252 



DISEASES DUE TO HELMINTHS 



Males only have been found to be infected, and these were usually 

 farmers and boatmen from the ages of youth to 54. 



The parasite differs from S. haematobium in but one or two small 

 features, viz. : it is smaller, the male has no tubercles, the eggs are 

 oval, yellowish, without an operculum, and no definite spine, but 

 Leiper has found a small protuberance in 75 per cent, of those 

 examined. 



Some suppose that the parasites feed on blood, and others that they 

 produce a toxin that causes a progressive anaemia in man. 



The life-history is unknown. Perhaps some fresh-water mollusc 

 or crustacean is necessary. 



PATHOLOGY. 



The blood-stream distributes the eggs, which are carried onwards 

 until they lodge as emboli in various organs, especially in the alimen- 

 tary canal and liver, ^\ liere bilharzial tissue is formed, causing 

 hsemorrhagic enteritis. 



P.M. 



On opening the abdomen there are signs of chronic peritonitis. 



Schistosoma japoniciim : liver showing eggs in the intra- and inter-lobular connective 



tissue. X (T. 80. (After Katsurada.) 



The liver is small, cirrhotic, with nodular surface. Glisson's 

 capsule is thickened, and is found to contain numerous ova. 



The intestine is thickened, mucous membrane swollen, hyperasmic, 

 friable, with patches of ulceration and necrosis, sometimes papillomata. 



