TRIANGULAR LIGAMENT OF THE URETHRA. 175 



stretched across the triangular space formed between these 

 bones. This ligament is vertical near the arch of the pubis, 

 and as far down as the bulb of the urethra, which is attached 

 to its front surface by cellular tissue. Below the bulb its 

 direction is obliquely backwards and downwards. This liga- 

 ment consists of two layers, an anterior and posterior, which 

 are nearly in contact below the arch of the pubis and separate 

 more widely at their inferior termination. Between the layers 

 are placed at the top the sub-pubic ligament, a considerable 

 part of the membranous portion of the urethra which pierces 

 both lamina at the orifices left for it about an inch below the 

 symphysis, Cowper's glands found a little below this orifice, 

 the compressor urethra muscle, described page 168, and the 

 pudic vessels which run up on the sides, and send in their 

 branches between the lamina to supply the bulb. There 

 are two openings through these layers above, by which the vena? 

 dorsales penis pass, upon the neck of the bladder so as to empty 

 the vesical plexus. 



Half an inch below the orifice of the urethra is found the 

 lower boundary of this middle perineal or triangular ligament. 

 At this level the anterior layer is united under the transverse 

 perineal muscles with the lower edge of the inferior perineal 

 fascia and the posterior layer is reflected backwards to the 

 rectum, the extremity of which intestine it aids the anal fascia 

 in supporting. The posterior sends back besides, a funnel- 

 shaped process along the membranous portion of the urethra, 

 which covers the prostate gland and is continuous with the 

 recto-vesical fascia lately described by Mr. Tyrrel. The use of 

 this remarkable aponeurosis, is to support the bulb and mem- 

 branous portions of the urethra, and form a strong septum of 

 defence to the outlet of the pelvis. The rigidity and tenseness 

 of this fascia around the urethra! passage, which has its fixed 

 curve at this point, constitutes an obstacle to the introduction of 

 the catheter, when its point deviates from the direction of the 

 canal. In the female the triangular ligament is perforated by 

 the passage of the vagina, as well as by the urethra. 



