GALLS CAUSED BY GALL- WASPS 43 



gall, that it was probably unknown in this country prior to 

 1830, about which time it seems to have been brought to 

 Exmouth in connexion with the cloth manufacture at 

 Exeter, Tiverton, and other places in the West of England, 

 but whether for dyeing purposes is not quite certain. The 

 insects escaping, the gall gradually appeared throughout 

 Devon, spreading east and west, and causing much con- 

 sternation at the time. A lot of nonsense was spoken and 

 written about the destruction of the Oak, and in 1852 the 

 labourers were exhorted to " rally round the pig," it being 

 maintained that the acorn crop was being destroyed and the 

 farmers ruined. The gall is now abundant over the whole 

 of Britain, and our oaks are none the worse. A most 

 interesting account of Cynips Kollari and its gall, with lists 

 of parasites, is given by Dr. Straton in Appendix I. to 

 " Alternating Generations" (pp. 163-167). 



Rolfe, in his notes on Oak galls occurring in the Quer- 

 cetum at Kew (1881), enumerates some of the above- 

 mentioned galls as occurring on several varieties of Quercus 

 pedunculata, also on Quercus Tumeri ( = Q.pedunculata x Q. ilex), 

 Quercus infectoria, and others. The same observer, with Miss 

 Ormerod, noted the galls of Callirhytis glandium on Quercus 

 cerris, var. Lucombeana { = Q. cerris x Q. ruber"). Miss Ormerod 

 also recorded the occurrence of the galls of Andricus circulans 

 and Dryophanta Taschenbergi on this Oak. She observed the 

 last named also on typical Q. cerris. Trail and Rolfe noted 

 the galls of Neuroterus baccarum on Quercus dentata. Rolfe 

 makes the highly interesting observation that he " never 

 found a gall of the Common Oak on either an American 

 species or on the European Q. cerris, the ' mossy cupped ' 

 oak, even when the branches interlaced, which shows the 

 existence of some barrier to their dispersal." 



I find, however, in Houard's "Zooc6cidies des Plantes 

 d'Europe," the galls of Biorrkiza pallida, Dryophanta Taschen- 

 bergi, Andricus trilineatus, A. testaceipes, A. ostreus, Neuroterus 

 albipes, N. lenticularis, and N. baccarum, mentioned under 

 Quercus cerris. 



