226 THE INFERIOR EXTREMITY 



If the subject is a male the dissector will have noted that as 

 the superficial external pudendal vessels pass towards the 

 symphysis pubis they cross superficial to a thick cord, the 

 funiculus spermaticus, which emerges from the abdominal wall 

 above the pubic tubercle, and descends across the upper and 

 medial angle of the front of the thigh into the scrotum. In the 

 female the round ligament of the uterus, which is less prominent 

 and less easy to define, lies in the position occupied by the sper- 

 matic cord in the male. At the upper part of the lateral margin 

 of the spermatic cord look for the ilio-inguinal nerve which 

 leaves the abdomen with the spermatic cord and sends branches 

 to the upper and medial part of the thigh (Fig. 107). 



When the ilio-inguinal nerve has been secured clean the 

 subinguinal lymph glands which lie along the line of the in- 

 guinal ligament, and trace some of the fine white lymph vessels 

 which enter and leave them. The subinguinal lymph glands 

 form two groups : a proximal group which lies parallel with 

 the inguinal ligament and a distal group, already displayed, at 

 the sides of the proximal part of the great saphenous vein. 

 Many of them are usually of fairly large size ; indeed they are 

 so large that, as a rule, they can be felt easily through the skin 

 in the living subject. They are recognised in the dissection, as 

 already stated, by their firm consistence and their yellowish- 

 pink colour (Figs. 105, 106). 



After the lymph glands have been located and cleaned proceed 

 to define the lateral and superior borders of the fossa ovalis 

 (Fig. 1 06). Commence at its inferior border, which has already 

 been displayed. Note that as the inferior border, which is 

 called the inferior cornu, passes medially it blends with the 

 upper part of the fascia lata which covers the muscles of the 

 medial part of the front of the thigh ; that part of the fascia 

 is known as the pectineal part of the fascia lata to distinguish it 

 from that part of the deep fascia which lies lateral to the fossa 

 ovalis and is called the iliac part of the fascia lata. 



The lateral end of the inferior cornu is continuous with the 

 falciform margin of the fossa ovalis which curves upwards and 

 medially to terminate in the superior cornu. The superior cornu 

 bends medially as the superior margin of the fossa and is 

 attached to the tubercle of the pubis and to the ligamentum 

 lacunare, which is an expansion of the medial end of the inguinal 

 ligament. The edge of the scalpel is needed to define the falci- 

 form margin and the superior cornu, for both are closely blended 

 with the cribriform fascia which extends across the fossa from 

 the falciform margin and superior cornu to the pectineal part of 

 the fascia lata. 



Clear away the cribriform fascia, dissecting out the arteries 

 and lymph vessels which pierce it, and display behind it the 

 anterior wall of the femoral sheath, a layer of fascia, which 

 surrounds the femoral vessels. Insinuate the handle of the 

 scalpel between the falciform margin and the femoral sheath 

 to demonstrate their independence, then pass the handle of 

 the scalpel behind the medial border of the femoral sheath to 

 demonstrate the fact that the pectineal part of the fascia lata 

 passes behind the femoral sheath. 



After the relations of the margins of the fossa ovalis have 

 been defined seek the remaining superficial nerves. Close to 



