No. 636] SHORTER ARTICLES AND DISCUSSIOX 



The yeast eontained appi-oximately 0.40 per cent, fat, 46.5 

 per cent, protein and 38.0 per cent, carbohydrate (32.26 "carbo- 

 hydrate" plus 5.8 crude fiber). Omitting- the negligible quan- 

 tity of salts the gross composition of the diets was as follows : 



17.8 % 



49.4^ 



27.25% 



7 Includes 0.3 per cent, crude fiber. 



The diets richer in vitamine had slightly low 

 The casein was prepared from the 40-mesh ( 

 uet by sliaking up for several houre successive 

 tions of 50 per cent, alcohol and one of 95 per 



diyi 



mmercial prod- 

 with two por- 

 3r cent, alcohol and 



iial cooking starch 



The starch was prepared from 

 (corn) by the same procedure as for casein. 



The lutter used was the clear fat obtained by decanting the 

 melted butter through a dry filter. 



The salt mixture was that described by Osborne and Mendel." 



The mice were kept in wire mesh cages under which wero 

 piecffi of glazed paper to catch feces and wasted food. The 

 food was placed in small salve jars having aluminum covers in 

 which i/o inch holes had been stamped. The jars were placed 

 in 5-inch glass crystallizing dishes during the second stage of 

 the experiment so that any waste food could later be found by 

 the mice and eaten. Almost never in the second stiige of the 

 experiment was any food found under the cao-<\ In all cases 



8 J. Biol. Chem., 1919, 37, 572. 



