THE PREPUCE 



583 



the penis when not erect. It consists of two parts, external and internal. The 

 external part or sheath extends from the scrotum to within two or three inches of 

 the umbilicus, where the external layer is reflected ventrally and laterally, forming 

 the thick margin of the preputial orifice (Ostium praeputiale) ; dorsally it is directly 

 continuous with the integument of the abdominal wall. It is marked by a median 

 raphe prseputii, a continuation of the scrotal raphfe. At the lower margin of the pre- 

 putial orifice there are often in the stallion two papillae, which are regarded as 

 rudimentary teats. The internal layer passes backward from the preputial orifice 

 a distance of about six to eight inches (ca. 15 to 20 cm.), lining the cavity of the ex- 

 ternal part of the prepuce, and is then reflected forward until it approaches the 

 orifice, where it is again reflected backward. It thus forms within the cavity of the 

 sheath a secondary tubular invagination, the prepuce proper, in which the anterior 

 part of the penis lies. This tubular cavity is closed behind by the reflection of the 

 internal layer on to the penis to form the penile layer of the prepuce. Its orifice is 



■^hdorrtihal Uja.ll 



Fig. 520. — Sagittal Section of Prepuce and Part op Penis op Horse. 



P, Internal part of prepuce or prepuce proper; P' , external part of prepuce or sheath; C.p., preputial cavity; F.g., 



fossa glandis; D, diverticulum of fossa glandis; P.u., processus urethrse. 



surrounded by a thick margin, the preputial ring (Annulus praputialis), which is 



connected ventrally with the external part by the preputial frenum (Frenulum 



prseputii). 



The arrangement differs from that found in man in the fact that the inner part of the pre- 

 puce as described above is equivalent to the entu-e human prepuce. This part, the prepuce 

 proper is well seen on sagittal sections, and can be demonstrated by puUmg the penis, enclosed 

 in this' prepuce, out of the cavity of the sheath; the arrangement of the free part of the penis and 

 prepuce is then like that in man. (In paraphimosis the penis is strangulated by the preputial 

 ring.) The external part might be distinguished as the sheath or vagina penis. 



Structure. — The outer skin of the external part resembles that of the scrotum. 

 The internal layers of skin, as far as the preputial ring, are almost hairless, variable 

 in color, and often irregularly pigmented; they form irregular folds, and are supplied 

 with numerous large sebaceous glands and coil glands, which reach their greatest 

 size at the ring. Beyond this the glands are absent, and the skin resembles a non- 

 glandular mucous membrane. The secretion of the preputial glands (Glandulse 

 praeputiales), together with desquamated epithelial cells, forms the fatty smegma 

 prseputii, which has a strong, unpleasant odor, and often accumulates in considerable 



