ANIMAL P:LI:CTRICITV. LECTURE V. I I9 



in the direction of the break previously observed by 

 V. Fieischl. My reasoning had evidently been im- 

 perfect ; starting from the no doubt theoretically 

 correct assumption that any exciting current should 

 arouse an action-current of the nature of a polarisa- 

 tion counter-current, I sought to obtain evidence of 

 it upon nerve, and failed to do so, partly by reason 

 of the fact that the excited state in nerve does not 

 remain localised but spreads rapidly, partly by reason 

 of the then unknown after-anodic action-current, 

 which on the contrary appears to be a prolonged and 

 localised state. Direct evidence during the passage 

 of an exciting current of an opposite action current 

 did not and does not exist, yet from a theoretical 

 standpoint, it was and is a rather crucial point, and 

 I intend as soon as possible to try the point upon 

 more slowly reacting tissue. Meanwhile as regards 

 nerve, the nearest approach to direct evidence is 

 afforded by the '' polarisation increment " to be 

 considered next ; this in my view is the negative 

 variation of a latent action-current opposed to the 

 polarising current. Indirect evidence is also afforded 

 by the abterminal and atterminal or abmortal and 

 admortal effects of Encrelmann and of Hermann, as 

 will be developed in a future lecture. 



Let me now ask your attention to another curious 

 and puzzling fact, concerning which I have no 

 glimrnering of an explanation to offer. 



