THE MALE PERINEUM. 211 



and is applied to the neck of the bladder ; and its sides 

 are in relation with the levator ani and with the pelvic 

 fascia. The prostate is invested by a fibrous capsule, 

 derived from the pelvic fascia. The density of this cap- 

 sule accounts for the intense pain of prostatic abscesses, 

 and forces the pus to find its way, unless relieved, into 

 the urethra. In opening these abscesses in the perineum, 

 there is a possibility of urinary fistula, and in the event 

 of their bursting in the perineum, such fistulse are cer- 

 tain to form. 



The position of the prostate gland is readily determined 

 by passing the finger into the rectum, and if healthy is 

 generally felt about as far up as the second joint of the 

 forefinger reaches, whilst in some forms of enlargement, 

 the upper border of the gland will be far out of reach of 

 the entire finger. 



The relations of the bladder and the rectum, within the 

 reach of the finger, are of great importance; thus, in 

 cases of retention of the urine, when it is necessary to 

 perform the operation of puncture per rectum, the dis- 

 tended bladder is felt overlapping the posterior margin 

 of the prostate at a point where, if the puncture be made 

 in the mesial line, no injury to surrounding parts could 

 take place, as the instrument would pass between the 

 vesiculse seminales, and perforate a space (trigone vesicce) 

 where these structures are neither covered by pelvic 

 fascia nor by peritoneum. The digital examination of 

 the bladder per rectum assists the surgeon in the detec- 

 tion or dislodgment of vesical calculi, in guiding the 

 point of a catheter or sound in cases of difficulty, and in 

 the detection of prostatic abscesses, or growths. 



Parts concerned in Lateral Lithotomy in the Adult. 

 The object to be attained, is that of opening the bladder 



