212 SURGICAL ANATOMY OF 



at one particular spot, its neck, and for the reason that 

 if opened at any other, urinary infiltration into the areo- 

 lar tissue of the pelvis will take place. The incisions 

 then must be made in the most direct way, to allow of 

 (1), the position of the staff, which has been introduced 

 into the bladder, being felt ; (2), the neck of the bladder 

 being opened, and room obtained for the extraction of 

 the stone. 



The perineum having been shaved, the skin and in- 

 teguments are to be steadied and rendered tense with the 

 fingers of the left hand, and the point of the knife is to 

 be entered about an inch and three-quarters in front of 

 the anus, a little to the left of the middle line, and car- 

 ried through the skin, in a direction downwards and 

 outwards, midway between the anus and the tuberosity 

 of the ischium. The left forefinger is next to be pushed 

 into this external wound, with the double purpose of 

 feeling for the position of the groove of the staif in the 

 urethra, and for the purpose of pushing the rectum in- 

 wards and backwards out of the way. When the groove 

 is recognized, the knife, lying flat under the introduced 

 finger, is pushed into the urethra just in front of the 

 prostate, and when the point is felt to be in the groove, 

 it is made to slide along it towards the bladder, dividing 

 in its course, the membranous urethra and left lobe of 

 the prostate to the extent of an inch. The forefinger is 

 now to be pushed along the groove, through the edges 

 of the deep wound, and insinuated into the incision 

 through the prostate ; the staff is then withdrawn by the 

 assistant in charge of it, whilst the finger passes into the 

 cavity of the bladder. The forceps are next guided by 

 the under surface of the finger into the bladder. When 

 the stone is felt, the blades must be opened, the finger 



