16 
* 
lessly until its first moult, when the injurious part of its 
life begins. Then it gains a skin beset with groups or 
small bands of excessively minute prickles, and by the 
pressure of this rough surface irritation and ulceration 
are caused, and swelling, and the bursting of an orifice 
in the warble, follows. This is the stage to which I wish 
more than all others to direct your attention, for, what¬ 
ever we may do before or after, if we could destroy the 
maggot at the first bursting of the warble, we should 
save, I believe I may say all, further trouble and loss. 
The grub is then to he found in the state in which it 
is best known ; it lies with the tail-end, which is fur¬ 
nished with two dark horny spiracles or breathing-pores 
(sometimes mistaken for the head), nearest the opening, 
so as to enable it to draw in supplies of air. The 
mouth-end, which cannot be called the head, lies to¬ 
wards the bottom of the cell, and when I have held one 
of these maggots in my hand a regular contraction and 
expansion of the tubercles by the mouth opening was 
very noticeable, and as this movement also kept the 
bunches of prickles near in constant motion, it must 
have acted as a perpetual irritant in the cavity. 
With the growth of the maggot it gains a deeper 
colour, until it is dark grey or almost black, with the 
patches or shagreening of minute prickles showing fairly 
plainly; the sac or cavity enlarges, and towards the 
May or early summer of the year after the egg was laid, 
when the maggot is come to its full growth, it presses 
itself out through the opening of the warble, and, falling 
to the ground, finds some place, as beneath a stone or 
in the turf, suitable for it to turn to chrysalis in, and 
there it changes to the perfect Fly. Occasionally 
(though I am not aware the exception has been brought 
forward before) the change to the chrysalis state takes 
place in the warble. 
The chrysalis is dark brown or black, and very much 
like the maggot in appearance; and, like that of many 
other kinds of Flies, it consists externally merely of the 
maggot-skin, which has contracted and hardened so as 
