MELANISM IN I.EPIDOPTERA. 153 



field of hay-grass outside the walls of York, after a few days 

 of dry weather and westerly winds, he will find his legs in 

 such a state that he will be glad to get into a cab and drive 

 home rather than walk through the streets : so that although 

 the country immediately around the city is purely agricultural, 

 yet I am satisfied there is a suflScient amount of soot 

 deposited on the plants to affect the colours of the Lepi- 

 doptera. 1 am the more inclined to think this is one great 

 cause o{ daxk varieties because a gentleman of high standing in 

 this district, who either is or was a calico-printer, has said 

 that he could produce varieties of moths by giving the 

 larvae chemicals along with their food. If he sees this and 

 would give us his experience, it might do more towards 

 arriving at some knowledge of the cause of Melanism than 

 any amount of papers written on the subject by those who 

 have not made any such experiments. 



I was much pleased with the observations of Mr. E. K. 

 Robinson, and think it is highly probable that other varieties 

 are caused by various kinds of food. 



With regard to anal appendages, the printers made me 

 say what I never intended — that the sexual organs oi Cei'astis 

 vaccina differ little from those of C. spadicea. I said there 

 was no difference. No one present at the meeting could per- 

 ceive any difference either between C. vaccinii and C. spadicea, 

 or between Acronycta psi and A. tridens. The two latter 

 species have such very different larvae that they must be 

 considered distinct, for we cannot have a better specific 

 character ; but until I know that the larva of C. vaccinii 

 differs from that of C. spadicea, 1 shall certainly consider 

 them mere varieties of one species. I shall be much 

 interested in Dr. White's investigations which are to appear 

 in the Linnean Transactions. 



Gorsey Hey, Liscard, May 8, 1877. 



Andrena ferox. — In the March number of the 'Entomo- 

 logist' (Entom. X. 62) Mr. F. Smith refers to Andrena ferox 

 as having been taken by me at Guestling. Will you allow 

 me to state that this specimen, which 1 had the pleasure of 

 submitting to him for identification, was taken not by myself, 

 but by the Rev. E. N. Bloomfield. — E. A. Butler ; University 

 School, Hastings, March I, 1877. 



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