THE BRAIN. 515 



It is even yet premature to dogmatize in regard to the site 

 of these centers ; especially are we not ready for large generali- 

 zations. In man the convolutions around the fissure of Rolando 

 constitute the motor area best determined. 



The whole subject of cortical localization requires much ad- 

 ditional study, especially by the comparative method in the 

 widest sense — i. e., by a comparison of the results of operative 

 procedure in a variety of groups of animals, and the results of 

 clinical, pathological, physiological, and psychological investi- 

 gation. Especially must allowance be made for differences to 

 be observed, both for the group and the individual ; and also 

 for the influence wJiich one region exerts over another. Be- 

 tween the weight , of the cerebrum, the extent of its cortical 

 surface, and psychic power, there is a general relationship. 



