77 



international manner by general discussion and consultation, 

 and such a method of consideration was highly desirable, if 

 only with a view to putting a stop, if possible, to some of the 

 freak legislation in existence. 



Mr. A. Bacot said that it was a mistake to consider that 

 Porthesia chrysotrhœa was a species which had gradually been 

 exterminated in England. Some twenty years ago, when he 

 was studying the British Liparids, he was unable to obtain living 

 specimens for love or money, yet within two or three years the 

 species had again established itself in its old haunts on the coast 

 of Kent ; and it soon spread itself along the shores of the Thames 

 and Medway. After a season or two of extension and plenty on 

 the S.E. coasts of England, the species had died back into its old 

 obscurity, and was absent save possibly in a few favoured spots 

 on the margin of our coasts. At the time when the species was 

 just beginning to wane, he was invited to spend a few days at 

 Ramsgate during late September. He and his friend made a 

 thorough search for the species in the neighbourhood of Ramsgate. 

 On a hedge close to the sea margin at Pegwell Bay, they found the 

 nests of hibernating larvae in great numbers, yet on the other 

 side of the road, only a few scattered examples could be obtained. 

 He had observed the same restriction over a period of five years 

 at Herne Bay. 



He placed a number of nests on Pear in a London garden, and 

 had several colonies of full-grown, healthy larvae feeding, unsleeved, 

 in the summer of the following year ; but although partly formed 

 cocoons were to be found in plenty, in every case the larva had 

 failed to pupate, and the cocoons contained the puparia of a 

 dipterous fly. 



There seemed no doubt that this species and Hypogymna 

 dispar were prevented from establishing themselves in England 

 by some limiting factor, probably low summer temperature, and 

 in the case of P. chrysorrhœa by insect parasites. Broadly speaking, 

 the English environment was .such that while little if any danger 

 was incurred from the importation of foreign insects, any English 

 species was a potential danger, if imported into a new continent. 



At this point it became evident that the section could not 

 continue through lack of time, and on the motion of Mr. Rowland- 

 Brown the meeting was adjourned until the following day. 



