OF THE ABDOMEN. 359 



across the lower part of the aponeurosis of the External oblique. They have 

 received their name from stretching across between the two pillars of the external 

 ring, describing a curve with the convexity downward. They are much thicker 

 and stronger at the outer margin of the external ring, where they are connected 

 to the outer third of Poupart's ligament, than internally, where they are inserted 

 into the linea alba. They are more strongly developed in the male than in the 

 female. The intercolumnar fibres increase the strength of the lower part of the 

 aponeurosis, and prevent the divergence of the pillars from one another. 



These intercolumnar fibres as they pass across the external abdominal ring are 

 themselves connected together by delicate fibrous tissue, thus forming a fascia, 

 Avhich as it is attached to the pillars of the ring covers it in, and is called the 

 intercolumnar fascia. This intercolumnar fascia is continued down as a tubular 

 prolongation around the outer surface of the cord and testis, and encloses them in 

 a distinct sheath ; hence it is also called the external spermatic fascia. 



The sac of an inguinal hernia, in passing through the external abdominal ring, receives an 

 investment from the intercolumnar fascia. 



If the finger is introduced a short distance into the external abdominal ring 

 and the limb is then extended and rotated outward, the aponeurosis of the 

 External oblique, together with the iliac portion of the fascia lata, will be felt to 

 become tense, and the external ring much contracted ; if the limb is on the con- 

 trary flexed upon the pelvis and rotated inward, this aponeurosis will become lax 

 and the external abdominal ring sufficiently enlarged to admit the finger with 

 comparative ease : hence the patient should always be put in the latter position 

 when the taxis is applied for the reduction of an inguinal hernia in order that the 

 abdominal walls may be relaxed as much as possible. 



Poupart's ligament, or the crural arch, is the lower border of the aponeurosis of 

 the External oblique muscle, and extends from the anterior superior spine of 

 the ilium to the pubic spine. From this latter point it is reflected outward to be 

 attached to the pectineal line for about half an inch, forming Gimbernat's liga- 

 ment. Its general direction is curved downward toward the thigh, where it is 

 continuous with the fascia lata. Its outer half is rounded and oblique in direction. 

 Its inner half gradually widens at its attachment to the os pubis, is more horizontal 

 in direction, and lies beneath the spermatic cord. 



Nearly the whole of the space included between the crural arch and the 

 innominate bone is filled in by the parts which descend from the abdomen into the 

 thigh. These will be referred to again on a subsequent page. 



Gimbernat's ligament is that part of the aponeurosis of the External oblique 

 muscle which is reflected upward and outward from the spine of the os pubis to be 

 inserted into the pectineal line. It is about half an inch in length, larger in the 

 male than in the female, almost horizontal in direction in the erect posture, and of 

 a triangular form with the base directed outward. Its base, or outer margin, is con- 

 cave, thin, and sharp, and lies in contact with the crural sheath, formino- the 

 inner boundary of the femoral ring. Its apex corresponds to the spine of the os 

 pubis. Its posterior margin is attached to the pectineal line, and is continuous 

 with the pubic portion of the fascia lata. Its anterior margin is continuous with 

 Poupart's ligament. Its surfaces are directed upward and downward. 



The triangular fascia of the abdomen is a layer of tendinous fibres of a 

 triangular shape, which is attached by its apex to the pectineal line, where it is 

 continuous with Gimbernat's ligament. It passes inward beneath the spermatic 

 cord, and expands into a somewhat fan-shaped fascia, lying behind the inner pillar 

 of the external abdominal ring, and in front of the conjoined tendon, and interlaces 

 with the ligament of the other side at the linea alba. 



Ligament of Cooper. This is a strong ligamentous band, which was first de- 

 scribed by Sir Astley Cooper. Its extends upward and backward from the base of 

 Gimbernat's ligament along the ilio-pectineal line, to which it is attached. It is 

 strengthened by the fascia transversalis, by the pectineal aponeurosis, and by a 



