XII.] 



VERTEBRAL VEINS. 



411 



inferior (Fig. 139, il). These vessels, whose development 

 has not been adequately investigated, form the common 



DIAGRAM OF THE CHIEF VENOUS TRUNKS OF MAN. 

 (From Gegenbaur.) 



cs. coronary sinus ; s. subclavian vein ; ji. internal jugular ; 

 Je. external jugular ; az. azygos vein ; ha. hemiazygos vein ; 



c. Jotted line shewing previous position of cardinal veins ; 



d. vena cava inferior ; r. renal veins ; il. iliac ; Ity. hypogas- 

 tric veins ; h. hepatic veins. 



The dotted lines shew the position of embryonic vessels 

 aborted in the adult. 



iliac veins, while the posterior ends of the cardinal veins 

 which join them become the hypogastric veins (Fig. 

 139 hy). 



Posterior vertebral veins, similar to those of Birds, 

 are established in connection with the intercostal and 



