404 A MANUAL OF ANATOMY. 



the ischium and pubes external to the line of the deep 

 fascia. Behind, it is continuous with the deep layer ; in 

 front, it extends to the subpubic ligament and is pierced 

 here for the dorsal vein, arteries, and nerves of the penis. 



It is separated from the deep layer by the compressor 

 urethrae muscle, imbedded in which are the dorsal nerve 

 and vein of the penis, the internal pudic artery and its 

 branches to the bulb, the crus, and the dorsal artery of the 

 penis, as well as the Cowper's glands and the membra- 

 nous urethra. It is pierced by the membranous urethra, the 

 ducts of Cowper's glands, the artery of the bulb, the dorsal 

 artery, vein, and nerve of the penis. 



DISSECTION. 



Fill the rectum with oakum and take two or three stitches in the anus. 



Incisions. (i) In the median line from the perineoscrotal junction (base 

 of the scrotum) to the tip of the coccyx, cutting close to the anus upon either 

 side. 



(2) Make an incision at the anterior and posterior end of No. I, about 

 three inches transversely outward toward the right and left. Do not cut across 

 the base of these flaps, nor make any other transverse incisions. 



Reflect the integument in the form of two large flaps. In doing so be care- 

 ful not to cut away the external sphincter of the anus, which lies close to the 

 skin. Notice that while the skin is thick in the other parts of the perineum, 

 about the anus it is very thin, and puckered into radiating lines by the contrac- 

 tion of the external sphincter. 



The Superficial Fascia. Diag. 28. 

 This consists of two layers : 



(a) A subcutaneous layer which varies in thickness ac- 

 cording to the amount of adipose tissue present. When 

 this is carefully scraped away a well-marked but thin layer 

 of fascia is seen covering the deeper parts. This is the 

 second layer of the superficial fascia, and is called the peri- 

 neal fascia, or fascia of Colles. 



(b) The perineal fascia, fascia of Colles, the deep 



