c 
AND ABDOMINAL VISCERA. 29 
formed by the corpus spongiosum, in the middle of 
which lies the urethra. The sides and upper surface 
are formed by the two corpora cavernosa, white tough 
bodies which are very vascular, and are attached to 
the ischial bones. At the distal end of the penis these 
bodies end in the long thick e¢ans fenzs, which forms 
the terminal portion of the corpus spongiosum. A 
cross-section through the penis will give a good view 
of the arrangement of the three corpora of which it is 
composed. 
11. The Os Penis. In the glans penis and for a 
short distance between the corpora cavernosa is found 
the large penis bone. It lies over the urethra, and is 
grooved on the under side. | 
12. The Prepuce. The end of the glans penis is 
covered by a movable fold of the integument, the 
_ prepuce. 
