OF THE PERITONEUM. 1 1 



In man, it is a complete sac, having no hole in it; but in wo- 

 man, its cavity communicates externally through the Fallopian 

 tubes. It has a double use: In consequence of covering the 

 viscera, it is so reflected from them to the sides of the abdomen, 

 that its processes keep the viscera in their proper places, and, 

 therefore, answer as ligaments: again, its internal surface being 

 smooth, indeed, highly polished, and continually lubricated by a 

 thin, albuminous fluid, corresponding with the synovial mem- 

 brane of the joints, the motions which the viscera have upon 

 each other in exercise, and in the peristaltic action of the bow- 

 els, are much facilitated. 



The manner in which a double night-cap is applied to the 

 head, will afford the easiest conception of' the reflections of the 

 peritoneum. If there were only one viscus in the belly, and that 

 of a somewhat regular outline, as the spleen, the comparison 

 would be rigid, and perfectly appreciable. One part of the cap 

 is close to the head, and compares with the peritoneal coat of 

 the spleen; the other is loose, and is equivalent to the peritoneum, 

 where it is in contact with the parietes of the belly. It is also 

 evident from this, that none of the viscera can be said to be 

 within the cavity of the peritoneum; that they are all on its out- 

 side; and that a viscus, in getting a coat from the peritoneum, 

 merely makes a protrusion into its cavity. Starting with this 

 simple proposition, it is easy to conceive of a second, a third body, 

 and so on, deriving an external coat from a protrusion into the 

 same sac. Admitting these bodies to be spheres, the proposition 

 is immediately intelligible; and, as a last step from it, the idea is 

 not rendered much more complex by substituting any bodies even 

 the most irregular in form, for these spheres. 



Such, then, is the fact in regard to the stomach, intestines, 

 &c.;-they all, with the exceptions to be stated, derive an ex- 

 ternal coat from the peritoneum. 



The Peritoneum is, for the most part, smoothly spread upon 

 the interior surface of the abdominal muscles. It adheres to 

 them with considerable firmness by means of intervening cellular 

 substance: this adhesion, where it closes the posterior opening of 

 the umbilicus, is unusually strong. Below, the uniformity of the 

 membrane as it descends from the navel to the pelvis is inter- 

 rupted by its being reflected over the urachus, and over the re- 

 mains of the umbilical artery on each side. Where the urachus 



