10 ON THE STRUCTURE AND 



down the throat. To most animals it is likewise useful in 

 other respects, serving, for instance, to clean their fur, and 

 when wounded, to anoint their wounds with saliva. The 

 structure of this member, as an organ of sense, will be men- 

 tioned hereafter. 



The alimentary canal commences at the mouth, and ex- 

 tends, through the interior of the body, to a termination at 

 the opposite extremity of the trunk. Its first part, which 

 descends along the neck and breast, is denominated the 

 oesophagus, or gullet. After it has entered the abdomen, or 

 lower belly, it is dilated into a large sac, or bag, called the 

 stomach, the anterior orifice of which has the name ofcardia; 

 and the posterior, of pylorus. The remainder of the ali- 

 mentary canal is more particularly called bowels, or in- 

 testines. 



The parietes of this canal are composed of several coats, 

 or tunics, analogous to those which form the external tegu- 

 ments of the body. These coats act in a mechanical man- 

 ner on the substances which they contain, by slight con- 

 tractions of their fibres ; and in a chemical manner, by the 

 liquors which are poured out within them. The parietes of 

 the stomach yield a liquor called the gastric juice, which 

 reduces the aliment to an homogeneous pulp. But, inde- 

 pendently of the juices which the different coats of the 

 bowels produce, there are some that are separated from the 

 mass of the blood by glands, and which penetrate the in- 

 testinal canal by particular conduits. The most remarkable 

 of these glands are the liver, and pancreas or sweet-bread. 



All the remaining animals have their stomach so divided 

 as to form four distinct cavities. This is likewise the case 

 in the Seals ; and the stomach of the Porpesse, Grampus, 

 and Pike-whale, has five divisions. In carnivorous animals 

 it is simple, and so little extended as to appear rather a di- 

 latation of the intestines than a distinct sac. The consequence 



of 



