SURGICAL OPERATIONS. 255 



adopted but in a case where the magnitude of the stone precludes 

 its extraction through the neck of the bladder. In all other cases, 

 lithotomy by the urethra is to be pursued. For _ts performance 

 are required a straight probe-pointed bistoury, a whalebone fluted 

 staff, and a pair of forceps, curved at the extremities. The ani- 

 mal should, if practicable, be maintained in the erect posture. 

 The tail plaited and carried round on the right quarter, the opera- 

 tor feels for the end of the staff introduced up the urethra, and 

 makes an incision directly upon it, from above downward, an inch 

 and a half or two inches in length. Next, he introduces the sound, 

 and passes it onward into the bladder. Now, placing the back of 

 the bistoury within the groove of the sound, by gliding the knife 

 forward, the pelvic portion of the urethra, and also the neck of the 

 bladder, becomes slit open — the latter in two places, in consequence 

 of a second cut being made in withdrawing the bistoury. The 

 opening made being, considered of sufficient dimensions, the oper- 

 ator introduces the forceps into the bladder, and seizes the calculus, 

 one hand being up the rectum, to aid him in so doing. The for- 

 ceps, clasping the stone, are now to be withdrawn, but with gen- 

 tleness, and with a vacillating sort of movement of the hand 

 from side to side, in order more easily to surmount any difficulties 

 in the passage, and the more effectually to avoid confusion or 

 laceration. M. Girard tells us ' that the cut through the pelvic 

 portion of the urethra ought always to be made obliquely to one 

 side. The operator should hold his bistoury in such a direction 

 that its cutting edge be turned toward the angle of the thigh. By 

 this procedure we shall gain easier access to the bladder, and not 

 only avoid wounding the rectum, but also the artery of the bulb, 

 as well as the bulb itself, and suspensory ligaments of the penis. 

 The parts cut through in the operation are, 1st, the fine thin 

 skin of the perineum, smooth externally, and marked with a 

 raphe ; densely cellular internally ; 2d, adhering to the tissue, the 

 fascial covering, derived from the fascia superficialis abdominis, 

 whhh has here become fibrous, it forms the common envelope to 

 the parts underneath, and is closely connected with the corpus 

 mnsculosum urethra? ; 3d, the corpus musculosum urethra?, that 

 penniform band of fleshy fibers which springs by two branches 

 from the ischiatic tuberosities embracing the sphincter ani, and 

 concealing the arteries of the bulb, whence they unite, and pro- 

 ceed to envelop the urethra ; 4th, the corpus spongiosum urethrse, 



