PHENOMENA OF MUSCLE. 233 



we have already shown, at the lower end of the semimem- 

 branosus. 



The significance of the circumstance, that the greater portion of 

 muscle-fibres in the neighbourhood of the anode are crossed by 

 transversely or obliquely running lines of current, and hence that 

 every such fibre has anodic spots of somewhat greater density of 

 current on the side turned towards the stimulating electrodes, and 

 kathodic spots of somewhat less density on the other side, we shall 

 not discuss at length here, for in order to do so it would be 

 necessary to go minutely into the so-called transverse polarisation 

 of muscle. In any case, it is apparent from the above-described 

 distribution of anodic and kathodic spots, that from the stimu- 

 lating electrode which lies on the side of the muscle in the 

 neighbourhood of the tendon, to the point where the muscle no 

 longer sensibly increases or diminishes in thickness, anodic or 

 kathodic spots must prevail as the case may be, and hence the 

 whole tract must be regarded as anodic or kathodic. 



Now, when the stimulating electrodes are in the neighbourhood 

 of the tendons of the muscle, and the galvanometer electrodes lie 

 near them, the galvanometer electrodes are within the region of 

 the anodic and kathodic tract, and this is the case at the lower end 

 of the pair of muscles on account of the unsymmetrical structure 

 of the semimembranosus, even if the stimulating electrodes lie at 

 some distance from the tendinous end. 



Even if the muscles had no tendinous intersection, still there 

 would be a polarisation-current in the galvanometer-circuit after 

 every break of the stimulating current, because all the anodic and 

 kathodic spots lying in the anodic and kathodic tracts are the seat 

 of a change caused by the stimulating current, which change must 

 have an electromotive action. 



Du Bois-Reymond has not stated how far the galvanometer 

 electrodes were from the stimulating electrodes, and these, as 

 appears from the description, were very near the tendons of the 

 pair of muscles. It is very probable that both galvanometer elec- 

 trodes were within the limits of the anodic and kathodic tracts, 

 and this may be assumed in any case of the lower electrode, because, 

 as we have already stated, the semimembranosus receives new fibres 

 very high up. 



But even if the galvanometer electrodes were at such a distance 

 from the stimulating electrodes that they were completely with- 

 drawn from the limit of the anodic and kathodic tracts as above 



