THE MALE GENITAL ORGANS 



The male genital organs (Organa genitalia masculina) are: (1) The two 

 testicles, the essential reproductive glands, with their coverings and appendages; 

 (2) the ductus deferentes, the ducts of the testicles; (3) the vesicul£e seminales; 

 (4) the prostate, a musculo-glandular organ; (5) the two bulbo-urethral (or Cow- 

 per's) glands; (6) the male urethra, a canal which transmits the generative and 

 urinary secretions; (7) the penis, the male copulatory organ. The vesiculiB 

 seminales, the prostate, and the bulbo-urethral glands discharge their secretions 

 into the urethra, where they mix with the fluid secreted by the testicles; hence they 

 are often termed the accessorv sexual glands. 



GENITAL ORGANS OF THE STALLION 

 THE TESTICLES 

 The testicles (Testes) are situated in the inguinal region, enclosed in a divertic- 

 ulum of the ^abdomen termed the scrotum. Their long axes are nearly longitu- 

 dinal.i They are ovoid in form, but considerably compressed from side to side. 

 Each presents two surfaces, two borders, and two extremities. The medial and 

 lateral surfaces (Facies medialis, lateralis) are convex and smooth; the former is 

 somewhat flattened by contact with the septum scroti. The free border (Margo 

 liber) is ventral and is convex. The attached or epididymal border (Margo epi- 

 didymidis) is dorsal; it is nearly straight, and is the one by which the gland is 

 suspended in the scrotum by the spermatic cord; the epididymis is attached to this 

 border and overlies it laterally. The anterior and posterior extremities (Extremitas 

 capitata, caudalis) are rounded. 



At the anterior extremity there is often a sessile or pedunculated sac which contains a clear 

 fluid; this is the appendix testis, from which a thread-like process extends baclsward toward 

 the ductus deferens. It is regarded as a remnant of the Miillerian duct of the embryo. 



A testicle of average size of an adult stallion is about four or five inches (ca. 

 10 to 12 cm.) long, two and a half to three inches (ca. 6 to 7 cm.) high, and two 

 inches (ca. 5 cm.) wide; it weighs about eight to ten ounces (ca. 225-300 grams). 

 They vary much in size in different subjects, and are commonly of unequal size, 

 the left one being more often the larger. 



The epididymis is adherent to the attached border of the testicle, and overlaps 

 somewhat the lateral surface. Its anterior enlarged end is termed the head (Caput 

 epididymidis) ; and its posterior, slightly enlarged end is the tail (Cauda epididy- 

 midis); the intermediate narrow part is the body (Corpus epididymidis). The 

 head is closely connected with the testicle by the efferent ducts of the latter, by 

 connective tissue, and by the serous membrane. The body is less closely attached 

 by the serous covering, which forms laterally a pocket beneath the epididymis 

 termed the sinus epididymidis. The tail is continued by the ductus deferens ; it is 

 attached to the posterior extremity of the testicle by a short ligament (Lig. epididy- 

 midis), which is formed by a thick fold of the tunica vaginalis and contains smooth 

 muscle-fibers. 



1 When the testicle is drawn up or has not completed its descent into the scrotum, its long 

 axis is almost vertical. 



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