164 'Journal of Comparative Neurology and Psychology. 



nervous system in the male exceeds that in the female by 1.13 per 

 cent/ 



It will be seen from the foregoing that the increase in the weight 

 of the nervous system in the female, when the body length is made 

 equal to that of the male, is 1.20 per cent, and the anticipated 

 difference is 1.13 per cent. It follows that the difference according 

 to sex in specimens of like body weight is accounted for by the differ- 

 ence in stature, the female having the smaller central nervous 

 system because the stature of the female is less than that of the 

 male. 



When, therefore, the influence of body weight and of stature is 

 taken into account, the weight of the entire central ner\-ous system 

 in the two sexes is similar. It still remains true, however, that there 

 is a characteristic division of this total weight according to sex, 

 whereby the male has a slightly heavier brain, but a lighter spinal 

 cord. These results are in accord with the more recent observa- 

 tions on the human nervous system. (Brain: Blakeman, '05; La- 

 picque, '08. Spinal cord: Mies, '93; Pfister, '03, and Donaldson, 

 '08.) 



COMPAKISON OF THE BoDY LeNGTH OF THE AlBINO KaT WlTIl 



THE SiTTiiN^G Height of Man. 



The objection is often made that the length measurements on the 

 lower mammals cannot be compared with the measurements of stat- 

 ure in man because of the differences in the relation of the head 

 to the trunk, and of the trunk to the legs. 



As a matter of fact, however, the body length (trunk -f- head) 

 which we have taken in the rat involves measurements of the pelvis, 

 vertebral column and the skull quite comparable with those made 

 in determining the sitting height in man. The chief difference is in 

 the case of the skull which is measured from base to vertex in man, 

 while in the rat the measurement is along the fronto-occipital axis, 

 and so includes the nasal bones. These latter grow a trifle more 

 rapidly than the cranium, especially in the male (Ilatai, '07), but 



'The value of 8 per eeut given in Donaldson, '08. iiage 300, ninth line, is an 

 error. The correct value is 1.13 per cent as given above. 



