OF FISHES IN GENERAL. 
39 
f efidence. Both eels and chart might he rendered ufeful 
Pond-fith ; as neither are too delicate for tranfportation ; 
an d, from experiments already made, the certainty of 
their thriving is fully eftablilhed. 
If the tranfiation of fifh has not been often attempted, 
certainly is not becaufe they are incapable of fuf- 
taining various degrees of heat, and of living in different 
climates. The neceffity of procuring a fupply of food ; 
°f feeking a fafe retreat for propagating their fpecies, or 
a temperature of that element in which they live, fuited 
to their conft ttutions, compels the fifties, as remarkably 
as terreflrial animals, to make extenfive migrations from 
°fe part of the fea to another. With regard, however, to 
this curious fubject, we have but few fafts upon which 
We can depend. 
The fifh, like land animals, are eiiher folitary or gre- 
garious : Of the former kind, trout, falmon, pike, See. 
the migrations are probably in queft of. a proper place 
to depoiite 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, depoiite their bur- 
Hen, and again return. The trout likewife afeends near 
the fourceof the rivulets at the feafon, when they enter the 
ftnaller branches that run into the main ftream, for the 
Purpofe of fpawn ing. It is then they are often feen in 
hnail rivulets upon the high grounds, in water fo flial- 
l°w as fcarcely to cover their bodies. 
Of the gregarious fillies that frequent frelh water, we 
no w b ut little concerning their migrations. It is pro- 
a e > that the perch and the minnow are llationary, and 
'at they retire only to the margin of the river to depofit 
1 e * r Ip a wn. The fifties, moil remarkably gregarious, 
are 
