NERVOUS SYSTEM OF THE FROG 



17 



not desirable to give any weight to the differences as observed in 

 1904. 



The value of this table as it stands is to show that we were 

 dealing in all cases with healthy frogs, as the frog readily shows by 

 changes in the amount of water in the nervous system, the effect 

 of infections or disturbing conditions. 



TABLE 13 



Showing the percentage of water in the brain and in tJie spinal cord. Averages from 



groups of three 



R. pipieng. 



BODY 

 WEIGHT 



[14.9 

 23.2 

 30.8 



[43.2 



PERCENTAGE OF WATER IN 



Spinal Cord 



Brain 



84.5 

 84.7 

 85.0 



85.7 



80.2 

 80.1 

 80.5 

 81.2 



R. esculenta 1904. 



15.9 

 22.0 

 35.0 [2] 

 40.2 



83.6 

 83.3 

 83.3 



83.2 



78.6 

 78.9 

 78.4 

 78.3 



R. esculenta 1909. 



R. temporaria 1904. 



83.6 

 83.6 

 83.6 

 83.6 



82.7 

 82.3 

 82.1 

 81.6 



78.6 

 77.9 

 78.4 

 78.3 



78.6 



77.2 

 76.9 



77.8 



R. temporaria 1909, 



f 18.0 [4] 



I 25.2 

 i 26.9 

 I 29.5 

 [34.8 



83.0 

 84.1 

 84.0 

 83.8 

 S3 . 6 



78.1 



78.7 

 78.4 

 79.1 



78.7 



The foregoing tables and the comments on them are intended 

 to demonstrate that a second series of observations on R. escu- 

 lenta and R. temporaria made in 1909 at an interval of five years 

 yield results substantially similar to those first obtained in 1904 



