18 
tion to that of a winged fly. Other avocations diverted my attention, 
and this vial was forgotten for a fortnight ; by which time the earth 
within had become so completely dried, that not doubting but the 
worms had all perished, no farther attention was paid to it, and it 
remained in a dry room over three months, until the middle of June, 
when, on examining it, half the specimens put into the vial were 
found to have completed their transformations ; a corresponding 
number of dead wheat-flies being found attached to a straw in the 
upper part of the vial. Prof. Henslow thinks that it is only those 
larve that are punctured by ichneumons, that leave the wheat-ears 
and enter the ground; but the facts now stated, show that this 
opinion is erroneous. 
On removing the earth from the vial above alluded to, the cases 
of the pupae from which the flies had proceeded, were found very 
perfect. These conclusively showed that the real pupa is not formed 
until in the spring, and that it is then altogether different in form 
from what has been described by writers as its pupa.* It corresponds 
identically in its appearance (perhaps with the exception of color) 
with that of the Cecidomyia salicis, as exhibited in the first volume 
of this Journal, Plate 2, fig. 1. It also closely resembles the figure 
of the pupa of Cecidomyia pini? as given from De Geer in West- 
wood’s Introduction to the Modern Classification of Insects, vol. ii. 
p- 518. fig. 125. no. 7. Its length is slightly less than that of the 
dormant larva. The antenne, legs and wings, are each enclosed in 
separate sheaths, which lay externally to the integument in which 
the body is enveloped. The three pairs of legs all lay parallel and 
in contact with each other upon the breast, reaching far down past 
the tips of the wings; the inner pair being shortest, and the outer 
pair longest. Judging from the analogy afforded by the Cecidomyia 
salicis, I presume the wheat-fly only remains in its pupa state three 
or four weeks in the latter part of May and the fore part of June. 
* Since making this discovery, I have strongly suspected that the pupa of the hessian 
ly has never been as yet detected; and that its “flaxseed state,” which has all along 
een regarded as its pupa, is only the same state which I have described as the dormant 
larve of the wheat-fly. 
+I cannot but regard the figure here referred to as inaccurate, in representing the 
wings as enclosed in one common case, over which the legs are laid, The tips of the 
wings should probably be rounded, instead of being brought to a point, 
