VAGINAL OVARIOTOMY IN THE MARE. 105 



break through the peritoneum into the cavity. Great care 

 must be exercised to make the thrust quickly and vigorously 

 or the peritoneum will separate from the adjoining tissues 

 and a large cavity be formed between the peritoneal and 

 muscular walls of the vagina with a large area of yielding 

 membrane which it is difficult to penetrate. It is not very 

 safe in such cases to attempt continuing the incomplete in- 

 cision with the scalpel, as it is very yielding and pushes 

 against neighboring organs before it is penetrated and affords 

 no signal to the hand by cessation of resistance when it has 

 passed through. 



Incomplete penetration of the vaginal wall is liable to 

 occur if the scalpel is dull or the vagina incompletely " bal- 

 looned " and flaccid, or if the operator is unduly timid. It 

 is best prevented by avoiding the cause as related, and once 

 it has occurred it is generally best to again " balloon " the 

 organ and make a new incision either to the right or left of 

 the first. It may be overcome also by thrusting the index 

 finger through the peritoneum as described in the preceding 

 paragraph. 



The mistaking of a ball of feces for the ovary has oc- 

 curred to inexperienced operators and the fatal error of re- 

 moving the portion of the rectum surrounding the fecal pellet 

 committed. The blunder is uncalled for ; the fecal ball is 

 movable in the bowel, the intestine is far more massive than 

 the broad ligament, and the ovary is to be definitely identi- 

 fied by its being lodged in the broad ligament just beyond 

 the end of the oviduct, which is continuous with the uterus 

 and coruna. If, therefore, one traces the uterus forward to 

 the coruna, thence along these to the oviducts, and thence 

 along the border of the broad ligament to the ovary, as above 

 directed, the error will not occur. 



The incision may readily be made too low and pass 

 beneath the broad ligament. It is to be avoided by being 

 careful to keep close to the median line and above the os uteri. 



