THE MUSCULAR SYSTEM. 245 



lymphatics really exist in the larger muscles, they do not run among the 

 secondary fasciculi, but only in the more vascular jy'.rimyslum between 

 the larger and more lax subdivisions, and especially where the latter 

 contains adipose tissue, and is consequently soft, as, for instance, in the 

 glutceus, and in the superficial layers of the muscles. 



Lymphatic vessels have never yet been noticed in tendons, fasciae, 

 and the synovial capsules of the muscular system. At the same time, 

 it cannot be said, at all events in the latter instance, that lymphatics 

 may not, as in other serous membranes, be contained in the sub-serous 



connective tissue. 



• 



§ 84. Nerves of 3Iuscles. — The distribution of the muscular nerves, 

 ■with respect even to their coarser relations, presents considerable pecu- 

 liarity, it being evident, in most muscles, that the nerves come in con- 

 tact with their fibres only at a few limited points, and are by no means 

 connected with them throughout their entire length. With respect to 

 the ultimate termination of the nerves, it may be stated that in all 

 muscles there exist anastomoses of the smaller branches, forming the so- 

 termed "plexuses." These anastomoses among the larger branches 

 are seen chiefly, if not altogether, where the entire ramification of the 

 nerves takes place within an extremely limited compass [vid. note) ; 

 elsewhere they rarely occur, or are wholly absent. Those between the 

 smaller and smallest branches {terminal plexuses, Valentin), on the 

 other hand, are very numerous everywhere, forming elongated roundish 

 meshes, which run for the most part parallel with the longitudinal 

 direction of the fasciculi. These terminal plexuses, composed, some- 

 times of smaller, sometimes of larger, meshes, and formed principally 

 by the ramules of one small branch, though not altogether isolated one 

 from the other, proceed to form what are termed by Valentin the ter- 

 minal loops; by which I understand nothing more than anastomoses of 

 the ultimate twigs, effected by means of one or a few primitive fibres 

 passing from one twig into another. It is consequently unimportant 

 whether they follow a straight course, or are curved in a looplike form 

 (Fig. 102). Whether, besides these loops, there are also free termina- 

 tions of the nerve-fibres, such as are known to exist in the lower animals, 

 and as I believed I once noticed in a Rabbit, is altogether doubtful; 

 whilst it is certain that, even in man, divisions of the nerve-fibres take 

 place, although they are rare, and detected with difficulty, and their 

 relation to the loops, it must be confessed, is still to be made out. 



The trunks entering the muscles are composed principally of thick 

 nerve-fibres, about twelve of the finer ones occurring, on an average, 

 among 100 of the larger (Volkmann). They become smaller in the 

 interior of the muscle, so that the terminal plexus consists only of 

 extremely minute fibrils, measuring 000-1-0-0025 of a line in diameter. 



