Abstract
The infection experiment of Paragonimus westermani in its first intermediate host, Semisulcospira libertina, was made by Nakagawa (1915), Kobayashi (1918), Yokogawa (1919) and Miyairi (1919, 1934) . But due to the difficulty in rearing this snail for a sufficient time after infection, no cercaria thereof was obtained in these experiments.
The present authors succeeded in maintaining this snail for a long time after exposure to miracidia, rendering possible the experimental infection of it with the miracidia of Paragonimus westermani, and were able to obtain the cercariae of this worm. The following is the summary of the results.
