PHYSIOLOGY. 



37 



external surface of the chorion, and arranged in small 

 vascular tufts, which are received into depressions on 

 the corresponding aspect of the uterus, and here the 

 exchange of nutrition takes place. 



In the Sheep and Goat, cotyledons are present, but 

 are concave instead of convex on their free surface, as 

 in the Cow. 



Fig. 17. 



Maternal and Fcetal Cotyledons of the Cow. 



A, Pedicle of the Maternal Cotyledon; B, B, Maternal Cotyledon; ,C, Fcetal 



Cotyledon; D, Placental Villi; E, Chorion. 



In the Pig, there are no cotyledons present, and 

 the connection resembles that seen in the Mare, with 

 this exception, that the vascular tufts are very 



