380 BOARD OF AGRICULTURE. 
him. At other times, this @sétrus gets between the fore-legs 
of the horse whilst he is grazing, and thus makes its attack on 
the lower lip. The titillation occasions the horse to stamp vio- 
lently with his fore-foot.against the ground, and often strike 
with his foot, as if aiming a blow at the fly. They also some- 
times hide themselves in the grass, and as the horse stoops to 
graze, they dart on the mouth or lips, and are always observed 
to poise themselves during a few seconds in the air, while the 
egg is preparing on the point of the abdomen.” The eggs are 
darker colored than those of the common bot-fly, and contain 
a nearly developed embryo, so that they very soon hatch, and 
the young larve are transferred to the mouth by the tongue, 
and thence get into the stomach. 
In other countries there are still other species of bot-flies 
that infest the horse, ass, and mule; among them Gast- 
rophilus inermis Br., which lives in the horse; G. flavipes 
Oliv., which inhabits the stomach of the ass and mule; and a 
species of Hypoderma, which lives beneath the skin of all three. 
But I am not aware that either of these has been observed in 
this country. 
The Meat-fly, Blowflies, ete. Figure 27. 
These flies are not true parasites, but naturally feed, while 
in the larval state, upon decaying flesh and other animal 
matter. Their larve are, however, frequently 
found in wounds and sores, both of animals 
and men, feeding upon the purulent matter, 
and when allowed to live undisturbed, not un- 
unfrequently attack the living flesh, when 
their food becomes exhausted ; and in this wa, 
if they gain access to wounds in large numbers, 
they will not only greatly aggravate and enlarge 
them, but in many cases, when neglected for a 
short time, they have caused the death of men 
and animals by actually eating away living tis- 
sues. The females in this group of flies are 
viviparous, the eggs being retained in capa- 
Figure 27.—Larva or maggot of the Blue-bottle fly (Musca Cesar Linn.), en- 
larged. From Packard’s Guide. 
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