Lumbar Hernia 305 



terior surface resting on the transversalis fascia. (For linece trans- 

 versce, see p. 296.) 



When suppuration occurs in the substance of the rectus, the pus 

 may be confined between two of the transverse intersections ; but if 

 the abscess be below the level of the inferior segment the pus finds 

 its way down towards the pubes. Pus between the planes of the ab- 

 dominal muscles is directed towards the linea semilunaris and may 

 there reach the surface, but it may work its way do\vn to the iliac 

 crest, or along the inguinal canal, and into the scrotum. The starting 

 point of such abscesses is, usually, caries of the spine. 



The quadratus lumborum is placed between the anterior and 

 middle layers of the lumbar aponeurosis of the transversalis muscle. 

 Three of its sides are attached, namely, to the iliac crest, the lumbar 

 transverse processes, and the last rib ; its outer border is entirely free, 

 and is a landmark in colotomy and in certain operations on the 

 kidney. 



In front of it are the diaphragm arising from the external arcuate 

 ligament, the psoas, kidney, the ascending or descending colon 

 (according to the side), the anterior trunk of the last dorsal nerve, the 

 ilio-hypogastric and ilio-inguinal nerves. The anterior divisions of 

 the lumbar arteries, and the erector spinas, are behind it. 



Lumbar hernia escapes on the outer side of the quadratus lum- 

 borum, taking, in addition to the covering from the peritoneum and 

 sub-peritoneal fat, the transversalis fascia ; it then causes a bulging of 

 the transversalis and internal oblique muscles, or passes through their 

 fibres, and escapes through the triangle oj Petit, bounded below by the 

 iliac crest, behind by the latissimus dorsi, and in front by the posterior 

 border of the external oblique. I have just recently had under 

 treatment a case of this sort, in which the hernia had emerged by the 

 track of a lumbar (spinal) abscess. The tumour was resonant on per- 

 cussion and reducible. Having returned it into the abdomen, I cut 

 down to the aperture, approximating its edges by deep sutures, having 

 thrust the sac within the abdomen. (' Brit. Med. Journal,' vol. i. 

 1888.) 



The supply of the muscles of the abdominal wall is from the 

 anterior divisions of the lower intercostal and of the lumbar nerves, 

 notably by ilio-hypogastric, ilio-inguinal, and genito-crural. These 

 nerves run between the inner oblique and the transverse muscles to 

 the outer border of the rectus. 



The blood-vessels are branches of the intercostals and lumbar ; of 

 the epigastric and circumflex iliac branches of the external iliac, and 

 of the internal mammary. The lymphatics are tributaries of lumbar, 

 pelvic, and mediastinal glands. 



The transversalis fascia covers the peritoneal surface of the ab- 

 dominal wall ; it is distinct from the transversalis aponeuroses 

 (p. 304). Lining the transversalis muscle, it is attached along the 



x 



