12 ON THE STRUCTURE AND 



V : 



called the peristaltic motion. After having been mixed 

 with the bile and the liquor supplied by the pancreas, and 

 had the chyle separated, it traverses the remainder of the 

 canal, and is then expelled from the body. 



The liver is a large glandular body, given for the secretion 

 of the bile. It is of a reddish brown colour, of a firm con- 

 sistence, and is furnished with a bag, (which contains the 

 bile,) called the gall-bladder. It generally consists of two 

 lobes, or divisions : but in the Lion it has seven. Tiie bile 

 has been considered by most physiologists as a stimulus for 

 creating the peristaltic motion. When the stomach is dis- 

 tended with aliment, the gall-bladder undergoes a certain 

 degree of compression, and the bile, in consequence, passes 

 out into the intestinal canal, to perform the above-mentioned 

 office. 



The pancreas, or sweet-bread, is a whitish oblong gland, 

 situated behind (he bottom of the stomach. In the human 

 subject it is about six inches long, two and a half wide, and 

 somewhat more than half an inch thick. The liquid pro- 

 duced from this gland is limpid and tasteless, not unlike 

 mucilage dissolved in water. Its use is supposed to consist 

 in diluting the alimentary pulp, for the purpose of incor- 

 porating it more easily with the bile. 



Th spleen is a thin body, composed of membranes filled 

 with blood, and, in all the mammiferous animals, is situated 

 betwixt the ribs and the stomach. From the relative situ- 

 ations of the spleen and stomach, it is supposed that this 

 member is chiefly of use in regulating the supply of blood 

 for the necessities of the stomach : for when the stomach is 

 full, by pressing upon the spleen, it forces more blood into 

 itself than it requires at other times. In the carnivorous 

 animals, the cells of the spleen are small : in the grameni- 

 vorous animals they are larger ; and, in those which rumi- 

 nate, their size is very considerable. The Porpesse has 

 $!> generally 



