Donaldson, Groiuth of Central Nervous System. 349 



TABLE 2. 

 Showing the mean brain weight according to sex. 424 males, 218 females. 



Average percentage deficiency in the weight of the female brain 1.5 per cent. 



Although the absolute value here given is somewhat greater, 

 this result accords with that of Hatai ('07A) who found the cranial 

 capacity in the male greater by about 0.43 per cent. 



Boycott and Damant ('08) have found the fatty acids in the 

 male rat to be on the average 4.4 per cent of the entire body weight, 

 and in the female 5.6 per cent. This datum, when applied as a 

 correction to the body weight, would tend to reduce the difference 

 between the brain weights of the sexes. It is further not improb- 

 able that the thoracic and abdominal viscera are also proportion- 

 ally different in the two sexes, and that as a consequence, there 

 is a characteristic sex relation between the weight and length of the 



