SUPPLEMENT 



ON 



FISH IN GENERAL. 



GENERAL VIEW OF THE NATURE AND ORGAN- 

 IZATION OF FISHES. 



More than two-thirds of the surface of the earth are covered 

 by the sea; the continents and islands every where inter- 

 sected by rivers of all sizes, and overspread with lakes, ponds, 

 and marshes, present an aggregate of waters so considerable 

 in extent as to exceed the dry land, and afford space within 

 them to animated beings no ways inferior in number and 

 in variety of species to those which inhabit the earth. On 

 land, the matter susceptible of life, is in a great measure 

 employed in the constitution and maintenance of vegetable 

 productions ; from these herbivorous animals draw their food ; 

 which, becoming animalized through this medium, affords 

 proper aliment to the carnivora, who do not constitute more 

 than one half of the terrestrial species of all classes. But in 

 the water, and particularly in the sea, where the vegetable 

 kingdom is much more restricted, all organized substances 

 appear to be animated, or ready to become so : existing at 

 the expense of each other, or deriving sustenance from the 

 mucosities or other detritus of living bodies. In that element 

 the animal kingdom presents the extremes of bulk and mi- 

 nuteness : from the myriads of monads, and other creatures, 

 which would ever have remained invisible to us, but for the 



