146 BIOLOGY OF THE LABORATORY MOUSE 



sisting of fibrous tissue, containing elastic fibers and a few smooth muscle 

 fibers. The cavernous spaces are lined by endothelium. The urethral 

 lumen, which occupies the center of the body, is lined by stratified columnar 

 epithelium, which near the external orifice changes into stratified squamous. 

 The fibrous lamina propria becomes continuous with the surrounding cavern- 

 ous tissue. Glands are absent in the penial urethra. The proximal part of 

 each corpus cavernosum penis is surrounded by its own tunica albuginea. 

 Toward the distal part this becomes a narrow septum which finally dis- 

 appears, and the cavernous spaces intercommunicate. The cavernous spaces 

 are smaller near the periphery and larger toward the center. A small bone, 

 the OS penis, is found within the fibrous septum of the two corpora cavernosa 

 penis and projects somewhat beyond the orifice of the penis. 



The terminal end of the penis, the glans, lies within a protective chamber, 

 the prepuce (or foreskin). The stratified squamous epithelium covering the 

 glans forms low filiform papillae which make the surface slightly rough. 

 Hair follicles are not present. The dense subcutaneous tissue contains 

 some smooth muscle fibers. The mucous membrane which lines the pre- 

 putial sack is a continuation of the covering of the glans (Fig. 63). 



Preputial glands. — The large, flat, leaf-shaped preputial glands are 

 homologous with the clitoral glands of the female (Fig. 63). They are large 

 sebaceous glands surrounded by connective tissue capsule and consisting of 

 rounded areas made up of large, flat, polyhedral epithelial cells with pale 

 staining nuclei. The nuclei gradually disappear, and the cells degenerate 

 forming a fatty secretion. Each gland has a long duct lined by stratified 

 squamous epithelium which opens on the side of the tip of the prepuce. 

 Near the orifice the epithelial cells of the duct and the subcutaneous tissue 

 around it usually contain some pigment in non-albino animals. 



Female Genital System 



Figure 75 shows the dissected female genital organs which include the 

 ovaries, the oviducts, the uterine horns, the corpus uteri, the cervix and 

 the vagina. The following description of the attachment of the female 

 genital system is based on the observations of Drahn (29) (Fig. 76). The 

 ligamentum suspensorium ovarii which originates at the ovarian hilus 

 extends anteriorly to the lateral surface of the kidney and attaches to the 

 dorsal abdominal wall. This ligament contains some smooth muscles from 

 which fibers project for a short distance into the ovarian capsule, increasing 

 its elasticity and serving as constrictor muscles. The ligamentum ovarii 

 proprium connects the hilus of the ovary to the cephalic end of the uterine 



