The Zoologist— April, 1871. 2569 



Briggs obtained about thirty larvte of each form: firstly, a male imago, 

 produced from a larva of the riuged form, was paired with a female of the 

 mottled form; secondly, these conditions were reversed: thirdly and 

 fourthly, each form was paired with its like. From these four experiments 

 in no one instance was the ringed form of larva obtained ; and it did not 

 reappear after breeding in to the third generation. 



March 20, 1871.— A. R. Wallace, Esq., President, in the chair. 



Election of Members. 

 Prof. P. M. Duncan, M.D., F.R.S., &c., and Ernest S. Charlton, Esq., 

 were ballotted for, and elected Members of the Society. 



Exhibitions, dc. 



Mr. Dunning read the following letter received from the Ptev. L. Jenyns, 

 of Belmont, Bath : — 



" I see in the Proceedings of the Entomological Society (Part v. 1870, 

 p. xxxiv.) notice of a communication, made at the Meeting of the 7th of 

 November, respecting large swarms of flies, referred to Chlorops lineata, 

 which had appeared in September in a room in the Provost's Lod^re at 

 King's College, Cambridge. It may be worth drawing the attention of the 

 Society to the circumstance of the same phenomenon having occurred, 

 probably in the same room, in 1831, thirty-nine years ago, where it was 

 witnessed by myself, the late Provost, Dr. Thackeray, having invited me to 

 come in and see it. Of that phenomenon I published a full account at the 

 time in Loudon's 'Magazine of Natural History ' (vol. v. p. 302), and it was 

 afterwards reprinted in my 'Observations in Natural History' (p. 275), 

 published in 1840. 



" In reference to the occurrence of this fly in King's Collef^e Lodge in 

 September last. Prof. Westwood ' thought it was with a view to hybernation.' 

 This in itself seems not improbable; but the remarkable thin^ is, in this 

 case, that the same house, if not the same room, should have been selected 

 by this species of insect for the above purpose over a period of nearly forty 

 years, during which time there must have been a succession of many 

 generations. On the occasion of the swarms in 1831, it was about the 17th 

 of September, so far as could be remembered, that these insects first 

 showed themselves ; and it was thought that they had entered the room 

 very early in the morning, by a window looking due north, which had been 

 open during part of the night, having been first observed between 8 and 

 9 A. M. For further particulars I would refer those who are interested in 

 the matter to my original notice of the phoenomenon." 



