CONSTITUENTS OF BODY 



181 



Using a different plan of analysis McCollum ('09) has given data 

 on the composition of the rat. The results appear in table 78. 

 To obtain the skeleton he boiled the entire animal and then sepa- 

 rated the skeleton from the boiled tissues. 



TABLE 78. 



Giving the composition of rats used in experiments vrith various rations. 



(McCollum '09) 



In connection with a study of the phosphorus compounds in 

 the Albino after ovariotomy Heymann ('04) has recorded the 

 P 2 5 distribution in the normal rat (see Keith and Forbes, '14). 

 His data for the normal appear in table 79. 



TABLE 79. 

 Giving the phosphorus compounds of rats as affected by ovariotomy (Heymann, '04) 



1 Apparently erroneous since the sum of the figures for nuclein, lecithin and phos- 

 phate phosphorus is 2.0381 per cent. 



2. In the nervous system. With the purpose of following the 

 changes in the chemical constituents of the brain with advancing 

 age, Koch, W. and M. L. ('13 a) have made a series of observa- 

 tions and to these have been added also observations on one spinal 

 cord at 120 days. The results are given in tables 80 and 81. 



