THE ABDOMINAL WALLS 265 



level, (c) The valve at the orifice of the left spermatic vein 

 may be absent, (d) The venous return from the left spermatic 

 vein may be obstructed by the pressure of the iliac colon, behind 

 which it passes as it ascends on the iliacus (Fig. 88). 



A varicocele on the right side generally indicates that the 

 right spermatic vein is pressed on by some tumour growth. 



In this condition the veins of the plexus are much enlarged 

 and very tortuous, and, when they have been exposed (p. 262), 

 they must be separated from the ductus (vas) deferens. The 

 vessels are then ligated above and below and the intervening 

 portion is removed. The ligated ends are then tied together 

 and the coverings of the cord are united over them. In the 

 process the internal spermatic artery is not uncommonly 

 resected, but the testis receives a sufficient supply from the 

 artery to the ductus deferens, which becomes increased in size. 



Undescended Testis (see also p. 258). In embedding an 

 imperfectly descended testis in the scrotum, the preliminary 

 steps are much the same as in the operation for varicocele, but 

 the external oblique aponeurosis may have to be slit up from 

 the subcutaneous inguinal ring. It is generally found that the 

 ductus deferens is sufficiently long to allow the testis to be 

 placed at the bottom of the scrotum, but it will be necessary to 

 divide all the other constituents of the cord, together with its 

 coverings. As the testis increases in size about puberty, 

 operative interference should be undertaken a year or two 

 before that period in order that the circulation, temporarily 

 disturbed by the division of the internal spermatic artery, may 

 be completely and efficiently re-established for the nutrition of 

 the growing organ. 



The Testis lies obliquely in the scrotum so that the upper 

 pole is antero-lateral to the lower, and the Epididymis is 

 closely applied to the lateral aspect of its posterior border. 

 Inside its fascial coverings (p. 255) the testis is invested by a 

 closed peritoneal sac, the Tunica Vaginalis. This sac possesses 

 a parietal layer, associated with the coverings (Fig. 81), and a 

 visceral layer, which covers the testis anteriorly, medially, and 

 laterally, but not posteriorly. The epididymis obtains a partial 

 covering from the visceral layer, and the medial aspect of its 

 body is separated from the postero-lateral aspect of the testis 

 by a small peritoneal recess the sinus epididymidis (digital 

 fossa). In large hydroceles this fossa may become so deep as 

 to separate the two structures completely. Above the testis 



