CIRCULATORY ORGANS. 301 
Fic. 307.—Development of posterior veins of rabbit, after Hochstetter. Cand D repre- 
sent only the hinder part of the whole shown in A toC. In B the veins for the postcaval- 
subcardinal system have tapped the postcardinal veins, which in C have lost their connec- 
tion with the anterior part and empty now through the postcava exclusively. In E the 
left posterior postcardinal is entirely lost. 7, ischiadic vein; ie, external iliac; z, jugular; 
mt, metanephros (kidney); , postcava; pc, postcardinal; s, subclavian; sc, subcardinal: 
sr, suprarenal; u, ureter. 
NE 
4 
Fic. 308.—Development of the anterior veins of a mammal. 4A, earlier stage, to be 
compared with fig. 307 C; B, definitive condition of adult. wu, azygos; ¢c, coronary; e, 7, 
external and internal jugular; ha, hemiazygos; 7, iliac; im, innominate; p, postcava; pc, 
postcardinal; pre, precava (superior vena cava); sé, superior intercostal veins. 
