibility that A. iris might have been trans- 

 formed into ilia through the agency of this unusual diet, the 

 former denying that food of any kind whatever exerts any 

 influence on the tints or markings of the future imago, but 

 insisting that soil has a very decided effect ; and he instances 

 the pale variety (dilucidaria) of Gnophos puUata, when 

 reared in a chalky district, as an example. My own im- 

 pression is that both food and soil do modify the future 

 results, but that their action is exceedingly slow. There is 

 another agency to account for the occurrence of pale varieties 

 in chalky districts, namely, that the more closely an insect 

 approximates to the colour of the ground, the greater will 

 be its chances of avoiding its natural enemies. 



Argynnis Niobe versus A. Adippe. 



A fritillary, which Mr. Doubleday considers to be Niobe, 

 but which others have regarded as merely Adippe, has been 

 captured. No doubt the female Niobe does differ very con- 

 siderably from the corresponding sex of Adippe, but we 

 have as yet no evidence of the occurrence of the female in 

 this country. 



In this case also there has been another little passage of 

 arms between our respected friends Messrs. Doubleday and 

 Butler, the latter contending that because he has met with 

 the two species or forms flying together and copulating, 

 they must on that account belong to the same species. Mr. 

 Doubleday holds an opposite opinion, and, in order to refute 

 Mr. Butler's theory, instances cases where widely different 

 species have paired. 



In another case however, namely, that of Tortrix ribeana 

 and cerasana, Mr. Doubleday adduces Mr. Butler's argument 



