348 'Journal of Comparative Neurology and Psychology. 



like weight must be compared, and since the females run to only 

 255 gms., the numbers available for comparison are somewhat 

 reduced (424 males, 218 females). When the data are tabulated, 

 the values given in table 2 show that the weight of the male brain 

 exceeds that of the female in 84 per cent of the groups and is on 

 the average 1.5 per cent greater. 



TABLE I. 



Giving the mean observed and calculated weights of the brain and of the spinal cord 

 in the albino rat. Sexes not distinguished. Brain 680 cases; spinal cord, 

 647 cases. 



