of River-drift would occur, of such an age and character as to be likely to contain Palæolithic implements. In more than one instance, indeed, as has already been mentioned, the probability of certain gravels containing these relics of human art, was pointed out before their actual discovery.
These are some, but by no means all, of the points in which the actual phenomena agree with those which must have resulted from river-action such as suggested in the hypothesis, and they are alone sufficient to raise the strongest presumption that the phenomena are due to such action, and that the theory that would account for them in this manner, cannot be far from the truth.
I will, however, now pass in review some of the principal localities where Palæolithic implements have been found in Drift-deposits, and see what other points of accordance, and what difficulties, if any, they present.
Taking first the basin of the Ouse and its tributaries, we find at Biddenham, near Bedford, one of the principal localities for Drift-implements, the gravel on the inner side of a bold sweep made by the river, and from forty to fifty feet above it. Its constituent stones are all derived either from the rocks in the neighbourhood, or from the Glacial beds which cap them, and which have evidently been cut through by the river. Throughout the beds are seams containing numerous freshwater shells, mixed with some derived from the land and from marshy places; numerous bones of terrestrial mammals also occur. In the valley of the Lark remains of such shells occur at Bury St. Edmunds, in the same beds as the implements. Farther down, at Icklingham, the beds at Rampart Field cap a rounded knoll on the inner side of a curve of the river, which appears, however, to have somewhat straightened its course since they were deposited. Below Icklingham, the whole surface of the country, and its drainage, have been so much modified by the invasion of the sea, which produced the wide level of the Fens, that we should expect to find any deposits of an ancient river, which existed before that great planing down of the adjacent country, in somewhat anomalous positions.
I need not here enter into the history of the origin of the Fens; it is enough to say that the subsoil of almost the whole district consists of clays, belonging either to the Oolitic or Cretaceous series, and unprotected by any rocks of a more durable nature towards the sea, which has thus been enabled to invade it. The presence of the sea is attested in various localities by marine
