39 
of the length of the body. The outer pair of feet come out from 
under the tips of the wings, and reach to the anterior margin of 
the penultimate abdominal segment, slightly curving inwards at 
their tips. The next pair of feet are somewhat shorter, and the 
inner pair are shorter still. They all lie in contact with each 
other, and in a direction nearly parallel with the body. ‘The ab- 
dominal segments are distinctly marked by strongly impressed 
transverse lines, and are of a milk-white color, the thorax and 
head being of a delicate pale pink-red, and the feet translucent- 
white. On the anterior margin is a chestnut-brown crescentiform 
mark. It will hence be perceived, that in all the details of its 
form, the pupa of the Hessian fly coincides precisely with those 
of the other species of this genus which have been described. 
lis change into a fly—tThe time for its final transformation 
having arrived, the pupa breaks open and crawls from its pupa- 
rium or flax seed case, and works its way upwards within the 
sheath of the leaf, until it arrives at some cleft in the now dead, 
brittle and elastic straw; through this cleft it gradually, by bend- 
ing from side to side, crowds its body until all except the tip 
of the abdomen is protruded into the air, the elasticity of the 
straw causing it to close together upon the tip of the abdomen, so 
much as to hold the pupa in this situation, secure from falling to 
the ground; and as if to preserve the body in a horizontal posi- 
tion, the feet are slightly separated from the abdomen, and di- 
rected obliquely downwards, with their tips pressed against the 
side of the straw, thus curiously serving, like the brace to the 
arms of a sign post, to support the body from inclining down- 
wards. Thus securely fixed, and now freely exposed to the dry- 
ing influence of the atmosphere, the outer membrane of the pupa 
speedily exhales its moisture, and as it becomes dried, cracks apart 
upon the back part of the thorax; out of this cleft the inclosed 
fly protrudes its head and thorax more and more, as it gradually 
withdraws its several members, the antenna, wings and legs, from 
the cases in which they are respectively enveloped—a process 
analagous to that of withdrawing the hand and its several fingers 
from a tight glove; until at length entirely freed, the now full- 
