402 THE HUMAN SPECIES 



The trematodes peculiar to man include the Distomum 

 rathouisi. perhaps identical with D. crassum (Plate VII., 

 fig. 7) ; the Distomum heterophyes, a rare suction-worm in 

 Eastern Asia, once seen by v. Siebold in Egypt (Plate VII., 

 fig. i), and the Distomum ophthalmobium Dies once observed 

 in the capsule of the lens of a child (Plate VII., fig. 2). 



Tapeworms which inhabit man only in their adult form are 

 Taenia saginata (mediocanellata), the tapeworm of diseased 

 beef (Plate VII., fig. 3); the Taenia solium, from measly pork 

 (Plate VII., fig. 4); the Taenia nana, found by Bilharz in 

 Egypt (Plate VII., fig. 5); the Taenia flavopunctata, first dis- 

 covered in America by Weinland (Plate VII., fig. 6), and the 

 Taenia madagascarensis of Davaine. 



Intestinal worms parasitic in various animals as well as in 

 man are Ascaris lumbricoides ; the common round worm which 

 also infests the gorilla is common to all the races on earth ; 

 Ascaris mystax, commoner in dogs and cats, is also found in 

 man ; Trichina spiralis is found in men, swine, rats, mice, cats, 

 martins and foxes. The Filaria medinensis occurs in man, dogs 

 and horses in all the tropical regions of the Old World. Eu- 

 strongylus gigas occurs in man, dogs and horses ; the small 

 Strongylus duodenalis, which produces extreme ansemia in man, 

 is also parasitic in the gorilla ; Strongylus longevaginatus has 

 been frequently observed in animals and seldom in man, and 

 finally the Echinorhynchus hominis, which is usually parasitic 

 in the larva of insects, has on a few occasions been found in man. 

 Flukes living in man and various animals are Distoma hepa- 

 ticum and Distoma lanceolatum ; neither of these are peculiar 

 to man but are more frequently found in sheep, cattle, rodents, 

 pachyderms and marsupials ; Distoma spathulatum occurs in 

 man and cats in Eastern Asia ; Distoma conjunctum occurs in 

 man and in the liver of pariah dogs in India and Eastern Asia ; 

 Distoma pulmonale occurs in the lungs of men and of tigers in 

 Eastern Asia. 



Tapeworms are parasitic in man and in various animals. 

 The eggs of Taenia cucumerina are transferred from the dog to 

 the dog-louse, and thence into the bodies of those who keep dogs. 

 Taenia echinococcus occurs in man, dogs, swine and herbivorous 

 animals; Bothriocephalus latus, which is transferred from pike 



