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 przeputiale); dorsally it is directly 
continuous with the integument of the abdominal wall. It is marked by a median 
raphé preputii, a continuation of the scrotal raphe. At the lower margin of the pre- 
putial orifice there are often in the stallion two papillee, 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 
ean ey OC Ott (Hal eae) 
Fic. 520.—Sacirrat Section oF Prepucre AnD Part oF Penis oF 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.w., processus urethra. 
surrounded by a thick margin, the preputial ring (Annulus prieputialis), which is 
connected ventrally with the external part by the preputial frenum (Frenulum 
preeputii). 
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 entire human prepuce. This part, the prepuce 
proper, is well seen on sagittal sections, and can be demonstrated by pulling the penis, enclosed 
m 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 (Glandule 
preputiales), together with desquamated epithelial cells, forms the fatty smegma 
Preputii, which has a strong, unpleasant odor, and often accumulates in considerable 
