44 VETERINARY OBSTETRICS. 



involuntary muscular contractions ; the longitudinal 

 fibres, in the primary stage of the act, and both 

 longitudinal and circular, in the later stages, contracting, 

 and thus the expulsion of the foetus is brought about. 



The umbilical cord is ruptured at the act of 

 parturition, or immediately afterwards. In a state of 

 nature, the parent tears the cord with her teeth, if it is 

 not ruptured in the act. The foetal membranes, or 

 envelopes, may come away with the foetus, or may be 

 retained in the uterus for several days, and require to 

 be removed by hand. 



Parturition in the Cow may be completed in from 

 half an hour to one and a half hours, but sometimes 

 may be prolonged for five or six hours, and both 

 mother and foetus do well. In the Mare, how- 

 ever, if the act is prolonged beyond two to two and 

 a half hours, there is danger of the foetus dying, 

 possibly also the parent. 



Parturition, as thus described, requires no assistance. 



Those cases in which mechanical or other inter- 

 ference is necessary, is called "difficult parturition," or 

 " difficult labor." 



