THE ABDOMEtt 



673 



inguinal cone are described as being attached to the testis and epididj-mis. 

 Tqferiorly, three attachments are ascribed to them, as follows: (i) The outer 

 ■undle is attached to the deep aspect of Poupart's hgament near its centre; 

 (2) the middle or principal bundle accompanies the gubemaculum testis to 

 the bottom of the scrotal chamber; and (3) the inner bundle is attached to the 

 pubic crest. 



T-wo views are thus entertained regarding the structure of the gubemaculum 

 testis. - According to one \'iew it consists solely of plain muscular tissue and 

 connective tissue arranged as a cord within the peritoneal fold, called the 

 plica gubematrix or plica inguinalis. According to the other \-iew, in addi- 

 tion to these fibro-muscular elements, there are superadded striated muscular 

 fibres derived from the internal obhque and transversalis abdominis muscles 

 in the form of the inguinal cone. However constituted, the gubemaculum 

 testis soon becomes a stout thick cord, the final destination of which will be 

 presenth' referred to. 



Descent of the Testis. — As stated, the testis originally hes in the abdomen 

 on a level with the last thoracic and first lumbar vertebrae, being placed 

 behind the peritoneum which forms its mesorchium. As it descends it takes 



Parietal 

 Peritoneum 

 Nodule 



Spermatic Cord 



Tunica 

 Albuginea 



Testis 



Tunica 

 Vaginalis Scroti 

 Tunica Vaginalis 

 Testis 



Fig. 292. — Varieties of the Tunica Vagin.\lis. 

 A, Normal Type ; B, Congenital Type ; C, Infantile Type. 



along with it the superficial cells of its germinal epithehum, and the mesor- 

 chium also accompanies it. 



The descent, or more properly the migration, of the organ commences 

 about the third month of intra -uterine hfe, and its usual destination is the 

 corresponding scrotal chamber. The migration is accomplished in jour 

 stages — pelvic, inguinal, intraparietal, and scrotal — and throughout all these 

 stages it follows the lead of the gubemaculum, which necessarily undergoes 

 shortening. 



The pelvic stage soon brings the testis into the ihac fossa, where it Ues near 

 the brim of the true pelvis, having the epididymis externally and the vas 

 deferens internally, the latter dipping into the peRic ca\ity. 



The inguinal stage takes the testis to the posterior aspect of the inguinal 

 portion of the anterior abdominal wall, at a point corresponding to the future 

 internal abdominal ring, where it arrives about the sixth month. 



Inasmuch as there are no abdominal rings and no inguinal canal at this 

 period, a pause now takes place in the migration of the testis, in order to 

 pemiit of a path being cleared for its progress. In the immediate vicinity of 

 the lower or inguinal end of the gubemaculum testis a peritoneal depression 

 is formed, and the principal part of the inguinal end of the gubemagulum 

 now slowly penetrates the compact anterior abdominal wall in the inguinal 

 region, thus giving rise to the ioguinal canal and abdominal rings. In pre- 



43 



