REPRODUCTION 



745 



THE REPRODUCTIVE ORGANS OF THE MALE 



The reproductive organs of the male comprise the testicles, vasa deferen- 

 tia, vesiculae seminales, and penis. 



The Testicles. The testicles are oblong glands, about 40 mm. in 

 length, 30 mm. in breadth and 20 mm. in thickness, and contained within 

 the cavity of the scrotum. A section of the testicle (Fig. 326) reveals the 

 presence externally of a dense fibrous membrane, the tunica albuginea, and 

 internally a connective-tissue framework consisting mainly of septa, which 

 enter the organ on its posterior aspect at the mediastinum testis, passing in- 

 ward in a diverging manner. The spaces between the septa are occupied 

 by the true gland substance, the seminiferous tubules. 



FIG. 326. DIAGRAM OF A VER- 

 TICAL SECTION THROUGH A TES- 

 TICLE, i. Mediastinum testis. 2, 

 2. Trabeculae. 3. One of the 

 lobules. 4, 4. Vasa recta. 5. 

 Globus major of the epididymis. 

 6. Globus minor. 7. Vas def- 

 erens. (Holden.) 



FIG. 327. VAS DEFERENS, VESICUL.E 

 SEMINALES, AND EJACULATORY DUCTS. 

 a. Vas deferens. b. Seminal vesicle. 

 c. Ejaculatory duct. d. Termination of 

 the ejaculatory duct. e. Opening of the 

 prostatic utricle. /., g. Verumontanum. 

 h. 1. Prostate. (Liegeois.} 



The seminiferous tubules are very numerous, the estimate as to their 

 number varying from 800 to 1000. When unraveled they measure from 30 

 to 40 cm. in length and 0.3 mm. in diameter. At their peripheral extremities 

 the tubules are very much convoluted, but as they pass toward the mediasti- 

 num testis, the convolutions disappear, and after uniting with one another 

 terminate in from twenty to thirty straight tubes, of small diameter, 

 the vasa recta, which pass through 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 efferentia, which soon become very much con- 

 voluted. 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 epididymis. 

 The seminal tubule consists of a basement membrane lined by granular 

 nucleated epithelium. 



