Donaldson, Groivth of Central Nervous System. 359 



TABLE 5. 



Weight of the central nervous system in the albino rat, given in mean values. Cal- 

 culations according to the formulae [i] and [3] and the 5th root of the body 

 weight. The heaviest group, 315 gms., is taken as the standard for the cal- 

 culation according to the 5th root, and at 135 gms., the values by the 5th root 

 and the logarithmic curve coincide. 



352 and 357), it appears that the weight of the central nervous 

 system diminishes in proportion to the 5th root of the body weight, 

 as far as the 135 gms. group. The rapid growth of the entire 

 central nervous system ceases then according to this criterion, at 

 135 gms. of body weight. The sum of the values determined in 



