368 journal of Comparative Neurology and Psychology. 



TABLE 10. 



To show the increase in the brain weight of man with age. Encephalon weighed 



entire with pia. (Compiled by Vierordt). 



, *It appears probable that the weight here given in table 10 for the female brain at birth is too high 

 (Handmann '06, S. 35); but it seemed best to hold to one table in this instance, and not attempt to 

 revise any single entry in it. Any lowering of the human brain weight at birth would tend to make 

 the weight relations in man even more similar to those found in the rat than the calculations given farther 

 on show them to be. 



profitable to discuss it until we learn both for man and the rat, 

 at what time cell-division in the brain ceases, and so can deter- 

 mine when the increase in weight becomes the expression of simple 

 enlargement alone. Nevertheless, it is of interest to note that 

 while nearly the same fraction of the span of life is used for the 

 rapid growth process in both forms, the actual period required 

 by man is thirty times that for the rat. 



