Superficial Veins in the Pig. 



451 



anterior limb bud out towards the region over the liver, and partly, 

 into two distinct, though very fine ropes of capillaries running up 

 under the anterior limb bud, the more dorsal of which is the 

 anlage of the thoraco epigastric vein (Vte). Over most of the 



Fig. 4.— Embryo 10 mm. long. 

 V.te, thoraco epigastric vein ; 

 vein. 



Enlarged 1.3 times. 



MR, membrana renniens; 



Vu, umbilical 



upper part of the membrana there are no blood vessels visible and 

 the superficial part of the umbilical vein, shown in Figs. 2 and 3, 

 appears to have atrophied. When compared with Fig. 5 it is evident 

 that the system draining into the umbilical vein is receding and 

 giving place to one draining longitudinally between the limb buds. 



