CHANGES IN COMPOSITION OF BODY OF RAT 



29 



TABLE 5 



Showing the relative growth of the dry suhatance in several mnmmals compared with that in 



the albino rat 



Indeed the percentage of solids in the rat at birth corresponds 

 with that of the foetal life of the other mammals here recorded. 

 This immaturity of the body at birth and subsequent rapid 

 growth of the body during the first three weeks must naturally 

 call for an appropriate quality and quantity of the milk itself. 

 The present results on the growth of dry substance agree with 

 those obtained by Lowrey ('13) who has not only determined 

 the dry substance of the entire body of the albino rat, but also 

 that of its various parts and systems. The only disagreement 

 between the results of Lowrey and of myself is exhibited by the 

 percentage of dry substance of the body at birth. Lowrey gives 

 11.7 per cent of solids, while I find 12.8 per cent. I am unable 

 to explain this discrepancy at the present moment. 



