Iji 



NERVOUS TISSUE. 



single fibrils, forming closer reticulations, and constituting I lie intra- 

 muscular plexus, which is disposed amongst the muscular fasciculi and 

 fibre-cells. 



Klebs states that in a single instance only he was able to trace an 

 apparent connection of a nerve with a fibre-cell. According to Julius 

 Arnold, on the other hand, excessively fine straight fibrils come oft' 

 at right angles from the nerves between the cells, to be connected 

 with the nucleoli of the muscular fibre-cells, through the substance 

 of which they are said to pass. 



B. In voluntary muscle. — The nerves of voluntary muscles terminate 

 for the most part in special expansions, to which the term motorial 

 end-plates has been applied. 



As mentioned in the account of the muscular tissue, the nerves in 

 the voluntary muscle form plexuses, of which the branches grow finer 

 and the meshes closer as they advance further into the tissue. The 

 individual fibres, while still associated in small bundles, undergo divi- 

 sion, and at length single dark-bordered fibres pass off to the muscular 

 fibres. These nerve-fibres on approaching or reaching a muscular fibre 

 often divide still further. The branches retain their medullary sheath 

 until they reach the sarcolemma, when it abruptly terminates, while the 

 primitive sheath becomes continuous with the sarcolemma (fig. 105, s). 

 The axis-cylinder as it passes into the fibre forms a clear flattened 

 expansion "(/^, /;.) which lies immediately under the sarcolemma, and, 

 according to Kiihne, is always more or less cleft into lobes or branches. 



Around and beneath this expansion is a layer of granular matter, 

 with large, clear nuclei imbedded in it, each having one or more bright 



Fi?. 105. 







Fig. 105.- — Nerve-Ending in JIuscular Fibre of a Liz;ard. (Lacerta viridis.) 



a, end-plate seen edgeways ; b, from the siirface. s, s, Sarcolemma ; 2^> Pt expansion of 

 axis-cylinder. In b the expansion of the axis-cylinder appears as a clear network branching 

 from the divisions of the meduUated fibre. Highly magnified (from KUhne). 



nucleoli. The sarcolemma over the seat of the end-plate, and the plate 

 itself, arc slightly raised above the general surface, so that the whole 

 structure has been designated by Kiihne as the nerve-eminence (Nerven- 

 hiigel). It would appear that a muscular fi^bre, when short, has but one 



