PEOPLE OF THE SUBMERGED FOREST 25 
of 140 feet is reached. When that land surface was in 
existence, it is highly probable, as already stated, England 
was joined to the Continent of Europe. Now, at various^ 
places and at various times, worked fiints have been 
discovered on and under this old land surface. They have 
always been worked in the style adopted by the men of 
the Neolithic period. The remains of the animals which 
have been unearthed at the " submerged-forest " level 
are those of beasts which are known to belong to the 
Neolithic period. 
The Neolithic territories which lie deep beneath the 
sea are beyond our reach ; at some future and far distant 
period, perhaps, they may again become dry land and 
afford the anthropologists of the time ample means of 
studying some of their Neolithic ancestors whose bones, 
no doubt, lie preserved there for all time. Fortunately 
for us, there are certain marginal corners of the sub- 
merged forest land within our reach. As the sea crept 
upon the land, at so slow a rate, we must suppose, that 
its gain was not apparent in the life-time of a generation, 
the estuaries of the sea invaded our river valleys. The 
estuary of the Thames, for instance, before the sub- 
sidence of the Neolithic period began, was far out in the 
North Sea ; London we must presume lay far above the 
tidal limit (fig. 1 1). In the course of time, as subsidence 
proceeded, the meadows and woodlands lying along the 
bottom of the valley became submerged in times of flood. 
Every flood or high tide left a veneer of slime behind, 
coating the floor of the valley and turning forest and 
meadow land into marsh. In the course of centuries, 
the marsh became a slimy expanse of mud, and the old 
land surface became buried under many feet of alluvial 
deposit or river sediment. That such has been the 
recent history of the Thames valley we have the most 
ample evidence. At the present time a trench, over 100 
yards wide, a mile in length and 40 feet in depth, has 
been cut across the marshland of the Thames valley to 
form a new dock for London (see fig. i). Along the 
whole length of the exposed sides of the trench — about 
