chap, xvi.] HERNIA. 311 



is in the male. It. is occupied by the round ligament, 

 and offers such slight inducement to the formation of 

 a i-upture, that acquired inguinal hernia is as rare 

 among females as it is common among men. In the 

 female foetus a process of peritoneum descends for a 

 little way along the round ligament. It corresponds 

 to the processus vaginalis of males, and is known as 

 the canal of Nuck. If this process remains patent, 

 as it not infrequently does, it may lead to a rupture that 

 corresponds to the congenital hernia of males. Indeed, 

 in quite early life the inguinal rupture is about the only 

 form met with in female children, if exception be made 

 of umbilical hernia. In all such instances of early 

 inguinal hernia the gut has travelled down a patent 

 canal of Nuck. 



It only remains to be said, that in endeavouring to 

 reduce an inguinal hernia by taxis the thigh should 

 be flexed and adducted, for in that position the ab- 

 dominal parietes that bound the inguinal canal are 

 the most relaxed. This position of the thigh affects 

 the inguinal region mainly through the attachments 

 of the fascia lata to Pou part's ligament. 



In herniotomy an incision is made along the 

 middle of the tumour and in its long axis, being 

 so arranged that its centre shall correspond to 

 the external ring. The superficial external pudic 

 artery is usually divided in the operation. It is im- 

 possible to distinguish the various layers of tissue that 

 cover the hernia, the only one, as a rule, that is re- 

 cognisable being the layer from the cremaster. In 

 dividing the constriction it is usually recommended to 

 cut upwards in all forms of inguinal hernia. The only 

 vessel in risk of being damaged is the deep epigastric. 

 In the oblique form of rupture an incision directly 

 upwards would quite avoid this artery ; but in a direct 

 hernia, where there is reason to suppose that the vessel 

 is in close connection with the neck of the sac, it is 



