Prof. Nordenskiald — Former Climate of Polar Regions. 529 



Cycadea?, most of which are referable to the genus Zamia, species of 

 which we meet with within the tropics, as also of the Conifers, some 

 of which arc nearly related to forms still existing in Florida, Japan, 

 and California. From this Heer draws the conclusion, that in the 

 early part of the Cretaceous period the climate of the now ice-covered 

 Greenland was somewhat like that which now prevails in Egypt and 

 the Canary Isles. 



Among the Ferns, Cycadeaa, and Coniferae of Noursoak peninsula 

 were found a few impressions of a species of Poplar. Populus jmmceva, 

 which formed the only, and at the same time the oldest known 

 representative of the forest vegetation now prevailing in the tem- 

 perate zone. Nevertheless the vegetation of the arctic tracts was 

 already during the Cretaceous period undergoing a complete trans- 

 formation. Evidence of this has been obtained from the same locality, 

 Atanekerclluk, on the south side of the Noursoak peninsula, from 

 which such magnificent remains of arctic vegetation of the Tertiary 

 period had previously been obtained, from strata at a somewhat 

 higher level. Here, out of the talus that has fallen from the lofty 

 fells, some black and tolerably easily crumbling strata of shale pro- 

 trude, among which, on careful inspection, impressions of plants may 

 be discovered belonging to the Cretaceous formation, not to the 

 lower, but the upper portion of it. The vegetation is here quite 

 different. The Ferns and Cycadeas have disappeared, and in their 

 place we find deciduous trees and other dicotyledons in astonishing 

 variety, and forms, among which a species of fig may be mentioned, 

 of which not only the leaves, but also the fruit have been obtained 

 in a fossil state ; two species of Magnolia, etc. The climate that 

 then prevailed over the whole globe was therefore still warm and 

 luxuriant, even if, at least in the Arctic regions, considerably modified 

 from what it formerly had been, inasmuch as that the flowerless 

 vegetation (which was now beginning to die out), as far as we can 

 judge from its present representatives, the ferns, required a warm 

 humid climate, whereas the new forms, with their luxuriant flowers, 

 which now began to characterize the vegetable world, required, in 

 order to develope all the grandeur of their colours, a clear and sunny 

 sky. The disappearance of sundry tropical and sub-tropical forms, 

 that are met with in the older Cretaceous strata, has led Heer to the 

 ■conclusion that difference of climate at different latitudes was now 

 beginning to show itself, and he calls attention to the circumstance 

 that this takes place synchronously with the development of the 

 dicotyledonous plants in greater variety. 



Unhappily, in the Arctic regions no fossil remains belonging to the 

 Eocene age, which immediately succeeded the Cretaceous period, 

 have hitherto been met with, and we are therefore destitute of the 

 actual data necessary for ascertaining its climatic character. But the 

 next following, or Miocene age, places at our disposal abundant 

 materials in the magnificent remains of plants obtained, we may say, 

 from all parts of the polar basin and its vicinity ; from West Green- 

 land by Inglefield, McClintock, Kink, Torell, Whymper, and the 

 Swedish Expeditions; from East Greenland by Payer; from Alaska 



