252 THE ANIMAL PARASITES OF MAN 



Sub-family. Opisthorchiinae, Looss, 1899. 

 Genus. Opisthorchis, R. Blanch., 1845. 



Opisthorchiinas with lobed testes. Laurer's canal present. Parasitic in the bile- 

 ducts of mammals and birds. 



Opisthorchis felineus, Riv., 1885. 



Syn. : Distoma conus, Gurlt, 1831 (nee Creplin, 1825); Distoma lanceolatum, 

 v. Sieb., 1836, v. Tright, 1889 (nee Mehlis, 1825 = Fasciolo lanceolata, Rud., 1803) ; 

 Distoma. sibiricum, Winogr., 1892 ; Distoma tenuicolle, Miihl., 1896. 



This parasite is yellowish-red in the fresh condition, and almost 

 transparent. The body is flat, with a conical neck at the level of the 

 ventral sucker marked by a shallow constriction ; this, however, 

 is only noticeable in fresh and somewhat contracted specimens. 

 Posteriorly to the ventral sucker the lateral borders run fairly parallel ; 

 the posterior end is either pointed or rounded off. The length and 

 breadth vary according to the contraction, being usually 8 to n mm. 

 by 1-5 to 2 mm. The suckers are about one-fifth to one-sixth of 

 the length of the body distant from each other, and of about 

 equal size (0*23 to 0^25 mm.). The oesophagus is hardly any longer 

 than the pharynx, which lies close behind the oral sucker ; the 

 intestinal caeca reach almost to the posterior border and are often 

 filled with blood. The excretory pore is at the posterior extremity, 

 and the excretory bladder forks in front of the anterior testis. The 

 testes in the posterior fourth of the body lie obliquely one behind 

 the other ; the anterior one has four lobes, the posterior one five 

 lobes ; the ovary is in the median line transversely, simple or 

 slightly lobed ; behind it lies the large pear- or retort-shaped recepta- 

 culum seminis and Laurer's canal. The uterus is in the median field. 

 The vitellaria occupy the fairly broad lateral areas, in about the 

 central third of the body, beginning behind the ventral sucker and 

 terminating at about the level of the ovary ; the acini are small and 

 arranged in groups of seven to eight, separated by interstices. The 

 genital pore is close in front of the ventral sucker. The eggs are 

 oval with sharply defined operculum at the pointed pole, 30 //, by 1 1 p. 



This species, which is frequently confused with others, inhabits the gall- 

 bladder and bile-ducts of the domestic cat especially ; but is also found in the 

 dog, in the fox, and in the glutton (Gulo borealis}. It has been observed in 

 France, Holland, North Germany (being particularly frequent in East Prussia), in 

 Russia, Scandinavia, Siberia, Japan, Tonkin, Hungary, and Italy. The North 

 American form (from cats and Cants latrans] is a distinct species (Opisthorchis 

 pseudofelineus) . 



In man this species was first found by Winogradoff in Tomsk (nine 

 cases), then by Kholodkowsky in a peasant from the neighbourhood 



