0^ I. IJIMA 



larvae. Symptoms appeared in 3 weeks and in a month every one 

 of them hegan to discharge Bothriocephalus eggs. At this, an- 

 thehninthic was given and in all more than 6 specimens of B. latus 

 were ohtained, averaging about 335 cm in length. Zschokke also 

 obtained positive results in several experiments on man. In 4 cases 

 symptoms appeared in lG-22 days after swallowing the larvœ and 

 the tape- worms obtained in 20-26 days measured about 129 cm on 

 an average. 



Some specimens of Bothriocepha]us-larva3 from Onchorhynchus 

 Perryi were sent to Prof. Leuckart for examination. He did not 

 hesitate to pronounce them as identical with those found in the pike 

 of Europe. 



Thus, the fact is established that Onchorhynchus Perryi does 

 harbour the larva of B. latus ; and I believe I am right in claiming 

 that fish to be at least one of the chief sources of B. latus in Japan. 

 Subsecjuently I have had occasion to examine 7 examples of that fish 

 at different periods of the year and found Bothriocephalus-larvœ in all 

 but one. The single negative case was a young 0. Perryi from the 

 Hokkaido. It was in a state of putrefaction, making the task of 

 search so unpleasant, that a thorough examination was abandoned. 

 Another Hokkaido specimen, said to have been sent in ice contained 

 at least 4 larvae. The other specimens Avere brought to the Tokyo 

 market from neighboring districts, probaljly from the Tonegawa. 

 The number of larvœ lodged in one fish was not large, 7 having been 

 the maximum. In one case, only a single larva could be found after 

 a laborious search. Even then it would be unsafe to assert that no 

 chance was left for some to escape unnoticed. At all events, the 

 number of the B. larvœ in 0. Perryi is much less than that found by 

 Braun or Zschokke in the pike, burbot, etc. But to judge from my 

 somewhat limited experience, their occurrence in O. Perryi seems to 



