VEINS OF THE WOLFFIAN BODY. 



247 



aorta toward and into the tail. (Veins and arteries in its path contribute 

 to its formation.) Duct of Cuvier is the name of the single vessel on each 

 side which conveys the blood from the cardinal veins to the right atrium; 

 the left duct of Cuvier crosses the dorsal surface of the heart in the atrio- 

 ventricular groove. The early arrangement of the cardinal veins is shown 

 in Fig. 278, A. A Wolman body has developed in the path of each pos- 

 terior cardinal vein, and has been a factor in causing the vein to form the 

 elongated loop shown in the figure. The dorso-lateral limb of the loop 



s-cl. 



FIG. 278. THE TRANSFORMATION OF THE POSTERIOR CARDINAL VEINS OF MAN, C REPRESENTING 

 THE ADULT. THE WOLLFIAN BODY is DOTTED. 



a. c., anterior cardinal; as. 1., ascending lumbar; az., azygos; c., caudal; c. c., cisterna chyli; c. h., com- 

 mon hepatic; c. il., common iliac; c. s., coronary sinus; d. C., duct of Cuvier; g., spermatic or ova- 

 rian; h., hepatic; h-az., hemiazygos; h-az.ac., accessory hemiazygos; i. j., internal jugular; 1. c. i., 

 left common iliac; 1. in., left innominate; m. s., median sacral; p. c., posterior cardinal; T., renal; 

 i. a., renal anastomosis; r. c. i., right common iliac; r. in., right innominate; s., suprarenal; s-c., 

 subcardinal; s-cl., subclavian; si., sinusoids; v. c. i., vena cava inferior; v. c., s., vena cava superior. 



.is the main stem of the posterior cardinal vein; it receives the inter segmented 

 veins (lumbar and intercostal). The ventro-medial limb of the loop is the 

 subcardinal vein found near the root of the mesentery, as seen in the cross 

 section, Fig. 276, C. Sinusoids extending among the Wolman tubules 

 connect the cardinal and subcardinal limbs with one another. (They 

 are shown only on the right of Fig. 278, A.) The sinusoids are less nu- 

 merous in mammals than in selachians and reptiles. 



The hepatic veins (Fig. 278, A) are ventral to the subcardinals, which 

 are at the root of the mesentery. When, however, the right lobe of the 



