8 
will have no power to work their way through the quan¬ 
tity of earth above them ; and the best known remedy 
for the Wheat Midge is the method in which this plan 
is carried out in Canada and the United States of 
America. This is, when the “Bed Maggot” is lying at 
the bottom of the stubble or a little below the surface 
in autumn, to skim off with the first turn-furrow of the 
plough about two inches of the surface-soil, with all the 
stubble, weeds, and vermin in it, and turn it to the 
bottom of the furrow; then raise another slice with the 
second turn-furrow, and, throwing it over the first, bury 
it some inches deep. By this means the pest may be 
got rid of, if the surface can be left undisturbed until 
after the natural time of development for the Wheat 
Midge in the following season has passed, for even if 
these gnat-like flies develop, their delicate powers are 
quite unsuited for piercing through the firm ground 
above them, and consequently they perish. It is, how¬ 
ever, necessary that the ground should not he turned 
up again too soon, or the chrysalids or maggots in their 
cases may develop, and we shall have no benefit from 
their temporary burial. 
I do not know the reason of the prolonged powers of 
life in some kinds of fly-maggots in circumstances which 
one might expect would kill them, but it may be con¬ 
jectured to be from their small amount of breathing 
apparatus. They have for the most part only two 
spiracles or breathing-pores, and in the case of the 
Daddy Longlegs ( Tipula ) grub, we know that they will 
bear at least fifty-eight hours’ total immersion without 
being either drowned or suffocated. 
In the next stage the embryo of many kinds of the 
two-winged flies may gain more protection from the 
pupa-case being formed of the hardened skin of the 
maggot, than what is afforded to moth or butterfly 
caterpillars by the mere hardened film of exuded gummy 
matter with which they are covered. 
Many of the fly-maggots (such as onion or cabbage 
maggots), when about to change to pupae, merely 
