116 
Primeval Man in the Valley of the Lea. 
tlie “ floor ” are occasional seams and blocks of London-clay, 
brought from a short distance to the north-west, where the 
clay comes to the surface. As a rule there are no very large 
blocks of flint or other large stones on the “floor.” The 
non-waterlaid covering mass often disturbs the “floor,” 
ploughs it up, and pushes underneath it. The twisting, 
contortion, and undulation of the material above the “ floor” 
seem to prove that it was laid down by moving ice from the 
north. This ice-deposited “trail” and “warp” is full of 
small whitish pebbles, fixed in the tenacious material at 
various angles. Abraded and whitened implements are also 
met with in the “ trail,” examples no doubt caught up from 
Fig. 6. 
old exposed surfaces by the ice-sheet, and brought from a 
distance to their present position. No Palaeolithic implements 
occur above the “ trail”; the “ trail” seals up all the relics 
of the Palaeolithic age, and, as far as the evidence of north¬ 
east London goes, Palaeolithic man had quite retired before 
the “ trail ” and “ warp ” were deposited. When implements 
are found on the surface, the ground may have been denuded, 
and the implements exposed. 
Fig. 6 is a measured section through the “ floor” facing 
west, on the other side of the section, illustrated in fig. 5 ; 
the “ floor ” is seen at from 3 ft. 6 in. to 4 ft. 10 in. beneath 
the surface; muddy trail, with sand and a few stones, is 
present at b and c ; d is humus. In the direction of the 
arrow, from north to south, the “ trail ” is seen pushing 
