42 VETERINARY OBSTETRICS. 



enlargement becoming gradually more marked until 

 the period of parturition. About two weeks before 

 parturition, in both these animals, a mucous discharge 

 makes its appearance from the inferior commissure of 

 the vulva, and at the same time the lateral aspect of 

 the croup begins to fall, owing' to relaxation of 

 the pelvic ligaments. This condition is known as 

 "slipping," or "loosening." When all these conditions 

 are present, the animal has arrived at the termination 

 of the period of gestation, and the more immediate 

 symptoms of parturition commence. The animal 

 becomes restless, continually on the move from one 

 hind foot to the other, lying down occasionally ; and 

 the Mare, especially if she has a hot temper, behaves 

 much in the same way as shown in colic. The pulse, 

 if felt in this condition, is quick, frequent, and irritable, 

 and the mucous membrane of the eye may be injected. 

 The uterine contractions now commence, the animal at 

 this period apparently suffering an amount of pain. 

 Each contraction may be accompanied by a groan, and 

 last only for a few seconds. The interval between 

 the contractions may be, at the primary stage of 

 parturition, from five to ten minutes. The contractions 

 now become more powerful and of longer duration, 

 the interval between being shorter. The "os uteri" 

 ^becomes dilated, the uterine contractions having forced 

 ihe foetal membranes through that opening. Shortly 

 afterwards, the amniotic sac appears at the margin of 

 the vulva, containing the " liquor amnii." This sac is 

 sometimes called the "water bag," sometimes the "sac 

 containing the fluids." The sac may rupture in the 



