species, and the arrival and spread of some others. The apes
living as far north as Germany in the Miocene Age were
restricted to Southern France and Italy in the Pliocene, and, at
its close, vanished altogether from Europe. The first living
species of mammals is found in the remains of the hippopotamus
that frequented the rivers of Pliocene times. The mastodon of
Miocene times was still to be seen, but along with it was a
species of true elephants. The hipparion survived into this
epoch, but the horse also makes its appearance. Great quantities
of deer roamed over the land; and, as might be expected where
they were so abundant, the carnivorous animals allied to the
bears and wolves, panthers, linxes, and tigers, were also to be
found. "At night," says Mr. Dawkins, "the Pliocene forests of
Central France echoed with the weird laughter of the hyena."

The gradual lowering of the climate is also shown by the remains
of the mollusks deposited in beds of marine or sea formation
during different eras of this age. It is found that the earlier
the bed, the more southern mollusks are found in it. This shows
us that, all through the Pliocene Age, the waters of the seas
surrounding England were gradually growing cooler, thus
compelling the retreat of those mollusks fitted only for a warm
climate, and allowing a gradual increase in those species fitted
for cold or northern latitudes. We also find, in deposits made
near the close of Pliocene times, numbers of stone which show
all evidence of having been borne thither by means of ice. So we
may conclude that rafts of ice came floating down the North Sea
during the closing period of the Pliocene Age.<56> Still, during
the entire length of the Pliocene Age, Europe certainly offered
an inviting home for man. Not only were the higher orders of