740 



MALE GENERATIVE ORGANS. 



Fig. 371. The Testis in Situ ; the Tunica 

 Vaginalis having been laid open. 



Artery 

 of Cord 



The intercolumnar fascia is a thin membrane, derived from the margin of the 

 pillars of the external abdominal ring, during the descent of the testis in the 

 foetus, being prolonged downwards around the surface of the cord and testis. It 

 is separated from the dartos by loose areolar tissue, which allows of considerable 

 movement of the latter upon it, but is intimately connected with the succeeding 

 layer. 



The cremasteric fascia consists of scattered bundles of muscular fibres ( Cremaster 

 muscle), derived from the lower border of the Internal oblique muscle, during the 

 descent of the testis. 



The fascia propria is a thin membranous layer, which loosely invests the 

 surface of the cord. It is a continuation downwards of the infundibuliform pro- 

 cess of the fascia transversalis, and is also derived during the descent of the testis 

 in the fcetus. 



The tunica vaginalis is described more appropriately, as one of the proper 

 coverings of the testis. A more detailed account of the coverings just described 

 may be found in the description of the surgical anatomy of inguinal hernia. 

 Proper coverings or investments of the Testis. The testis is invested by three 



tunics, the tunica vaginalis, tunica albu- 

 ginea, and tunica vasculosa. 



The Tunica Vaginalis is the serous 

 covering of the testis. It is a pouch of 

 serous membrane, derived from the peri- 

 toneum during the descent of the testis, 

 in the fcetus, from the abdomen into the 

 scrotum. After its descent, that portion 

 of the pouch which extends from the 

 internal ring to near the upper part of 

 the gland becomes obliterated, the lower 

 portion remaining as a shut sac, which 

 invests the outer surface of the testis, and 

 is reflected on the internal surface of the 

 scrotum ; hence it may be described as 

 consisting of a visceral and parietal por- 

 tion. 



The visceral portion (tunica vaginalis 

 propria) covers the outer surface of the 

 testis, as well as the epididymis, con- 

 necting the latter to the testis by means 

 of a distinct fold. From the posterior 

 border of the gland, it is reflected on to the internal surface of the scrotum. 



The parietal portion of the serous membrane (tunica vaginalis reftexa) is far 

 more extensive than the visceral portion, extending upwards for some distance in 

 front, and on the inner side of the cord, and reaching below the testis. The inner 

 surface of the tunica vaginalis is free, smooth, and covered by a layer of squamous 

 epithelium. The interval between the visceral and parietal layers of this mem- 

 brane constitutes the cavity of the tunica vaginalis. 



The Tunica Albuginea is the fibrous covering of the testis. It is a dense fibrous 

 membrane, of a bluish- white color, composed of bundles of white fibrous tissue, 

 which interlace in every direction. Its outer surface is covered by the tunica 

 vaginalis, except along its posterior border, and at the points of attachment of 

 the epididymis ; hence the tunica albuginea is usually considered as a fibro-serous 

 membrane, like the dura mater and pericardium. This membrane surrounds the 

 glandular structure of the testicle, and, at its posterior and upper border, is 

 reflected into the interior of the gland, forming an incomplete vertical septum, 

 called the mediastinum testis (corpus Sighmorianum). 



The mediastinum testis extends from the upper, nearly to the lower, border of 

 <.he gland, and is wider above than below. From the front and sides of this 



