MALE PERINEUM 149 



of the penis. It is of special interest because it marks the 

 line along which the inferior wall of the urethra was com- 

 pleted and the two halves of the scrotum fused together. It 

 corresponds in position with the urogenital cleft of the 

 female. 



Subdivision of the Space. It is customary to subdivide 

 the diamond- shaped perineal space into two portions by 

 drawing an imaginary transverse line between the anterior 

 parts of the ischial tuberosities, immediately in front of the 

 anus. Two triangles are thus mapped out. The anterior of 

 the two may be appropriately called the urogenital triangle^ 

 because the most important objects which it contains are the 

 urethra and the root of the penis ; the posterior is dis- 

 tinguished as the anal triangle, because it contains the anal 

 canal. 



Preparation of the Perineum for Dissection. After the 

 boundaries of the perineum have been defined, and before 

 the dissection is commenced, a staff must be passed along the 

 urethra into the bladder, the anal canal must be slightly 

 distended and the anal orifice stitched up. 



Having obtained a staff, oil it or smear it with vaseline, 

 and hold it in the right hand, stand on the left side of the 

 body and seize the penis with the left hand. Hold the staff 

 at right angles to the long axis of the body, introduce its 

 point into the orifice of the urethra and pass it along the 

 urethra, keeping it in contact with the floor of the canal and 

 guiding it with the fingers of the left hand until it arrives at 

 a point about midway between the root of the scrotum and 

 the anus the central point of the perineum. When the point 

 of the staff has reached the central point of the perineum 

 it has passed through the .third or penile portion of the 

 urethra. It has now to be passed through the second or 

 membranous part and the first or prostatic part. In order to 

 make it traverse those parts successfully the following steps 

 must be taken: (i) Rotate the staff through quarter of a 

 circle, carrying the handle across the lower part of the 

 abdomen until it lies in the median plane of the body. (2) 

 Steady the point of the staff with a finger of the left hand 

 and with the right hand carry the handle of the staff down- 

 wards towards the perineum. If the manoeuvre is successful 

 the point of the staff will rise slightly and will pass through 

 the membranous and prostatic parts of the urethra into the 

 n106 



