EXCRETORY AND REPRODUCTIVE SYSTEMS 205 



toneum. The visceral layer of peritoneum is quite delicate 

 and transparent and lies close to the testis. Within the tunica 

 vaginalis, is the tunica albuginea, closely investing the testicle 

 and adjacent to the epididymis, penetrating the substance of 

 the gland, forming a septum known as the mediastinum testis 

 or corpus Highmori (Fig. loi). 



The testis is about ij^ centimeters long by i centimeter 

 thick. On its dorsal surface lies the epididymis, an elongated 

 body composed of an enlarged extremity, 

 the globus major, and an attenuated por- 

 tion, the globus minor. The main por- 

 tion of a testicle is composed of many 

 minute coiled tubules, tubuli seminiferi, 

 which unite into a few tubules near the 

 surface of the testis beneath the globus 

 major, into which they extend. These 



, , 1 7 7' /r • ^^^- 102. SpERMA or 



tubules are the auctuii ejjerentes testis, male Germ Cells. 

 The epididymis is composed of a single ^ ^T'h d- / tail 

 greatly convoluted tubule of which the 

 ductus deferens is a continuation. The latter proceeds 

 craniad to the external abdominal ring, which it enters to 

 traverse the inguinal canal into the abdominal cavity. It 

 then curves caudad and enters the urethra on its dorsal as- 

 pect in the region of the prostate gland. 



The inguinal canal begins with the external abdominal ring, 

 which is an opening in the tendon of the external oblique 

 muscle, and ends with the internal abdominal ring, which is an 

 opening in the fascia of the transversalis muscle (Fig. 56). 

 By accident, a fold of the small intestine in man sometimes 

 descends through the inguinal canal, which condition is known 

 as hernia or rupture. 



The penis is a cylindrical pointed body about three centi- 

 meters long when in repose. It is composed of two kinds of 

 tissues arranged in three bundles. The corpus spongiosum is 

 the median ventral bundle, extending throughout the length 



