"wave of translation," which would of necessity bring in materials not to be found in the existing basins.
That the various deposits resulting from a flooded river, should contain some of the land and freshwater shells, and animal bones of the period, is, as has been shown, most natural. Such shells and remains are of constant occurrence in the Quaternary gravels. If they prove nothing else, their evidence as to the freshwater origin of the beds must be accepted as conclusive. It is true that in all cases such land and freshwater remains have not as yet been found; but if in a dozen instances we find beds of a certain character containing these remains, and also flint instruments wrought by the hand of man; and in a dozen other instances, similar beds in analogous positions, also containing implements of the same kind, but, so far as is known, no such organic remains; we are justified in regarding both sets of beds as due to the same original cause, and in believing that the organic remains, if actually absent, are so from some accidental circumstance. We may indeed accept the implements as being truly characteristic fossils of a certain class of deposits. The character of the beds, consisting as they do, of gravel, sand, and fine silt, brick-earth or loess, and their manner of deposition, are also absolutely in accordance with the river-hypothesis.
On the higher levels above but near the valleys, we frequently find these beds at a considerable distance from the existing stream; we find them at all levels on the flanks of the valleys, and occasionally almost at their bottom, or even below it. In these lower beds, the implements, if of the same form and character as those in the upper beds nearer the source, are, in accordance with what would be the case under the hypothesis, very frequently much rolled and water-worn. The beds at the low level are also usually, so far as the gravel is concerned, of a finer character than those at the high level, and present a greater abundance of sand and brick-earth. They seem, in fact, indicative of some such amelioration of climate as that supposed.
Looking again at the position of the deposits with regard to the neighbouring rivers, we find them, as a rule, exactly in such positions as might have been expected, had their presence been due to the action of a stream in the process of excavating its valley, in such a manner as that described. So constantly is this the case, that a practised geologist, from a mere inspection of the Ordnance map, could with almost certainty predict where deposits
