FUNCTIONS OF FISHES. 19 



animals continue to live, has not yet been ascertained. The age of man seems not 

 equal to the life of the most minute species. In the royal ponds of Marli, in Franco, 

 there are some particular fish which, it is said, have been preserved tame since the 

 time of Francis the First, and which have been individually known to the persona 

 who have succeeded to the charge of them ever since that period. 



Fish, Hive land animals, are either solitary or gregarious. Some, as Trout, Salmon, 

 Sc, migrate to considerable distances in order to deposit their spuwu. Of the 

 gea-fish, the Cod, the Herring, and many others, assemble in immense shoals, and 

 migrate in these shoals through vast tracts of the ocean. 



In the Gmelinian edition of the Systema Naturae, the Fishes are divided into six 

 orders : 



1. Apodal; with bony gills, and no ventral fins, as the Eels. 



2. Jugular ; with bony gills, and ventral fins before the pectoral ones, as the Cod 

 and Haddock. 



3. Thoracic; with bony gills and ventral fins placed directly under the thorax, m 

 the Turbot, Sole, Perch, and Mackerel. 



4. Abdominal ; with bony gills, and ventral fins placed behind the thorax, as the 

 Salmon, Pike, Herring, and Carp. 



5. Braiichiostegous : with gills destitute of bony rays, as the Pike-fish and Lump* 

 fieh. 



6. Chs^ndropierygious ; with cartilaginous gills, as the Sturgeon, Shark, Skate, and 

 Liamprey. „ 



