they divide the flora with the deciduous trees. Palms, fig-trees, and fine-leaved acacias abound in the lower, while in the upper strata they are to a great extent replaced by maples and poplars. The palms are found throughout, but are more rare in the upper strata. The greatest change, as we might expect, occurs at the time when the sea rolled over part of Switzerland in the middle, or Helvetian stage.
The elaborate investigations of Professor Heer show that the climate of middle Europe was in the lower Meiocene stage similar to that now prevailing in Louisiana, the Canaries, North Africa, and South China, with a mean annual temperature of from 68° to 69⋅8° Fahr.; while that of the Upper Meiocenes resembled that of Madeira, Malaga, Southern Sicily, Southern Japan, and New Georgia, with a mean annual temperature of 64⋅4°, 66⋅2° Fahr.
While the climate was warm in the region south of the Baltic, it was temperate in Iceland, where the flora consists of species capable of living under temperate conditions. The same remark holds good with regard to the Meiocene plants of Spitzbergen, in which we do not find any tree or shrub with evergreen foliage. It also holds good for that of the western coast of North Greenland, in 70° north latitude, where magnolias, chestnuts, oaks, planes, and vines, indicate "climate analogous to that now characteristic of the lake of Geneva."
These conclusions as to the nature of the climate[1] in
- ↑ Heer, Primeval World of Switzerland, ii. 147. We must note that the Polar vegetation taken by Heer to be Meiocene is considered by Dawson and Starkie Gardner, Eocene. This question is discussed in the second chapter of this work.
