ON THE LEA VALLEY.
9
appeared at the surface in the bottom of the old channel shown
towards the southern end of Fig. 5. A few yards beyond the
southern limits of Fig. 5 the section resembled that seen at its
northern end.
I do not propose to say anything here about the fossil
remains found in these reservoir excavations as a list of mam-
malian or molluscan genera and species, or to touch upon them
in any way except so far as they may tend to throw light on
various questions connected with the deposition of the beds and
their relations to each other. Judging from the great variety of
views which have been expressed by geologists of more or less
eminence as regards river deposits of somewhat greater age, it
seems desirable to point out the bearing on those questions of
the evidence of these more recent beds. For light may fairly be
expected from an appeal from the more obscure and fragmentary
remains of the older river deposits to the fuller and more com-
Fig. 6. New Reservoirs. Section from the Old Channel of the Lea north-
ward, near the spot where the ship was found. October 1st, 1900.
plete evidence of the newer. It is true that in very recent times
rivers like the Thames and Lea have been canalized more or
less, and that, consequently, floods and specially high tides no
longer deposit mud on the marshes adjacent to the streams as in
more ancient days. But in the present case we have, on the
other hand, the very unusual advantage of being able to inspect
an old disused channel, which would be impossible but for the
canalization of the stream for navigation. And, as I have
already remarked, the length and varied direction of the sections
shown in these reservoirs have given almost unique opportunities
of noting the nature and variations of the strata and the way in
which changes occur. As we have seen, the constant consti-
tuents of any section are the loam or clayey loam at the surface
and the gravel towards the base. Their respective thicknesses
may vary, but where they only are present the gravel always
makes a larger proportion of the whole section than where peat,