In 1902 I published a paper, the outcome of several years' observation, on certain phenomena associated with the glacial deposits of the Cleveland area, which I attributed to the former presence of a series of temporary lakes and lakelets upheld in the recesses of the hills by the margin of a great ice-sheet occupying the greater part of the North Sea. This interpretation met with so wide an acceptance, even by those geologists familiar with the district who had previously attributed the glacial deposits to a marine origin, that during the succeeding thirteen years I have steadfastly refrained from replying to criticism, hoping by this abstention to keep the issues unclouded by a controversy that might at any stage develop an acerbity not always lacking in earlier discussions.