illustrated by responses to extracts of tunny and yellowfin while the 

 fish were being fed on skipjack^ and responses to extracts of skip- 

 jack while the fish were being fed yellowiin or bigeye tunao 



It may be concluded that the response of the tunny m 

 captivity IS not directly conditioned to the species of food wh^ch was 

 fedo However^ there still remains the possibility that the tunny 

 formed a mental association between feeding and the smell or taste 

 of the dead food^ which was cut up or otherwise macerated and 

 exuded juices of similar composition to the extractSo An association 

 such as this would not necessarily be present in the case of wild fish 

 feeding on whole living organisms at sea, ThiSj, or some other 

 subtile type of conditioning to life in the pond^ may have contributed 

 to the response. 



The part played by conditioning can be ascertained only 

 by testing the extracts on schools of fish at seao Certain materials 

 for sea testing have already been prepared and pond-tested (Nos, Z64, 

 279, 29I0 304 to ilZc 350 to 356'jo The results of sea tests of these 

 and other preparations will be discussed in a later reporto For the 

 present it may be stated that the preliminary sea tests were largely 

 negative o 



61 



