LATER DEVELOPMENT OF VASCULAR SYSTEM By At 
¢. Usc.d 
Nai V3.5. 
Fia. 213.— Reconstruction of the venous system of 
a chick of 5 days. Ventral view. (After Miller.) 
a., Mesonephric veins. <Ao., Aorta. A. se. s., Left 
sciatic vein. Other abbreviations as before. 
the right and left posteardinal veins passes through the vas- 
cular network of the mesonephros, and empties into the sub- 
cardinal veins, from which it flows into the vena cava inferior, 
and so through the meatus venosus to the heart. Prior to the 
sixth day, however, the greater portion of the blood in the pos- 
Fic. 212. — Reconstruction of the venous system of a chick of 90 hours, 
ventral view. (After Miller.) 
A. o. m., Omphalomesenterie artery. a. sc. s., Left sciatic artery. A. 
u. s., Left umbilical artery. b., Vessels enclosed within ventral side of meso- 
nephros. V.c. p. d., s., Right and left posterior cardinal veins. YV. c¢. 1., 
Vena cava inferior. V. sc. d., s., Right and left subeardinal veins. 
