16 
COEN. 
seen under a ^-inch power, resembles nothing so much as a nutmeg- 
grater. It is covered with most minute tubercles, each about the 
height of its own width, and each with a depression or 
orifice in centre. The two figs, at No. 5 give a view side¬ 
ways and from above of these tubercles from the dried 
skin of a larva, with the anchor-process attached, taken 
from the puparium. 
About the beginning of October, on again examining 
the contents of a “flax-seed,” I found the larva or maggot 
within considerably altered. It did not as yet, as far as 
I saw, show any development of limbs, but it was now 
changed to a reddish yellow colour, of a brighter red along the back. 
As these changes of tint are stated by Dr. Wagner to follow almost 
immediately on the rudiments of the coming wings being observable, 
it is probable that examination with a better light, or with a stronger 
microscope-power, would have shown their appearance. 
No. 5.—Skin 
of larva, 
magnified 
No. 6.— Cecidomyia desteuctoe, Say. Hessian Fly, nat. size and magnified.* 
The Imago or perfect Fly. 
On the 8th of September the first fly developed from my “ flax¬ 
seeds ” or puparia. This to the naked eye was a stout-made little 
brown gnat, with darker head and body, legs of rather lighter brown, 
brown horns, and a pair of smoky-grey wings with longitudinal veins. 
It was exactly one-eighth of an inch in length. 
In order to note the successive changes in colour occurring up to 
maturity and immediately after death, I observed the specimen at 
intervals for about three days, and endeavour to give the result as 
plainly as I can. The fly was first noticed about four in the after¬ 
noon amongst my specimens of infested straw, and I secured it by 
passing a long fine rod of twisted paper just moistened at the tip with 
chloroform beneath it; this stupefied but did not quite kill it, so that 
I could observe it with very slight disturbance from movements of the 
insect. 
* The position of the imago is after the fig. /. by Mr. Burgess in plate iv. of 
paper on Hessian Fly in Third Eeport of U. S. A. Ent. Comm, already quoted; the 
details, &c., from my own British specimen. 
