98 Prof. O. Heer vn the. last Discoveries 



species, such as the marsh-cypress, the poplars, the hazel, 

 and the oaks [Quercus plataiiia and Q. groenlandica, Heer), 

 were also spread over the isthmus which united the two lands, 

 and that the whole of Greenland had the same vegetation. 



This forest vegetation disappeared during the following or 

 Pliocene period, and during the glacial epoch, when our coun- 

 tries themselves had a climate which in many respects resem- 

 bled that of high northern latitudes. The Swedish expeditions 

 have collected important observations upon the manner in 

 which this remarkable change was brought about in the arctic 

 regions ; but the space at my disposal will not allow me to 

 enter into details on this subject. I may, however, be per- 

 mitted to mention briefly some facts which stand forth more 

 clearly than ever from the information brought back by Mr. 

 Whymper and by the last Swedish expedition. 



In the first place, it becomes evident that our knowledge of 

 extinct plants and animals has ceased to be so incomplete and 

 to present so many gaps as the partisans of the doctrine of the 

 mutability of species are pleased to assert — an assertion, how- 

 ever, which is very necessary to their hypothesis. The ani- 

 mals and plants obtained from the rocks of these distant 

 northern countries belong in good part to species already 

 known. Nevertlieless the conditions of life then, at least in 

 one particular, must have been very different from those whicli 

 prevailed elsewhere ; for the glacial zone, in ancient geological 

 periods as at present, must have had a long day of summer 

 and a long night of winter. The night lasts nearly a third of 

 the year on the shores of the Ice fiord. In Bear Island the 

 flora of tlie Carboniferous epoch presents in general not only 

 the same species as those of Europe, but we find in them the 

 slight shades which characterize these species in our countries, 

 and we can have no hesitation as to the phase of the Carboni- 

 ferous period to which that flora must be referred. This is 

 also the case with the much more recent Miocene flora of 

 Greenland and Spitzbergen. In this we have throughout 

 well-marked species, as in our countries. The marsh-cypress 

 of northern Spitzbergen is exactly the same as that of North 

 Carolina and Virginia. This species has maintained its ex- 

 istence down to our own day ; after a number of centuries 

 which it is impossible to estimate, it produces in Virginia the 

 same branches covered with elegant leaves, the same flowers, 

 and the same fruits as formerly in Spitzbergen, on the shores 

 of the Tec fiord. 



Is it otherwise with the animal kingdom? The marine 

 animals of Spitzbergen belonging to the (Jarboniferous, Tri- 

 assic, and Jurassic formations furnish the same demonstration. 



