METORCHIIN.E 26l 



malignant biliary adenoma. The bile-ducts have their connective 

 tissue wall greatly sclerosed. These fuse with one another, forming 

 areas of sclerosis devoid of liver tissue. As a result of these changes 

 the liver cells atrophy and undergo fatty pigmentary and granular 

 degeneration. Besides these changes, due probably to the toxic action 

 of the flukes, mechanical obstruction due to the actual plugging of the 

 ducts by the flukes causes retention of bile and icterus, and through 

 pressure on veins, ascites and hypertrophy of the spleen. 



To what extent blood or bile respectively forms the food of the 

 flukes is uncertain. 



Life-history. (Kobayashi, 1911, Mitteilungen aus dem kaiserlichen 

 Institnt jiir Infektions-Krankheiten zu Tokio, pp. 58-62.) 



It results from the work of Kobayashi in Japan that fresh-water fish 

 form the second intermediate host for Clonorchis endemicus. He fed 

 cats with encysted flukes (cercariae) from various fish and easily 

 succeeded in infecting them, e.g. a kitten, proved to be uninfected by 

 repeated examination of its faeces, was fed on infected fish ; a month 

 later innumerable flukes were found in the bile-ducts, gall-bladder, 

 pancreas and even in the duodenum. The fish infected were Leuco- 

 gobis gunthcri, Pseudorasbora parva, and to a less extent Acheclognathus 

 lanceolata, Acheclognathus limbata, Paracheclognathus rhombea, Pseudo- 

 perilanipiis typns, Abbott ina psegma, Biwia zezera and Sarcocheilichthys 

 variegatus. The cysts occur throughout the muscles and subcutaneous 

 tissue of the fish. Length 0-13 mm., breadth o-i mm. The cercaria 

 lies folded in the cyst, length o'5 mm. breadth o'i mm. It tapers 

 posteriorly. Skin at first covered with fine spines, disappearing as they 

 grow older. Body dotted with fine pigment. 

 intermediate host is still unknown. 



Sub-family. Metorchiinae, Liihe, 1909. 

 Genus. Metorchis, Looss, 1899, emend, auctor. 



Hind end rounded. Gut forks reach extreme end. Testes only slightly lobed, 

 filling the hind end. 



Metorchis truncatus, Rud., 1819. 



This species, which attains a length of 2 mm., is slender and conical, 

 the anterior end is pointed and the posterior truncated, and provided 

 with a muscular tuberosity that resembles a terminal sucker ; for this 

 reason the discoverer of the species (Rudolphi) classed it with the 

 Amphistomes. The cuticle in the young, as well as in the adult 

 specimens, is entirely and closely covered with spines. Suckers about 

 equal in size (0-134 to 0-172 mm.) ; the ventral sucker lies somewhat 



