184 



VISCERAL ANATOMY. 



Tunica Vaginalis, the Serous Covering, having a visceral layer (tunica 

 vaginalis propria) and a parietal layer (tunica vaginalis reflexa). It was 



FIG. 91. 



originally derived from the peritoneum, and 

 the upper part being obliterated, it remained 

 a closed sac. (See 6 Fig. 91.) 



Tunica Albuginea, the Fibrous Covering, 

 formed of white fibrous tissue, and forming 

 an incomplete vertical septum within the 

 gland, the Corpus Highmorianum or Medi- 

 astinum Testis? from which fibrous bands 

 (trabeculse) cross the gland, dividing its inte- 

 rior into spaces for the lobules of the organ. 



Tunica Vasculosa, the Pia Mater Testis, is 

 the vascular tunic, lying beneath the tunica 

 albuginea, and giving off numerous .pro- 

 cesses between the lobules. 



Name the Coverings of the Testicle. From without inwards they are 

 6 in number, as follows, the 



(1) Skin, of the scrotum, closely adherent to the dartos. 



(2) Dartos, or superficial fascia. 



(3) External Spermatic Fascia, Intercolumnar Fascia, derived from the 



margins of the external abdominal ring. 



(4) Cremasteric Fascia, derived from the lower border of the internal 



oblique muscle. [Called also the Cremaster Muscle.] 



(5) Internal Spermatic Fascia, or Fascia Propria, the infundibuliform 



process of the transversalis fascia. 



(6) Tunica Vaginalis,* originally a process of peritoneum. [Shown by 



dots in Fig. 91.] 



Describe the Structure of the Testicle. The glandular structure is 

 composed of small, convoluted tubes, the Tubuli Seminiferi* (Fig. 92), which 

 are collected into Lobules, about 30x3 in number, from which straight ducts, 

 the Vasa Recta,^ enter the mediastinum and form an ascending plexus of 

 anastomosing tubes, the Rete Testis? which gives off some 12 to 20 ducts, the 

 Vasa E/erentia ; 6 these perforate the tunica albuginea of the testis, and 

 form a number of conical masses, the Coni Vasculosi? which together con- 

 stitute the Globus Major 7 of the Epididymis. 8 



What is the Epididymis ? 8 It is an appendix to the testicle, lying 

 along its posterior border, and consists of a single duct about 20 feet in length 

 when unraveled, but which is wound upon itself so as to occupy a very small 

 space. The 



