Ventricl 



Liver 



R. vitelline vein 



y Aortic arches 7-4 



A It in m 

 Vitello-umbilical vein 



L. umbilical vein 



If' 

 Fig. 83. — Ventral reconstruction of a 3.2 mm. embryo, showing vessels (His). 



Fig. 84. — Lateral view of human embryo of 4.2 mm., showing aortic arches and venous trunks (His). 

 mx, Maxillary process; mn, mandibular arch; d.C, common cardinal vein; p., anterior cardinal vein; 

 ex., posterior cardinal vein; v.v., vitelline vein; u.a., umbilical artery; n.v , umbilical vein; all., allantois; 

 pi, placental attachment of body-stalk; «//., olfactory pit; ot, otocyst. 



