VARIETIES OF INGUINAL HERNIA. 765 



or at the internal ring ; more frequently in the latter situation. If it is situated at 

 the external ring, the division of a few fibres at one point of its circumference is 

 all that is necessary for the replacement of the hernia. If in the inguinal canal, 

 or at the internal ring, it will be necessary to divide the aponeurosis of the Ex- 

 ternal oblique so as to lay open the inguinal canal. In dividing the stricture, 

 the direction of the incision should be directly upwards. 



"When the intestine passes along the spermatic canal, and escapes from the 

 external ring into the scrotum, it is called common oblique inguinal or scrotal hernia. 

 If the intestine does not escape from the external ring, but is retained in the 

 inguinal canal, it is called incomjylete inguinal hernia or bubonocele. In each of 

 these cases, the coverings which invest it will depend upon the extent to which 

 it descends in the inguinal canal. 



There are two other varieties of oblique inguinal hernia : the congenital and 

 infantile. 



Congenital hernia is liable to occur in those cases where the pouch of perito- 

 neum which accompanies the cord and testis in its descent in the foetus remains 

 unclosed, and communicates directly with the peritoneum. The intestine descends 

 along this pouch into the cavity of the tunica vaginalis, and lies in contact with 

 the testis. This form of hernia has no proper sac, being contained within the 

 tunica vaginalis. 



In infantile hernia, the hernial sac descends along the inguinal canal into the 

 scrotum, behind the pouch of peritoneum which accompanies the cord and testis 

 into the same part. The abdominal aperture of this pouch is closed, but the 

 portion contained in the inguinal canal remains unobliterated. The hernial sac 

 is consequently invested, more or less completely, by the posterior layer of the 

 tunica vaginalis. from which it is separated by a little loose areolar tissue ; so that 

 in operating upon this variety of hernia, three layers of peritoneum would require 

 division, the first and second being the layers of the tunica vaginalis, the third 

 the anterior layer of the hernial sac. 



DIEECT INGUINAL HERNIA. 



In Direct Inguinal Hernia, the protrusion makes its way through some part of 

 the abdominal wall internal to the epigastric artery, and passes directly through 

 the abdominal parietes and external ring. At the lower part of the abdominal 

 wall is a triangular space (Hesselbach's triangle), bounded, externally, by the 

 epigastric artery ; internally, by the margin of the Eectus muscle ; below, by 

 Poupart's ligament. The conjoined tendon is stretched across the inner two- 

 thirds of this space, the remaining portion of the space being filled in by the 

 transversalis fascia. 



In some cases [more often, perhaps, than is generally supposed], the hernial 

 protrusion escapes from the abdomen on the outer side of the conjoined tendon, 

 pushing before it the peritoneum, the subserous cellular tissue, and the transver- 

 salis fascia. It then enters the inguinal canal, passing along nearly its whole 

 length, and finally emerges from the external ring, receiving an investment from 

 the intercolumnar fascia. The coverings of this form of hernia are precisely 

 similar to those investing the oblique form of protrusion. 



In other cases, and this is the more frequent variety, the intestine is either 

 forced through the fibres of the conjoined tendon, or the tendon is gradually dis- 

 tended in front of it, so as to form a complete investment for it. The intestine 

 then enters the lower end of the inguinal canal, escapes at the external ring, lying 

 on the inner side of the cord, and receives additional coverings from the super- 

 ficial fascia and the integument. This form of hernia has the same coverings as 

 the oblique variety, excepting that the conjoined tendon is substituted for the 

 Cremaster, and the infundibuliform fascia is replaced by a part of the general 

 fascia transversalis. 



The seat of stricture in both varieties of direct hernia is most frequently at the 



