1864.] 
489 
to appear “ when the gall season again arrives” ? The question is an 
interesting one.* 
12. White oak. QrdXX q. Jicms Fitch, (autumnal.) Well figured and 
described, N. Y. Rep. II, §314. Some of the central cells in these 
galls contain in February living larvae about .05 inch long and occa¬ 
sionally a blackish pupa about .08 inch long, evidently from the struc¬ 
ture of its antennae Chalcididous. About one-fourth of these galls in 
the winter exhibit external perforations, and their central cells are 
then invariably perforated, indicating that the maker of the gall had 
already vacated his cell. With such as are not perforated, the central 
cell generally contains in February and March the above-mentioned 
chalcididous larva or pupa, which is no doubt identical with a Chalci- 
dide that I have bred abundantly in May from these galls. The cells 
in which the guest gall-fly most probably lives are attached to the ex¬ 
ternal rind of some few galls only, in addition to the central cell which 
is found in every gall and in which, according to all analogy, the maker 
of the gall must reside. I have found larvae in March in some of these 
external cells; and in the same gall in which one of the external cells 
was tenanted by a larva, the central cell was also tenanted by a chalci¬ 
didous larva; thus furnishing confirmatory evidence, that in certain 
cases the guest gall-fly does not destroy the gall-fly, or, which is the same 
thing, its chalcididous parasite. The twigs on which the galls are placed, 
unless very large, always perish the next season, and where recent galls 
are found, a great quantity of old, last year’s, dry galls on dry and 
half-rotten twigs may always be observed. This circumstance seems to 
have led Dr. Fitch to imagine that there were two crops of these galls 
every year. He makes the same supposition with regard to the galls 
seminator Harris, and q. inanis 0. S. {—confluenta Fitch), but in the 
latter case I know from close and continued observation that the sup¬ 
position is incorrect. I doubt the fact of any oak-inhabiting Psenide 
^ Mr. Bassett has subsequently discovered that he was mistaken in supposing 
the few 9 gall-flies with a red thorax, which he had observed to be mixed up 
with numerous C. seminator, to be parasites or inquilines. (See above, page 
466, note.) They proved to be specimens of C. q. operator 0. S., the gall of 
which, though it occurs on different oaks, closely resembles that of seminator, 
and small pieces of which must have been accidentally mixed up by him with 
the seminator galls.—March 31, 1864. 
