An inference of immediate interest is to the effect that if Professor Rutot's view be adopted, the high-level terrace of the Thames valley is not contrasted so strongly with continental deposits containing the same mammals, as Mr Hinton suggests. For Professor Rutot's Strépyan period is earlier than the Chellean. It may be questioned whether Mr Hinton is right in assigning only Acheulean implements to the high-terrace gravels. Indeed Mr E. T. Newton (1895) expressly records the occurrence at Galley Hill, of implements more primitive than those of Acheulean form, and 'similar to those found by Mr B. Harrison on the high plateau near Ightham,'--_i.e._ the Mesvinian type of Professor Rutot. A final decision is perhaps unattainable at present. But on the whole, the balance of evidence seems to go against Mr Hinton; though _per contra_ it will not escape notice that since 1903, Professor Rutot has 'reduced' the Galley Hill skeleton from the Mafflian to the Strépyan stage, and it is therefore possible that further reduction may follow. Leaving these problems of the Galley Hill implements and the Strépyan period, the Mesvinian and Mafflian types are described by Professor Rutot as representatives of yet older and more primitive stages in the evolution of these objects. As remarked above (Chapter III), the Mauer jaw is referred by Professor Rutot to the Mafflian (implement) period of the early Pleistocene age, though the grounds for so definite a statement are uncertain. More primitive, and less shapely therefore, than the Mafflian implements, are the forms designated 'Reutelian.' They are referred to the dawn of the Quaternary or Pleistocene period. But with these the initial stage of evolution seems to be reached. Such 'eoliths,' as they have been termed, are only to be distinguished by experts, and even these are by no means agreed in regarding them as products of human industry. If judgment on this vital point be suspended for the moment, it will be seen that Professor Rutot's scheme carries this evidence of human existence far back into the antiquity denoted by the lapse of the Pliocene and Miocene periods of geological chronology. But let it be remarked that when the names Kentian, Cantalian and Fagnian are employed, no claim is made or implied that three distinctive types of implement are distinguished, for in respect of form they are all Reutelian. Herein the work of M. Commont must be contrasted with that of Professor Rutot. For the gist of M. Commont's researches lies in the demonstration of a succession of types from the more perfect to the less finished, arranged in correspondence with the superimposed strata of a single locality. A vertical succession of implements accompanies a similar sequence of strata.