160 THE PHYSIOLOGY OF REPRODUCTION 



convoluted tube situated at the posterior margin of the organ and 

 attached to the mediastinum. This is the epididymis. Its lower 

 extremity is prolonged into a thick-walled muscular tube (the vas 

 deferens) which is the passage of exit for the seminal fluid or 

 sperm-containing secretion. The glandular substance of the testis 

 is composed of the convoluted seminiferous tubules, two or three 

 of which join together to form a straight tubule which passes into 



FIG. 46. Section through human testis and epididymis. (After Bohm 

 and von Davidoff, from Schafer.) 



a, Glandular substance divided into lobules by septa of connective tissue ; 

 6, tunica albuginea ; <?, part of epididymis ; d, rete testis ; e, body of 

 epididymis ; /, mediastinum ; g, sections through commencing portion 

 of vas deferens. 



the body of the mediastinum. The straight tubules within the 

 mediastinum unite in their turn, giving rise to a network of vessels 

 called the rete testis. From the rete the vasa efferentia are given 

 off. Between the tubules is a loose connective tissue containing 

 a number of yellow epithelioid interstitial cells. The connective 

 tissue also contains numerous lymphatics and blood-vessels (branches 

 of the spermatic artery). The nerves of the testis are derived from 

 the sympathetic system, but a few filaments come from the hypo- 

 gastric plexus. 



