542 



EPIDIDYMIS. 



Fig. 162.t 



mosing frequently with each other near to their extremities, termi- 

 nating in loops or in free ca?cal ends, and of the same diameter 

 ( T |o- Lauth) throughout. The tubuli seminiferi are of a bright yel- 

 low colour ; they become less convoluted in the apices of the lobules, 

 and terminate by forming between 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 com- 

 municate freely with each other, and constitute the rete testis. At 

 the upper extremity of the mediastinum, 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 epididymis. 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, pre- 

 viously to their termination in the vas deferens. 

 The more numerous convolutions and the ag- 

 gregation 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 con- 

 volutions of the single tube at the lower ex- 

 tremity, the globus minor. The tubuli are 

 connected together by a very delicate cel- 

 lular tissue, and are enclosed by the tunica 

 vaginalis. 



A small convoluted duct, of variable length, 

 is generally connected with the duct of the epi- 

 didymis immediately before the commencement 

 of the vas deferens. This is the vasculum 

 aberrans of Haller ; it is attached to the epi- 

 didymis by the cellular tissue in which that 

 body is enveloped. Sometimes it becomes 

 dilated towards its extremity, but more fre- 

 quently retains the same diameter throughout. 



* Each vas deferens with its cone measures, according to Lauth, ahout 8 inches. 

 The entire length of the tubes composing the epididymis, according to the same 

 authority, is about 21 feet. 



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

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

 efferentia, of which five only are represented in this diagram. 1. 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. 



