The historical review of the epidemiology of schistosomiasis japonica in Formosa from Japanese literature as given above shows clearly that the chief endemic area of this disease is Changhua Hsien (Taichu Prefecture) in the mid-western part of this island. Possibly another endemic area exists at Laonung in Kaohsiung Hsien (Takao Prefecture), in the south-western part of Formosa. The current idea abroad that Shinchiku (= Hsinchu Hsien) in the northwestern part of the island is the main endemic area of this disease is without foundation in the Japanese literature. Dr. S. Yokogawa, in a personal communication, dated March 25, 1951, agrees with us and states, “It is true that there was no schistosomiasis japonica in Shinchiku, either human case or animal case.” There is, furthermore, no report in the literature of the finding of living Oncomelania snails in Shinchiku.
The above review also shows that the riddle of the human cases of schistosomiasis as given by Takegami should be solved, the incidence of animal infection verified, and the distribution of the intermediate host, O. formosana, in this island thoroughly re-studied.