1903.] Phenomena in Mammalian Non-medullated Nerve. 



169 



•0005 

 volt. 



Fig. 2 (Exp. 717, V.).— Median of same animal as Fig. 1. All details as before. 



the horse commonly retain their excitability for 8 — 10 hours post- 

 mortem, the medullated for about half this time. 



I have been unable so far to trace any quantitative relation between 

 the current of injury and the negative variation as determined above. 



Obtaining a non-medullated nerve, subjecting it to a series of 

 repeated tetanisations, and recording the successive negative variations 

 by the galvanographic method, it appears at once that the results are 

 very different from the corresponding phenomena in medullated nerve. 

 Figs. 1 and 2 are records from two nerves, the one splenic and the 

 other median, from the same animal under identical conditions. The 

 successive negative variations from the latter are approximately equal, 

 those from the former fall off very rapidly, and this rapid decrease in 

 the negative variation is characteristic of mammalian non-medullated 

 nerve. The following experiments were made : — 



