Since then, other carcases of elephants have been discovered, in a greater or less degree of preservation; as also the remains of rhinoceroses, mastodons, and allied pachyderms—the mammoth more abundantly in the old world, the mastodon in the new. In every case these animals differ from existing species: are of more gigantic dimensions; and, judging from their natural coverings of thick-set curly-crisped wool and strong hair, upward of a foot in length, were fitted to live, if not in a boreal, at least in a coldly-temperate region. Indeed, there is proof positive of the then more milder climate of these regions in the discovery of pine and birch-trunks where no vegetation now flourishes; and further, in the fact that fragments of pine-leaves, birch-twigs, and other northern plants, have been detected between the grinders and within the stomachs of these animals. We have thus evidence, that at the close of the tertiary, and shortly after the commencement of the current epoch, the northern hemisphere enjoyed a much milder climate; that it was the abode of huge pachyderms now extinct; that a different distribution of sea and land prevailed; and that on a new distribution or sea and land, accompanied also by a different relative level, these animals died away, leaving their remains imbedded in the clays, gravels, and other alluvial deposits, where, under the antiseptic influence of an almost eternal frost, many of them have been preserved as entire as at the fatal moment they sank under the rigors of external conditions no longer fitted for their existence. It has been attempted by some to prove the adaptability of these animals to the present conditions of the northern hemisphere; but so untenable in every phase is this opinion, that it would be sheer waste of time and space to attempt its refutation. That they may have migrated northward and southward with the seasons is more than probable, though it has been stated that the remains diminish in size the farther north they are found; but that numerous herds of such huge animals should have existed