296 NORTH AMERICAN INSECTS. 
case, but, on the contrary, as may be seen almost every day 
in spring and the beginning of summer, the female of this 
fly deposits her eggs, often five hundred in number, upon 
the fore-legs of the horse. In about four days these eggs are 
hatched; and as by their motions they produce a tickling 
or itching, the horse tries to remove them with his tongue, 
and in doing so swallows most of them, by which means 
they are transported to the stomach, where each one fastens 
itself, by means of two horny hooks, to the internal coat, 
there sucking its fleshy fibres and feeding on the gastric 
juice. When full grown, and about three quarters of an 
inch long, they leave this viscus, are carried along through 
the intestines, and, with the balls of fecal matter, fall to 
the ground, enter it, and transform themselves into pupae, 
from which, after three or four weeks, they come out, as 
perfect flies. 
As each of these maggots, for its habitation, bores a cell 
as large as a grain of Indian corn, and by this operation 
causes more or less of irritation, often inflammation of the . 
stomach; and as their number often amounts to many hun- 
dreds, we may imagine that the consequences would be very 
serious, as indeed they are, often causing fatal epidemic dis- 
eases of horses. In such cases the animal loses his appe- 
tite and flesh, is afflicted with cough, bites its sides, dis- 
charges much phlegm from the nose, breathes with great dif- 
ficulty, and will die unless remedies are successfully used to 
expel these larve, such as mild laxative oils, ete. 
But as the gad-fly that infests the horse is found only in 
fields, bots are found only in such horses as feed in pas- 
tures or work in the fields, and hence much may be done 
in the way of preventing their ravages by currying and 
cleaning the horse twice a.day. 
Dr. Harris, in his work on Injurious Insects, mentions 
also the Small Red-tailed Bot-fly (@strus hamorrhoidalis), 
which deposits her eggs on the lips, and the Brown Farrier 
