Chap, xvii.] THE SMALL INTESTINES. 307 



transverse, and, in consequence of the greater mus- 

 cular development of the jejunum, wounds of that part 

 gape more than do those of the ileum. Transverse 

 wounds gape most when inflicted across the free 

 border of the gut, since in that place the longitudinal 

 muscular fibres are thickest. 



In one remarkable case a man was stabbed in 

 the belly. It was subsequently found that there 

 was a small puncture in the ileum, which had 

 been plugged by the mucous membrane, and further 

 secured by recent lymph. The man did well until 

 the fourth day, when he died somewhat suddenly. 

 It was then found that an intestinal worm (ascaris 

 lumbricoides) had worked its way through the 

 wound, breaking down the adhesions, and had escaped 

 into the peritoneal cavity. Extravasation followed, 

 and thus the worm was the immediate cause of the 

 man's death. 



Any part of the small gut may be ruptured 

 by severe contusions. The calibre of any piece of 

 the intestine depends mainly upon the condition of 

 its muscular wall. In peritonitis and in certain other 

 conditions the muscular coat is paralysed and the 

 bowel becomes intensely dilated by gas (tympanitis). 



The second and third parts of the duodenum are the 

 most fixed portions of the small bowel, and the only 

 parts that have not a complete peritoneal investment. 

 The termination of the duodenum is held in place 

 by a strong fibrous band that descends from the left 

 crus, so that, no matter how much the gut may be 

 disturbed by distension, that part will still retain a, 

 constant position. It will be understood that the 

 duodenum, if approached from behind, may be 

 wounded without injuring the peritoneum, since it has 

 a large non-peritoneal surface (Fig. 33). On account of 

 their fixed position the second and third parts of the 

 duodenum are never herniated. In connection with 



