Days 



FIGURE 13. GROWTH ON FOODS CONTAINING ZEIN+TRYPTOPHANE 

 -j- LYSINE. The growth obtained on this diet may be contrasted with 

 maintenance without growth in the absence of the lysine (see Figure 12) 

 and/ailure to be maintained in the absence of both lysine and tryptophane 

 (Figure 11), thus demonstrating the r61e of these amino acids in growth 

 and maintenance respectively. That lysine cannot replace tryptophane in 

 maintenance is shown by Rat 1900. [From the Journal of Biological 

 Chemistry, volume 17.] 



