84 THE ACTIVE FORCES OF LIVING ORGANISMS 



All nerves It will be well, however, to recall a statement which 

 ceUs are we made when discussing the nature of the nervous 

 in chemi- impulse. It was then pointed out that oxidation of a 



cal action. n j ni_' j ii'j.i 



nerve-cell or of a collection oi nerve- cells is the very 

 essence of nervous action, at least, under normal 

 conditions. It will be seen, therefore, that to this 

 extent every nerve-cell in the body is concerned in 

 chemical action or metabolism. But we may go even 

 farther, for we may say that no action of any kind 

 whatsoever takes place in any organism which does 

 not lead either directly or indirectly to oxidation in 

 the active part. If you do but press with your finger 

 on the palm of your hand, you cause a temporary 

 decrease in the rate of oxidation followed when 

 reaction takes place by a proportional increase. If 

 you lift a heavy weight from the ground, chemical 

 action of an intense kind occurs, and in both instances 

 it is governed by the nature of the sensory nervous 

 impulses and their motor reaction. We must, there- 

 fore, perforce arrive at the conclusion that every nerve- 

 cell and every nerve-fibre in the ordinary course of 

 functional activity helps to regulate the processes of 

 metabolism in the part it supplies. With respect to 

 that metabolism which takes place in a state of repose, 

 and in which the anabolic tendency is, there seems 

 reason to suppose, especially marked, we may also 

 believe that it is under nervous control, the latter 

 being modified by the conditions which have existed 

 during functional activity. How important the 

 metabolism of repose is for the building up of nervous 



