THE ANTERO-LATERAL MUSCLES OF THE ABDOMEN 



411 



the aponeurosis of the Obliquus externus, describing curves with the convexities 

 downward. They have received their name from stretching across between the 

 two crura of the subcutaneous inguinal ring, and they are much thicker and stronger 

 at the inferior crus, where they are connected to the inguinal ligament, than supe- 

 riorly, where they are inserted into the linea alba. The intercrural fibers increase 

 the strength of the lower part of the aponeurosis, and prevent the divergence of 

 the crura from one another; they are more strongly developed in the male than in 

 the female. 



As they pass across the subcutaneous inguinal ring, they are connected together 

 by delicate fibrous tissue, forming a fascia, called the intercrural fascia. This inter- 



Superficial iliac 

 circumflex vein 



Subcutaneous inguinal 

 ring 



FIG. 393. The subcutaneous inguinal ring. 



crural fascia is continued down as a tubular prolongation around the spermatic 

 cord and testis, and encloses them in a sheath; hence it is also called the external 

 spermatic fascia. The subcutaneous inguinal ring is seen as a distinct aperture 

 only after the intercrural fascia has been removed. 



The Inguinal Ligament (ligamentum inguinale [Pouparti] ; Poupart's ligament) 

 (Fig. 394) . The inguinal ligament is the lower border of the aponeurosis of the 

 Obliquus externus, and extends from the anterior superior iliac spine to the pubic 

 tubercle. From this latter point it is reflected backward and lateralward to be 

 attached to the pectineal line for about 1.25 cm., forming the lacunar ligament. 

 Its general direction is convex downward toward the thigh, where it is continuous 

 with the fascia lata. Its lateral half is rounded, and oblique in direction; its 



