52$ Prof. Nordenskibld — Former Climate of Polar Regions. 



blooded animals lived at that time in the vicinity of the 80th 

 degree of latitude attests beyond all doubt climatal conditions very 

 different from that of the present day. 



At the entrance of Ice-fjord and at Mount Agardh, in Stor-fjord, the 

 Triassic strata are covered with marine formations belonging to the 

 immediately subsequent geological era, the Jura period, and, as far as 

 we can judge from the few fossil remains hitherto discovered in these 

 strata, no diminution had as yet taken place in the warmth of the 

 polar climate. But great changes now came to pass in the portion 

 of the polar basin north of Europe, the ocean being again trans- 

 formed into a continent, which, though shattered and reduced, still 

 exists up to the present time. The upper portion, therefore, of the 

 Jura formation of Spitzbergen does not contain any marine organ- 

 isms, but in the place of them beds of sandstone and slate, witli 

 coal-seams and impressions of plants. From the strata belonging 

 to that age met with at Cape Boheman in Ice-fjord, situated 

 between the 78th and 79th degrees of latitude, the Swedish Ex- 

 peditions have brought home numerous impressions of palm-like 

 Cycadeasand Conifera3,fhe representative species of which now flourish 

 in the neighbourhood of the tropics. This already leads to the sup- 

 position of a warm climate, which supposition is further confirmed 

 by a comparison with the European fossil flora of the same date, 

 which indicates that the climate of Spitzbergen did not then mate- 

 rially differ from that of Central Europe. 



The Swedish Expeditions have also succeeded in obtaining, partly 

 from Greenland and partly from Spitzbergen, from two separate 

 epochs of the Cretaceous era, extensive collections of fossil plants, 

 lately described by Prof. Heer in the Transactions of the E. Swedish 

 Academy. By this we have been enabled not only to determine the 

 epoch when differences of climate first begin to show themselves 

 on the surface of the earth, but also pretty closely to follow an 

 extremely remarkable change in the appearance of the vegetable 

 world which took place during the course of that period. 



Within the polar basin we meet with the lowest division of the 

 Cretaceous age on the north side of the Noursoak Peninsula, in 

 North- Western Greenland. The crown of the hills is here com- 

 posed of black, ancient lava-streams and immense beds of volcanic 

 tuff, hardened in process of time into solid rock. 



Over these volcanic formations now rests a covering of perpetual 

 ice, and beneath them on the sea-shore vast strata of sand are dis- 

 covered, containing inconsiderable Coal-beds, interstratified with 

 clay-beds and a fine-grained argillaceous shale singularly fitted for 

 preserving the impressions of fossils that have been imbedded in it. 

 These plants belong to the lowest portion of the Cretaceous age, and 

 among the collections brought from this spot Heer has succeeded in 

 distinguishing 75 different species, among which are 30 Ferns, 

 9 Cycadeaa, and 17 Coniferaa. 



The third part of the Ferns belongs to one genus, Gleiclienia, which 

 still flourishes in the neighbourhood of the tropics and warmer parts 

 of the temperate zone, and the same remark holds good of the 



