WARBLE AND BOT FLIES. 145 
At the next advance in growth, in*which I had opportunity of 
observing the maggot, it was still straight-sided (see figures below), 
and somewhat worm-like in shape, about a quarter of an inch long by 
a third of that measure in width, and prickly; the next obvious change, 
though still very small, was to a somewhat club-shape, and the prickles 
now were observable, when magnified, as being in sixteen short bands, 
placed for the most part in very narrow and broader stripes. 
At the time, I took very careful observations, with microscopic pre- 
parations of my specimens, some of which I still preserve,—some of 
spiracles and other details; but the important point relatively to the 
present enquiry seems to me to lie in the size of the larve, as observed 
in the American experiments, in the cesophagus, and by myself in the 
subcutaneous tissues of the hide. 
Larve of Hypoderma bovis.—Worm-like specimen, four times natural length ; 
club-shaped, slightly less magnified. 
In the American paper previously quoted (p. 3138), the measure of 
the larve found in the esophagus, considered to be in the second stage, 
is stated to be from eleven to fourteen millimétres (that is, a little less 
to a little more than half an inch). In my own observations I found 
the young maggot lying at the base of the fine gallery up through the 
hide to be of a size only just perceptible to the naked eye; and this 
appears to me to prove that our attack is wholly different from that 
alluded to in the American paper; for a larva which was half an inch 
long when it started from the gullet could not by any possibility be 
confused with one which was only just of a perceptible size, noticed in 
the beginning of its subsequently observed progressive growth beneath 
the hide. Should, however, the American attack of maggots in the 
gullet be observed in the course of the coming season, I should be 
greatly obliged by specimens for examination. 
