Charles F. W. McClure 379 
scapule (V. t. s.); (3) the V. cephalica (V.cep.), which arises on the 
radial side of the hand and forearm (this vein also opens into the axil- 
lary vein); (4) two veins which may open separately or by a common 
trunk into the dorsal portion (do.) of the venous ring, one of which (b.) 
returns blood from the superficial muscles on the ventral surface of 
the neck, while the other (c.), besides uniting with the internal max- 
illary vein, collects blood from the side of the larynx. 
In addition to the above mentioned tributaries, the external jugular 
veins anastomose with each other across the middle line of the neck. 
This anastomosis may be accomplished in one of two ways: Hither by 
means of two vessels which run between the dorsal and ventral por- 
tions of the venous rings of opposite sides and fuse in the middle line 
of the neck (V. an.), or by means of a single vessel which extends be- 
tween the ventral portions of the two venous rings as in Text Fig. IV 
CVie am.): 
The affluent veins of each external jugular are, as mentioned above, 
the V. submaxillaris (V. s. max.), the V. maxillaris externa (V. m. e.) 
and the V. maxillaris interna (V. m.i.). The submaxillary veins are 
Guite large and anastomose with each other on the dorsal surfaces of 
the geniohyoid muscles. Each submaxillary vein receives the follow- 
ing tributaries: Veins from the tongue and the floor of the mouth; 
the V. submentalis (V. s. ment.) and small veins from the submaxillary 
and sublingual glands (a.). 
The external maxillary vein collects blood from the face and the 
internal maxillary from the regions supplied by the internal maxillary 
artery. 
THE VEINS OF THE VERTEBRAL CANAL AND THE DEEP LYING VEINS OF 
THE CERVICAL AND THORACIC Recions.’ (Text Fig. II.) 
Text Fig. III is a diagram of the veins of the vertebral canal and the 
deep-lying system of veins of the cervical and thoracic (first five inter- 
costal spaces) regions. These two regions need a special description, 
since the relations which exist here among the veins are quite unusual. 
The Vv. columne vertebrales (Vv. c. ve.) consist of two large 
venous sinuses which lie ventral to the spinal cord and extend, on 
each side, within and along the entire length of the vertebral or spinal 
canal. In the region of the first thoracic vertebra they anastomose 
at one poirt dorsal to the spinal cord. 
9This deep-lying system of veins was largely studied by means of corrosions. 
