130 



PHYSIOLOGY 



CHAP. 



axis of the principal canal (Fig. 26, d}. The wall of the vas 

 defer ens is very strong, hard, and resistent to pressure ; for this 

 reason it is easily distinguished by digital examination from the 

 other constituents of the spermatic cord. The wall is composed 

 of a thick mucous coat, a still thicker muscular coat, and a thin 

 fibrous coat or tunica adventitia. 



In the vicinity of the vas deferens are found almost always 

 longitudinal fasciculi of the internal creniaster muscle (Fig. 2*7, /). 



w Wl 



f$$i ^ 



A 



Fio. 25. Vas defereus (left side) with ampulla 

 and coiTesiXHiding vesicula seminalis, in 

 frontal section, (l)isse.) D, vas doferens ; A, 

 ampulla ; V, vesicula seminalis ; E, ejaculatory 

 duct ; d, diverticula ; o, opening of the vesi- 

 cula seminalis into the ejaculatory duct ; m, 

 mucous coat ; ins, muscular coat ; a, tunica 

 adventitia. 



Fio. 26. Model of the vesicula seminalis 

 (i i.ulit side) seen from the anterior face 

 (from a preparation made by corrosion 

 by Banchi). Natural si/e. i>s, vesicula 

 seminalis ; c, its principal canal ; d, a 

 diverticulum ; erf, vas deferens ; ce, 

 duetus ejaculatorius. 



In the interior of the duct of virile subjects an abundant quantity 

 of semen is found always. 



The ejaculatory ducts are formed by the union of the narrow" 

 ends of the corresponding deferent ducts with the vesiculae 

 seminales at the base of the prostate. They traverse the prostate, 

 and after a course of 15-16 mm., along which they become finer, 

 they open by small elliptical orifices into the floor of the prostatic 

 portion of the urethra, in the so-called colliculus seminalis. Their 

 structure is similar to that of the vasa deferentia, but they have 

 much thinner walls. 



