24 VETERINARY OBSTETRICS. 



fluid is secreted called the "liquor amnii," or "amniotic 

 fluid," in which the fcEtus floats in the later period of 

 pregnancy. This fluid assists in regulating the 

 temperature of the foetus, also, by diffusing shock, 

 prevents injury from external violence. It also assists 



Fig. 15. 

 Chorion of the Mare at Mid-term (inflated). 



A, Posterior portion occupying the Body of the Uterus; B, Left Cornu 

 plicated and sacculated; C, Right Cornu, longer than the left, and con- 

 taining a portion of the Foetus. 



in the act of parturition by dilating the passage, or 

 cavity, and when the sac is ruptured the fluid assists in 

 the lubrication of the vagina and vulva. 



The AUantois. 



This allantoid membrane is composed of two 

 contiguous layers : a superficial one, which is applied 

 to the inner aspect of the chorion ; and an internal or 

 deep layer, which is applied to the external aspect of 

 the amnion. These two layers come together at the 

 umbilical opening to form a constricted hollow passage 

 or tube. This constricted portion passes into the 



