82 BOVISE OBSTETRICS 



The foetal placentae lying close about the internal opening 

 of the cervix become already detached during the labor-pains 

 which dilate the cervix uteri, detachments also occur now and 

 then during the expulsive stage. Any placenta3 separated by 

 the uterine contractions follow, together with the remaining 

 fcetal envelopes, the direction of the cervical canal, and may 

 hang from the vulva. As a rule, shortly after birth of the calf 

 a thin cord hangs from the vulva, usually a piece of the 

 amnion, of 20 to 30 cm. length. The piece gradually becomes 

 longer, more and more foetal membranes appearing after each 

 pain. 



The detached chorion, also leaving the vulva, has a char- 

 acteristic surface, with flat, round or oval, ragged, reddish- 

 brown spot, 4 to 7 or 8 to 12 cm. in size. These are the fcetal 

 placentae. The pendulous piece increases in length and thick- 

 ness ; finally the whole mass drops when the union between 

 the last foetal and maternal placenta is severed. 



As soon as the after-birth has been expelled, a limited 

 amount of uterine milk, mixed with blood, mucus and fcetal 

 liquor, which had remained between the envelopes, is dis- 

 charged. 



Expulsion of the placenta of the cow takes place four to 

 six hours after parturition. It may happen that, expulsion 

 occurs earlier, or is retarded, or the foetal membranes are 

 retained in the uterus. Here they may cause various disturb- 

 ances, with which we shall acquaint ourselves later. 



The post-partum or after-pains concerned in the expulsion 

 of the placenta are not always of the same intensity. The 

 weaker they are the slower the cotyledon becomes ansemio 

 and the slower is the separation of the foetal from the maternal 

 placentas. When the uterus is greatly dilated, as in dropsy of 

 the foetal membranes (Hydramnios, Hydrallantois), twins or an 

 oversized foetus, the action of the uterine muscle is weak, and 

 detachment of the placenta may take a long time. In many 

 instances feeble after-pains are assisted by the auxiliary 

 abdominal muscles. When this occurs danger of an inversion 

 of the uterus is present. A limited amount of aid by the 



