26 
The possibilities of injury by a single puncture are illustrated by 
Prof. N. Leon, of Jassy, Roumania, in an article published in 
1909.* A soldier was bitten once upon the upper eyelid on the 
afternoon of April 19, with the effect to close the eye before the 
next day. Altho the swelling was reduced within four days by 
antiphlogistic applications, the pressure on the blood-vessels of 
the eyeball had caused a dry gangrene which permanently blinded 
the eye. 
Injuries to Domestic Animals 
I find, however, no record of human suffering to parallel that 
of the domestic animals, especially cattle, when heavily attacked 
by the black-fly. In these, hard tumors are produced which sup¬ 
purate within a few hours, lasting eight or ten days. These are 
most numerous on the less hairy parts of the body—the mouth, 
the nose, the eyes, the ears, the mammae, and the abdomen. The 
flies often penetrate the nasal cavities, causing inflammation and 
consequent difficulty of respiration which may even produce death 
by asphyxiation. When first attacked, horses and mules become 
perfectly frantic, rush hither and thither, rolling on the ground, 
dashing off wildly again, and repeating* these actions until they 
become worn out. Cattle act very similarly, rush through dense 
thickets to rid themselves of their tormentors, but all in vain, as 
the speed of the black-fly on the wing is greater than that of its 
victims. Even hogs run madly about, burying themselves in mud 
holes if these are accessible; and sheep run about blindly, with 
piteous bleats. In Louisiana, in 1882, the deer were driven from 
the woods by them, frequently taking refuge from their tormentors 
in the smudges built by planters for the protection of their cattle 
When in their agonies, they would allow people to rub the gnats 
from their bodies, and would even lie down in the glowing embers 
or hot ashes in their frantic efforts to seek relief.f 
When domestic animals are lightly attacked the condition of 
the victim is not particularly threatening, and health may be re¬ 
stored within a few days. Indeed, herds subject to this infesta¬ 
tion become partially immune to it, suffering much less than cat¬ 
tle brought in from outside districts. If, however, the number of 
punctures is great, threatening symptoms appear, invariably end¬ 
ing in death. The appearance of fatigue, the complete failure of 
*Centralblatt fur Bakteriologie, Parasitenkunde, und Infektionskrankheiten. 
Bd. 51, p. 659. 
fBull. U. S. Div. Ent., No. 14. p. 32. 
