484 CYCLOPEDIA OF LIVE STOCK AND COMPLETE STOCK DOCTOR. 



later, -when the membranes are forcibly dilating the neck, it is continuous, 

 the Momb and vagina becoming, by the dilatation, one continuous cavity. 



Expulsion of the Foetus. — The water-bag, having dilated the neck of 

 the womb, passes outward and appears at the vulva. The severe straining 

 soon ruptures it, allowing the feet of the fcetus to protrude. The head, 

 resting in most cases as described in the next section, aids in dilating the 

 I)arts. Nature usually allows a short rest after forcing the head through, 

 to prepare for the severest part, the passage of the shoulders, after which 

 all is easy. The umbilical cord is usually broken when the foal falls to 

 the ground, and it is freed from its coverings. 



Expulsion of the After-birth. — This usually takes place a few minutes 

 after birth, but occasionally not for a longer time. If not detached within 



^^^r^'^'^ 



KKCUMBKNT I'OSITION. 



The large water-bag has just appeared. 



a few hours it becomes a serious matter, as in removing it hemorrhage is 

 liable to occur. During and after the expulsion of the membranes, the 

 womb rapidly contracts and diminishes in size ; the neck of the womb also 

 grows smaller, and in a short time assumes normal proportions. 



In the cow the placenta (after-birth) may be retained for one, two or 

 three days without causing any trouble, owing to its formation being 

 different from that of the mare. 



II. The Different Presentations. 



The variety of positions in which the fcetus may be presented is sur- 

 prising, but there are four presentations to which, because of their being 

 by far the most frequent, we will call special attention, namely: (1) the 



