DEVELOPMENT OF THE VEINS 



269 



Right vitelline vci 



Ventricle 



f^eft umbilical vein 

 Left vitelline vein 



FIG. 279. Reconstruction of the blood vessels of a 4.2 mm. human embryo in ventral view 



Ductus venosus 



Right horn of sinus venosus 



Caudal anastomosis of vitelline veins 



Right vitelline vein 



Left horn of sinus venosus^ ; 

 Left vitelline vein 



Cranial anastomosis of vitelline 

 veins 



Middle anastomosis of vitelline 

 veins 



Right umbilical vein -W *m I " e umbilical vcin 



<ns B^ 



Left vitelline vein 



FIG. 280. Reconstruction of the veins of the liver in a 4.9 mm. human embryo (after Ingalls). 



