A HISTORY OF HERTFORDSHIRE moreover able, by bringing fragments of flint together, to reconstitute the original blocks out of which implements had been chipped. The occupation by man of the ' Paleolithic floor ' must have extended over a long space of time, and Mr. Smith thinks that two series of implements may be distinguished. The contorted beds of brick-earth in and below which they are found seem to belong to a more recent date than the Glacial period, during which the boulder clay of this part of England FIG. i. FIG. 2. FIG. 3. FIG. 4. FIG. 5. was deposited. Specimens of the implements from the Caddington dis- trict are shown above in figs, i to 5. There are at present no more Palaeolithic discoveries to record from the basin of the Colne ; but it may be mentioned that I have a flake from the brick-earth at Barnard's Heath near St. Albans, which has the appearance of belonging to Palaeolithic times, so that a further search upon the spot might lead to more conclusive results. I have also recorded the finding of an implement at North Mimms, 1 but possibly there may be some mistake in the matter. We must now consider the watershed of the Lea and its tributaries so far as Hertfordshire is concerned. A passing reference only need be 1 Proc. Sac. Ant., 2nd ser. vol. v. p. 165. 226
