CYSTIC CALCULI. 627 



The hand of the operator, being well oiled, is to be introduced 

 into the vagina, on the floor of which, at a distance of four 

 inches from the external opening, the meatus urinarius may 

 easily be felt. The operator, after carefully lifting up the fold 

 of mucous membrane, which here acts as a valve, is to introduce 

 the fore-finger into the urethra; retaining the finger in the 

 urethra, he must pass the smaller spoon-bill forceps with the 

 other hand. It is necessary that the passage of the forceps bo 

 guided by the finger which is already in the urethra, as it is almost 

 an impossibility to pass it beyond the valvular fold without this. 

 When the forceps is fairly in the urethra, its entrance into the 

 bladder is to be effected slowly, its blades being at the same time 

 slightly opened and closed, for the purpose of dilating the passage. 



The forceps having reached its destination, the operator is to 

 introduce his right hand along the vaginal canal, or if he cannot 

 get it sufficiently forward, into the rectum, and guide the stone 

 into the blades. 



Firm hold of the stone having been thus obtained, the forceps 

 is to be withdrawn with a gentle rotatory movement ; but 

 should its blades be too small to grasp the calculus, a larger 

 pair must be introduced, or it may be necessary to crush the 

 stone before its removal can be effected. The urethra of the 

 mare is much larger than that of the horse, and, by patience and 

 care, it can be dilated sufficiently to allow the passage of a very 

 large calculus. 



LITHOTOMY IN THE HORSE OR GELDING. 



Cast the animal upon the off side ; and when anaesthesia 

 is fully induced by chloroform, an assistant is to draw out 

 the penis and introduce the male catheter. The operator, 

 having placed his right hand in the rectum, is to direct the 

 catheter into the bladder, as it is apt to enter the ejaculatory 

 ducts, and mislead him during the rest of the operation. The 

 liability of the catheter to enter one of the ejaculatory ducts 

 rather than the bladder is a matter that seems to have escaped 

 attention ; but it is liable to occur, especially in aged animals : 

 the operator must therefore feel that the instrument passes along 

 the median line into the bladder. 



The catheters made by the instrument makers answer the 



