The universal geography : earth and its inhabitants

96 SCANDINAVIA.North Sea with the Baltic, as clearly shown !>y tracts now covered with marinefossils. Oysters have been picked up on the south shore of Aliilar, a sure proofthat these waters had formerly at least 17 parts in 1,000 of salt. Bjorko, one ofits islands, was till recently strewn with the bones of sea- fowl as well preserved asif they had been just forsaken by the mews after breeding season. Nay, more, therestill survive small animals of marine origin whose organism has been slowlyadapted to the fresh water gradually replacing the sea in the lacustrine basins.Even the Norwegian Lake Mjtisen, notwithstanding its distance from the strait ofwhich "Wetter and "Wener are detached links, still harbours the Mysis relicta,Fig. 48.Lake Malar.Scale 1 : 695,000.a living species bearing witness to its former connection with the neighbouringseas, whose temperature was at that time as low as is now the Frozen Ocean.Henceforth severed from the sea by slowly widening isthmuses, the greatlacustrine basins dividing Sweden into two distinct regions have continued to risewith the rest of the land. Their surface is now above sea-level, although the bedsof most of them are below the surface of the Baltic. Wener, the largest of theScandinavian lakes, with an area one-tenth the size of all the rest together,* has amean elevation of over 144 feet, with an extreme depth of 290 feet. It is thustwo or three times larger than Lake Geneva, and about one-fourth the size ofLadoga. Wetter, at twice the altitude of Wener, is also deeper, measuring413 feet, and 125 below the level of the surrounding seas. Hjelmar, lying nearer—* Area in square miles : "Wener, 2,386 ; Wetter, 733 ; Malar, 668.