A Day's Elephant Hunting in. Essex. 49
duration the few thousands of years which make up the
poor sum of the so-called historical period.
THE SITE OF THE ILFORD GRAVES.
The kind of hiding-place in which these old British
quadrupeds are found deserves to be carefully noted. The
site of the Ilford graves will help to tell us in what par-
ticular physical areas of our landscapes we may expect to
find similar memorials of Pleistocene Britain; they may
put us on the track of fresh discoveries.
Let it be noted, then, that these strange relics—these
remains of British bison and gigantic deer, of hippopotami,
rhinoceroses, and elephants—are found not on the site of
the old pastures and forests of Essex, but in the old water-
courses. How has this happened?
These animals died the death of all wild creatures in a
state of nature. Some were slain by the carnivores, and
some, in sickness and old age, retired to the silence of the
thicket to die. Some died by the watercourses, and some
were swept into the river by floods, and were soon entombed
in a natural grave. The greater number would die on the
land and leave their remains unburied and exposed to
natural dissolution and decay. The bones which the
hyaenas spared would lie bleaching for a few years, and
soon perish and disappear from natural decay. Of the
skeletons thus exposed, nothing would be left to tell us that
these animals ever existed.
How has it happened, then, that this interesting group
of Pleistocene mammalia has been so wondrously pre-
served? The answer is readily given, if we but look at
the function of a river valley in the economy of the land
surface.
A RIVER VALLEY AS THE HISTORIAN OF THE LANDSCAPE.
Our old river valleys cannot fail to be rich in relics of
the physical and zoological history of the countries which
they drain. The Thames and its tributaries may well be
rich in memorials of the physical and zoological history of
south-eastern England. From the time when the present