On the opposite page (PLATE XXVIII.) an attempt is made to represent the appearance of Europe during the epoch we have under consideration. The Bear is seated at the mouth of its den--the cave (thus reminding us of the origin of its name of _Ursus spelæus_), where it gnaws the bones of the Elephant. Above the cavern the _Hyæna spelæa_ looks out, with savage eye, for the moment when it will be prudent to dispute possession of these remains with its formidable rival. The great Wood-stag, with other great animals of the epoch, occupies the farthest shore of a small lake, where some small hills rise out of a valley crowned with the trees and shrubs of the period. Mountains, recently upheaved, rise on the distant horizon, covered with a mantle of frozen snow, reminding us that the glacial period is approaching, and has already begun to manifest itself. All these fossil bones, belonging to the great Mammalia which we have been describing, are found in the Quaternary formation; but the most abundant of all are those of the Elephant and the Horse. The extreme profusion of the bones of the Mammoth, crowded into the more recently formed deposits of the globe, is only surpassed by the prodigious quantity of the bones of the Horse which are buried in the same beds. The singular abundance of the remains of these two animals proves that, during the Quaternary epoch, the earth gave nourishment to immense herds of the Horse and the Elephant. It is probable that from one pole to the other, from the equator to the two extremities of the axis of the globe, the earth must have formed a vast and boundless prairie, while an immense carpet of verdure covered its whole surface; and such abundant pastures would be absolutely necessary to sustain these prodigious numbers of herbivorous animals of great size. The mind can scarcely realise the immense and verdant plains of this earlier world, animated by the presence of an infinity of such inhabitants. In its burning temperature, Pachyderms of monstrous forms, but of peaceful habits, traversed the tall vegetation, composed of grasses of all sorts. Deer of gigantic size, their heads ornamented with enormous horns, escorted the heavy herds of the Mammoth; while the Horse, small in size and compact of form, galloped and frisked round these magnificent horizons of verdure which no human eye had yet contemplated.