NUTRITION \M> GROW1 II 



In the pioneer investigations, studies on the nitrogen balance in young 

 animals yielded results from which it was concluded thai tl ditions 



for the disintegration <>!' protein are less developed in young animals 



than in adults, s<> that the growing organs rapidly withdraw circulating 

 protein and build it into tissue protein. 



In consideration of the accumulation of data extendii pal 



decades, Rubner denied these conclusions, and showed that the diel 

 the growing infant is by no means relatively rich in protein. II" con- 

 cluded that "growth is no1 proportional to the quantity of protein in I 

 diet." Important though this pioneer work may have been in the de- 

 velopment of our present-day conception, the viewpoinl of the men who 

 carried it out was very much narrowed on accounl of the paucity 

 knowledge concerning the structure of the protein molecule. No all* 

 ance was made for the fact, which has recently been firmly established, 

 thai the protein molecule may vary extremely in regard to the d 

 of which it is composed, and that the growing tissues may demand, 

 so much an abundance of protein as such, but rather a prop 

 all the building stones which are required for growth Mendel . 



Quantitative Comparison of Amino a. eds Obtained b'v H' 



(Compile! by T. B. Osborne, 19] 



• i bt te bi 

 chemists. 



tThe fiRiircs for the 



From the accompanying table giving the 

 amino acids, etc., present in certain proteins, it will be evident that tl 

 arc very marked variations in the units of which differ* 

 composed ft any one of these units should be essential owth and 



