The association of man and the mastodon is somewhat startling to most people; but, as has been time and again conclusively shown, it is no unwarranted fancy. We are apt to consider the mastodon as a creature of so distant a time in the unrecorded past, that man must necessarily have appeared much later upon the scene. The truth is, comparatively speaking, the creature so recently became extinct that, in all probability, our historic Indians were acquainted with it. Certain it is that, in the distant long ago of the great Ice age, the mastodon existed, and equally certain that with him lived that primitive man who fabricated the rude implements we have described. The bones of the animal and the bones and weapons of the man lie side by side, deep down in the gravels deposited by the floods from the melting ice-sheet. In February, 1885, I walked to and fro over the frozen Delaware, where it reaches a full mile in width, and saw at the time many horses and sleighs passing from shore to shore. I recalled, as I walked, what the geologists have recorded of the river’s history, and it was no wild whim of the unchecked imagination to picture the Delaware as a still more firmly frozen stream; so firmly ice-bound, indeed, that the mastodon might pass in safety over it—not cautiously, even, but with the quick trot of the angry elephant—and picture still further a terror-stricken Stone-age hunter fleeing for his life. Just as our brief yearly winter gives way to milder spring, so, as the centuries rolled by, the mighty winter of the Ice age yielded to changes that were slowly wrought. Century by century, the sun’s power was exerted with more telling effect; constantly increasing areas of northward-lying land were laid bare, and the forest followed the retreating glacier’s steps. This great but gradual change had, of course, its influence upon animal life, and many of the large mammals that have been named appear to have preferred the cooler to the warmer climate and followed the ice-sheet on its northward march.