He intends to use archaeology and geology to "draw aside the veil" covering the situations of the peoples mentioned in proto-historic documents, such as Caesar's "Commentaries" and the "Agricola" of Tacitus. Adopting Lyell's scheme of the Tertiary, he divides Pleistocene into Early, Mid- and Late. Only the Palaeolithic falls into the Pleistocene; the Neolithic is in the "Prehistoric Period" subsequent. Dawkins defines what was to become the Upper, Middle and Lower Paleolithic, except that he calls them the "Upper Cave-Earth and Breccia," the "Middle Cave-Earth," and the "Lower Red Sand," with reference to the names of the layers. The next year, 1881, Geikie solidified the terminology into Upper and Lower Palaeolithic: