FRESH WATER FISHES. 131 



kind of vitality to resist the noxious qualities of 

 the fluid in which they swim, that would be fatal 

 to others. This curious arrangement in the plan 

 of creation is most admirable, contributing to 

 the universal diffusion of animals over the whole 

 globe. 



There is not a spot of land on earth, nor a pool 

 on the face of it, that is not teeming with its count- 

 less millions of organized beings, possessing all the 

 necessary apparatus for supplying their physical 

 wants, and for propagating their species. But the 

 boundaries by which the animal creation is re- 

 strained, are not so arbitrary that no deviations are 

 allowable : the fish, or the quadruped, like 

 man, can change its residence, and by being 

 gradually climated, the function of the vital organs 

 become accommodated to the condition of a mod- 

 ified element. 



Here then, we can find the origin of the crea- 

 tion of new genera ; in the meeting of strangers, 

 and in the aerial and aqueous influences effected 

 on the offspring. 



We have long entertained the opinion, that the 

 sea is the natural habitation of all fishes. By 

 the wandering habits of some, the fleeing of 

 others from their enemies, and the operation 

 of physical causes, they became gradually dis- 

 persed in the tributary waters of the great reser- 

 voir of the world. 



