198 THE ENTOMOLOGIST. 



imago produced by temperature were being made the subject of 

 systematic research by Professor Weismann, Dr. Standfuss, Mr. E. 

 Fischer, and others. Mr. Elwes asked if these experiments had been 

 made on pupae only, or on the larvae as well. Mr. Merrifield said that 

 the results were only noticeable when the experiments were made on 

 pupae. The effect of them on larvae was not apparent. Mr. Kirkaldy 

 exhibited and made remarks on ova of Notonecta (jlauca Y&r. /areata. 

 Mr. Tutt exhibited living larvae of Ajnimea ophiogravwia, together with 

 the grass on which it was feeding. He said the species was formerly 

 considered rare in Britain, but was now found freely in any localities 

 where ribbon-grass {Diyraphis arundinacea) was plentiful. The Secretary 

 read a communication from Mr. E. Meyrick on the subject of Professor 

 Radcliffe-Grote's criticisms, contained in his paper published in the 

 'Proceedings' of the Society, 1896, pp. x-xv, on the use of certain 

 generic terms by Mr. Meyrick in writing on the group of Lepidoptera 

 known as the Geometridae. Mr. Meyrick stated that he rejected the 

 main assumption on which the criticisms were based. Mr. McLachlan 

 opened a ''Discussion as to the best means of preventing the extinction 

 of certain British Butterflies." He referred to the extinction of Chry- 

 sophanus dispar, Lyccena acis, and Aporia cratagi, and to the probable 

 extinction, in the near future, of Papilio machaon, and more especially 

 of Melitoia cinxia and Lycana avion. He stated that one of the objects 

 he had in view in bringing this matter forward was to see whether some 

 plan could not be devised to protect those narrowly localised species 

 which were apparently in danger of being exterminated by over- 

 collecting. Professor Meldola said he fully sympathised with the 

 remarks of Mr. McLachlan, and he thought that a resolution passed 

 by the Society, possibly in conjunction with kindred Societies, might 

 produce some effect. Mr. Goss stated that P. machaon, although 

 apparently doomed to extinction in its chief locality in Cambridgeshire 

 (Wicken Fen), would probably linger on in the county in smaller fens, 

 such as Chippenham, where the larvae had been found feeding on 

 Anyelica sylvestris. It would certainly survive in the Norfolk Broads, 

 both from the irreclaimable nature of the fens there, and the extensive 

 range of the species in the district, which Mr. Goss said he had 

 explored in 1887 in boats. He stated that Melitaa cinxia, although 

 gradually disappearing from most of its old localities in the south of 

 the Isle of Wight, was still found in the island further west in localities 

 in which he had seen it in some numbers in May, 1895. He added 

 that L. arion was far from extinct in Gloucestershire, and was distri- 

 buted over a much wider area in the extreme south-west of England 

 than was generally supposed. Its disappearance from South Devon was 

 due to the burning of the grass, and the consequent destruction of the 

 food-plaut. Mr. Elwes stated that in the district in which he lived, 

 in Gloucestershire, he had found L. ario7i in three or four places on his 

 own property some ten or twelve miles distant from its known localities, 

 but the species had disappeared of late years. The fact that L. 

 arion had disappeared from his own property, where it was not 

 collected, seemed to point to the fact that it was dying out from 

 natural causes, perhaps owing to changes in climate. Colonel Irby 

 said that L. arion had disappeared many years ago, not only from 

 Barnwell Wold, Northamptonshire, but from another part of the county 



