THE NERVOUS SYSTEM 



173 



resulting action, however this be determined, tends to lay 

 down a path which will again be followed. 



(2) Not only will the previous training of the brain thus 

 act as the directive force in the response to stimuli, but the 

 nutrition of the brain also plays an important part. The 



S TOMNG. 



RECEIVING. 



\ 



p I (VA L AR.C 



FIG. 96. Diagram to illustrate different possible channels of cerebral 

 response to stimulation. 



action of a brain when well nourished and freely supplied 

 with pure blood is often very different to that of the same 

 brain when badly nourished or imperfectly supplied with 

 healthy blood. Since the education of the brain really con- 

 sists in developing proper responses to various stimuli, the 



