322 SURGICAL APPLIED ANATOMY, rchap xvn. 



reached by introducing the finger under the psoas 

 muscle. Through this incision the author has removed 

 the whole of the body of the first lumbar vertebra 

 that had been separated as a sequestrum.* The 

 lumbar arteries are avoided by keeping close to the 

 transverse process of the vertebrae. Through this 

 incision a psoas abscess may be most conveniently 

 opened. 



CHAPTER XVII. 



THE ABDOMINAL VISCERA. 



THE peritoneum. Certain of the viscera, as, 

 for example, the stomach, spleen, and small intestines, 

 are so closely invested with peritoneum that they could 

 not be wounded without that membrane being wounded 

 also. Inflammatory affections of such viscera are also 

 very apt to involve the peritoneum. Other organs, 

 such as the kidney, descending colon, pancreas, etc., 

 are so imperfectly covered with the serous membrane 

 that a wound of those organs need not involve it, 

 nor need it be implicated in even extensive inflam- 

 matory changes. Large abscesses may, for instance, 

 form about the kidney and discharge themselves 

 through the skin without any peritonitis being 

 induced. Spontaneous perforation, of the small intes- 

 tine must involve the peritoneum, while, on the 

 other hand, the caecum and descending colon may 

 become perforated, and the matter escape into the 

 subserous tissue without the serous membrane being 

 in any way involved. It is a strange fact that it is 

 singularly easy to set up inflammation of the perito- 

 neum if the membrane be approached from its 

 inner surface, but comparatively difficult if it be ap- 

 proached from without. Thus a small puncture of the 

 *Med.-Chir. Trans., 1884. 



