52 
COHN. 
on the above grasses in Britain, but the fact that the “ flax-seeds ” may 
be there is another reason for at least doing all that can be done to 
clear the surface of infested fields. Skimming, and dragging the 
stubble and rubbish together and burning it, would get rid of some 
amount of “ flax-seeds ” which had not yet developed their contents, 
and also of some couch-grass which might have served as a nursery in 
that autumn, or in the following season; and ploughing with a skim- 
coulter, so arranged as thoroughly to bury down the skimmed upper 
surface, is a well-known preventive of attack. 
Hessian Fly, natural size and magnified. 
Full description of the Hessian Fly in its various stages, and also 
of the method of the injury and appearance of the injured straw, has 
been so often given, that it is unnecessary to repeat them again at 
length here ; but the reader is referred to the accompanying figures 
for requisite representation. These show (at page 48) the shape, size, 
and position above a joint (usually the 2nd joint from the ground) of 
the pup anum, or chrysalis-case, commonly known as the “flax-seed”; 
also the method in which the straw elbows down above the injured 
part, which is weakened by the sucking of the maggot at one spot. 
The maggot is legless, whitish (with sometimes 
a little green tint from the coloured juice on 
which it feeds showing through the skin), and 
in shape resembles the so-called “flax-seed,” 
to which it presently turns. This gradually 
becomes of a deep chestnut-brown, and towards 
the time of maturity is striated longitudinally 
with fine ridges and furrows, as figured. The 
fly may be generally described as looking like 
a little brown gnat, about one-eiglitli of an inch in length, with one 
pair of smoky-grey wings. 
For full technical description of the Hessian Fly in imago, or 
perfect condition, the reader is referred to the fully-detailed account 
given by Mr. B. H. Meade, of Bradford, from examination of living 
Puparia or “ flax-seeds” 
in different stages. 
