_Fauna of Europe._--Among the Fauna may be mentioned the gigantic elephants, of nearly twice the bulk of the largest individuals that now exist, which roamed in herds over England, and extended across the Siberian plains and from Behring Strait to South Carolina. Two-horned rhinoceroses wallowed in the swamps of the ancient forests. Hippopotamuses inhabited the lakes and rivers. The great cave-bear, which sometimes attained the size of a horse, and the cave-tiger, twice as large as the living tiger, preyed upon the animals of less strength than themselves. Troops of hyenas, larger than those of South America, disputed with other beasts of prey. A species of wild-cat, lynx, and leopard found retreats in the same forests. Then there was a remarkable carnivorous animal called _Machairodus_, about the size of a tiger, and from the shape and size of the sword-like teeth, must have been a very destructive creature. The lemming and the musk ox found a home, and the wild horse pranced about unrestrained by the hand of man. The great Irish elks swiftly moved over the ground, and must have been very numerous, as their remains occur in abundance in peat-bogs and marl-pits. Nor should it be unmentioned that there was also a species of gigantic ox nearly as large as an elephant, that subsisted on the plains. All these animals followed the retreat of the glaciers and some of them were in close proximity to the ice. _Geological Period._--The glacial epoch occurred during the geological period known as the post-tertiary. The tertiary had gradually passed away and its time had been recorded on the pages of geological history. A new epoch began to dawn. This was the epoch of ice, the birth and almost the childhood of the post-tertiary. _Probable Date._--In discussing the probable date of the glacial epoch, Sir Charles Lyell says, "The attempt to assign a chronological value to any of our geological periods except the latest, must, in the present state of science, be hopeless. Nevertheless, independently of all astronomical considerations, it must, I think, be conceded that the period required for the coming on of the greatest cold, and for its duration when most intense, and the oscillations to which it was subject, as well as the retreat of the glaciers and the 'great thaw' or disappearance of snow from many mountain-chains where the snow was once perpetual, required not tens but hundreds of thousands of years. Less time would not suffice for the changes in physical geography and organic life of which we have evidence. To a geologist, therefore, it would not appear startling that the greatest cold should be supposed to have been two hundred thousand years ago, although this date must be considered as very conjectural, and one which may be as likely to err in deficiency of time as in excess."[6]