That this astonishingly mild and uniform climate prevailed over these regions until and during the time of the mammoth, we ought not to have a shadow of doubt. =What single bit of positive evidence is there to show that it did not?= That he must have had some such vegetation on which to feed is certain, and there is no proof of any previous interruption of these conditions save a series of hypotheses. He and his fellows browsed on semi-tropical and warm temperate plants far within the Arctic Circle, if there happened to be land there, doubtless over the very Pole itself; but suddenly!! lo, something caught him with the grip of death-- "And wrapped his corpse in winding-sheet of ice, And sung the requiem of his shivering ghost." Who has not read of their untainted meat now making food for dogs and wolves? Their stomachs are well filled with undigested food, showing, as one author remarks, that they "were quietly feeding when the crisis came." Dr. Hertz recently reported one not only with its stomach full of food, but with its mouth full, too. No wonder that even an orthodox geologist like Prof. Dana is compelled to say that these things prove "that the cold finally became =suddenly= extreme, as of a single winter's night, and knew no relenting afterward." Here then is one very notable geological event which has taken place within the human epoch, and the only thing of its kind of which geology has an undeniable record, viz., a sudden and radical change in the earth's climate; =a cosmic affair, and not a local phenomenon=. I need not here attempt to discuss the how of this world catastrophe as it must have been, or the other changes inseparably involved. The fact itself is as certain as Man's own existence. The next division of our subject, in further consideration of the changes that have taken place since Man's existence, as stated at the beginning of this chapter, relates to the changes of land and water distribution since "Middle Miocene times." And here again I shall try to take the classification of these rocks just as I find them.