KATHODIC POLARISATION OF MUSCLE. 359 



That is to say, if the negative preliminary jerk is to be regarded as 

 essentially an immediate after-effect of the closing excitation, then 

 like this, it must be altogether or partially suppressed by killing at 

 the kathodic end, as is in fact always the case. On the other hand, 

 it was shown earlier, that also during the existence of a persistent 

 excitation of the kathodic parts of the fibre of a muscle treated 

 locally with veratrine, a battery current of corresponding direction 

 produces only a feeble closing excitation or none at all. 



If we take into account the very striking agreement which exists 

 in regard to the conditions of commencement and mode of mani- 

 festation of positive kathodic polarisation in veratrine muscle on the 

 one hand, and on the other, after the death of the kathodic ends of 

 fibre in normal striated muscle, it certainly seems a very natural 

 idea to refer the phenomenon to the same cause in both cases. 

 Hence, here as there, we should have to deal with inhibition of 

 an existing state of excitation, and with the consequent relative 

 positivity of the points of exit of the current as compared with 

 other points in the muscle, this inhibition being produced at the 

 physiological kathode on opening the exciting current. 



However little reason there may be to doubt the correctness of 

 this conception as regards locally veratrinised muscle, the generalisa- 

 tion thus indicated requires a more complete justification. 



It cannot be denied, that after killing at one end the terminations 

 of the fibre of a normal regularly constructed muscle, the nearest 

 excitable transverse sections of it are in a condition of more or less 

 strong persistent excitation, and this betrays itself moreover often 

 macroscopically by local contraction, but in all cases, it is easily 

 recognised by means of the microscope. 



But under this hypothesis, the occurrence of positive kathodic 

 after-currents, when a muscle injured at one end is traversed 

 by an atterminal current, is no longer surprising ; for under the 

 hypothesis of an opening kathodic inhibition, this is an immediate 

 and necessary result which ought to follow the procedure to which 

 it has been subjected. Such a preparation does not behave differently 

 in any essential point immediately after a momentary excitation, 

 from a muscle which has been treated locally with veratrine ; and 

 everything which has been previously communicated as to the 

 behaviour of secondary electromotive phenomena in such a muscle 

 can be applied directly to the case now before us. 



In connection with the preceding discussion it is worth noticing 

 that the way in which the end of the muscle is killed is not quite 



