STRUCTURE OF THE EPIDIDYMIS. 



543 



Fig. 239 * 



of an inch, Lauth) throughout. The tubuli semiriiferi are of a bright 

 yellow colour ; they become less convoluted in the 

 apices of the lobules, and terminate by forming be- 

 tween twenty and thirty small straight ducts of about 

 twice the diameter of the tubuli seminiferi, the vasa 

 recta. The vasa recta enter the substance of the 

 mediastinum, and terminate in from seven to thirteen 

 ducts, smaller in diameter than the vasa recta. These 

 ducts pursue a waving course from below upwards 

 through the fibrous tissue of the mediastinum ; they 

 communicate freely with each other, and constitute 

 the rete testis. At the upper extremity of the medi- 

 astinum, the ducts of the rete testis terminate in from 

 nine to thirty small ducts, the vasa efferentia,\ which 

 form by their convolutions a series of conical masses, 

 the coni vasculosi ; from the bases of these cones 

 tubes of larger size proceed, which constitute, by 

 their complex convolutions, the body of the epi- 

 didymis. The tubes become gradually larger towards 

 the lower end of the epididymis, and terminate in a 

 single large and convoluted duct, the vas deferens. 



The Epididymis is formed by the convolutions of the excretory seminal 

 ducts, externally to the testis, and previously to their termination in the 

 vas deferens. The more numerous convolutions and the aggregation of 

 the coni vasculosi at the upper end of the organ constitute the globus 

 major; the continuation of the convolutions downwards is the body; and 

 the smaller number of convolutions of the single tube at the lower extre- 

 mity, the globus minor. The tubuli are connected together by a very 

 delicate areolar tissue, and are enclosed by the tunica vaginalis. 



A small convoluted duct, of variable length, is generally connected 

 with the duct of the epididymis immediately before the commencement of 

 the vas deferens. This is the vasculum aberrans of Haller ; it is attached 

 to the epididymis by the areolar tissue in which that body is enveloped. 

 Sometimes it becomes dilated towards its extremity, but more frequently 

 retains the same diameter throughout. 



The Vas deferens may be traced upwards in the course of the seminal 

 fluid, from the globus minor of the epididymis along the posterior part of 

 the spermatic cord, and along the spermatic canal to the internal abdomi- 

 nal ring. From the ring it is reflected inwards to the side of the fundus 

 of the bladder, and descends along its posterior surface, crossing the direc- 

 tion of the ureter, to the inner border of the vesicula seminalis. In this 

 situation it becomes somewhat larger in size and convoluted, and termi- 

 nates at the base of the prostate gland, by uniting with the duct of the 

 vesicula seminalis and constituting the ejaculatory duct. The ejaculatory 



* Anatomy of the testis. 1, 1. The tunica albuginea. 2, 2. The mediastinum testis. 

 3, 3. The lobuli testis. 4, 4. The vasa recta. 5. The rete testis. 6. The vasa enV 

 rentia, of which six only are represented in this diagram. 7. The coni vasculosi 

 constituting the globus major of the epididymis. 8. The body of the epididymis 

 9. The globus minor of the epididymis. 10. The vas deferens. 11. The vasculum 

 aberrans. 



j-Each vas offerens with its cone measures, according to Lauth, about 8 inches. The 

 entire length of the tubes composing the epididymis, according to the same authority, i 

 about 2 1 feet. 



