APONEUROSIS OF THE EXTERNAL OBLIQUE. 267 



Its margins are named pillars, and differ in form and strength, inner side or 

 The inner one, thin and straight, is attached below to the front of plUar; 

 the symphysis pubis, where it decussates with the corresponding 

 piece of the opposite side. The outer pillar is stronger, and is 

 curved, .so as to form a kind of groove for the support of the outer pillar ; 

 spermatic cord ; it is continuous with Poupart's ligament and is 

 attached below to the pubic spine. A thin membrane (intercolumnar fascia pro- 

 fascia), derived from some fibres on the surface of the apoueurosis, margin ; r D 

 covers the opening. 



The external ring gives passage in the male to the spermatic cord, objects 

 and in the female to the round ligament ; and in each sex the trans- through. 

 initted part lies on the outer pillar as it passes through, and obtains 

 a covering from the intercolumnar fascia. Through this aperture an 

 inguinal hernia protrudes from the wall of the abdomen. 



The intercolumnar Jibres (tig. 97) run transversely on the surface of intercolum- 

 the aponeurosis, and bind together its parallel iibres, so as to con- 

 struct a firm membrane. Interiorly, where they are strongest, some attachment 

 well-marked bundles are connected with the outer third of Poupart's 

 ligament, and the anterior end of the iliac crest. At the external 

 abdominal ring the fibres stretch from side to side, and close the 



upper end of that opening ; and as they are prolonged on to the cord they pro- 

 ,, r * \. ., : . * . * , duce inter- 



irom the margin of the ring, they give rise to a membrane named columnar 



the intercolumnar or spermatic fascia. On the left side, where the fascia - 

 fascia is entire, this thin covering will be manifest on the surface of 

 the cord, or on the round ligament in the female. 



Dissection, To see the attachments and connections of Poupart's To see 



T j. -11 i n i ^i -i f ^-L. -L j insertion of 



ligament, it will be necessary to reflect, on both sides of the body, Poupart's 

 the lower part of the external oblique aponeurosis towards the iig ament 

 thigh. For this purpose an incision is to be carried inwards, 

 through the aponeurosis, from the front of the iliac crest to a spot 

 about three inches from the linea alba ; and the tendon is to be throw down 

 detached from the subjacent parts with the handle of the scalpel, external 



When the aponeurosis cannot be separated farther from the tendons 

 beneath, near the linea alba, it is to be cut in the direction of a line 

 descending to the symphysis pubis. 



After the triangular piece of the aponeurosis has been thrown and show 

 towards the thigh, the spermatic cord is to be dislodged from the faS?* * 

 surface of Poupart's ligament, to see the insertion of the ligament 

 into the pubis, and to lay bare the fibres (triangular fascia) which 

 ascend therefrom to the linea alba. 



Poupartfs ligament (fig. 97) is the lower border of the aponeurosis Poupart's 

 of the external oblique, which is thickened and folded backwards, so lg 

 as to form a slight groove with the concavity upwards. In the hollow 

 of the ligament the lowest fibres of the internal oblique and trans- 

 versalis muscles and the cremaster take their origin. Externally it outer and 

 appears round and cord-like, and is attached to the anterior superior inner attach* 

 iliac spine. Internally it widens as it approaches the pubis, and is m< 

 inserted into the pubic spine and the pectineal line of the hip-bone forms 

 for about three-quarters of an inch, forming a triangular piece with 



