170 THE CANADIAN ENTOMOLOGIST. 



when the insect is emitting the flashes of light it moves these segments 

 and so reveals more of the light. 



Mr. Martin stated that he had observed a Fire-fly in a spiders web, 

 and that it emitted very rapid flashes of light at first, but that they gradu- 

 ally diminished in brilliance till at length they died out. 



On motion the meeting then adjourned till 8 o'clock p. m. 



TUESDAY EVENING SESSION. 



At 8 o'clock the Entomological Club met at the Hotel Vendome, Dr. 

 J. G. Morris in the chair. 



Mr. H. F. Bassett, of Waterbury, Conn., gave an account of " the 

 Structure and Development of certain Hymenopterous Galls." He exhi- 

 bited specimens of galls produced on plants and trees, and spoke of the 

 alternation of two forms belonging to one species. The seminator 

 deposits its eggs in the young acorn, and from the sting or puncture the 

 gall grows, having the appearance of another acorn. This falls to the 

 ground in September, and remains twenty-one months, at the end of which 

 time the gall-flies are produced, which are all females. These females lay 

 their eggs in the buds of the trees in the spring, and from these galls are 

 formed, out of which are developed flies of both sexes. All galls may be 

 divided into two classes : — First, those formed in autumn, which do not 

 develop till the next or a succeeding year, the imagos or perfect insects 

 hatched from them being always females ; and secondly, those formed in 

 the spring, the progeny of which are of both sexes. He considered that 

 the woolly substance that covers these galls is an excessive development 

 of the pubescence of the leaf, and thought that the growth of the galls is 

 produced by the action of the poison that is infused by the parent insect 

 when making the sting or puncture, because he often could find in a gall 

 no trace of any larva. 



Prof. Riley expressed his opinion that galls are formed both by the 

 poison injected with the egg, and by the irritant action of the larva. He 

 spoke also of the sweet exudation on galls, and remarked that honey-dew 

 is in some cases the natural exudation of the plant independent of the 

 action of insects upon it. 



Prof. C. H. Fernald, of Orono, Me., exhibited three volumes recently 

 published by Lord Walsingham on " North American Micro-Lepidoptera, 

 Tortricida;," illustrated with colored plates, and forming part of the British 

 Museum Catalogues for 1879 ; also by the same author a volume on the 

 " New and little-known species of North American Tineidae," and another 



