590 



GENITAL ORGANS OF THE BULL 



are about an inch (ca. 2 to 5 cm.) apart on the root of the penis, where they lie 

 in a groove on either side of the bulbo-cavernosus. They then come close together 

 and pass on either side of tlie ventral curve of the sigmoid flexure. Further for- 

 ward they are on the ventral surface of the penis, and end about five or six inches 

 (ca. 12 to 15 cm.) behind the glans. 



The prepuce is very long and narrow. Its orifice is about two inches (ca. 

 5 cm.) behind the umbilicus; it is only large enough to admit a finger readily, and 

 is surrounded by long hairs. The preputial cavity is about fifteen inches (35 to 40 

 cm.) long and a little over an inch (ca. 3 cm.) in diameter. The lining membrane 

 forms longitudinal folds; it is covered with squamous stratified epithelium, and 

 has coiled tubular glands. The penile layer is glandless, and is reddish in color. 

 It presents lymph nodules in its posterior part. 



There are two pairs of preputial muscles which are derivatives of the cutaneus 

 muscle. The anterior preputial muscles or protractors of the prepuce (Mm. 

 preeputiales craniales) are two flat bands, two inches or more (5 to 6 cm.) in width, 

 which arise close together in the xiphoid region, about eight inches (20 cm.) in 



Processtis urethra: 



Galea glandis 



Corona glandis — 5 

 Collum glandis 



Prepuce 



Raphe 

 glandis 



Processus urethroe 

 Galea glandis 

 Corona glandis 



Tuberculum 

 Collum glandis 



Prepuce 

 Raphe prceputii 



Fig. 526. — Anterioh Part of Penis of Ram. 

 A, Right side: B. left side. (After Bohm.) 



front of the preputial orifice. Traced backward they diverge, leaving the umbilicus 

 and an area about one and a half inches wide free, and then unite behind the pre- 

 putial orifice. They draw the prepuce forward. The posterior preputial muscles 

 or retractors of the prepuce (Mm. praeputiales caudales) arise in the inguinal region 

 and converge on the anterior part of the prepuce. They draw the prepuce back- 

 war d.^ 



The urethra in its pelvic part is about five inches (12 cm.) long, and is of 

 relatively small and uniform caliber. The urethral muscle encloses the tube 

 ventrally and laterally; it is very thick, crescentic in cross-section, and is covered 

 by an aponeurosis. Dorsally the aponeurosis is thick and the muscle absent. 

 Inside of these the pars disseminata of the prostate surrounds the urethra as far 

 back as the bulbo-urethral glands. The coUiculus seminalis is a rounded promi- 

 nence about an inch (ca. 2.5 cm.) in length. On it there are two slit-like opeiungs,, 

 situated close together. These are the ejaculatory orifices, at which the ductus 

 deferens and the excretory duct of the vesicula seminalis open. The urethral 



^ These muscles are subject to a good deal of variation. The retractor may be absent. Many 

 fibers come in from the cutaneus on either side, dip under the protractor, and are inserted into 

 the skin just behind the preputial opening. The homologue of the protractor is present in the 



