316 THYSIOLOGY OF MUSCLES AND NERVES. 



far from being understood. But at any rate it is impossible 

 to conceive the matter, as though the currentless condition of 

 the muscles — that is to say, the same tension on the longi- 

 tudinal and transverse sections — were normal, and as if every 

 negativeness on the transverse section were the result of 

 injury. For all possible degrees of parelectronomy are to be 

 found- even the reversed order, in which the cross-section is 

 more positive than the longitudinal section — in uninjured 

 muscles ; while in other cases the ordinary muscle-current 

 is found powerfully developed in quite uninjured muscles. 

 Moreover, as we have stated in the text, the question whether 

 differences of electric tension occur in uninjured muscle has 

 no bearing on the question whether electromotive forces are 

 present within the muscle. We declare ourselves in favour 

 of this hypothesis, because it most simply and easily explains 

 all the phenomena. We also apply it to structures on 

 the outer surface of which it can be proved with certainty 

 that no differences of tension are present, as in the electric 

 plates of fishes. For this assumption we have the same 

 grounds on which physicists rely in claiming the existence of 

 molecular magnets in every, even quite unmagnetic piece of 

 iron. Whatever, therefore, may be the true explanation of 

 parelectronomy, it cannot essentially affect our well-founded 

 conception of the electric forces of muscles. If, however, 

 du Bois-Keymond's supposition is confirmed, that the pulsa- 

 tions which occur during life leave behind them an after- 

 effect on the muscle-ends, which makes the latter less nega- 

 tive, some approach wou\l be made to an explanation of the 

 phenomenon. 



15. DisciiAUGE Hypothesis and Isolated Teansmissiox 

 IN THE Nerve-Fibre (p. 249). 



The explanation of the fact that the processes of ex- 

 citement remain isolated in a nerve-fibre without passing 

 into adjacent nerve-fibres, ajipears the more inexplicable, if 



