138 



FEEDING EXPERIMENTS WITH ISOLATED FOOD-SUBSTANCES. 



Chart CXXIX. 



20 



40 



60 



80 



100 



120 140 



Days 



J 60 



180 



200 220 240 260 



Chart CXXIX (rat 157, male) shows the failure of 

 a well nourished rat (see period 1), to be maintained on a 

 diet containing protein-free milk and zein as the sole 

 protein. It should be noted that precisely similar mix- 

 tures in which zein was replaced by any of the other 

 proteins studied, sufficed either to induce growth or at least to maintain 

 body-weight for an equally long period. Attention is directed to the con- 

 tinued fall in weight despite the large food intake. The composition of the 

 food was mixed for period 1 ; for period 2 it was as shown herewith. 



Period 2. p. cl. 



Zein 18.0 



Protein-free milk. 28.2 



Starch 23 . 8 



Agar 5.0 



Lard 25 . o 



New Haven, Connecticut, U. S. A., 

 July i, 191 i. 



