424 DISSECTION OF THE ABDOMEN. 



placed beneath it. With a view of avoiding the surrounding vessels, the 

 cut is directed upwards on the front and mid-part of the hernia. 



Other designations. This kind of hernia has other names applied to it 

 sometimes by surgeons, according as it has passed certain points in the 

 wall of the abdomen. If the intestine remains in the inguinal canal, 

 the term bubonocele is applied to the swelling ; but if it has extended into 

 the scrotum, the appellation scrotal rupture, or oscheocele, is given to the 

 tumor. 



Varieties of the external hernia. There are two varieties of the oblique 

 inguinal hernia (congenital and infantile), which are distinguished by the 

 condition of the peritoneal covering. 



Congenital hernia. This kind is found for the most part in the infant 

 and the child, though it may occur in the adult male. In it the tube of 

 peritoneum, which accompanies the testicle from the abdomen in the foetus, 

 remaining unclosed, the intestine descends into a sac already formed for 

 its reception. 



As it takes the course of the inguinal canal, it will possess the cover- 

 ings before enumerated for the external hernia ; and it passes at the first 

 to the bottom of the scrotum, instead of being arrested at the top of the 

 testis. 



With care it may be distinguished, whilst it is of moderate size, by its 

 position in front of the testicle. 



For the seat, cause, and division of the stricture, refer to what is before 

 stated for external hernia. 



Infantile hernia is much rarer than congenital, and cannot be distin- 

 guished from the common external hernia during life. It was first recog- 

 nized in the young child, and received its name from that circumstance ; 

 but, like the congenital, it may be met with in the adult. Its chief dif- 

 ferential character is derived from the state of the peritoneum. 



The peritoneum has the following condition : the tube of that mem- 

 brane passing with the testicle in the foetus, is closed only at the internal 

 abdominal ring, instead of being obliterated from that point down to the 

 testicle, so that a large serous sac will be situate in front of the spermatic 

 cord, and may occupy the inguinal canal. With this state of the perito- 

 neum, should an external hernia with its coverings descend along the cord 

 in the usual way, it will pass behind the unobliterated sac, like a viscus 

 into serous membrane. In this way there will be two sacs ; an anterior 

 (the tunica vaginalis), containing serum, and a posterior inclosing the 

 intestine. 



The infantile hernia is first recognized during an operation by the knife 

 opening the tunica vaginalis. The operator then proceeds to lay bare the 

 neck of the hinder or hernial sac, and to treat the stricture of it as before 

 described (p. 423). 



The INTERNAL or DIRECT INGUINAL HERNIA escapes on the inner side 

 of the epigastric artery, and has a straight course through the abdominal 

 parietes. Its situation and coverings, and the seat of stricture, will be 

 better understood after the examination of the part of the abdominal wall 

 through which it passes. 



Anatomy of the internal hernia. At the lower part of the abdominal 

 wall is a triangular space (fig. 140) which is bounded by the epigastric 

 artery on one side, the outer edge of the rectus muscle on the other, and 

 the inner half of Poupart's ligament below : it measures about two inches 

 from above down, and one inch and a half across at the base. 



