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themselves in thick clusters by means of two dark brown 
hooks, one of which is placed on each side of the slit or 
opening which serves the larva or Bot for a mouth. 
These hooks are movable at the will of the maggot, and 
are found in various kinds, if not all, of those of the Bot 
Fly maggots that live attached to mucous membrane, or 
membrane of the internal cavities,—stomach, nostrils, 
&c.,—but are not in those of the Ox Bot Fly or Warble 
Fly (as we may more precisely call it), which live free of 
attachment within the skin. 
Maggots of Horse Bot Fly (partly grown) attached to membrane 
of stomach. 
The commonest kind of internal horse maggots, those of 
the Gastrophilus Eqni, are of a whitish red, about an inch 
long when full grown, of the somewhat barrel-like shape, 
figured, and surrounded with double rows of horny points. 
These are considered to require twelve months fully to 
complete their growth, and this period may be stated in 
a general way to last from one summer until the next. 
When this time is completed the maggot looses its hold, 
and, passing onwards with the food along the intestines, 
is thus (in the case of the kind we are now considering) 
completely got rid of. The maggot then seeks a shelter 
