6 THE HUMAN BODY. 



about 800. Near the posterior side of the testis the tubules 

 unite to form about 20 v asa recta (b), and these pass out of 

 the gland at its upper end, as the vasa efferentia (d), which 

 become coiled up into conical masses, the coni vasculosi; 

 these, when unrolled, are tubes from 15 to 20 cm. (6-8 

 inches) in length; they taper somewhat from their com- 

 mencements at the vasa efferentia, where they are 0.5 mm. 

 (-^Q inch) in diameter, to the other end where they termi- 

 nate in the epididymis (e, e, Fig. 160). The latter is a nar- 

 row mass, slightly longer than the testicle, which lies- 

 along the posterior side of that organ, near the lower end 

 of which (g) it passes into the vas deferens, h. If the 

 epididymis be carefully unraveled it is found to consist of 

 a tube about 6 meters (20 feet) in length, and varying in 

 diameter from 0.35 to 0.25 mm. (-fa to -fa inch). 



The vas deferens (li, Fig. 160) commences at the lower 

 part of the epididymis as a coiled tube, but it soon ceases 

 to be convoluted and passes up beneath the skin covering 

 the inner part of the groin, till it gets above the pelvis and 

 then, passing through the abdominal walls, turns inwards, 

 backwards, and downwards, to the under side of the urinary 

 bladder, where it joins the duct of the seminal vesicle; it is 

 about 0.6 meters (2 feet) in length and 2.5 mm. (fa inch) 

 in diameter. 



The vesiculce seminales, two in number, are membranous 

 receptacles which lie, one on each side, beneath the bladder, 

 between it and the rectum. They are commonly about 5 

 cm. (2 inches) long and a little more than a centimeter 

 wide (or about 0.5 inch) at their broadest part. The nar- 

 rowed end of each enters the vas deferens on its own side, 

 the tube formed by the union being the ejaculatory duct, 

 which, after a course of about an inch, enters the urethra 

 near the neck of the bladder. 



The prostate gland is a dense body, about the size of a 

 chestnut, which surrounds the commencement of the ure- 

 thra; the ejaculatory ducts pass through it. It is largely 

 made up of fibrous and unstriped muscular tissues, but 

 contains also a number of small secreting saccules whose, 

 ducts open into the urethra. 



