102 BRITISH OAK GALLS. 
form. The galls occur in groups and in large num- 
bers on the under-surface of the leaf attached to the 
mid-rib and the lateral offshoots, in parallel rows, 
and numbering as many as sixty on a leaf. Hach 
_gall is complete and distinct from those near it, and 
is held in its position by an extremely short and 
delicate peduncle, so slender that the gall is easily 
detached. During the month of September they appear 
as if by magic. The growth is rapid and the first 
stage is completed very speedily. During October the 
peduncle shrivels, and the galls fall to the ground. A 
few will persist until early in November if climatic 
conditions are favourable. I have found specimens as 
late as the 12th of the month. 
Rearing the imagines is a difficult matter. The 
larvee are but partly grown when the galls fall, and 
they do not pupate until the early autumn of the 
following year. Some emerge during the months of 
December and January, most of the remainder not 
until May and June following; while a few delay their 
appearance for six or even twelve months longer. 
The best place to search for these galls 1s amongst 
the leaves of stunted oak-bushes on hedge banks that 
have a northern aspect; and in well wooded districts 
they may be found in great profusion. 
Cynips Kollari, Hartig. 
(Plates XXXV to XXXIX.) 
Cynips Kollavi, Mayr, Schenck., Newman, Fitch, Straton, 
Walker ; C. lignicola, Marshall, Stainton, Parfitt; C. quercus petioli, 
Quercus terminalis, Westwood ; C. tinctoria, Vollenhoven. 
English names of gall.—‘‘ The Devonshire Gall,” “ The Oak 
Marble,” “ The Oak Nut,” “The Marble Gall.” 
Position of gall.—On twigs and on branches. 
Manner of growth.—Single, solitary, gregarious, coalescent, 
glabrous, spherical. 
Colours.—Pale green, golden yellow, emerald green, dark green, 
brownish-yellow, reddish-brown. 
Average dimensions of a mature specimen.—65 mm. 
