1865.] Distribution of Nerves to Striped Muscle. 249 



delicate nerve-fibres, the nuclei or masses of germinal matter being very close 

 together, so that a considerable number are to be observed within a com- 

 paratively small space. Here a complex network of fibres, the meshes of 

 which are very small, is found. But this plexus or network is not terminal, 

 nor does it result from the branching of a single fibre, as has been repre- 

 sented. Many fibres enter into its formation ; and from various parts of it 

 long fine fibres pass off to be distributed upon the surface of the sarcolemma. 

 This is explained in these figures from the frog, from the white mouse, and 

 in this one from the maggot. 



It seems most probable that at the situation of these coils the contraction 

 of the muscular fibre would commence, and that, from the nerve-current tra- 

 versing several fibres collected over a comparatively small portion of muscle, 

 the contraction at these points would be most intense, while it is probable 

 that the contractions commencing at these points would extend, as it were, 

 from them along the fibre in opposite directions. 



I consider these nerve- tufts therefore simply as collections of nerve-fibres, 

 differing only from the ordinary arrangement before described, somewhat in 

 the same manner as the compressed nerve-network in a highly sensitive 

 papilla differs from the lax expanded nerve-network in the almost insensitive 

 connective tissue. 



Of the arrangement of the nerve-fibres in other forms of striped muscle, as 

 the branching fibres of the tongue, the muscular fibres of the heart, 

 and lymphatic hearts of the frog. 



To certain forms of striped muscle in which no distinct membranous 

 tube of sarcolemma can be demonstrated, nerves are freely distributed ; but 

 all attempts to demonstrate end-organs or terminal extremities in such tex- 

 tures have hitherto failed. In the heart the existence of delicate nerve- 

 fibres arranged to form networks is distinct ; and perhaps the most favour- 

 able locality for demonstrating these fibres is the auricle of the frog's 

 heart. Bundles of exceedingly fine nerve-fibres, much resembling those 

 in the bladder, can be seen running in different directions and branching 

 amongst the delicate networks of exceedingly fine muscular fibres. Very 

 fine fibres may be observed in thin specimens with the aid of high powers, 

 crossing the fine muscular fibres at different angles, then dipping down 

 in the intervals between them, and being soon lost in consequence of their 

 ramification in the deeper layers. 



In this drawing the relation of the nerve-fibre to the finest part of some 

 of the branching muscles of the tongue is represented ; and I have observed 

 an arrangement precisely similar in the case of the muscular walls of the 

 lymphatic hearts of the same animal. The very thin and narrow mus- 

 cular fibres of the heart and tongue would appear to offer very many ad- 

 vantages for the demonstration of ends and end-organs, supposing them to 

 exist ; but the most careful observation under the most favourable circum- 

 stances and with the aid of the highest powers, reveals only delicate nu- 



