HERNIA 253 



and falx inguinalis should now be cleaned, and their precise 

 relations to the spermatic cord studied. Notice that the fleshy 

 lower border of the internal oblique overlaps the lateral part of 

 the cord, whilst, towards the outlet of the inguinal canal, the 

 falx inguinalis lies behind the cord. Next, replace the aponeurosis 

 of the external oblique, and introduce the point of the forefinger 

 into the subcutaneous ring and press directly backwards. Note 

 that the finger rests either upon the lig. inguinale reflexum, 

 which lies anterior to the falx inguinalis, or, if the reflex inguinal 

 ligament is absent, upon the falx inguinalis itself ; that, in fact, 

 the ligament and the falx and the fascia transversalis intervene 

 between the finger and the extra-peritoneal fatty tissue and the 

 peritoneum. The lower part of the internal oblique muscle 

 should now be separated from the transversalis by insinuating 

 the handle of the knife between them. When that is done, 

 divide the internal oblique close to the inguinal ligament, and 

 throw it medially. At the same time, make a longitudinal 

 incision through the cremaster muscle, and turn it aside from 

 the surface of the cord. 



All further dissection must be effected from the inside. Divide 

 the abdominal wall horizontally, from side to side, at the level 

 of the umbilicus. When the lower part is raised and its posterior 

 aspect is examined three peritoneal folds are seen the plicce 

 umbilicales a median and two lateral. In the median fold lies 

 the middle umbilical ligament or urachus, which descends from 

 the umbilicus to the apex of the urinary bladder, and in each 

 lateral fold is the obliterated portion of the umbilical branch of 

 the hypogastric artery of the corresponding side. Each lateral 

 fold, with the contained obliterated artery, descends from the 

 umbilicus to Tfte side of the bladder if the latter is distended, 

 and to the side wall of the pelvis if the bladder is empty. The 

 lower part of each lateral fold lies on the posterior surface of the 

 abdominal wall, a short distance to the medial side of the ab- 

 dominal inguinal ring. Still more lateral on each side, close to 

 the abdominal inguinal ring, is another fold, caused by the 

 inferior epigastric artery as it ascends to the posterior aspect of 

 the rectus abdominis. 



By means of the folds three fossae are mapped out on each 

 side of the middle line above the inguinal ligament ; they are 

 termed the supravesical, the medial and lateral inguinal fossce, 

 and they are regarded as determining, to some extent, hernial 

 protrusions in the inguinal region. The supravesical fossa lies 

 between the middle umbilical fold and the lateral umbilical fold ; 

 the subcutaneous inguinal- ring is in front of its lower part, 

 separated from it by the most medial part of the posterior wall of 

 the inguinal canal. The medial inguinal fossa, narrow but 

 frequently very deep, lies between the lateral umbilical fold and 

 the fold containing the inferior epigastric artery. It is behind 

 that part of the posterior wall of the inguinal canal which is 

 formed by the transversalis fascia only. The lateral inguinal 

 fossa lies to the lateral side of the fold formed by the inferior 

 epigastric artery, and its lowest, medial, and deepest part corre- 

 sponds with the abdominal inguinal ring. 



Having determined these points, the dissector can proceed as 

 follows : Divide the lower part of the abdominal wall in a 

 vertical direction along the linea alba, from the umbilicus to the 



