146 Kansas Academy of Science. 



proteins, two of them, lysine and tryptophane, have been shov/n 

 to be indispensable in maintaining body weight and producing 

 normal body growth. This fact alone must profoundly modify 

 our ideas on the nutritive values of food stuffs. Practically the 

 beginnings are now being made and we may well look to the 

 immediate future for a much larger application of this knowl- 

 edge. 



Side by side with our advances on the amino acid contents of 

 foods has come the realization that certain other constituents 

 of foodstuffs are intimately concerned with their nutritional 

 value. The work of McCollum and his coworkers at Wisconsin 

 has shed much light on this phase of nutritional investigation. 

 They have succeeded in isolating two substances, one water 

 soluble, the other alcohol soluble, which play important and in- 

 deed essential roles in maintaining normal growth and develop- 

 ment in animals. Nothing as to the composition of these two 

 substances is known, and they have been labeled for the pres- 

 ent as water-soluble A, and alcohol-soluble B. This work con- 

 stitutes a second link in our understanding of the chain of 

 nutritional metabolism. It may safely be said that the future 

 has many surprises in store for us along these lines. If there 

 is one thing we may profit by as a result of the late investiga- 

 tions mentioned it is the fact that the little heretofore consid- 

 ered unimportant constituents may play a role quite as pro- 

 found as do the more obvious and abundant ones. 



University of Kansas, Lawrence. 



