1919] Cort: The Cercaria of the Japanese Blood Fluke 487 



p. 23) soon after this also published the statement that the intermediate 

 host had been discovered by Miyairi in a new species of Blanfordia. 

 These statements were the first hints to scientific workers outside of 

 Japan that this problem has been solved. 



Credit for the discovery of the intermediate host and the first 

 study of the larval stages of the Japanese blood fluke goes to two 

 Japanese workers, Miyairi and Suzuki (1913, 1914). Miyairi and 

 Suzuki solved the problem experimentally by infecting snails of the 

 species Blanfordia nosophora with the miracidia of S. japonicum. 

 They found that development of sporocysts containing cercariae fol- 

 lowed. The cercariae when fully developed escaped from the snails 

 and produced schistosomiasis by penetration through the skin of mice 

 exposed to the water containing infected snails. These authors also 

 described and figured the structure of the stages found in the snails. 

 Two years later Leiper and Atkinson (1915) also produced experi- 

 mentally the development of the cercariae of S. japonicum in the 

 Katayama snail, Blanfordia nosophora (Robson). Adults of S. japon- 

 icum were experimentally developed in mice after skin penetration 

 of cercariae so produced. Leiper and Atkinson (1915) briefiy 

 described the sporocysts and cercariae and figured the snail inter- 

 mediate host and the larval stages. Appended to their account is the 

 description of the intermediate host by G. A. Robson as Katayama 

 nosophora nov. gen nov. spec. Fujinami (1914, p. 23) stated that this 

 snail is a new species of the genus Blanfordia. Miyagawa (1916, 

 p. 97) discussed fully the question of the systematic position and 

 name of the intermediate host of S. japonicum. He placed it in the 

 genus Blanfordia A. Adams, and accepting the priority of Robson 's 

 specific name designated it as Blanfordia nosophora (Robson). Since 

 the discovery of the intermediate ho.st and cercaria of S. japonicum 

 additions to the knowledge of this stage have been made by a 

 number of Japanese workers. In 1916 Fujinami, Tsuchiya and 

 Miyagawa (1916) published in Japanese an extensive monograph 

 on Japanese schistosomiasis. In this monograph Fujinami con- 

 tributed the discussion on the history of the subject and the path- 

 ological anatomy, Tsuchiya the part on symptomology, and IMiyagawa 

 the part on the etiology. In his part of this monograph Miyagawa 

 (1916) gives the most extensive account of the intermediate host and 

 larval stages of S. japonicum to be found in the literature. He also 

 included a critical analysis of the Japanese work along this line 

 which proved to be very helpful. Parts of the papers of Fujinami 



