406 A MANUAL OF ANATOMY. 



layer of the superficial fascia. All these terms are applied 

 to the membranous lamina of the superficial fascia, which 

 covers over the structures forming, and contained within, 

 the perineal triangle. It is attached behind to the base of 

 the triangular ligament, curving backward over the trans- 

 verse perinei muscle to do so ; laterally, to the inner margin 

 of the rami of the ischium and pubes external to the 

 attachment of the superficial layer of the triangular liga- 

 ment. Forward, it passes over the .bulb of the penis into 

 the scrotum, where it receives a reinforcement of involun- 

 tary muscular fibres, and is called the dartos of the scrotum 

 (it is also continuous with the dartos of the penis or labium 

 majus). After leaving the scrotum (and penis or labium 

 majus) it passes upward to become continuous with the 

 deep layer of the superficial (Scarpa's) fascia of the abdo- 

 men over the spermatic cord (round ligament) at the exter- 

 nal abdominal ring. 



The perineal fascia, after surrounding the scrotum and 

 penis (as the dartos), becomes attached to the front of the 

 symphysis pubis as explained on page 438, forming the 

 suspensory ligament of the penis, or clitoris. 



The Anus. Figs. 82, 85. 



The anus is the opening of the bowel externally. The 

 lower part of the rectum and the anus is surrounded by 

 circular muscle fibres, the external sphincter, that wrinkles 

 the skin into radiating lines. For this muscle see below. 



The Inferior Pudendal Nerve, or Nerve of Scemmering. 



Fig. 82. 



This nerve is a branch from the small sciatic under the 

 gluteus maximus ; it winds forward around the tuberosity 

 of the ischium, perforates the deep layer of the superficial 

 fascia about an inch external to the tuberosity, passes for- 



