EARLY MAN ferruginous deposit, as it has been shown that the colouring matter may have been contributed by the flint itself, the iron being liberated in the process of alteration. 1 Neolithic implements rarely if ever ex- hibit these characteristics, although their surfaces are often whitened or rendered of a milky colour and smooth or glassy to the touch. Palaeolithic implements vary in shape from a pointed form not unlike a flattened pear to a flattened ovoid shape with a cutting edge all round. There are also large flakes, scrapers, and, of course, the cores or nodules of flint from which flakes have been struck off. Generally speaking the implements are such as would be useful for scraping, chopping, cutting and piercing purposes, and they do not exhibit the specialization of form for particular uses which is found in neolithic implements. Many of the palaeolithic implements found in Surrey have been procured from beds of drift gravel, most of the stones of which are much battered and abraded. The implements show the same character- istics, and have in most cases been modified by drift wear, particularly upon the angles and ridges. Perhaps an even more significant fact, as pointing to the geological changes which have occurred since the implements were made, is to be found in the position which the gravel beds containing implements now occupy high above the present valleys. From its very nature and the causes which have produced it we know that gravel of this character must have been deposited in the lowest parts of the valleys of the district in which it now occurs. Since it is now found high up on the sides of the valleys, or even in terraces which seem to have a closer relation to the tableland which the present valleys traverse than to the valleys themselves, it follows that these lower valleys must have been eroded subsequently to the time when what is now the high level gravel was laid down. Owing to the practically indestructible nature of gravel we should expect to find, and as a matter of fact we do find, that much of the harder portions of the high level gravel has been carried down to the lower levels where it is mixed up with other materials. It is these facts which give so much importance to discoveries of palaeolithic implements among beds of undisturbed drift gravels, etc., and although the knowledge so obtained does not enable us to fix the exact number of years by which the palaeolithic age is removed from our own, because we cannot ascertain the rate at which the natural forces have operated, yet it gives us good reason to infer that there was a great gap between the age of palaeolithic man and that of neo- lithic man. In attempting a brief sketch of the story of Surrey in the palaeo- lithic age it will therefore be convenient to pay special attention to the positions in the drift gravels, etc., in which the implements occur. A glance at the map of Surrey will show that one of the chief physical features in the surface of the county is the long range of chalk 1 Quarterly Journal of the Geo/ogical Society, Ivi. 8, 9. 229 Q*
