34 TROPICAL MEDICINE AND HYGIENE 



Nothing is known of the life-history or intermediate 

 host of this parasite. 



Gastrodiscus hominis (Amphistomum hominis) was first 

 described by Lewis and McConnell in 1876. It is a 

 small gastrodiscus, and the flat plate forming the posterior 

 extremity is concave ; behind the centre of the concavity is 

 the acetabulum. The under-surface of this disc is smooth 

 and not marked by any of the papillae or projections so 

 common in many of the species belonging to this genus, 

 e.g., Gastrodiscus sonsino, common in horses throughout 

 Africa. The opening of the genital pore is at the base of 

 the conical part of the worm, not on the disc (fig. 18). 



FIG. iS. Gastrodiscus hominis. Slightly magnified. (After Leuckhart.) 



Gastrodiscus hominis is a common parasite in Assam, 

 and has been found in other parts of India. Outside 

 India it has only been found in natives of India, and is 

 therefore in such countries an imported parasite. It 

 does not seem to spread under these conditions. This 

 parasite is found in the alimentary canal, and is expelled 

 when thymol is administered. 



Anaemia has been attributed to this parasite, but, as in 

 the case of Fasciolopsis and other flukes, the parasites 

 were associated with Ankylostoma, and therefore the 

 anaemia may have been due to those worms. Dysenteric 

 symptoms have been present in most cases. 



DIAGNOSIS OF TREMATODE INFECTION, 



For the diagnosis of the presence of these worms it is 

 not necessary to find the adult, as the eggs are discharged 

 from the body in the faeces, when the parasites inhabit 



