EXPLANATION OF PLATE I. 
A healthy stock of wheat on the left, the 
one on the right dwarfed and the lower 
leaves beginning to wither and turn yel¬ 
low: the stem swollen at three places, 
near the ground where the flax seed (7i) 
are situated, between the stem and 
sheathing base of the leaf. 
a egg of the Hessian Fly (greatly enlarged, 
as are all the figures except e and h), 
6, the larva, enlarged, the line by the side, 
in this and other figures, showing the na¬ 
tural length. 
\ 
c, the flaxseed, puparium or pupa case. 
d, the pupa or chrysalis. 
e, the Hessian Fly, natural size, laying its 
eggs in the creases of the leaf. 
/, female Hessian Fly, much enlarged^ 
. male Hessian Fly, rmmh enlarged^ 
, flaxseed between the le'ayes andlstalk. 
i, Chalcid or Ichneumon paS’asikebf the 
Hessian Fly, male, enlarged. 
Figs, b, drawn by Mr. Riley; d and /, by 
Mr. Burgess; a, g, and c, i, by the author; 
drawn on wood by L. Trouvelot. 
