96 WARFARE IN THE HUMAN BODY 



into historic ecclesiastical tradition and custom, has pro- 

 duced mere inability, and reduced the inhibited to temporary 

 paralysis. Taking the word into science has produced 

 similar results since some eminent physiologists have used 

 the very word "influence " of the supposed vagus action 

 on the heart. They would doubtless own that they, too, 

 employed the word as shorthand ; but if, as I think the 

 facts show, all sorts of inhibition, save those due to the 

 pathological conditions vaguely summed up as "shock," 

 are the result of substituted excitational actions, direct 

 or upon other paths, there is no more need to use the 

 word as opposed to excitation than there is to say that 

 work is inhibited by the sound of the dinner-bell. What 

 really happens in such a case is the conditioned reflex- 

 closing of some synapses of the brain, and the easy opening 

 of others leading to the reflex instinctive satisfactions of 

 food. 



The answer to these questions seems to depend upon 

 the processes which take place in one muscle when its anta- 

 gonist is stimulated. There are probably few more difficult 

 subjects in physiology than that of contractile tissue ; but 

 to say that when a muscle goes out of action it is " in- 

 hibited," surely takes us no further, since it is only putting 

 into obscure words what we already know. It was the 

 belief that the action of the stimulated cardiac vagus was 

 excitatory of some really active process which led me to 

 inquire whether inhibition in the sense of weakening ever 

 occurred save in pathological cases, for, if it did not, it 

 seemed to follow inevitably that the relaxation of a muscle 

 was in some way a positive process in which there was some 

 substituted action, not a time of rest. For a muscle's time 

 of rest should be the refractory period. At first it seemed as 

 if the facts could be explained, if not by a process of 



