a correction by methods like those described above Of course in doing this one 

 must have in advance a general idea of the depth at which the fish are caught 

 (the level at which the fish swim) o Some studies have already been made of the 

 environmental factors which affect the density,, concentration, and biting 

 qualities of the buna schools within the zones of suitable temperature, but 

 there are still many points left for future studyo 13.)l4)l5). 



In conclusion 1 express my deep thanks to Dr. liobuyoshi Ogura, Dr = 

 LScrisaburo Tauchi, Mro Mitsuyo Okada, Mr^ Itaro TaJcayamaj Mro Kinosuke 

 Kimura, and Mr. toorisaburo Sakai, who gave me valuable instruction and 

 comments on this studyo 



(December 9, 1934) 



13) 



Shimoda, Mokuichis A Survey of the Skipjack and Tuna i^'isheries in the 



waters of British Borneo and the Netherlands East Indies., Suisei , April 



1930o 



' Ikeda, Nobuyas On Oceanographic (Conditions on t he Tuna Longlining Grounds 

 and the Level at Wliich the Tuna Swim in the Outer South Seas o Gyorokai 

 Shi, No. 1. 1932. "~~ 



15) Suzuki, Shins Tsuri Hy!°ikutai „ Chapter 4o February 1931o 



8 



