were of different shapes, as in fig. 7, and varied according 
Fig. 7.—Young Maggots, Fig. 8.—Mouth Forks of very young Maggots, 
much magnified. much magnified. 
to whether they were alive and distended with fluid, or other 
circumstances. In the youngest condition the maggot was 
furnished with a pair of strong mouth forks. These mouth 
forks are a most important item in its structure, and have not 
previously been noticed in the young maggots of this species 
of CEstrus or Warble Fly. The apparatus consists of a pair 
of crescent-shaped forks, placed nearly side by side, at the 
extremity of processes somewhat bent apart at the ends by 
which they are attached to the crescents, and attached by the 
other ends to the membranes or tissues forming the gullet or 
internal sac of the maggot. In fig. 8, Nos. i and 3, the 
crescent-shaped forks are shown in slightly different positions, 
and at No. 2 they are shown sideways, so as to present the 
curved ends of the processes to view. The material is 
chitinous or horny, and the colour yellowish-brown ; and, 
though excessively minute, the hook forms a very serviceable 
cutting or dragging instrument. The possession of this 
apparatus by the maggot in its early stage is a great con¬ 
firmation of the belief that the creature gets down to the sub¬ 
cutaneous tissues of the hide by cutting its way forward. We 
appear here to have both cause and effect, for we find, as a 
regular thing, that there is a minute track down to the 
embryo warble beneath the hide, which track has the appear¬ 
ance of having been cut or gnawed, and in the exceedingly 
young and still worm-shaped maggot found on January 27th, 
there was the apparatus for cutting or gnawing. The Warble 
Maggot in the early stage is oval, legless, and headless, and is 
white, transparent, and smooth. “ Up to the time of its first 
moult,” according to Dr. Friaedrick Brauer, “ the maggots lie 
quite free in the sub-cutaneous tissues and skin muscles, and 
are not contained in any capsular formation ; but in its second 
stage it is thickly beset with groups of prickles, which soon 
