PARASITOLOGY. 167 



enters, are swollen and appear slate colored or black. 

 The serous membrane adjacent to the liver is slate 

 colored. The young flukes may migrate through the 

 diaphragm and become lodged in the posterior lobe 

 of the lung, where they form a cyst as in the liver ; 

 the attention is first attracted to the infested part by 

 the interlobular substance being stained dark, often- 

 times black ; upon closer examination a tumefaction 

 is found which, when sectioned, is foimd to contain 

 the characteristic cyst. The adult fluke lives about 

 six months. The symptoms and general debilitating 

 conditions are the same as in infestation with the 

 Distoma Hepaticum. Often cattle are infested with 

 both Distoma Hepaticum and Distoma Americanus. 



Distoma Lanceolata (Lancea — lance). 



Distribution.— ¥o\xn6. in countries and localities 

 where the preceding species are found. 



Description.— T\iQ body is lancet shaped, brownish 

 in color and semi-transparent ; when the uterus is 

 filled with ova the body presents a mottled appear- 

 ance, on account of the fact that the integument is 

 semi-transparent. The intestinal tract consists of 

 two non-ramifying branches. The adult is from one- 

 third to one-half inch in length and one-tenth inch 

 wide. 



Life Cycle.— The life cycle is the same as in the 

 preceding species ; the ovum undergoes segmenta- 

 tion and develops embyos in the maternal body , but is 

 not hatched until it has been in water three weeks. 

 The embryo is globular or pyriformin shape, ciliated 

 on the anterior third of the body, and armed with a 

 sharp protractile and retractile cephalic needle. 



