of the small tables may be compared with a corresponding figiire in 

 either another small table or in Table 1 if the figures are both in 

 the same time period. The figures in the two periods, 12 and 2li weeks j, 

 were computed from the same original base; consequently the 2[i-'week fig- 

 ure included the 12-week figure. 



The discussion of the results accomplished by feeding different 

 diets is made by giving, if necessary, a general description of the 

 variable or. variables that were tested and the justification for test- 

 ing them. After this description, the results of the tests are presented 

 in terms of deficiency symptoms, mortalities, and growth rates as they 

 occurred in the cold-water period and the warm-Wc.ter period. 



Beef Liver Control 



Flukey beef liver was used as the .sole component of the standard 

 control diet (Table 1, -^iet 1), This diet gave results that were 

 quite comparable to the results produced by this same diet in previous 

 years. The feeding of flukey beef liver resulted in gains during the 

 cold-water period that were as good or better than all the other diets 

 except the meat-viscera mixtures (Table 1, Diets 13 and li^). During 

 the warm- water period, however, beef liver produced gains that fell 

 significantly below those of most other diets. The mortality rate 

 during the entire experiment was among the lowest achieved by any diet. 



Tuna Liver 



Tuna liver from the yellowfin tuna (i^eothunnus macropterus ^ was 

 tested as the sole component of a single diet (Table 1, Diet 15). In 

 common with the previous Leavenworth trials on tuna viscera, tuna liver 

 did not produce good groMth. At the end of the cold water period, the 

 fish on this diet had a low mortality rate, i'^et a very low per cent 

 gain„ During the last half of the experiment, the mortality became 

 excessive and the growth rate continued low in spite of the warmer 

 water temperatures. 



At 18 weeks and thereafter, pronounced lamella swelling and 

 some clubbing of the gills were prevalent. Hemorrhagic areas occur- 

 ring on the exterior portions of the body and fins were also qiiite 

 noticeable during this time. No anemia was present, however, at any 



time. 



Tuna liver obviously was not a good single component dietj but, 

 since this liver apparently does contain the anti-anemic factors, it 

 should be tested under experimental conditions as a substitute for 

 all or part of the beef liver in a composite diet. 



