MUSCLES. 53 



As they enter the substance of a muscle, its nerves 

 are united in bundles, and pursue a course almost at 

 right angles to its fibres. Very soon they divide and 

 subdivide, gradually approaching the same direction 

 as the fibres of the muscle, and finally the smaller 

 branches run almost parallel with them (PL XI). In 

 their course, the nervous filaments separate sometimes 

 from each other without anastomosing; and, again, 

 they unite after separating, in such a manner as to 

 form loops, and even many series of loops, or a net- 

 work of anastomoses. 



As to the mode in which nervous filaments ter- 

 minate in muscle, the following is the result of our 

 examination of different muscles of the frog. At the 

 points where the little bundles of nerves separate, 

 the majority of their primitive fibres present a dis- 

 tinct contraction in diameter, a strangulation, to half 

 their previous size. From these contractions two 

 branches usually, sometimes three, take their origin ; 

 and these, after running a short distance, undergo a 

 similar contraction and branching. Finally, the ter- 

 minal fibres taper off quite rapidly, soon show but a 

 single outline, and at last seem to lose themselves on 

 the sarcolemma (PL XIV. fig. I). 



Can we infer from these facts a similar distribution 

 of the nerves of striated muscle in man ? From the 

 researches of Valentin,* confirmed in part by Kol- 

 liker, it would seem not. Both of these authorities 

 assert that they have seen nervous fibres terminating 



* G. Valentin, Professor of Anatomy and Physiology in the Uni- 

 versity of Berne, author of the treatise on " Nemologie 1 ' 1 in the Encyclo- 

 pedie Anatomique, Lehrbuch der Physiologic, etc., etc.-~(.E$.) 



