NEW CONCEPTIONS IN SCIENCE 



it could, and meanwhile sent headquarters an ac- 

 count of the smash. 



But the remarkable thing is that the message 

 to headquarters does not go through on a direct 

 wire, but through a chain of them, apparently 

 linked together. You see now why the question 

 as to whether there is actual contact between one 

 nerve and another is so important. If there is no 

 actual contact, how does the nerve -wave travel 

 from one to another, as it surely does? And if 

 there is contact, how does an impulse ever stop, 

 as it surely seems to do? 



A great variety of answers have been given to 

 these and allied questions, according as different 

 experimenters have reached different results. Some 

 have thought to find on the branches of nerves, 

 killed in the moment of intense action, little bead- 

 like protrusions, which they have considered suf- 

 ficient to effect a momentary union between close- 

 lying nerves. Others, more recent still, have ob- 

 served, in the watery-like substance in which the 

 nerve material proper is embedded, thin filaments 

 reaching through from one nerve to another. 



And others deny all these results in toto. 



Some, theorizing on rather scant evidence, have 

 thought that the nerve in action may pulsate like 

 an amoeba, and throw out little arms, which are 

 quickly retracted, and that it is by means of this 



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