452 



Helen Williston Smith. 



Plexa6 Yes 



Fig. 5.— Embryo 15% mm. long. Enlarged 10 times. 

 A few vessels in the deptli are dotted. 



V.m, border vein; MR, membrana reuuieus ; V.te, thoraco epigastric vein; 

 Ves, superficial epigastric vein; V.u, umbilical vein. 



