THE MUSCULAR SYSTEM. 247 



be recognized as arteries and veins. I have not seen how they termi- 

 nate ; arid this much only I know that they are never met with on the 

 capillaries, and very frequently, also, are not to be found on the smallest 

 arteries and veins. Occasionally, one or more fibrils from the terminal 

 plexus of the muscular nerves may be seen to join these vessels ; a cir- 

 cumstance quite in accordance with the demonstrable fact that the vas- 

 cular nerves in many parts, for instance in the extremities, are derived 

 from the spinal nerves. 



The smaller tendons contain no nerves, and the larger, such as the 

 tendo Achillis and the tendon of the quadriceps femoris, only vascular 

 nerves. The fascice and sheaths of tendons are also without nerves, as 

 well as the synovial capsules of the muscular system, BO far as I am at 

 present aware. 



In many of the small muscles, the extent of space included in the 

 distribution of the nerve is extremely limited, as for instance in the 

 superior belly of the omohyoid, in a portion of which, three inches long, 

 the space over which the nerves are distributed, does not exceed from 

 five to eight lines in length. The trunk of the nerve entering in the 

 middle of the transverse axis, divides into two equal primary branches, 

 one passing towards the left, and the other towards the right, border of 

 the muscle, and each giving rise to numerous anastomosing branches of 

 all sizes, and thus supplying the entire thickness of the muscle from the 

 most superficial to the deepest layers. Whilst this distribution of the 

 nerve takes place at one point, a distribution not unlike that in an 

 organ of sense, the rest of the muscle presents the utmost poverty, or 

 even a complete deficiency, of nerves. In one case, which I examined 

 closely, I was unable, besides the few vascular nerves in these portions, 

 to detect more than three small nervous twigs of 0-021, 0-028, 0-042 of 

 a line, which, though derived from the main nerves, differed from the 

 other branches in their distribution. Two of them ran directly towards 

 the lower, and one towards the upper, end of the belly of the muscle, 

 giving off a few filaments composed of one or two primitive fibrils which 

 passed through the muscle, and terminated, a little before reaching the 

 intermediate and terminal tendons, in the most minute twigs and single 

 nerve-fibrils. I found the same conditions of the nerves in the sub- 

 cruralis, and in one of the costo-cervical muscles (arising from the first 

 rib in the cervical fascia), as in the omohyoid ; in the sternohyoid, 

 Bternothyroid, omohyoid (inferior belly), the same condition in some 

 parts was noticed, whilst, in others, one apparently different existed, 

 that is to say, the branches of the nerves frequently did not all divide 

 at the same level, but were more widely spread. It was easily seen, 

 however, that the above-described mode of division essentially obtained, 

 also, in this case, viz. : that the separate portions of the muscles are in 



