14 THE STABLE FLY. 
a portion of which may be seen projecting forward from beneath the 
head. The proboscis of the house fly is short and broad and not 
capable of piercing. The stable fly is usually slightly stouter than 
the house fly, and the spots on the abdomen also aid in distinguish- 
ing it from that species. 
The horn fly is also related to this species but is of much smaller 
size, and the color is considerably different. When on a host these 
TS 
Fig. 4.—The stable fly: Adult female as seen from above. Greatly enlarged. (Original.) 
flies may be readily differentiated by the attitudes they assume. 
The stable fly usually attacks the lower portions of the legs of its 
host and nearly always sits with the head up. The horn fly is more 
inclined to feed on the back and sides of the animal and always feeds 
with the head downward, while the house fly may be seen sitting in 
any position but never with its head pressed into the hair as though 
feeding. 
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