The Fetal Membranes 67 



to the allantois detains the former within the chorion, leav- 

 ing it an essential part of the afterbirth which may only 

 escape with the chorion. The ruminant is, therefore, born 

 naked. 



Fig. 35— Necrotic Tips of Fetal Sac, Cow. 

 /, /, /, Living allantois ; 2, 2, 2, necrotic tips ; 3, chorionic placenta. 



The fetal placental structures, originating as outgrowths 

 from the allantois-chorion, consist fundamentally of branch- 

 ing, arborescent capillary tufts continuous with the great 

 vascular network of the allantois. Regardless of placental 



