112 FEEDING EXPERIMENTS WITH ISOLATED FOOD-SUBSTANCES. 



Chart LXX. 



Period 2. 



p. ct. 



Edestin 18.0 



Starch 29 . 5 to 32 . S 



Sugar 150 17.0 



Agar 50 



Salt mixture I 2.5 



Lard 25.0 30.0 



120 140 



Days 



Chart LXX (rat 133, female) shows mainte- 

 nance on a diet in which edestin was the sole protein 

 during 161 days. Period 1 on a mixed diet shows 

 normal growth. Period 2 is of interest because the 

 food was also purine-free and devoid of organically 

 combined phosphorus. All growth ceased during the 

 edestin feeding (period 2), in contrast with other experiences where protein- 

 free milk was present in the dietary. 



Chart LXXI (rat 218, female) shows inadequate growth on a diet 

 of edestin + milk-paste (period 1) followed by growth during period 2, 



chart lxxi. in which the food contained pro- 

 tein-free milk and edestin as its 

 sole protein. In growing to several 

 times its original weight the animal 

 must have synthesized its purine- 

 and phosphorus-containing com- 

 plexes from purine-free food. The 

 influence of size on food require- 

 ment is shown by the food-intake 

 curve. The diet consisted of 



Period I. 

 Edestin food (edestin, 18 0; starch. 

 32.5: sugar, 17.0; agar, 5.0; salt 



p. ct. 



90 



Edest'.n f ood ?.Q%^_ . . toest , n + Protein-free milk- 



Milk u 1 % 



mixture I, 2.5; lard, 25. 0) 

 Milk food (Trumilk, 60.0; starch J5-T, 



salt mixture I. 1.0; lard, 23.3.) 10 



Period 2. 



Edestin 18.0 



Protein-free milk 28 . 2 



Starch 23. 8 



Agar 5 



Lard 25.0 



20 



40 60 80 



Days 



100 



120 



