58 Observations on Cynipidae. 



described above, developes from a bud, and its base 

 is surrounded by the bud-scales. It is of an elongated 

 oval shape with a distinctly depressed umbilicus at the 

 apex, and when fresh it is covered with a brown sappy 

 rind. The gall is formed in October, and at the end of 

 the month, when mature, it falls out of the bud to the 

 ground. The sappy rind is then loosened from the 

 woody inner gall, which shows on its surface faintly 

 marked furrows. (Fig. 13.) 



The fiy does not appear until the second year. The 

 flies emerged in April, 1878, from the galls collected 

 in October, 1876. 



Fly. Size 3 mm. long ; head and thorax black ; the 

 latter dull and wrinkled ; abdomen shining, dark on 

 the back, reddish brown on the sides ; legs reddish 

 brown, trochanters dark. Appears in April. 



It was to be expected that an alternate generation of 

 this species would be found, not only from its great 

 resemblance to Aphilotrix globuli, but also from the 

 time of the gall's appearance. The flies emerge in 

 April, but, as the galls are not formed until October, 

 in a winter bud that is not in existence in April, 

 it is evident that another generation, which forms the 

 gall, must intervene. I have not made direct experi- 

 ments in breeding with Aphilotrix auiumnaliSy but I have 

 watched these flies ovipositing. At first I believed that 

 they would prick flower buds only, as it was these that 

 they pricked so vigorously under m}'' own observation 

 when I put some flies on detached twigs. I convinced 

 myself afterwards that they pricked other buds without 

 making any distinction. Perhaps the flower buds may 



