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TEXT-BOOK OF PHYSIOLOGY. 



the mediastinum and form the rete testis. At the upper part of 

 the mediastinum the tubules unite to form from nine to thirty small 

 ducts, the vasa eflerentia, which soon become very much convoluted. 

 After a short course they unite to form a single tortuous tube, about 

 7 meters in length and 0.4 mm. in diameter, which descends behind 

 the testicle to its lower border. This tube is known as the epididy- 

 mis. The seminal tubule consists of a basement membrane lined 

 by granular nucleated epithelium. 



The vas defer ens, the excretory duct of the testicle, is about 60 cm. 

 in length and from 2 to 3 mm. in diameter, and extends upward 



from the epididymis to the 

 inguinal canal, through which 

 it passes into the abdominal 

 cavity and then to the under 

 surface of the base of the 

 bladder, where it unites with the 

 duct of the vesicula seminalis to 

 form the ejaculatory duct. 



The vesiculae seminales 

 are two lobulated pyriform 

 bodies, about 40 mm. in length, 

 situated on the under surface 

 of the bladder. Each vesicula 

 seminalis consists of an external 

 fibrous coat, a middle, muscular 

 coat, and an external mucous 

 coat. The mucous coat con- 

 tains a number of small tubu- 

 lar albumin-producing glands 

 which secrete a characteristic 

 fluid. 



The ejaculatory duct, formed 

 by the union of the vas deferens 

 and the duct of the vesicula semi- 

 nalis, opens into the prostatic 

 portion of the urethra (Fig. 322). 

 The prostate gland is a musculo-glandular mass situated at the 

 posterior extremity of the urethra. It contains a large number of 

 tubules, more or less branched and convoluted, and lined by columnar 

 epithelium. They secrete a fluid which is poured into the urethra 

 at the time of the ejaculation of semen. 



The penis consists of three parts: the corpus spongiosum below, 

 through which passes the urethra, and the two corpora cavernosa, 

 one on either side and above. The corpus spongiosum terminates 

 anteriorly in a conic- shaped structure, the glans penis; the corpora 



FIG. 322. VAS DEFERENS, VESICULAE 

 SEMINALES, AND EJACULATORY 

 DUCTS. a. Vas deferens. b. Semi- 

 nal vesicle, c. Ejaculatory duct. d. 

 Termination of the ejaculatory duct. 

 e. Opening of the prostatic utricle. 

 /, g. Veru montanum. h, I. Pros- 

 tate. (Liegeois.} 



