70 



On Abortion in Cows. 



of a temporary urinary bladder for the foetus. There is a canal 

 called the urachus, 7, leading into it, which passes through the 

 nave] opening. 



Fig. 6. 



FCETUS AND ITS MEMBBiNES, AS CONTAINED IN THE UtERUS- 



1, 1, ], 1, Uterus cut open, and its inner surface and contents shown, 2, 2, 2, 2, Cotyledons, 

 or vascular points giving attachment to corresponding elevations on the Chorion. 3, 3, 3, 3, 

 Chorion cut open, and inner surface shown. 4, 4, 4, 4, Outer surface of Chorion, on which are 

 placed vascular eminences, 5, 5, 5, for connection with Cotyledons of the Uterus. 6, 6, 6, 6, 

 Arteries and Veins passing between Foetus and Membranes. 7, Urachus. 8, 8, Allantois. 

 9, Umbilical Cord, or Navel String, formed by blood-vessels and Urachus. 11, 11, 11, Amnion 

 Membrane, containing liquor amnii, through both of which Foetus is seen. 



The chorion, 3, 3, 3, 3, is outside of, and, as its derivation 

 implies, contains the amnion. It is somewhat rough and resisting, 

 and studded with numerous large, elevated, vascular patches or 

 tufts, 6, 6, 6, called cotyledons, which are attached to correspond- 

 ing points, 2, 2, 2, 2, on the uterus. The chorion is the chief 

 medium of mechanical and nutritive connection between the 

 foetus and interior of the maternal uterus. The chorion, amnion, 

 and allantois are attached to the navel opening of the foetus by 

 the umbilical cord or navel-string, which is formed partly by a 

 continuation of these membranes, and in part by blood-vessels. 

 During the later period of gestation the foetus progressively 

 manifests a resemblance to the future animal ; and when it has 

 attained the full development which its uterine connections are 

 fitted to supply, and requires a means of support in common with 



