THE ABDOMEN, INTERIOR. 525 



spermatic vessels (in female, ovarian), and at the bladder 

 by the vas deferens (in the female by the round ligament). 



The Ilio-Psoas Fascia. Fig. 103. 



Is attached to the crest of the ilium, the outer part of 

 Poupart's ligament blending with the transversalis fascia ; 

 when the femoral vessels are reached it passes behind them 

 to form the posterior layer of their sheath (as the transver- 

 salis does the anterior layer) ; it is then attached to the ilio- 

 pectineal line, brim of the true pelvis, to the bodies and 

 intervertebral substances, and bases of the transverse pro- 

 cesses of the lumbar vertebrae, as well as to the tendinous 

 arches which bridge over the lumbar arteries ; when the 

 diaphragm is reached this fascia becomes thickened to form 

 the ligamentum arcuatum internum, extending from the 

 body of the first to the transverse process of the second 

 lumbar vertebra, arching over the psoas muscle ; along the 

 outer margin of the psoas the fascia is attached to the ante- 

 rior lamella of the lumbar fascia. 



It is the existence of this fascia that determines the course 

 of purulent collections beneath it to point beneath Poupart's 

 ligament at the outer side of the femoral artery, forming a 

 psoas abscess. Such abscesses are, in the great majority 

 of cases, due to tubercular disease of the lumbar vertebrae 

 (Pott's disease). 



The anterior layer of the lumbar fascia is seen covering 

 the quadratus lumborum muscle. Its attachments have 

 already been given (see page 451). Below, it becomes 

 attached to the crest of the ilium and the iliolumbar liga- 

 ment ; above, it forms the ligamentum arcuatum exter- 

 num, q. v. (page 451). 



The Femoral Opening. Figs. 103, 106. 



To the inner side of the external iliac vein, just under 



