22 ORGANS OF DIGESTION. 



omenta, The serous membranes have also a power of contrac- 

 tion equal to that of their extension; but it should not be con- 

 founded with that condition where they are simply restored by 

 the connecting cellular substance, to the surfaces to which they 

 originally belonged. 



The sensibility of the serous membranes, from the want of 

 nerves in them, is extremely obscure in a natural state, and only 

 affords an imperfect sensation f touch. This is proved by the 

 impunity with which they may bo irritated on living animals. 

 But, when the condition of inflammation is once established, they 

 feel the most acute and, distressing pain. Though they resist 

 most frequently, and for a long time, disease in adjacent parts, 

 yet it not unfrequently is extended to them at last. In such 

 cases, it is generally a local instead of a universal affection, which 

 is communicated to them: Thus, in the. cancer and scirrhus of 

 the uterus; in disease of the spleen, and so on ; the portion of pe- 

 ritoneum nearest the affected organ manifests the marks of the 

 disease by preternatural adhesions and by disorganization, with- 

 out the whole membrane being involved. 



As the serous system consists in many species of sacs, so each 

 of them has some peculiarity of organization, of attachment, and 

 of vital properties, which is stated elsewhere in the account of 

 the species themselves. 



CHAPTER III. 



OF THE CHYLOPOETIC VISCERA. 

 SECT. I. OF THE STOMACH. 



THE Stomach (Pentriculus, Slomachus) is a hollow viscus 

 situated in the epigastric region, intended to receive at one end 

 alimentary matters from the oesophagus, and to transmit them, 

 at its other extremity, after digestion, into the intestinal tube, 

 where the nutritious part of the food is absorbed into the circu- 



