208 PHYSIOLOGY OF MUSCLES AND NKRVES. 



of muscle-currents. Due regard being l::ul 

 tn all these circumstances, the conclusion mav vet be 



drawn ihal entirely uninjured muscles situated in their 

 natural position are in themselves electrical! v aetive. 

 It is true that this has been repeatedly denied by many 

 observers. Our reason for reasserting it is that the ex- 

 planation of the phenomena on the assumption of the 

 absence of electromotive opposition in uninjured muscle 

 necessitates very forced and complicated assumptions, 

 while our view is able to explain all the known facts 

 very simply and in a thoroughly satisfactory manner. 



3. The electric action of muscles which, though ex- 

 tracted, are otherwise uninjured, is often verv weak, 

 and is sometimes even reversed; that is to say, the 

 natural cross-section is not negative, but positive, in 

 opposition to the longitudinal section. This condition 

 is found chiefly in the muscles of frogs which have 

 been exposed during life to severe cold. It is, however. 

 only necessary to remove, in any way, the natural cross- 

 section with its tendonous covering, in order to elicit 

 action of normal character and strength. In parallel- 

 fibred muscles it is often necessary to remove a short 

 piece, of from 1 to 2 mm. in length, from the end 

 of the muscle-fibres, before meeting with an artilieial 

 cross-section in which the aeti.ni is powerful. 



This phenomenon, which was called ]></,< // roiio/,, >/ 

 by K. du r.oi.-K'eymoud, l>ee;nise it differs from the 

 ii-ual electric action of muscles, gave rise to that e\- 

 planat ion of the electric phenomena, according to which 



t lie elect I ic opposit ion | let \\eell different portions of the 



muscle is not. present in the normal muscle, but . onlv 



intervenes OH the exposure of the mu-ele. The (litli- 



eully in. ntioned above, of showing the mu>c|e-currents 



