164 Appendix I. 



the gall of a grass green colour. By August the primary 

 nutritive tissue has disappeared, and secondary nutritive 

 tissue, containing proteids, oil globules, and the so-called 

 brown-bodies, is formed at the expense of the starch. The 

 gall remains soft until almost mature, but at this time, if it be 

 pierced by a needle, a sclerenchymatous layer can be detected 

 covering the nutritive tissue, giving a certain hardness to the 

 larva chamber, and affording a protection against parasites. 



The larva chamber is normally single, but occasionally, 

 where the gall-maker has been destroyed, it is found divided 

 radially into several cells inhabited by parasites. The 

 inquilines are usually found in larva chambers arranged 

 around the central chamber, between it and the surface. 

 When twin galls are formed closely together, they occa- 

 sionally unite and have one larva chamber \ 



Fly. Length 4-8-6 mm. Whole body reddish yellow. 

 Looked at from above, the head appears widened behind the 

 eyes ; cheeks half as long as the eyes, without wrinkles ; 

 antennae filiform, thirteen-jointed, second joint longer than 

 thick, third joint the longest, twelfth and thirteenth joints 

 partially united. Thorax brown, covered with short hairs, 

 parapsidal furrows complete ; scutellum with two thickly 

 haired foveae at its base, metanotum black, vertical, over- 

 hung by the scutellum. Abdomen smooth and shining ; 

 second segment covering half the dorsum, very dark above, 

 with two large hairy spots ; the other segments fringed with 

 silky hairs. Ovipositor long and spiral. Venter exposed. 

 Wings as long as the fly, hyaline, finely haired ; radial 

 cellule open at the margin, elongate, with the areolet opposite 

 its base ; basal abscissa of the radius angled ; cubitus opposite 

 to, but not reaching, the middle of the transverse basal nervure ; 

 legs yellow, margin of the fore tibiae fringed with short 

 depressed hairs ; hind coxae broad ; claws bifid. According 

 to Mayr the fly closely resembles Cynips corruptrix Schl. ; 



^ Lacaze-Duthers, ' Recherches pour serv'ir a I'histoire des galles/ 

 Ann. Sc. Nat. Bot. 1853, p. 291. Beyerinck, M. W., Beobachtungen 

 iiber die ersten Entwicklungsphasen einiger Cynipidengallen, 

 Natuurk. Verh. dey Koninkl. Akadeniie, Deel xxii. 



