the Residence of certain Fishes. 211 
might not succeed, by forcibly transporting the salmon to lakes 
from which they could not reach the sea, is yet to be tried; but 
certainly there are not at present any salmon found inthe Scottish 
lakes, except where they have the power of making their annual 
migrations into salt water. That salmon are attached to the parti- 
cular rivers where they have been spawned and bred, is believed by 
all the fishermen; but this does not prove that they are naturalized 
to those fresh waters, as they inyariably return to the sea after 
haying deposited their spawn. 
According to Pallas, the sturgeon, the sterlet, and some species 
of salmon reside in the river Kama without ever descending to the 
Caspian sea; and the authority of such a naturalist is perhaps suf= 
ficient to establish this interesting fact. 
These, then, are the whole of the proofs“which, in M. Nouel’s 
paper, are adduced in support of this project ; it remains to be seen 
by what other facts and reasonings its plausibility may be supported, 
and an inducement offered to those who have it in their power, to 
make such experiments as alone can establish it among those facts 
in natural history which are capable of being applied to the uses 
of man; to increasing the quantity, or adding to the accessible 
variety of his food. 
In the first place, it must be remarked, that the habits of many 
sea-fish are, in this respect, so convertible, or so easily assimilated 
to the requisite change, that a large portion of their time is passed 
in fresh water. The common salmon, the grey salmon, and the 
salmon trout, Salmo Salar, Salmo Eriox, and Salmo Trutta, are fa- 
miliarly known to frequent rivers for the purpose of spawning; re- 
turning to the sea when this operation has been performed. The 
Salmo Migratorius leaves the lake Baikal for the same season; and, 
with us, the 8. Lavaretus, or Gwiniad, and the S. Eperlanus or 
smelt, also quit the sea; ascending rivers at the spawning season, 
as does the Salmo Autumnalis, an inhabitant of the frozen ocean. 
Now though M. Nouel is wrong in saying that the salmon 
is found in the Scottish lakes excluded from access to the sea, 
it is a fact that the salmon trout, or sea trout, as it is called in Scot- 
land, is now a permanent resident in a fresh-water lake in the 
