CONDUCTIVITY 143 



might be expected the result was the same as in former investiga- 

 tions. They show however even more strikingly the abruptness 

 of the disappearance of conductivity simultaneously for the weak- 

 est and the strongest stimuli. The curve produced by the centrally 

 placed electrode remains at the same height for a considerable 

 period, then suddenly abruptly declines. Those of the electrodes 

 within the chamber likewise sink, at first slowly, then with in- 

 creasing rapidity in successive order corresponding to the dis- 

 tance which they are situated from the point of exit of the 

 nerve, so that the curve of the most distant electrode reaches the 

 abscissa first, that of the electrode nearest the muscle in the 

 chamber, last. The experiments demonstrate with complete 

 clearness that in contrast to all those points within the affected 

 stretch, where the conductivity, though already obliterated for 

 weaker stimuli, still exists for stronger, that with stimulation 

 of a point towards the center above the affected stretch, con- 

 duction ceases simultaneously for all different strengths of 

 stimuli. This last state at the points within the affected stretch 

 might be ascribed to the diminution of the excitability of this 

 stretch, and the idea entertained that the weak stimuli no longer 

 produce excitation capable of further conduction. 



This assumption is contradicted, however, by the fact that 

 subsequently to the disappearance of the response at a point sit- 

 uated at the greatest distance from the place of exit, an effect of 

 stimulation can be obtained at the Clearest point to the exit with 

 the same or even less strength of the current. As the irritability 

 in the affected stretch is reduced at all points in equal measure, 

 the fact of a weaker stimulus becoming inoperative whilst a 

 stronger remains effective can only be attributed to the circum- 

 stance that the wave of excitation set free at some point of the 

 influenced stretch by a weaker stimulus is sooner obliterated on 

 its way to the muscle than that produced at the same point by a 

 stronger stimulus. These experiments, in which the manifesta- 

 tions of the nerves in response to stimuli applied centrally above 

 the chamber in the normal stretch are compared to those in 

 response t<]^ a stimulus acting on *ke affected atreteli,. clearly 

 demonstrate the totally dift'erent effect in both cases. In stimula- 



