THE GAEL FLY. 49 1 
plant, is however, fufficient to account for the large ft galls 
that have yet been obferved *. 
The cynips quercus folii f , is of a burniihed Ihining 
brown colour ; the antennae are black; the legs and feet 
of a chefnut brown ; and the wings white, without mar- 
ginal fpots. Thofe fmooth round galls that are feen under 
the oak leaves, are the birth places of thefe infefts : com- 
monly a fingle one is found in each gall. Inftead of the 
natural inhabitant of this gall, a larger inf:ft of a brown 
colour is fometimes feen to proceed ; this is the ichneu- 
mon, who is neither the builder nor the legitimate ovener 
of the dwelling, but a parafite produced from an egg de- 
polited there by his progenitors. 
Of all the trees with which we are acquainted, the oak 
affords food and an habitation to the greatdl number of 
infefts. There are above fifty different fpecies that in 
this country inhabit that plant , and probably in warmer 
climes the numbers of its tenants is much greater. The 
Norway ink, fo celebrated for its colour and permanency, 
is the produce of a gall in that country, fimilar to that 
feen upon our oaks in the month of 'June. The fly which 
produces it is perhaps the fame J. 
The gall fly of the rofe, cynips rofce, is found on the 
gall of that flirub, and is diftmguifhed by the black pro- 
tuberances of the antennae ; the abdomen below is ferru- 
gineous, the feet yellow, and the wings without fpots 
* Reaumur, Tom. HI. Syft. Nat. fpec. 5. 
i Barbut, p, *34. § Fauna Swecica, No. 938. 
3 Q.* 
