THE ABDOMINAL WALL 225 



the body), a small gap or interval is seen to exist between 

 the arched lower border of the transverse muscle and the 

 inguinal ligament. The membrane which fills up that interval 

 is part of the transversalis fascia. At no part of the abdominal 

 wall is the transversalis fascia stronger than in that region, and 

 the accession of strength is obviously for the purpose of com- 

 pensating for the deficiency in the transverse muscle, which, 

 in that area, does not descend so low as the inguinal liga- 

 ment. In the area the transversalis fascia has an im- 

 portant relation to the spermatic cord. It is pierced by the 

 cord, but as yet no opening is visible. Take hold of the 

 cord and draw it downwards and medially. The margins of 

 the aperture through which it passes will be observed to be 

 prolonged downwards upon the cord in a funnel-shaped 

 manner, so as to invest it upon all sides with a tube of fascia. 

 The investment, which is thus seen to come directly from the 

 fascia transversalis, is called the internal spermatic fascia. 



Dissection. It is now the object of the dissector to demon- 

 strate the more important attachments of the transversalis fascia. 

 He must, therefore, divide the fibres of the transverse muscle 

 along the lateral part of the inguinal ligament and along the 

 crest of the ilium, and, raising the muscle from the subjacent 

 fascia, throw it upwards. It is not necessary to reflect the entire 

 muscle. 



Attachments of the Fascia Transversalis. When the fascia 

 is cleaned with the handle of the scalpel, it will be seen to be 

 attached laterally to the internal lip of the iliac crest. Along 

 the line of that attachment, which is by no means firm, it 

 becomes continuous with the fascia iliaca, which is merely 

 the portion of the same fascial stratum covering the iliacus 

 and psoas muscles in the iliac fossa. Close to the crest of 

 the ilium the fascia transversalis is pierced first by the ascend- 

 ing branch, and then by the deep circumflex iliac artery 

 itself. Anteriorly, in the inguinal region, its connections are 

 more complicated, and must be studied at three different 

 points (i) between the anterior superior spine of the 

 ilium and the femoral artery, where it will be seen to be 

 attached to the inguinal ligament ; along that line also it 

 becomes continuous with the fascia iliaca; (2) opposite the 

 femoral vessels, where it is carried distally into the thigh 

 behind the inguinal ligament, to form the anterior part of 

 the femoral sheath (Vol. I., p. 240) ; (3) medial to the femoral 



VOL. ii 15 



