PHYSIOLOGY. 39 
and the inner aspect of the chorion; finally these 
vessels enter into the vascular tufts found on the 
external aspect of the chorion. From these vascular 
tufts the numerous branches which meet to form the 
umbilical vein take their origin. These unite to form 
one vein, which passes along the cord and enters the 
Fa@TAL CIRCULATION: ADVANCED PERIOD. 
A, Placentulz; B’, B', Umbilical Veins, with their Common Trunk, B; 
D, Vena Porte, and its Anastomosis, C; E, Ductus Venosus, F, Pos- 
terior Vena Cava; G, Right Ventricle of Heart; H, Pulmonary Artery; 
J, J, Aorta; I, Ductus Arteriosus; K, Umbilical Arteries, with their 
Anastomosis at the extremity of the Umbilical Cord. 
abdomen of the fcetus at its umbilical opening. From 
this situation it passes forwards, discharging its 
contents into the foetal heart. 
