SEC. 3. THE FUNCTIONS OF THE CEREBRAL 

 CONVOLUTIONS. 



Using the word cerebral hemisphere for brevity's sake to 

 denote the cortical substance of the cerebrum (for we have no 

 reason to think that the fibres of the white matter serve for 

 any other than conducting functions, and it is advisable to keep 

 apart the consideration of the corpora striata) we have endeavoured 

 to shew that in respect to function a broad line separates these 

 structures from the rest of the brain. We have seen reason to 

 think that will and intelligence are associated with the former, 

 while the latter are concerned in elaborating and coordinating 

 afferent and efferent impulses in such a way as to furnish a com- 

 plicated nervous machinery of which the former makes use in 

 carrying out the voluntary and intelligent movements of the body. 

 It is not uncommon to speak of the cerebral hemispheres as 'the 

 seat of will and intelligence. Such a phrase is however open to 

 objection. It suggests that if the cerebral hemispheres could be 

 kept alive quite isolated from the rest of the brain, the processes of 

 volition and intelligence, though unable to manifest themselves by 

 any outward show, would still go on. But we are not in a position 

 to accept, without hesitation, such an assumption. All we know 

 is that the existence of volition and intelligence are dependent 

 on the connection of the cerebral cortex with the rest of the 

 brain. When that connection is broken they disappear; and it 

 may be that what we call volition and intelligence are the product 

 of both the cerebral hemispheres and other parts of the brain 

 working together by virtue of their connections and ceasing so to 

 work when the connections fail; on the other hand it may 

 be that they are generated in the former alone, and that the 

 connections only serve to allow the former to make use of the 

 machinery of the latter. Our present knowledge will not allow us 



