286 Anatomy Applied to Medicine and Surgery. 



vein and nerve of the penis. The triangular ligament 

 which forms the floor of this space is composed of two 

 planes, a superficial and a deep, united to each other, be- 

 hind, near the transversus perinei but separated, in front, 

 where they are attached to the subpubic ligament. Later- 

 ally, they are attached to the rami of the pubes and isch- 

 ium. The space between the two layers contains the 

 membranous part of the urethra and the compressor 

 urethrse muscle, Cowper's glands and ducts, the dorsal 

 nerves of the penis along with the internal pudic, the bul- 

 bar and the cavernosal arteries and veins. On removal of 

 the deep layer of this triangular ligament, the prostate 

 gland is exposed, with its apex touching this layer of 

 the ligament and its base situated posteriorly and connect- 

 ed with the muscular wall of the bladder. This gland is 

 surrounded by a fibrous capsule derived from the recto- 

 vesical portion of the pelvic fascia, and has in front of it 

 the pubo-prostatic ligament and the vesico-prostatic plex- 

 us of veins, while its posterior surface rests on the rectum, 

 but is separated from it by some unstriped muscular tis- 

 sue and connective tissue. 



The anal triangle. In this, there is situated, in the medi- 

 an line, the anus with the corrugator cutis ani muscle puck- 

 ering up the integument, and the external sphincter, which, 

 lying immediately beneath the skin and extending from 

 the tip of the coccyx behind, to the central tendon of the 

 perineum, tightly closes the anus. On either side of the 

 anus, between it, internally, and the ischial tuberosities, 

 externally, are the superficial tissues forming the base of 

 the ischio-rectal fossa. This fossa is a cuneiform, or wedge- 

 shaped space, with the edge of the wedge directed up- 

 wards and received into .the angle formed by the separa- 

 tion of the anal fascia from the obturator fascia. Each 

 fossa is bounded in front by the base of the triangular 



