THE UROGENITAL SYSTEM 91 



Dissect away the muscle and connective tissue surrounding 

 it, including the preputial glands and foreskin. The body 

 of the penis consists of three parts, the two corpora cav- 

 ernosa penis, and the corpus cavernosum urethrae. The 

 former comprise the dorsal part of the body when in its 

 normal position, the latter lies in a deep groove on the 

 ventral side of the corpora cavernosa penis. Carefully 

 separate the corpora cavernosa penis from the corpus 

 cavernosum urethrae. Cut the former transversely. Ob- 

 serve that they consist of two lateral spongy masses of 

 tissue, firmly united in the middle, but separated above 

 by a groove carrying a blood vessel, and below by the 

 groove inclosing the corpus cavernosum urethrae. Dis- 

 tally the corpora cavernosa penis terminate in one or two 

 bones. These bones extend to the tip of the glans dorsal 

 to the urethra when the glans is turned forward. The 

 corpora cavernosa penis diverge proximally, forming the 

 two crura penis. Each cms penis is a tough body firmly 

 attached to the posterior border of the innominate bone. 

 The corpus cavernosum urethrae terminates distally at 

 the tip of the glans penis. Proximally it expands into a 

 semilunar structure, probably homologous to the hulb of 

 human anatomy. The ducts of the bulborurethral glands 

 enter the urethra in front of the bulb. The urethra trav- 

 erses the whole length of the corpus cavernosum urethrae 

 and extrudes the urine or seminal fluid through the external 

 urethral orifice. 



Slit the urethra lengthwise from the external urethral 

 orifice to the region of the prostate gland. The incision 

 should be lateral in the vicinity of the bladder to avoid 

 cutting into the neck of the bkdder. Within the penis 

 the lumen of the urethra is of small calibre, but between 

 the penis and urinary bladder it expands and contains a 

 plug of secretion. Note the diverticulum leading off into 



