THE VASCULAR SYSTEM 233 



scapulae is received from the MM. dorsalis scapulae and dorsalis 

 humeralis, and at about the same point a large branch from the V. 

 brachialis medialis as well as the F. cutanea humeri -posterior from the 

 M. anconaeus and the skin covering it. The vessel, which may now 

 be called the V. circumflexa scapulae (v.circ.sc), passes lateral to the 

 ventral end of the scapula, between this bone and the muscles cover- 

 ing it, and dorsal to the head of the humerus. At the anterior border 

 of the scapula the V. brachialis lateralis joins the vessel, as well as 

 small factors from the MM. cucullaris and opercularis and also a 

 larger cutaneous vein, the V. cutanea dorsalis scapulae anterior (v. cut. 

 d.sc.a.) which latter drains the skin covering the M. dorsalis scapulae. 



The subclavian vein (v.scL), as it may now be called, continues 

 directly forwards along the dorso-lateral margin of the procoracoid, 

 and, near the anterior extremity thereof, receives the V. supracora- 

 coidea (v.sup.cor.). This factor drains the muscles of the same name, 

 and then penetrates the coracoid foramen and crosses the dorsal sur- 

 face of the procoracoid almost at right angles to its long axis. After 

 receiving the supracoracoid vein, the subclavian turns in mesially 

 and joins the internal and external jugulars and post-cardinal to form 

 the ductus Cuvieri. 



There is a small vessel joining the anterior aspect of the subclavian 

 vein just before it enters the ductus Cuvieri which Bethge calls the 

 V. cutanea parva (v.cut.pa.). It collects from the posterior margin of 

 the thymus gland, and from the overlying skin, and it also receives 

 some small twigs from the M. cucullaris. The hypoglossal nerve 

 passes between this vein and the V. subclavia, and thus forms a useful 

 landmark for identifying the vein. 



{c) Veins of the Fore-limb, These arise between the fingers as the 

 FF. interdigitales which flow into a venous arc stretching across the 

 dorsal surface of the hand at about the level of the centre of the meta- 

 carpals — the Arcus venosus dorsalis manus (Osawa). On the radial side 

 of the limb this arc flows into the F. superficialis radialis (Osawa), 

 and at about the same point a large palmar cutaneous vein enters. 

 The V. superficialis radialis continues along the fore-arm, just under 

 the skin, between the flexor and extensor muscles of the radial side. 

 It drains the muscles by several large twigs, and, at the elbow, it 

 receives a large R. communicans from the V. interossea. From this 

 point to the shoulder the vessel becomes the F. brachialis lateralis 

 (Osawa). It receives, just proximal to the elbow, one or two large 

 cutaneous factors, as well as several twigs from the adjoining muscles. 

 At the proximal end of the arm, quite close to the shoulder, there is 

 yet another deep plexus, lying on the flexor side of the humerus, 



