244 SPECIAL HISTOLOGY. 



each separate primitive fasciculus is lodged, to a certain extent, in a 

 plexus of capillaries, and being surrounded on all sides by them, is 

 very abundantly supplied with blood. The capillaries of muscle are 

 among the most minute in the human body, their diameter being often 

 less than that of the blood-corpuscles themselves. In one of Hyrtl's 

 preparations, they measure 0-0025-0-003 of a line; in the pectoralis 

 major, when filled with blood, 0-002-0-003, and when empty 0-0016- 

 0-0020 of aline. 



The tendons may be reckoned amongst those parts of the body which 

 are the most scantily supplied with blood-vessels. The smaller tendons, 

 in the interior, present no trace of vessels, whilst externally, in the more 

 lax connective tissue by which they are surrounded, there exists a wide- 

 meshed capillary plexus. In the larger tendons, a few vessels occur in 

 the superficial layers, and in the largest, by means of the microscope 

 and injection, a scanty vascular network may also be rendered evident 

 in the deeper layers ; but even in this case the innermost portions of the 

 tendon are entirely without vessels. The tendon-ligaments present the 

 same conditions as the tendons, only, that in them even still fewer ves- 

 sels can be perceived. The thinner fascias, also, are altogether non- 

 vascular ; sparing ramifications, exclusive of those in the lax connective 

 tissue, amply supplied with blood-vessels, which covers their surface, 

 are found in the thicker fasciae, such as the fascia lata. The synovial 

 membranes of the muscular system, on the other hand, are very vascular, 

 and especially their processes ;* with respect to these synovial mem- 

 branes, however, since they agree in all respects with the synovial capsules 

 of the osseous system, nothing further need be remarked in this place. 



B. The muscles are very scantily supplied with lymphatics ; the 

 smaller muscles, in fact, such as the omohyoid, subcrural, &c., have none 

 at all, either in their substance or on the surface ; and among the largest 

 muscles, it is only in some, that solitary lymphatics, measuring J and J 

 of a line are seen accompanying the blood-vessels. The deep or mus- 

 cular blood-vessels in the extremities, it is true, are accompanied by 

 lymphatics, but these are few in number ; and from the latter two circum- 

 stances, it may be concluded, that even the larger muscles are but poorly 

 supplied with these vessels. If they had not actually been observed in 

 the fasciculi in certain cases, it might have been a question, whether 

 muscles in general did possess lymphatics at all ; the occurrence of 

 the deep lymphatic vessels proves nothing towards this, it being quite 

 possible that the contents of these vessels, scanty as they are, might be 

 derived from the skin (vola manus, planta pedis, &c.), from the joints, 

 or perhaps from the bones. It may also be concluded, that if a few 



* [The vessels generally form loops, which communicate with each other by means of 

 delicate branches, and which can readily be traced to the extremity of each process. DaC.] 



