Page:Popular Science Monthly Volume 37.djvu/321

Rh from the glacier, though seldom able to detect its primitive form, the greater part, say at least six sevenths of its volume, sinking below the surface.

If Greenland, like other regions, passed through a glacial epoch, the fossil remains preserved in its sedimentary rocks show that it had also its hot and temperate periods. The old formations





which have yielded Carboniferous, Triassic, and Jurassic fossils, present types of organisms comparable to those at present found in the torrid zone. The upper chalk beds, abounding in vegetable forms, analogous to those of the subtropical and temperate zones, had already been examined by Giesecke at the beginning of this century. They supplied to Nordenskjöld a very remarkable flora, especially rich in dicotyledonous plants represented by numerous families of Cycadea, a tree-fern, and even a bread-fruit tree. At that time the mean temperature must have been as high as 68° Fahr.

The Miocene flora, whose general physiognomy corresponds to a more temperate climate, averaging about 53° or 54° Fahr., is illustrated by splendid specimens discovered chiefly in Disco Island