A. BLYTT. 



Iii the beginning of the Tertiary epoch, when the sea, in 

 the higher latitudes, had retreated far back, the climate of Eu- 

 rope was (cfr. Saporta: Le monde des plantes avant r'apparitioii 

 de rhomnie. Paris 1879) temperate rather than tropical. Ac- 

 cording as the sea rose and the Eocene transgression proceeded, 

 the climate became warmer, and at the close of the Eocene epoch 

 ^he climate of South Europe was hot and dry. The rich Ter- 

 tiary flora of the Arctic regions is (cfr. Saporta and Gardner) 

 rather Eocene than (as Heer thought) Miocene. At the margin 

 between the Eocene and the Oligocene the sea retreated, and the 

 Arctic Tertiary flora began to migrate into Europe, supplanting 

 the southern plants. Then came the Miocene transgression, and 

 with it a rich tropical or subtropical flora. But just as the 

 Miocene sea retreated, the flora of Europe lost, little by little, 

 its richness and beauty, and the tropical elements became more 

 rare. During the Pliocene epoch the sea retreated still farther, 

 and the climate became colder and colder until the Glacial age* 

 arrived. But the last Quaternary transgression has, again, after 

 .several oscillations, compelled the ice to retreat, and our climate 

 has again become temperate. There is thus a distinct connection 

 between the climate and the geographical conditions. Great 

 seas in higher latitudes bring warm climate and vice versa. 



Now. we have seen that these great geographical changes 

 were, in all probability, a consequence of the mean value of the 

 eccentricity rising and sinking, and we must therefore believe 

 that those great changes in the climate had a cosmic origin, and 

 appeared at the same time over the whole Globe. As yet we 

 know too little of the geology of the tropical regions, but there 

 is reason to believe that there, also, great changes have taken 

 place in the division of land and sea, and that these changes 

 must, also, have had influence on the climate of the warm 

 countries. 



It is, still further, probable that the force of volcanicity 

 stands in relation to changes of the eccentricity. Each of the 

 great geological formations, quite from the pre-Cambrian epoch, has 

 (cfr. A. Gertie's Textbook p. 259—260) had its volcanoes, and 



