372 



S. HATAI 



relations between nitrogen values and the solids — with different 

 lipoid contents — varies widely. Altogether seventy rats, one 

 hundred and six days old, and twenty-five rats, one year old, 

 have been used for this study. 



Table 6 shows clearly that the number ot milligrams of nitro- 

 gen per gram of solids is higher in both the cerebellum and the 

 cerebrum than in the stem or spinal cord. Again the stem shows 

 a higher figure than that given by the spinal cord. The same 

 relations are found in the nitrogen values given by the amino- 

 acids, the urea and the ammonia. We further notice that the 

 corresponding values given by the one year old brains are def- 

 initely lower than those given by the brains one hundred and 



TABLE 6 

 Showing the nitrogen content in the non-proteins, the amino acids, the urea and the 

 ammonia in jour different parts oj the central nervous sTjstem oj the 



albino rat 



six days old. If the relations already found in connection with 

 the studies on the gray and white matter are true, and without 

 doubt they are, we should expect that the nitrogen values should 

 be higher in the cerebellum and .cerebrum than in the stem or 

 spinal cord; again the stem should give a higher value than the 

 spinal cord; since the amount of the lipoids contained in these 

 four parts relatively increases from cerebellum to spinal cord 

 in the order given in the table. In support of this assumption 

 the actual amount of lipoids in these four parts was determined 

 by repeated extractions with alcohol. The extraction was 

 carried on with boihng 95 per cent alcohol repeatedly for several 

 hours in each case and until the alcohol showed no more the 

 typical lipoid color, even after two hours of continuous boiling. 



