CHAP, vi.] THE BRAIN. 635 



that the nervous system is not to be considered as a collection of 

 isolated organs each fulfilling its functions independently of its 

 fellow, but as a large machine, integrated into a whole, the consti- 

 tuent parts of which are in almost all its actions acting and react- 

 ing on each other in various ways. So much so does this appear to 

 be the case, that the secondary influences, often of the kind called 

 inhibitory, of outlying parts prove as important to the due function 

 of any particular structure as its own more direct action. 



