42 BRITISH GALLS 



maturity, in September usually. These galls are com- 

 monly gregarious, and not infrequently coalescent. The 

 larval cavity is central ; twin galls often have but one larval 

 chamber. Parasites are numerous. The wasp {Cynips 

 Kollan) emerges in September or October by a circular hole. 



According to Beyer inck, the bud gall of the Turkey Oak 

 results from the attack of this wasp. He saw Cynips 

 Kollari pierce the buds in October, 1901, and the follow- 

 ing April the galls matured. The wasps therefrom are 

 the Andricus circulans. I have not succeeded in finding the 

 Turkey Oak bud gall, though I have repeatedly searched 

 for it in many districts. The illustration of it is drawn up 

 from Cameron's figure, and the following notes are taken 

 from his "British Phytophagous Hymenoptera" (vol. iv., 

 pp. 105, 106) : " The galls are found in the axillary leaf buds 

 of Quercus cerris gregariously, one, four, or eight being found 

 in a bud, and they may be packed so closely together that 

 they become compressed and flattened. They are glabrous, 

 well hid in the bud, in colour varying from brownish-yellow 

 to bright red, thin-walled ; in shape an elongate ovoid, and 

 in length 2 to 5 mm. 



"Miss Ormerod found at Kew some galls which, although 

 not quite typical, yet still may safely be referable to 

 A. circulans. My figure is taken from a specimen I had 

 from Professor Mayr. According to the latter authority, 

 the normal time for the flies issuing from the galls is 

 towards the middle of April." 



Beyerinck did not succeed in getting Andricus circulans to 

 oviposit in Quercus rohur. The fact that the Turkey Oak 

 bud gall has not been observed in this country since Miss 

 Ormerod obtained specimens at Kew in 1878 makes it 

 very desirable that Beyerinck's experiments be carefully 

 repeated. It seems unlikely that the alternate generation 

 of Cynips Kollari is to be found on Quercus cerris, an Oak 

 which is usually avoided by the gall- wasps which frequent 

 Quercus rohur. 



It may be of interest to note, in reference to the marble 



