90 ANATOMY OF THE RAT 



Divide the pelvic ^rdle along the symphysis pubis, re- 

 move the ventral part of this girdle, clear away the adja- 

 cent muscles, and expose the urethra. This runs back 

 through the girdle ventral to the rectum. The urethra 

 joins the penis at the posterior end of the pelvic girdle. 

 At this place the two hulho-urethral (Cowper's) glands 

 pour their secretion into the urethra through a pair of long 

 ducts. Each of these glands is ovoid in shape and about 

 ^\e millimeters long. It lies lateral to the rectum and 

 just behind the posterior border of the ischium. It has 

 been suggested that the secretion protects the spermatozoa 

 against the harmful effects of traces of urine. 



Dissect away on one side the tissues surrounding the 

 penis. Note that it has the form of a figure 7, with the 

 angle anteroventral. Carefully insert one blade of the 

 scissors into the genital orifice and slit the integument 

 lengthwise of the body. Press aside the flaps of skin and 

 note that the terminal section of the penis, the glans, lies 

 loose in a chamber surrounded by the prepuce or foreskin. 

 The surface of the glans is slightly rough. Its blunt free 

 end points backward. The two preputial glands, one on 

 either side of the glans penis, discharge their secretion near 

 the posterior edge of the prepuce. Dissect away the sur- 

 rounding tissue and locate the duct and its opening. Each 

 gland is dorsoventrally flattened, rounded anteriorly, and 

 tapers back to the edge of the foreskin. Insert a fine pair 

 of scissors into the orifice of the duct and slit it length- 

 wise. Note the relatively very large calibre of the duct 

 beyond the opening, and the soapy character of the con- 

 tained secretion. It has been claimed that this secretion 

 protects the integument in this region from being injured 

 by the excretions. 



The penis is the structure which is used to carry the 

 seminal fluid from the male to the vagina of the female. 



