It is quite clear that at the opening of the period with which this volume deals, the greater part of England stood fully 70 feet above its present level, for the oldest deposit we deal with is a land-surface covered with oak-forest and lying 60 feet below tide-level. The oaks cannot have flourished lower, but they may have grown on a soil well above sea-level. Perhaps taking the whole of the evidence into account, a subsidence of nearly 90 feet is the most probable measure of the extent of the subsequent movement. We do not yet know whether in England this movement was a depression of the land or a rise of the sea; but the fact that the relative levels seem to have been quite different in Scotland and in Scandinavia seems to indicate that it was the land that moved, not the sea. We begin, therefore, with a period when the whole of the southern part of the North Sea was an alluvial flat connecting Britain with Holland and Denmark, and to some extent with France. The Isle of Wight was connected with Hampshire, and the Channel Islands with France. Probably the Isles of Scilly were islands even then, for the channel between them and Cornwall is both deep and wide, though this may possibly be due to tidal scour. The animals and plants yet known from this lowest submerged forest are disappointingly few; but the prevalence of the oak shows that the climate was mild, and that we have no clear indication of conditions approaching to those of the Glacial Epoch. In fact, in all the submerged forests the fauna and flora seem poor and monotonous, consisting essentially of living British species, with a few mammals since locally exterminated by man, and all known to have a wide range both in climate and latitude. This in itself, however, is a point gained in the study of the origin of our flora; for though the deficiency is no doubt largely due to insufficient collecting, I am convinced that it is a true characteristic of this period of transition. Much time has been spent in examining and collecting the fossils of these submerged forests, and various friends have also worked at them; but everywhere we seem to get the same result, and many abandon the study because there is so little to show for it. The deposits certainly contain a much poorer fauna and flora than either the Pleistocene or the recent alluvial strata.