i5 
irritate the surrounding parts, the tissue of the hide is dis¬ 
turbed and thickens, new formations of tissue take place, and 
the maggot becomes enclosed in a sac ; and, from the con¬ 
tinued irritation, ulceration is set up, and the weakest part of 
the skin is burst through into an orifice.” 
After its first moult, however, it gains a skin beset with 
groups or small bands of very minute prickles, and by the 
presence of this rough surface, irritation and ulceration are 
set in. After the opening of the warble, the maggot lies with 
its tail end (which is furnished with two dark horny spiracles 
or breathing pores) nearest the opening, so as to enable it to 
draw in supplies of air. The mouth end lies towards the 
bottom of the cell. As the maggot grows older it gets darker 
in colour, until it is dark grey or almost black, with the 
patches of minute prickles showing fairly plainly, the sac or 
cavity enlarges, and when the maggot has come to its full 
growth, in the May or early summer after the egg was laid, it 
presses itself out of the opening of the warble, and, falling to 
the ground, finds some suitable place, as under a stone or clod 
of earth, or in the turf, to turn to chrysalis in, and there it 
changes into the perfect fly. Occasionally the change to the 
chrysalis state takes place in the warble, and in that case very 
likely there will have been something to prevent its escape— 
either inability to get out, or perhaps a blow outside of hide. 
The sore, caused by the suction and movement of the 
small tubercles and patches of prickles that surround the 
opening which serves as a mouth, gradually advances before 
the mouth end of the maggot, till, when it is full sized, in the 
following year after it is hatched, it may be found lying, some¬ 
what bent, in a cell more than an inch long ; which, when the 
hide is taken off, may be seen pressed out beneath by the 
contained grub, like the end of a glove with the finger in it. 
At this time the lowest part of the warble cell is an ulcerated 
flowing sore, but the upper part may be found nearly skinned 
over round the perforation as 
in fig. 9. On pressing the 
warble after the maggot has 
come to its full size, the mag¬ 
got is squeezed out, and on 
placing it on the hand, I 
Fig. 9-Warble Cell, slightly larger than life. noticed j t kept Up a regular 
