SOME FRUITS OF HAWAII 



109 



placed on the following diet: extracted casein (62, p. 100) 18 percent, 

 salt mixture 4 percent, cod liver oil 2 percent, butter fat 8 percent, corn- 

 starch 68 percent. The average time for depletion was 24 days, when 

 the rats weighed an average of 49 grams. For these experiments, 

 vitamin B was supplied the rats by feeding daily either 4 drops (0.12 

 to 0.13 gram) of tikitiki extract obtained from the Bureau of Science, 

 Manila, P. I., or an extract of tikitiki made in the nutrition laboratory. 

 The latter was prepared so that 0.1 cc, which was fed daily, was equiva- 

 lent to 1 gram of rice bran. 



From each litter of rats were chosen 2 or more negative controls 

 which were continued on the basal diet only and, except in the case of 

 guavas, 2 or more positive controls which were fed 0.1 gram of auto- 

 claved yeast. 



Because no International Standard has been chosen for vitamin G 

 experiments and in order, to have some uniform basis for comparison, 

 0.1 gram of autoclaved yeast was arbitrarily chosen as a standard. The 

 results of feeding this quantity of yeast to positive controls were re- 

 markably uniform (Table 13), the average gain of 20 rats for 5 weeks 

 being 23 grams. 



Supplements of the fruits and autoclaved yeast were fed daily except 

 Sunday. Table 13 and Figure 15 summarize the results of feeding 

 autoclaved yeast, figs, guavas, papayas, pineapples or pohas as the sole 

 source of vitamin G. 



Vitamin C: Standard guinea pigs raised in our laboratory were 

 used to test the vitamin C potency of the fruits. The guinea pigs were 

 fed Sherman's (62, p. 169) scorbutic basal diet plus fresh alfalfa plus 

 the supplements until they ate the fruits or fruit juices readily. The 

 alfalfa was then discontinued and the supplements fed to the guinea 

 pigs for the periods recorded in Table 14. 



Negative controls were not used for every group of guinea pigs 

 fed on a particular fruit but were used at intervals and in some cases 

 one group of guinea pigs fed a poor antiscorbutic served as controls 

 for those fed a good antiscorbutic. All fruits were fed daily except 

 Sunday. All juices and coconut water were accurately measured and 

 fed by means of a glass hypodermic syringe with a small rubber tip. The 

 International Standard, ascorbic acid, was not yet available for use when 

 these tests were made. 



At the end of the experiments the histological examination of the 

 incisor teeth recommended by Hojer (21) was employed. The results of 

 the experiments are summarized in Table 14. 



