l68 THE ANIMAL PARASITES OF MAN 



2. Opisthorchis sinensis (Cobb.), 1875. 



Syn.: Distoma sinense, Cobbold, 1875; Dist. spathulatum, R. Leuck^ 

 1876 (nee Rudolphi, 1819); Dist. hepatis endemicum, s. permciosiim, v '~B3.elz, 

 1883; Dist. hepatis innocuum, Baelz, 1883; Dist. japonicum, R. Blanch., 

 1886. 



This parasite resembles Opisthorchis fcli'neus in shape and colour, 

 though the form may differ according to the condition of contrac- 

 tion and state of preservation ; the length is 10 14 mm., the 

 breadth 2*4 3-9 mm. No spines. The oral sucker is larger than 

 the ventral sucker, and one is about one-fourth of the length 

 of the body distant from the other. The testes are in the pos- 

 terior third of the body, one behind the other, greatly ramified 

 and extending beyond the intestinal bifurcation ; the cucumber-shaped 

 receptaculum seminis lies in front of them, and in front of the 

 receptaculum seminis is the slightly lobate ovary. The uterus 

 spreads in obliquely directed convolutions into the central field 

 between the ovary and ventral sucker ; the genital pore lies close 

 in front of the ventral sucker. The vitellaria situated in the 

 lateral areas, commence more or less near the ventral sucker, and 

 extend to the level of the ovary. The eggs are oval with a 

 sharply-defined operculum at the pointed pole ; they measure 

 0-027 0-030 : 0-015 0-0175 mm. 



This parasite inhabits the bile ducts and gall - bladder of 

 domestic dogs and cats, as well as of human subjects. It 

 was discovered in man by McConnell, in Calcutta (1874), in a 

 Chinaman who died soon after his admission to hospital. McGregor 

 confirmed eight more cases in Chinese in St. Louis (Mauritius), 

 and subsequently some Japanese doctors and Baelz found the 

 worm in Japan. At the present date the worm is known to 

 occur in Tonquin, China [and Japan] ; it has also been found in 

 Hindoos in Bengal ; one case also has been observed in New 

 York in a Chinaman. Opisthorchis sinensis occurs sporadically 

 all over Japan, and is endemic in certain districts of several pro- 

 vinces of Hondo (Central Japan), and in Kiushu (South-west 

 Island). The province of Okayama, in Central Japan, has a 

 specially evil reputation in this respect, for, according to Katsurada, 

 there are isolated regions in which it was discovered (by examina- 

 tion of the faeces) that 56 to 67 per cent, of the population were 

 infected. The number of worms that may collect in a person is 

 said to amount to over 4,000 (counted !), and in about 12 per cent, 

 of the cadavers examined by Katsurada they were also present 



