248 



with the liquid just alluded to, it assists in the 

 process of digestion and assimilation. Fishes 

 generally bolt their food their gullet being of 

 enormous size and this is accordingly often 

 found in their stomach retaining its natural form, 

 but when touched, quickly dissolving into a jelly. 

 From this circumstance it would appear, that 

 digestion is in them the result of some menstruum 

 capable of dissolving the food, without mastica- 

 tion, as in the mammalia, or trituratiori, as in 

 birds. The lacteal or absorbing vessels of the 

 intestinal canal of fishes are very numerous ; 

 and these, having collected all the nutritious 

 juices from the intestines, unite together into 

 several large ducts, which run upwards along the 

 side and back part of the oesophagus, and pour 

 their contents, to be mingled with the blood, into 

 the subclavian vein. 



The heart of fishes, for the most part, is tri- 

 angular, and generally very small in proportion 

 to the size of the animal. It consists of only 

 one auricle and ventricle ; and from the latter 

 cavity a large vessel is sent which is entirely dis- 

 tributed upon the gills. These latter organs per- 

 form the same office as the lungs in the higher 

 animals affording a means by which the blood 

 is enabled, by coming into contiguity with the 

 air, either on land or in the water, to abstract 

 a portion from it and thereby become fit to per- 

 form the multifarious purposes for which it is 

 destined. They are placed on each side, im- 

 mediately below the neck if, indeed, an ani- 



