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 cavernosa 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. Observe 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. Distally 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 crus 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 bulb of human anatomy. The ducts of the bulborurethral glands enter the urethra in front of the bulb. The urethra traverses 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
