74 MEETINGS. 



and read the following note about the interesting gall-fly 

 Spatheg aster baccarum : — 



" These curious galls, looking much like a bunch of 

 currants, appear on the male catkins of the oak in the 

 month of May. The fly quits the gall in June, lives for 

 a few days only, and nothing more is seen until the male 

 catkins appear again the following May. 



" What becomes of the eggs during this long interval ? 

 Spontaneous generation of the insect within a gall which had 

 no external opening, had its advocates. Later it was believed 

 that a form of metempsychosis took place, and galls were 

 among the stepping-stones in the path of organic evolution by 

 which the vegetable passed into the animal soul. By some it 

 was supposed that the eggs, found in the fly in June, reached 

 the ground, whence they were drawn up mingled with the sap, 

 and arrested next spring in the leaves or flowering catkins, 

 there to form the currant galls again. It remained for Dr. 

 Hermann Adler, M.D., of Schleswig, to solve the mystery. 

 He has proved, by a great number of experiments in breeding, 

 the existence of alternating generations in many species of 

 gall flies, for instance, eggs laid by the flies emerging from 

 the Currant Galls, Spathegaster baccarum, are deposited in the 

 young oak leaves on the under surface, and produce an alto- 

 gether different form of gall, viz., the common Spangle Gall, 

 Neuroterus lenticular?*, 01., the flies emerging from these 

 spangles laying eggs, which in their turn produce the Currant 

 Gall. For further information on this subject, one of the 

 most wonderful chapters in the history of insect life, I must 

 refer you to Dr. Adler's monograph on " Alternating Gener- 

 ations : a Biological Study of Oak Galls and Gall Flies," 

 which has been recently translated into English by Charles 

 B. Straton, F.R.C.S., F.E.S., and published at the Clarendon 

 Press, Oxford." 



He also shewed an addition to the Diptera of Guernsey, 

 viz., Merodon equestris. 



The Monthly Excursions having commenced since the 

 last meeting, the Sectional Secretaries described the work 

 done at the excursions to l'Ancresse, Fermain and Moulin 

 Huet Bays. 



Monthhj Meeting held July 8th, 1896, Mr. A. Collenette, 

 ■President, in the chair. 



The Report of the May meeting having been read and 

 signed, Gen. Hubert Le Cocq was unanimously elected. 



