Uterine muscle 

 Remains of yolk sac 



Fetal villi of, 

 chorion 



Maternal blood 



sinus 

 Decidua basatis 



Placenlal septum 



Marginal sinus 



Fused decidua vera and 

 capsularis 



Chorion 

 Amnion 



FIG. 249. Section of the uterus, showing the relation of an advanced fetus to the placenta and mem- 

 branes (Ahlfeld). 



