It seems not improbable that it was when the continents had attained to their greatest extension and when animal and vegetable life had again over-spread the new land to its utmost limits, that man was introduced on the eastern continent, and with him several mammalian species, not known in the Pliocene period, and some of which, as the sheep, the goat, the ox, and the dog, have ever since been his companions and humble allies. These, at least in the west of Europe, were the "Palaeolithic" men, the makers of the oldest flint implements; and armed with these, they had to assert the mastery of man over broader lands then we now possess, and over many species of great animals now extinct. In thus writing, I assume the accuracy of the inferences from the occurrence of worked stones with the bones of post-glacial animals, which must have lived during the condition of our continents above referred to. If these inferences are well founded, not only did man exist at this time, but man not even varietally distinct from modern European races. But if man really appeared in Europe in the Post-glacial era, he was destined to be exposed to one great natural vicissitude before his permanent establishment in the world. The land had reached its maximum elevation, but its foundations, "standing in the water and out of the water," were not yet securely settled, and it had to take one more plunge-bath before attaining its modern fixity. This seems to have been a comparatively rapid subsidence and re-elevation, leaving but slender traces of its occurrence, but changing to some extent the levels of the continents, and failing to restore them fully to their former elevation, so that large areas of the lower grounds still remained under the sea. If, as the greater number of geologists now believe, man was then on the earth, it is not impossible that this constituted the deluge recorded in that remarkable "log book" of Noah preserved to us in Genesis, and of which the memory remains in the traditions of most ancient nations. This is at least the geological deluge which separates the Post-glacial period from the Modern, and the earlier from the later pre-historic period of the archæologists.[AM] [AM] I have long thought that the narrative in Gen. vii. and viii. can be understood only on the supposition that it is a contemporary journal or log of an eye-witness incorporated by the author of Genesis in his work. The dates of the rising and fall of the water, the note of soundings over the hill-tops when the maximum was attained, and many other details, as well as the whole tone of the narrative, seem to require this supposition, which also removes all the difficulties of interpretation which have been so much felt.