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 ta 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. 



Tabanus Atratus (Ater — black j. Horse-fly. 



Synonyms. — Mourning horse-fly ; large black horse- 

 fly; black gad-fly; breeze-fly. 



History. — Widely distributed throughout the United 

 States. 



Description. — The largest fly of the family Taban- 

 idae. It measures about one inch in length. 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. 



Life 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 and a quarter in length. The adult 

 emerges from the pupa by splitting the case length- 

 wise. 



Animals Attacked. — Horses and cattle are attacked 



