Chan, xvn.) ABDOMINAL VISCERA. 351 



finger be placed in this angle, and the patient be 

 rolled over to the left side, the bowel that falls into 

 the finger cannot well be other than the descending 

 colon. The gut is drawn forwards, stitched to the 

 wound, and opened by a transverse cut. The width 

 of the non-peritoneal surface varies from four-fifths 

 of an inch to an inch in the empty state, and may 

 attain to two inches or more in the distended con- 

 dition (Braune). The part of the descending colon 

 usually opened is the highest portion of that bowel, so 

 that the finger can often be thrust into the transverse 

 colon, or the opening of that intestine can be seen. 

 In this, as in other circumstances, the large bowel may 

 be distinguished from the small by its sacculi, its three 

 longitudinal muscular bands, and its appendices epi- 

 ploicse. As regards dimensions, the small intestine 

 may, especially in cases of obstruction, be much larger 

 than the so-called large intestine. When empty, the 

 diameter of the descending colon is about equal to that 

 of the jejunum, the measurement in the two cases 

 being about one and a half inches. The average dia- 

 meter of the ileum is one and a quarter inches, and of 

 the caecum and commencing colon two and a half 

 inches. 



Lumbar colotomy is often performed through a 

 vertical or oblique incision in the place of the one just 

 given. 



The operation does not materially differ from that 

 described, when it is performed on the right side. 



Iliac or inguinal colotomy. In this very 

 excellent and simple operation the sigmoid flexure is 

 exposed and opened in the left iliac region. - A line 

 is drawn from the anterior superior iliac spine to the 

 umbilicus, and an incision some two inches in length is 

 made at right angles to this line and at a distance of 

 about one and a half inches from the point of bone. The 

 three muscles of the abdomen and the peritoneum 



