THE VASCULAR SYSTEM 235 



non-existent, but a larger vessel, leaving the V. axillaris at about the 

 same point, passed anteriorly, ventral to the nerves, and entered the 

 subclavian vein anterior to the shoulder. Grodziriski (1930) states 

 that the vessels supplying the developing fore-limb in Amblystoma 

 form a network just proximal to the glenoid region, from which the 

 subclavian and other veins develop by the enlargementof some vessels 

 at the expense of others, so that the network ultimately disappears. 

 Assuming that the development of Salamandra follows similar lines, 

 it is easy to understand the rather considerable variations in the 

 connexions just described. 



The V. anastomotica hrachii (v.anas.br.) has already been mentioned 

 several times. It is a curious little vessel which arises in the plexus 

 just proximal to the elbow and passes up the flexor side of the arm 

 between the two main veins. It passes right across the ventral side 

 of the shoulder-joint and penetrates the M. coraco-brachialis brevis 

 to join the V. pectoralis (cf. p. 231). It drains the muscles alongside 

 which it passes, and communicates with the other two brachial veins 

 at the plexus just distal to the shoulder, as already described. 



It should be noted that the vessel which Bethge calls the 'Vena 

 cutanea magna' comprises those here described under V. lateralis, 

 V. axillaris, V. circumflexa scapulae, and V. subclavia. 



Veins of the Lungs. 



The pulmonary veins arise on the mesial aspect of the lungs and 

 pass transversely from the proximal ends of those organs across the 

 ventral wall of the oesophagus, where they fuse, near the middle 

 line, to form a single unpaired vessel which runs directly forwards 

 and enters the left auricle of the heart. The junction of the right 

 and left pulmonary veins occurs immediately dorsal to the apex of 

 the ventricle. 



A few small factors from the ventral oesophageal wall also enter 

 the pulmonary veins. As the pulmonary vein passes between the 

 oesophagus and the sinus venosus it becomes embedded in the tissues 

 of the dorsal wall of the latter. Its entry into the left auricle is not 

 valved (see also p. 188). 



Veins of the Portal Systems 



The Hepatic Portal System (PI. XXII). 



A. F. ahdominalis (v.abd.) (Hochstetter) (see also PI. XVI). An 

 abdominal vein is present as in the Frog, but instead of being formed 

 largely by the fusion of the two pelvic veins, as in that animal, it 



