164 ANATOMY OF THE ABDOMEN, ETC. 



of cord, known as Pouparfs ligament, and which is con- 

 tinuous by its lower border with the fascia lata of the 

 thigh. When properly dissected, small foramina will be 

 noticed in the aponeurosis, giving exit to the cutaneous 

 nerves and vessels ; the nerves are branches of the inter- 

 costals, and of the lumbar plexus, and the arteries are 

 chiefly from the internal mammary, lumbar, and circum- 

 flexa ilii. The outline of the rectus muscle can be plainly 

 seen through the tendon of the external oblique; the curved 

 line which indicates its external border and extends from 

 the os pubes to the chest is called the linea arcuata. At 

 the pubes the fibres of the aponeurosis split, and leave a 

 space which affords passage to the spermatic cord in the 

 mals and the round ligament in the female : this space is 

 very variable in size, and is usually larger in the male than 

 the female subject ; although there is nothing annular in 

 its conformation to give it such a name, it is called the 

 external abdominal ring. The fibres forming its superior 

 border or pillar interlace with those of the opposite side 

 in front of the symphysis pubes ; its inferior border or 

 pillar is formed from the internal portion of Poupart's 

 ligament. Just above the spermatic cord this separation 

 in the aponeurosis is traversed by a series of transverse 

 fibres, variable both in size and number ; they extend for a 

 considerable distance on either side of the pillars, and 

 constitute what are called the inter-columnar fibres. Be- 

 tween the pillars, covering in the cord and prolonged upon 

 it, is a thin and delicate expansion called the spermatic 

 fascia; if this is divided transversely upon the cord, the 

 handle of the scalpel may be passed under it and pushed 

 upward beneath the tendon ; this will demonstrate its ex- 

 istence as a layer distinct from the elements of the cord. 



The external oblique is to be removed by dividing it transversely 

 across its fleshy part ; the change in the direction of the fibres will 

 show when the internal oblique is reached. In accomplishing the 

 Reparation of these two muscles, the fascia of the internal muscle 

 should be removed with the external. In order to reserve the in- 

 guinal region, the tendon should be divided transversely from the 

 anterior superior spinous process to the linea alba, and down the linea 

 alba to near the pubes, so far as the close union with the muscle 

 beneath will permit, the portion below being left for further examina- 

 tion. The obliquus internus is thus exposed, except at its lower 

 part, which, by a little manipulation, may also be seen, on turning 

 downward that portion of the external oblique which has been left 

 attached. 



