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ZALIA JENCKS 



Mixed diets. In order to learn what difference, if any, existed between 

 the effect of our standard (synthetic) diet and that of scrap food on the 

 rate of blood regeneration, two rats were fed on dog biscuit for 2 days 

 before bleeding and then during the entire period of the manufacture 

 of new blood. The results are shown in table 3. In both cases the 

 organism regenerated hemoglobin more rapidly than red cells. This 

 may have been merely accidental, but the same circumstances occurred 

 in the case of one rat fed on table scraps (meat, lettuce, bread, etc.). 

 This opens the question as to what factor or factors are here present 

 which we did not have in the standard basal diet with added yeast as 

 a source of vitamin B. 



TABLE 4 



Blood regeneration in adult rats after a single hemorrhage on a limited food intake 



5 grams per day 



Underfeeding. A series of hemorrhages was made on animals with 

 a limited supply of food, i.e., 5 grams per animal per day, including 

 0.2 grams yeast daily added to the standard basal diet as above. This 

 limited food consumption did not prolong the duration of regeneration 

 appreciably, the normal being reached from 6 to 7 days after the initial 

 loss of blood (table 4) . Loss of body weight occurred in each case, as 

 might be expected since the caloric intake was insufficient, but the 

 animals remained healthy and active throughout the period of limited 

 feeding. 



Starvation. When animals were not allowed any food throughout 

 the period of blood regeneration, the rate of return to normal hemoglobin 

 value and number of erythrocytes was slower than in the above cases, 

 the period for one animal being as long as 13 days. A control rat with- 



