chap, xvi.] HERNIA. 289 



pubes and the uppermost fibres of the obturator ex- 

 ternus muscle. The obturator vessels may be either 

 found on the outer or inner side of the sac, or above it. 

 The proximity of the nerve renders it very liable to 

 be pressed upon, and pain along the nerve is often a 

 marked feature of the rupture. The hernia presents 

 beneath the pectineus muscle, to the inner side of the 

 capsule of the hip, behind and to the inner side of the 

 femoral vessels, and to the outer side of the adductor 

 longus tendon. Pain on moving the hip is generally 

 a conspicuous symptom. This hernia is more common 

 in females ; and it is worthy of note that the orifice of 

 the obturator canal can be examined, to some extent, 

 through the vagina. Professor Wood reports a re- 

 markable case where a hernial protrusion of a part of 

 the adductor longus through a rent in its aponeurosis 

 was mistaken for an obturator hernia. 



Rare forms of hernia. In perineal hernia 

 the sac, covered by the recto-vesical fascia, escapes 

 through the anterior fibres of the levator ani muscle, 

 between the prostate (or vagina) and the rectum. 

 In pudendal hernia the sac lies in the posterior inferior 

 half of the labium pudendi, escaping between the 

 ascending ramus of the ischium and the vagina. In 

 sciatic hernia the gut escapes through the sciatic 

 notch in front of the internal iliac vessels, above or 

 below the pyriformis, and appears under the gluteus 

 maximus muscle. As regards umbilical hernia, 

 nothing remains to be added to what has been already 

 said (page 269), save that the sac from its position 

 nearly always contains omentum, and may contain 

 stomach. In lumbar hernia the gut escapes in front 

 of the quadratus lumborum muscle, and appears on the 

 surface through the triangle of Petit (the gap between 

 the latissimus dorsi and external oblique muscles), and 

 therefore just above the highest point of the iliac 

 crest. The sac must either force before it, or (in cases 

 T 



