e north coast of the Isle of Wight from its base to its junction
with the Oligocene (or Lower Miocene according to some), and along the
northern coast of Kent from its base to the Lower Bagshot Sand. It has been
intersected by railway and other cuttings in all directions and at all
horizons, and pierced by wells innumerable; while from its strata in
England, France, and Belgium, the most extensive collections of organic
remains have been made of any formation yet explored, and from nearly all
its horizons, for at one place or another in these three countries nearly
every horizon may be said to have yielded fossils of some kind. These
fossils, however, whether they be the remains of a flora such as that of
Sheppey, or of a vertebrate fauna containing the crocodile and alligator,
such as is yielded by beds indicative of terrestrial conditions, or of a
molluscan assemblage such as is present in marine or fluvio-marine beds of
the formation, are of unmistakably tropical or sub-tropical character
throughout; and no trace whatever has appeared of the intercalation of a
glacial period, much less of successive intercalations indicative of more
than one period of 10,500 years' glaciation. Nor can it be urged that the
glacial epochs of the Eocene in England were intervals of dry land, and so
have left no evidence of their existence behind them, because a large part
of the continuous sequence of Eocene deposits in this country consists of
alternations of fluviatile, fluvio-marine, and purely marine strata; so
that it seems impossible that during the accumulation of the Eocene
formation in England a glacial period could have occurred without its
evidences being {70} abundantly apparent. The Oligocene of Northern Germany
and Belgium, and the Miocene of those countries and of France, have also
afforded a rich molluscan fauna, which, like that of the Eocene, has as yet
presented no indication of the intrusion of anything to interfere with its
uniformly sub-tropical character."[14]

This is sufficiently striking; but when we consider that this enormous
series of deposits, many thousand feet in thickness, consists wholly of
alternations of clays, sands, marls, shales, or limestones, with a few beds
of pebbles or conglomerate, not one of the whole series containing
irregular blocks of foreign material, boulders or gravel, such as we have
seen to be the essential characteristic of a glacial epoch; and when we
find that this same general cha