154 HUMAN PHYSIOLOGY. 



GENERATIVE ORGANS OF THE MALE. 



The Generative Organs of the Male consist of the testicles, vasa 

 deferentia, vesiculae seminales and penis. 



The Testicles, the essential organs of reproduction in the male, are 

 two oblong glands, about an inch and a half in length, compressed from 

 side to side, and situated in the cavity of the scrotum. 



The proper coat of the testicle, the tunica albuginea, is a white, fibrous 

 structure, about the -j=% of an inch in thickness; after enveloping the testicle, 

 it is reflected into its interior at the posterior border, and forms a vertical 

 process, the mediastinum testes, from which septa are given off, dividing the 

 testicle in lobules. 



The substance of the testicle is made up of the seminiferous tubules, 

 which exist to the number of 840 ; they are exceedingly convoluted, and 

 when unraveled are about 30 inches in length. As they pass toward the 

 apices of the lobules they become less convoluted, and terminate in from 

 20 to 30 straight ducts, the vasa recta, which pass upward through the 

 mediastinum and constitute the rete testis. At the upper part of the 

 mediastinum the tubules unite to form from 9 to 30 small ducts, the vasa 

 efferentia, which become convoluted, and form the globus major of the 

 epididymis ; the continuation of the tubes downward behind the testicle 

 and a second convolution constitutes the body and globus minor. 



The seminal tubule consists of a basement membrane lined by granular 

 nucleated epithelium. 



The Vas Deferens, the excretory duct of the testicle, is about two feet 

 in length, and may be traced upward from the epididymis to the under sur- 

 face of the base of the bladder, where it unites with the duct of the vesicula 

 seminalis, to form the ejaculatory duct. 



The Vesiculse Seminales are two lobulated, pyriform bodies, about 

 two inches in length, situated on the under surface of the bladder. 



They have an external fibrous coat, a middle muscular coat, and an in- 

 ternal mucous coat, covered by epithelium, which secretes a mucous fluid. 

 The vesiculae seminales serve as reservoirs, in which the seminal fluid is 

 temporarily stored up. 



The Ejaculatory Duct, about % of an inch in length, opens into the 

 urethra, and is formed by the union of the vasa deferentia and the ducts of 

 the vesiculae seminales. 



The Prostate Gland surrounds the posterior extremity of the urethra, 

 and opens into it by from twenty to thirty openings, the orifices of the pros- 



