PARASITOLOGY. 19 
rostrum they pierce the skin, suck the blood and in- 
still a poison into the wound which produces inflam- 
mation and pain. The animals may inhale the small 
insects in numbers, and in this way they produce 
irritation which results in mechanical injury, causing 
bronchitis and pneumonia. Many animals die. The 
greatest loss among live stock has been reported in 
the lower Mississippi Valley. 
Treatment.—Rub parts affected with five percent 
ammonia water. In weak animals give stimulants, 
as carbonate of ammonia, one dram to one pint of 
whiskey, three times a day. Keep animal in cool, 
dark stable. Solutions of quassia, tobacco and oil 
of tar are often applied externally as a preventive. 
TaBANnus ATRaTus (Ater—black). Horse-fly. 
Synonyms.— Mourning horse-fly; large black horse- 
fly; black gad-fly; breeze-fly. 
fistory.—Widely distributed throughout the United 
States. 
Description.—The largest fly of the family Taban- 
idae. It measures about one inchinlength. Entire 
fly is black. The wings are large, and set almost at 
right angles with the body. Its head is provided 
with a powerful proboscis. 
Lite Cycle.—The adult fly lays her eggs in moist 
places; they hatch into larvae composed of twelve 
segments each. The pupal stage is passed in the 
ground, and lasts only a few days. The pupae are 
nearly an inch anda quarter in length. The adult 
emerges from the pupa by splitting the case length- 
wise. 
Animals Attacked.—Horses and cattle are attacked 
