72 [May 1, 



a pale fibre running along the border of a muscular fibre sometimes 

 presents serpentine bendings, which appear alternately under and over 

 the muscular fibre, and in the latter case are clearly exterior to the 

 sarcolemma. Moreover I have observed that the pale fibres derived 

 from one dark fibre are sometimes distributed to two muscular fibres, 

 and must therefore run outside and between them, an appearance 

 not reconcileable with the descriptions of Kuhne, who states that 

 nerve-fibres retain their dark contours until they penetrate the 

 muscular fibre, and that the whole of the terminal pale filaments 

 derived from a nerve-fibre are contained within one muscular fibre. 



In further corroboration of what has been said I may add, that in 

 surface- views of the parts in question the pale nerves always appear 

 above the cross striae of the muscular fibre, also above its nuclei ; 

 which fact would, it is true, not decide whether the pale fibres were 

 outside or inside the sarcolemma, but is sufficient to prove that they 

 do not lie amidst the contractile substance. Further, this contractile 

 substance within the sarcolemma may, by means of dilute hydro- 

 chloric acid, be softened and reduced to a fluid state, and neverthe- 

 less the pale fibres retain their original position unaltered, even when 

 the liquefied contents of the sarcolemma with the muscular nuclei 

 flow backwards and forwards within the tube. Lastly, when muscular 

 fibres are treated with acetic acid of a certain strength, the whole 

 contents of the sarcolemma are squeezed out in the form of long 

 transversely striated cylinders ; so that on cutting across the fibres 

 of a muscle near the part where it receives a nerve, and treating it in 

 the way indicated, the proper substance of the fibres may be 

 examined apart from the sarcolemma, at the place where their nerves 

 reach them. Now, on repeatedly trying this experiment, I have 

 never found a trace of the nerve-fibres on the extruded portions, 

 whilst on the other hand they are still to be seen on the emptied 

 sarcolemma. 



It remains for me yet to say a word as to the mode in which the 

 pale nerve-fibres actually terminate, a point on which I confess I 

 have still some doubt. It is true that I have observed apparently 

 free ends as represented by Kuhne ; but, on the other hand, appear- 

 ances sometimes present themselves . which suggest the question, 

 whether on the muscular fibre, as in the physiologically allied electric 

 organ of the torpedo, there may not be an extremely fine network 



