METABOLISM 



593 



The animal receiving Diet i will fail to grow because of the deficiency of 

 cystine. On the other hand, the rat receiving Diet 2 will grow normally, because 

 cystine is present in proper amount. The rats should be weighed at short 

 intervals. See Fig. 183. 



^ 

 o 



x 



(f> 



31? 



o 



\f 

 tueens /i 4r (5 



FIG. 184. CURVE SHOWING INFLUENCE OF A DEFICIENCY OF LYSINE IN THE DIET. 

 (Hawk, Smith and Bergeim : Unpublished data.) 



(b) Demonstration of Lysine Deficiency. Make this demonstration the 

 same as (a) above, using the diets listed in the following table : 



LYSINE DEFICIENCY DIET 



Diet i 

 per cent 



Diet 2 

 per cent 



Rolled oats 1 j 60.00 



Gelatine 1 1 o .00 



Dextrin or starch j 30 .30 



Salt mixture ' | 4 7o 



Butter fat 5- 



60.00 

 10.00 

 20.30 



4:70 



5.00 



x Oat proteins are low in lysine. Gelatine is relatively high in this amino acid (McCol- 

 him: "Newer Knowledge of Nutrition," New York, 1918, p. 170). 



38 



