236 



Four months. . . . 



Six months 



Nine months . . 



HUMAN PHYSIOLOGY. 



Absent 

 noticeable. 



Absent. 



Absent . 



Seven eights of an inch in 

 diameter; clot pale and fibrin- 

 ous; convoluted wall dull yel- 

 low. 



Still as large as at the end of 

 second month; clot fibrinous; 

 convoluted wall paler. 



Half an inch in diameter; 

 central clot converted into a 

 radiating cicatrix; external 

 wall tolerably thick and con- 

 voluted, but without any bright 

 yellow color. 



GENERATIVE ORGANS OF THE MALE. 



The generative organs of the male consist of the testicles, vasa deferen- 

 tia, vesiculae seminales, and penis. 



The testicles, the essential organs of reproduction in the male, are two 

 oblong glands, about i ^ inches 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 % 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 testis, from which septa are given off, dividing the 

 testicle into 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 un- 

 ravelled are about thirty inches in length. As they pass toward the apices 

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

 to thirty straight ducts, the vasa recta, which pass upward through the 

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

 num the lobules unite to form from nine to thirty small ducts, the vasa effer- 

 entia, 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 surface 



