CENTRAL NERVOUS SYSTEM. 



725 



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" 



FIG. 204. Curves for each sex, showing the weight of the brain according to age. For the first 

 twenty-five years the curve is formed from annual averages based on the figures of H. Vierordt ; from 

 twenty-five years on the curves are formed from decennial averages based on the observations of 

 Bischoff. All the data are from observations on the less fortunate classes. The dotted curve for emi- 

 nent men is formed from decennial averages based on forty-five observations. 



fifth decade (males), fourth (females), although there is a premaximum in the 

 middle of the second decade (at thirteen and fifteen years for males and four- 

 teen years for females), in which the too early and too vigorous growth of the 



