GAD-FLY. 
457 
taneous muscles at this season of the year *, occa- 
sioned by the continual teasing of the flies, till at 
length these muscles act involuntarily on the slight- 
est touch of any body whatever. 
a The inside of the knee is the part on which 
these flies are most fond of depositing their eggs, 
and next to this on the side and back part of the 
shoulder, and, less frequently, on the extreme ends 
of the mane. But it is a fact worthy of attention, 
that the fly does not place them promiscuously 
about the body, but constantly on those parts which 
are most liable to be licked with the tongue ; and 
the ova, therefore, are always scrupulously placed 
within its reach. 
“ The eggs thus deposited 1 at first supposed 
were loosened from the hairs by the moisture of the 
tongue, aided by its roughness, and were conveyed 
to the stomach, where they were hatched : but on 
more minute search I do not find this to be the 
case, or at least only by accident ; for, w hen they 
have remained on the hairs four or five days, they 
become ripe, after which time the slightest appli- 
cation of warmth and moisture is sufficient to bring 
forth in an instant the latent larva. At this time, 
if the tongue of the horse touches the egg, its 
operculum is thrown open, and a small active worm 
is produced, which readily adheres to the moist sur- 
face of the tongue, and is from thence conveyed 
with the food to the stomach. If the egg itself be 
* August and part of September. 
