"II. Glacial Epoch, in which man lived cotemporaneously with the mammoth (Elephas primigenius), rhinoceros (R. tichorrhinus), cave-bear, etc.
"III. Post-glacial Epoch, in which man lived cotemporaneously with the mammoth and reindeer (Cervus tarandus).
"IV. Last Epoch, or epoch of the Pile-buildings, in which man lived cotemporaneously with the Irish elk (Megaceros hibernicus), aurochs (Bison Europæus)," etc.[2]
Westropp divides the periods of man, in respect to his stages of civilization, as follows: Savagery, hunters, herdsmen, and agriculturists.
In the following pages a somewhat different classification has been adopted, and may be thus explained:
I. Pre-glacial Epoch; that period antedating the glaciers of the post-tertiary, in which man lived cotemporaneously with the animals of the tertiary, southern elephant (E. meridionalis), etc.
II. Glacial Epoch; that period of the post-tertiary when man was forced to contend with the great ice-fields and the floods immediately succeeding them, when the mammoth (E. primigenius), rhinoceros (R. tichorrhinus), cave-bear, etc., began to flourish.
III. Interglacial Epoch; that period between the glacial and the second advance of the ice, in which man lived cotemporaneously with the animals of the preceding epoch, and the cave bear became extinct.
IV. Reindeer Epoch; that period when the glaciers again advanced; in which man's chief food consisted of the flesh of the reindeer (C. tarandus), that animal having made its way in numerous herds as far south as the Pyrenees.
V. Neolithic Epoch; that period in which man polished his weapons of stone, and sought to domesticate certain animals, the dog, etc.