316 - On the Glacier Phenomena 
character of the diluvial fauna; for a mass of ice so considera- 
ble could not be melted without materially chilling the waters 
which bathed it. The cold having slowly disappeared, the tem- 
perature would have been gradually elevated, and the fauna of 
the waters would take by degrees the more temperate character 
which distinguishes it at the present day. 
To this epoch of the invasion of Scandinavia by the waters 
of the sea, we should refer the arrangement in beds of the mud, 
sand, and gravel, which the great glacier has left in place in 
testimony of its ancient extent. The action of waves coming 
in upon this movable soil, has here overturned and heaped up 
the debris of marine life upon the shore, where the remains 
* are found mingled with scratched rocks and pebbles. if such is 
really the origin of these deposits, there is no reason for surprise 
The waves. 
or only occasionally, distinct beds in the properly glacial deposits. 
Those which are met with, ordinarily. occur in the neighborhoo 
of torrents.* 
After this epoch of immersion, even the proximate duration of 
which it is impossible at present to ascertain, the country of 
Scandinavia was again elevated. 'The shores bordering the high 
central regions, the plains of Sweden, and those of Finland, were 
successively raised from the bosom of the waters, bringing back 
with them to the surface the same mud, the same diluvial gravel, 
which had been deposited by the glaciers and which had under- 
gone no other change in the interval than that of being irregu- 
larly stratified and mingled with shells. The depressions of the 
soil alone remained covered with water, and formed the lakes 
of Sweden and Finland, as well as the Gulf of Bothnia. ‘The 
last, isolated from the ocean by the elevation of the intermediate 
land, has lost by degrees its saltness; and this explains the char- 
acter of its fauna, which is rather the fauna of brackish water 
than that of the sea. The interior lakes also were transfo 
completely into freshwater, and here and there may perhaps be 
found some indications of their ancient condition. It appears 
that certain fishes in particular have resisted these changes in the 
water, and according to researches of Scandinavian zoologists, 
especially of Mr. Esmark, the trout of Swedish lakes (Salmo 
* Voy. Rod Blanchet, Terrain erratique alluvien du Cassin du Léman. 
