Page:Quarterly Journal of the Geological Society of London, vol. 28.djvu/504

410 singular group of Cervidæ, consisting of, at the very least, the following species:—

The first three of these are not of Pliocene age, if the Mammaliferous strata of Auvergne, Marseilles, and the Val d'Arno be taken as the Pliocene standards. Their presence, therefore, in the Forest-bed points forwards rather than backwards in time, since they are abundant in the caves and river-deposits of the Pleistocene age. The next, on the other hand, is a well-known Pliocene species; while the Cervus carnutorum is common to the Forest-bed and the river-strata of St.-Prest, and the last two peculiar to the Forest-bed.

This peculiar mixture of Cervine species seems here to indicate that, in classification, the Forest-bed belongs rather to an early stage of the Pleistocene than to the Pliocene; and this inference is corroborated by the presence of the Mammoth, which is so characteristic of the Pleistocene age.



The Pleistocene period was one of very long duration, and embraced changes of great magnitude in the geography of Europe. The climate, which in the preceding Pliocene age, in Northern and Middle Europe, had been temperate, at the beginning of the Pleistocene gradually passed into the extreme arctic severity of the glacial period; and this change caused a corresponding change of the forms of animal life, the Pliocene species (whose constitutions were adjusted to temperate or hot climates) yielding place to those which were better adapted to the new conditions; and since, as we