Page:Popular Science Monthly Volume 57.djvu/438

428 present to the world a clear idea of the vegetation of the Cretaceous land, scarcely known to science until elucidated by him. It developed that in Heer's time, among the fossil plants found in Spitsbergen alone were 7 ginkos, 8 pines, a short bamboo, 7 poplars, 3 maples and a fossil strawberry.

Dr. Nansen was fortunate in securing the co-operation of Prof. A. G. Nathorst in the examination of the fossil plants collected in Franz Josef Land, as he has devoted much time to the flora, present and past, of various portions of the Arctic regions, especially Spitzbergen and King Charles Land. Nathorst had the advantage of the notes of Newton, J. H. Steele and R. Curtis on the fossils of Franz Josef Land, published in the Quarterly Journal of Geological Science, London, vols. 53-54, 1897-1898.

Most unfortunately, the fossils were very fragmentary, the leaves in themselves small and often indistinguishable in color from the rock, so that their examination was made almost entirely under the magnifying lens. While the organic substance of the plants was sometimes still to be seen in a soft, brownish variety of rock, yet the harder yellowish varieties offered only impressions, or cavities, their organic substance having entirely disappeared. In cross fractures there were sometimes cavities which were complete transverse sections of coniferous leaves.

There were twenty-nine species, of which the entire number are coniferous except one fungus, one fern, two palms and one uncertain.

Nathorst says: "The plant-bearing strata of Franz Josef Land, which are yet known to us, all belong, with the exception of those from Cook's Eock and Cape Stephen, the age of which is still uncertain, to the upper Jurassic, or the transition beds to the cretaceous, while as yet no tertiary strata have been discovered."

In geological age, while the Franz Josef flora resembles most the previously known Jurassic floras of Siberia and Spitzbergen, yet Nathorst considers the geological age different, and naturally places it between the two, it being evidently younger than that of Siberia.

It is interesting to note that Doctor Koettlitz found in an isolated basalt nunatak (rock or hill protruding from a glacier) fossil plants similar to those found by himself and Nansen on the north side of Cape Flora. These nunatak plants, which Koettlitz believed to be in situ, are identified by Nathorst as Upper Jurassic, and came from an elevation variously estimated as from six hundred to seven hundred and fifty feet above the sea.

Nansen agrees with Koettlitz in believing that tree-trunks found by them, charred into charcoal or partly silicified, chiefly belonged to conifers growing on the soil over which basalt flows were discharged during the Upper Jurassic or Lower Cretaceous age, and that they have been charred by a flowing mass of lava that overwhelmed them.