XV 
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 Cjnips — 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 in 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 apparently 
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 difference 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, aud 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.-spougifica, Osten-Sacken, 
and those European species which, though reared in countless numbers^ 
