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. 

 DiSTOMA 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, leaf-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. 



