478 



CHORD AT A. 



Fig. 329. — Diagrams of the Fci.tal Membranes of a 

 Mammal. 



A |r 



Epiblastic Disc. 



TTvnoljlastIc Disc. 



K])iblast. \ Extra- 

 llypoblast. /embryonic, 



Fluid in Yolk-sac. 

 A, The diploblastic embryo of a mammal in section. 



//// 



Be 



Amniotic 

 Folds. Epiblast of Embryo. 



2^ 



- p .-:_ < , Villi of Serosa. 



Fluid in Yolk-sac. 



B, A later stage with serosa villi and a developing amnion. 



