1 82 ELEMENTS OF MAMMALIAN ANATOMY. 



parent and lies close to the testis. Immediately sur- 

 rounding the latter is a dense capsule, the tunica albu- 

 ginea, sending septa into the interior. 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 Highmorianum (Fig. 87). 



The testis is about i J 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 portion, the globus minor. 



The main portion 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 ex- 

 tend. These tubules are the i)asa 

 \ ' efferentia. The epididymis is com- 



FIG. 88. - - SPERMATOZOA posed of a single greatly convoluted 

 x* 5^0 IvE GERM CELLS ' tubule of which the vas def erens is 

 h, Head; t, tail. a continuation. The latter pro- 



ceeds cephalad to the external ab- 

 dominal ring, which it enters to traverse the inguinal canal 

 into the abdominal cavity. It then curves caudad and 

 enters the urethra on its dorsal aspect 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 transver- 

 salis muscle (Fig. 51). By accident, a fold of the small 

 intestine sometimes descends through the inguinal canal, 

 which condition is known as hernia or rupture. 



