THE WEIGHT OF THE BRAIN AND SPINAL CORD. 



99 



in stature is accompanied by a decrease in the weight 

 of the encephalon and in all its subdivisions, and that 

 in these respects the two sexes are similar. I have also 

 recast the figures of Marshall in such a way that in the 

 above table the weight of the encephalon is in each 

 instance made the standard, being taken as equal to 

 100, and the percentage weights of the constituent 

 subdivisions are then calculated. There is a remarkable 

 constancy in the percentage values of the subdivisions 

 of the encephalon of all ages, all statures, and both 

 sexes. The value of the cerebrum in the female is in 

 most of the averages less than 0-4 per cent, below that 

 in the male, and this of course raises the percentage 

 values of the other subdivisions, but whether any real 

 importance is to be attached to this difference is 

 debatable, although, so far as it goes, it is, in my 

 opinion, significant. Advanced age in the female is also 

 associated with a decrease in the proportional weight 

 of the cerebrum. In Table 14 the averages have been 

 made according to age, stature being neglected, and in 

 Table 15, according to stature, age being neglected. The 

 constancy in the proportions of the subdivisions of the 

 encephalon is -the most important fact thus demonstrated. 



TABLE 14. SHOWING THE PERCENTAGE OF WEIGHT OF THE 

 SUBDIVISIONS OF THE ENCEPHALON, THE RECORDS BEING 

 GROUPED ACCORDING TO AGE. BASED ON TABLE 13. 



