Yet the forest growth reminds us of that prevalent during the
Miocene Age. The fig-tree, canary, laurel, and box-tree grew in
profusion. These are all southern forms. One severe winter would
kill them all, and even hard frosts would prevent the ripening
of their fruits.

Neither were the Summers hot and dry. This is shown by the
presence of numerous plants which can not thrive in hot and dry
localities, but live in the shady woods of Northern France and
Germany. The evidence of this forest growth surely presents us
an inviting picture of Europe during a portion of the
Glacial Age.

We are not without evidence, also, of a much more severe
climate. In a lignite bed (a species of coal) found in nearly
the same latitude as the forest growth just mentioned, we detect
the presence of trees that grow only in cold northern climates,
such as birch, mountain pine, larch, and spruce.<18> And in some
peat-bogs of Southern Europe belonging to this age<19> are found
willows now growing only in Spitzbergen, and some species of
mosses that only thrive far to the north. It is quite evident
that this deposit testifies to an altogether different climate
from that indicated by the deposit before mentioned. No theory
of migration can explain this assemblage of plants, unless it be
migration taking place very slowly, in consequence of an equally
slow change of climate.

From what we have just learned of the animals and plants living
in Europe during this age, we can frame some conception of the
different climatic conditions of Europe. On the one hand, we