While it was declared that man belonged to the alluvial stratum, it was at the same time stated, according to the doctrine of Cuvier, which had the weight of a dogma, that man could not have belonged to an older geological stratum or era, and therefore not even to the next older one, the Drift. The beginning and the end of geological eras are marked by mighty transformations which have caused a local interruption in the formation of the strata of the earth’s surface. In many cases we can point to volcanic eruptions as the chief causes, but more especially to a change in the distribution of land and water. Cuvier had conceived these changes involving the transformation to have been violent terrestrial revolutions, the collapse of all existing things, in which all living beings belonging to the past epoch must have been annihilated. It appeared impossible that a living thing could have survived this hypothetical battle of the elements, and passed from an older epoch into the next one; and the new epoch was supposed to have received plants and animals by re-creation. All this had to be applied to man also; he was supposed to have come into existence only in the alluvial period. Not without consideration for the Mosaic account of the Creation, which, like the creation legends of numerous peoples scattered far and wide over all the continents of the earth, tells of a great deluge at the beginning of the present age, the Pleistocene Epoch of the earth’s formation preceding the present period had been termed the Flood Epoch, or Diluvium. In its stratifications it was thought that the effects of great deluges could largely be recognised; but the human eye could not have beheld these, for, according to the catastrophe theory, it appeared out of the question that man could have been “witness of the Flood.” [Sidenote: What Actually Happened]