OF FISHES IN GENERAL, *59 



refidence. Both eels and charr might be rendered ufeful 

 pond-fifli ; as neither are too delicate for tranfportation ; 

 and, from experiments already made, the certainty of 

 their thriving is fully eftablifhed. 



If the tranflation of fifh has not been often attempted, 

 it certainly is not becaufe they are incapable of fuf- 

 tainiiig various degrees of heat, and of living in different 

 climates. The neceflity of procuring a fupply of food ; 

 of feeking a fafe retreat for propagating their fpecies, or 

 a temperature of that element in which they live, fuited 

 to their conftituticns, compels the fiflies, as remarkably 

 as terrellrial animals, to make extenfive migrations from 

 one pcirt of the fea to another. With regard, however, to 

 this curious fubjed", we have but few fads upon which 

 we can depend. 



The filh, like land animals, are either folitary or gre- 

 garious : Of the former kind, trout, falmon, pike, &cc, 

 the migrations are probably in quefl of a proper place 

 to depofite their fpawn. The falmon, for this purpofe, 

 leave the fea, and mount the rivers in the beginning of 

 winter, where they dig in the gravel, depofite their bur- 

 den, and again return. The trout likewife afcends near 

 the fourceof the rivulets at the feafon, when they enter the 

 fmaller branches th.it run into the main ftream, for the 

 purpofe of fpawning. It is then they are often feen in 

 fmall rivulets upon the high grounds, in water fo fhal- 

 low as fcarcely to cover their bodies. 



Of the gregarious filhes that frequent frefli water, we 

 know but little concerning their migrations. It is pro- 

 bable, that the perch and the minnow are ftationary, and 

 that they retire only to the margin of the river to depofit 

 their fpawn. The fifties, mod remarkably gregarious, 



are 



