100 THE PALAEOLITHIC PERIOD During the high-level epoch man does not seem to have been able to control the shape of the flakes, as they are nearly always large and somewhat clumsily produced, but by the time the low- level drifts were deposited he seems to have acquired great dexterity in the manipulation of flint, for the flakes are now usually small and neat, while others of designed shape, as for instance the long narrow flakes with a triangular section, such as require great skill in their production, are common. A good example of a designedly-shaped flake is that shown in Fig. 2. There can be no doubt that this was meant to be used as a knife, the broad end probably being bound round with vegetable fibre or animal sinew, after the style of the Australian knife figured by Sir John Evans,1 and as such one cannot but admire its effectiveness. Even more eloquent of the ability of the later Palaeolithic people is the testimony of the spear-heads, one of which is represented by Fig. 3, for their shape is clearly the result of the skilful execution of a previously thought-out pattern. A fine example in the Natural History Department of the British Museum, in which the point has been artistically finished by small secondary chipping, bears a close resemblance to the obsidian spear-heads used by the natives of the Admiralty Islands. A rare instrument of this period is the saw. Fig 4 shews a specimen from the low level drift at Ilford. It is a flake of slate-black flint, which has been serrated carefully along the edge. I found this, together with other flakes, in situ, in a bed of gravel, which yielded bones of rhinoceros and shells of land and fresh-water molluscs.2 Still more characteristic of the Palaeolithic period are the peculiar tongue-shaped implements. Eolithic man confined his work to the edges of the pieces of flint, but the tongue-shaped implements of Palaeolithic man are skilfully chipped all over, sometimes into delicate tapering points, and sometimes into thin flat blades. What these implements were used for is still a mystery, in spite of the attention that has been paid to them. Probably the majority were used as javelin or axe-heads, but our knowledge, meagre though it be, of the uses to which the 1 Sir John Evans, Ancient Stone Implements . . . . of Great Britain. London: 1872 and 1897. 2 J. P. Johnson, "Palaeolithic Implements from the low-level drift of the Thames Valley."—Essex Naturalist, vol. xii. (1901).