if THE STABLE FLY. 
stamping of the feet and striking at the legs with the head and tail 
indicate the point of attack, while when the horn fly is present the 
animals pay particular attention to the back and sides. The bite of 
the stable fly is evidently much more severe than that of the horn 
fly, as it causes very great annoyance even when the flies are present 
in much fewer numbers. 
SUMMARY OF LIFE HISTORY. 
Like all other flies, this species has four stages in its life history, 
namely, the egg, larva, pupa, and adult. 
The egg.—The eggs of this fly are elongate ovoid and of a creamy 
white color. They are about one twenty-fifth of an inch in length 
and under a mag- 
nifying glass show 
a distinct furrow 
along one side. - 
When placed on 
any moist sub- 
stance they hatch 
in from one to 
three days after 
being deposited. 
In hatching a 
small slit is made 
around one end of 
the groove, and 
the minute mag- 
got crawls out. 
Figure 1 shows 
four eggs on a 
piece of straw; the 
Fig. 1.—Eggs of the stable fly (Stomorys calcilrans) attached to a straw. two at the right 
Greatly enlarged. (Original). Hila hiateheee 
The larva, or maggot.—When first hatched the larve, or maggots, 
are about one-twelfth of an inch in length and, being translucent, 
are not easily seen with the naked eye. Development takes place 
fairly rapidly when the proper food conditions are available, and 
the growth is completed within eleven to thirty or more days. When 
full grown the larve (fig. 2) are pale yellow or nearly white and 
about four-fifths of an inch in length. They have the typical shape 
and action of most maggots of this group of flies. The hind end is 
large and the body tapers to the head. The larva moves quite rap- 
idly by means of minute projections on the edge of each segment 
along its underside. When exposed to the light it quickly dis- 
appears again in the straw or other matter in which it is breeding. 
540 
