504 



MALE GENITAL ORGANS OF THE PIG 



the prepuce (Mm. prseputiales caudales), arise in the inguinal region and converge 

 on the anterior part of the prepuce. They draw the prepuce backward. 



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

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

 the skin just l^eliind the preputial opening. The homologue of the protractor is present in the 

 cow. 



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

 relatively small and uniform caliber. The urethral (Wilson's) muscle incloses 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 colliculus seminalis is short, but 

 prominent; from it the urethral crest extends forward to the trigonum vesicae. 

 The extrapelvic part has an enlargement, the bulb, at its origin; it then gradually 



Processus urethroe 



Galea glandis 



Corona glandis 

 Collum glandis 



Prepuce 



Raphe 

 glandis 



Processus urdhrce 

 Galea glandis 

 Corona glandis 



Tuherculum 

 Collum glandis 



Prepuce 

 Raphe prceputii 



A B 



Fig. 403. — Anterior Part of Penis of Ram. 



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



diminishes in diameter, and is relatively very small at its termination. Other 

 features have been mentioned in preceding paragraphs. 



In the ram the urethra lies in a groove on the ventral surface of the corpus 

 cavernosum. Its terminal part projects commonly 3 to 4 cm. beyond the glans 

 penis, forming a twisted processus urethrse. 



MALE GENITAL ORGANS OF THE PIG 



The scrotum is situated a short distance from the anus, and is not so sharply 

 defined from the surrounding parts as in the other animals. 



The testicles are very large and are soft in texture. Their long axis is almost 

 vertical, the free border being posterior and the tail of the epididymis dorsal. 

 The mediastinum testis is well developed. The epididymis is closely attached to 

 the testicle and the tunica vaginalis; the tail is specially large. 



The spermatic cord is necessarily very long (20 to 25 cm. in a boar of medium 

 size). The vas deferens in its testicular part is flexuous, and is closely attached 

 to the tunica vaginalis; it forms no ampullae. The cremaster externus is well 

 developed, and extends to about the middle of the scrotal part of the tunic. 



