Donaldson, Nerve Cell Bodies in the Cortex. 



145 



ferences are probably even less than those occurring between 

 normal and imbecile persons, and would therefore be still more 

 difficult of detection by the method of weighing. 



In Table I, have been given the difference in brain weight 

 as determined for race, sex, mental power, stature and age, 

 and we wish now to show how far these differences in weight 

 can be attributed to the several portions of the neurone as enu- 

 merated above. 



TABLE I. 



Differences IN the Weight of the Encephalon among Different Groups 

 OF Persons. All the Records are Averages Given in Grams. 



Average Weight 

 of Ence[)haIon 



Australian. 

 1 190 Males 



1 2 18 Females. 



Average 



1360 



Males. 



1331 Males 164 

 cm. and 

 under. 

 Males 

 (Aged) 



'305 41-70 yrs. 



1 p. 115. Table 22. Averages for males — European and Australian. 



* p. 97. Table 13. Males and females — intermediate stature — age, 20-40 yrs. 



^ p. 128. Table 26. The average of all the brain weights for eminent men 

 between 39 71 yrs., inclusive, equals 1494. 



p. 97. Table 13. Males, stature 172-167 cm., and age 20-40 yrs., give the 

 standard for the average male. 



* p. 97. Table 13. Males. The average for the tallest compared with that 

 for the shortest, both groups 20-40 yrs. of age. 



^ p. 97. Table 13. Intermediate stature group. The average of those 20-40 

 yrs. of age (prime of life) compared with those 71-90 yrs. (aged). 



It is seen that even the smallest difference recorded, namely 

 that between the prime of life and old age, exceeds not only 

 the weight of the nerve cell bodies in the cortex, but in the en- 



