INCREASE OF THK BRAIN IN WEIGHT. 



107 



appears. The records made by Boyd show the follow- 

 ing relations : 



TABLE 18. THE AVERAGE WEIGHT OF THE ENCEPHALON IN 

 GRAMMES IN CHILDREN STILL-BORN AND IN THOSE BORN 

 LIVING. (Condensed from Boyd,} 



It is a suggestive fact that the greater part of the 

 growth of the brain takes place before any of the formal 

 educational processes have begun, for the mild schooling 

 that occurs before the age of seven or eight years can 

 hardly have much influence. It may be, perhaps, that 

 such a slight increase in weight as occurs during the 

 twenty years that follow is so distributed as to be much 

 more effective than we at present imagine, but to this 

 suggestion I shall return in a later chapter. 



Exact measurements support common observation in 

 the conclusion that the proportional development of the 

 body is different at maturity from that at birth, and in 

 the same way the proportional development of the 

 encephalon changes during the period of growth. The 

 most recent figures are given in Table 19. These 

 observations were made by Danielbekof on two hundred 

 Russian children, whose average age was one month. 1 

 The second table is based on the observations of Boyd. 2 



1 Danielbekof, Materialien zur Frage ilber das Volumen des 

 Gehirns und der Medulla oblongata bei Kindern b eider lei Gesch- 

 lechtes, Inaug. Diss., St. Petersburg, 1885 (Russian). 



2 Boyd, Phil. Trans., 1861. 



