Chap, xviii.] THE PERINEUM. 351 



back. In all cases the gut should be well emptied by 

 enema before the operation. (3) The pudic vessels 

 can hardly be wounded unless the incision is 

 very carelessly made, and the knife carried almost 

 against the bone as it is being withdrawn, (b) In the 

 second incision the knife may be passed beyond the 

 prostate, and may so incise the visceral layer of the 

 pelvic fascia as to open up the pelvic cavity. It wil 

 be understood that the lateral lobe of the prostate may 

 be cut freely without this cavity being endangered. 

 The gland is enveloped by the pelvic fascia, but the 

 incision made into the prostate is well below the su- 

 perior reflection of the membrane. The incision in the 

 neck of the bladder, therefore, must be strictly limited 

 to the prostate. The prostatic plexus of veins cannot 

 avoid being wounded. The left ejaculatory duct 

 would be cut if the prostatic incision be carried too far 

 backwards. 



In children the pelvis is relatively narrower than 

 in the adult, the bladder is more an abdominal than 

 a pelvic organ, and the neck of the bladder, therefore, 

 is high up. The viscus, moreover, is very movable, 

 and has less substantial attachments than has the 

 adult's bladder. It thus happens that in forcing the 

 linger into the bladder after the second incision, the 

 viscus has actually been torn away from the urethra. 

 In children the prostate is rudimentary, and thus more 

 of the actual neck of the bladder itself has to be cut. 

 From the small size of this gland, also, it happens that 

 in some cases the knife has passed too far beyond the 

 prostatic area, and has opened up the pelvic fascia. 



Median lithotomy. In this operation the 

 knife is entered in the middle line, just in front of the 

 anus. The staff has a central groove, and the point of 

 the knife should hit the instrument as near as possible 

 to the apex of the prostate. As the knife is withdrawn, 

 the whole of the membranous urethra is incised, and 



