CLONORCHIS 25 



is unknown. Destruction of sputum of the patients is 

 hardly practicable. 



An accurate knowledge of the intermediate hosts, of 

 the usual hosts and their habits would perhaps render it 

 possible to prevent or diminish the frequency with which 

 these infections take place. 



In the genera next to be considered, the ovary is round 

 or lobulated, not branched. The intestines are nearly 

 straight, and there are no diverticula. The cirrhus pouch 

 is inconspicuous. In Dicroccslium the testicles are lobu- 

 lated and anterior. D. lanceatum is an occasional acci- 

 dental parasite of man (fig. 10). In the others the testes 

 are posterior, either lobulated and placed one behind the 

 other (Opisthorchis) (figs, n and 13), side by side (Metorchis) 

 (fig. 12), or much branched (Clonorchis) (fig. 14). 



In these groups the extent to which the lateral margins 

 are occupied by the yolk-glands is of value as indicating 

 a specific difference. The presence or absence of spines 

 on the cuticle is of importance. Size, within limits, 

 varies so much that even with the sexually mature worms 

 it is of little value. The size of the eggs is of more value. 



Opisthorchis noverca and 0. conjunctmn have been found 

 in man, but are rare parasites in him; the dog is the true 

 host (figs, n and 13). 



Opisthorchis noverca (Distomnni conjnnctnm) is found 

 in man in India. The spines on the cuticle, and the 

 distribution of the yolk-glands, which are in the middle 

 of the body (fig. 13), distinguish it from 0. conjunctmn 

 {fig. n), also a rare accidental parasite of man. 



CLONORCHIS. 



Clonorchis differs in that the testes are much branched. 

 They are arranged one behind the other. One species of 

 Clonorchis is a very common parasite in Chinese 

 Clonorchis sinensis. 



Clonorchis sinensis is a narrow worm with a bluntly 

 rounded extremity, and tapering slowly to a slightly 

 sharper tail. It ordinarily measures 10 to 14 mm. by 



