PHENOMENA OF MUSCLE AND NERVE. 291 



the frog 1 are provided 1 . If a current is led through the entire 

 length of the muscle, then clearly each fibre has an anodic and a 

 kathodic region where it is broken by the inscriptio. Supposing 

 one led-off region to lie in the lower half of a gracilis through 

 which an ascending current passes, and to be symmetrically placed 

 between inscriptio and the muscle end ; then it is by no means, 

 as might be thought, in the anodic region, but exactly mid- 

 way between an anode and a kathode. That, in spite of this, the 

 gracilis and semimembranosus show for the most part the before- 

 mentioned relations may be due, first, to the oblique direction of their 

 inscriptiones, a truly symmetrical position of leading-off contacts 

 between these and the lower ends of the muscles not being pos- 

 sible ; secondly, to the fact that the inscriptio does not completely 

 traverse the semimembranosus 2 ; and thirdly, to the close proximity 

 (as close as possible) of the led-off region to the lower end of the 

 muscle. 



In any case, as the inscriptio must tend to obscure any law, it was 

 advisable to pass on to other muscles, and I chose the sartorius. This 

 rewarded investigation by bringing out, without exception and in 

 the most forcible manner, the following simple law : 



In muscle the + phase either, as is generally the case, appears only 

 in the led-off portion near the anode ; or, if it comes into view in the 

 kathodic region (which is the case when strong currents are itsedj, is 

 incomparably weaker than in the anodic. 



The (first) phase, on the other hand, is stronger in the kathodic 

 region ; but this difference is much less marked, and can be ex- 

 plained by the fact that the strong development of the -f effect 

 must necessarily prevent the complete accomplishment of the de- 

 flection. 



Example. Two sartorius muscles, both attached to the symphysis 

 S. Current led in at the knee-ends A and B. Leading-off contacts 

 in the neighbourhood of the knee-ends at cc' and dd'. The follow- 

 ing schema gives the intervals : 



1 See Pfluger's 'Archiv,' vol. x. p. 49 ; vol. xv. p. 223. 



'See du Bois-Reymond, 'Archiv fur Anat. u. Physiol.' 1876, p. 351 (Gea. Abh. 

 & P- 573)- 



U 2 



