PARASITOLOGY. 165 
in dependent parts, as intermaxillary space, along the 
trachea, under part of the thorax. Pain is noted on 
pressure on the region over the liver. 
Fourth Period,—That of emigration of the flukes, 
can be considered the period of convalescence. All 
symptoms grow gradually less. The liver, though 
infected only once, never entirely recovers. 
There is great mortality among sheep. Not such 
a large percentage of mortality among cattle. The 
symptoms in cattle are similar to those given above 
for sheep, though cattle have a greater resisting 
power to the effects of the invasion. 
Treatment.—Tonics to aid in tiding over the attack. 
DistomMa AMERICANUS (Americanus—America). 
Synonyms.—Distoma Magna; Fasciola Ameri- 
canus; Distoma Texicanum; Fasciola Magna; 
American liver fluke. 
Distribution. — Found common in the cattle from 
the low-lying lands of the South and Southwest. 
Description.—The body is flattened, leat-like and 
slate colored; it measures one to one and one-quarter 
inches long and about one inch wide; it is provided 
With two suckers, oral and ventral, as in the preced- 
ing species. The mouth is located at the bottom of 
the oral sucker. The ramifying intestinal branches 
permeate the entire worm and can be plainly seen 
when the worm is placed between two glass slides 
and pressed. It is a hermaphrodite, the male and 
female genital organs being placed anterior to and 
around the ventral sucker. The ventral sucker is 
located about ne-fourth inch behind the oral one. 
Life Cycle.—The life cycle is similar to that of the 
Distoma Hepaticum. 
