The Zoologist— May, 1873. 3539 



Mr. Albert Miiller read the following remarks communicated to him in 

 a letter from Mr. W. F. Bassett, of Waterburj, Connecticut, U.S. : — 



" I found, early in the spring, almost as soon as the buds began to swell, 

 large numbers of a female Cyiiips — the species unknown to me — ovi- 

 positing in these buds. I had seen the same in the two preceding seasons, 

 but in only a few instances. The insect, standing on the summit of the 

 bud, thrust the ovipositor down between the bud-scales, but did not in any 

 case, so far as I noticed, penetrate the scales. I inferred that the eggs 

 were laid in or on the embryo leaf. I marked several trees where I found 

 these female flies, and watched with much interest to see what species, if 

 any, would be found on them. I found the leaves, when developed, to 

 contain galls of C. q.-futilis, Osten-Sacken, and with few if any other species 

 intermixed ; and the abundance of this species was in close agreement with 

 the number of females ovipositing before the leaves appeared. These galls, 

 when found at all, are usually very numerous, and on some of these trees 

 there was hardly a leaf that did not contain from one to eight galls, each of 

 which would produce from three to five insects. The fly of C. q.-futilis 

 (found ill both sexes) is much smaller than the species I found ovipositing. 

 I think that when we come to find out the true history of these dimorphous 

 and, in one generation, unisexual species, we shall find that those com- 

 posing the generation of females are generally larger, and perhaps struc- 

 turally distinct from the bisexual brood. What form of gall these appai'ently 

 immediate progenitors of C. q.-futilis may come from I cannot say, though 

 I still hope to trace them to their gall. 



" I repeated last spring the expeiiment tried several previous seasons, — 

 that of raising a brood of flies from the galls found in the form of irregular 

 swellings on the twigs of an oak growing near my residence. I raised an 

 immense number, all of which were females ; and in June I reared still 

 greater numbers, male and female, from enormously swollen petioles of 

 leaves of the same tree. These two broods are remarkably alike, so much 

 so that I could not separate them if mixed. There is, in this instance, 

 no perceptible diiference in the size of the individuals composing the two 

 broods. 



" It seems to me to be settled now that most, if not all, our species of 

 Cynips are double-brooded, and that one of these generations consists of 

 females only. Besides the two cases I have mentioned, where the connexion 

 between the two broods is apparently well established, there are so many 

 one-gendered species that we may reasonably suppose each to be the pro- 

 genitor of some one of the equally numerous doubled-gendered species, but 

 whose relationships have not yet been observed. I am willing to venture the 

 remark that probably no one-gendered species exists — that those apparently 

 unisexual species, C. q.-punctata, Bassett, C. q.-spongifica, Osten-Sacken, 

 and those European species which, though reared in countless numbers, 



