ACCESSOEY ORGANS OF THE MUSCLES. 417 



cases attenuated to a sharp point, frequently as fine as a fibre of the 

 white fibrous tissue. (Kblliker^) 



In the mylo-hyoideus muscle of the frog, Eeichert found 160 to 

 180 fibres, and the nervous trunks to contain " 7 to 10 fibres, ulti- 

 mately forming from 290 to 340 filaments by continual division, or 

 more than one for each muscular fibre." 



Fig. 270. 



Divisions of nerve-fibres in a small twig from the cutaneous thoracic muscle of the frog. . Bifur- 

 cation, b. Threefold division. Magnified 350 diameters. (KtilliJcer.) 



ACCESSORY ORGANS OF THE MUSCLES. 

 Under this head are included : 



1. The muscular envelops, or fasciae, 



2. Ligaments of the tendons. 



3. Tendinous sheaths and the synovial sacs (bursse mucosae). 



4. Fibro-cartilages and sesamoid bones. 



1. The Muscular Envelops (Fasciee), &c. 



The fasciae are fibrous membranes surrounding single muscles 

 (sartorius, &c.), or entire groups of muscles, with their tendons. 

 The deep fasciae of the extremities (femoral, brachial, and ante-bra- 

 chial aponeuroses, &c.), are illustrations. These also give insertions 

 to muscles, and thus become tendons (tensor vaginae femoris), or 

 27 



