SUMMARY
To what conclusions do the foregoing somewhat monotonous pages lead?
Do they help us to explain the origin of our fauna and flora? What
light do they throw on the antiquity of man in Britain, or on the
race problems that everywhere confront us? Can the deposits therein
described be in any way connected with written history or with
legend? Do they give us any approach to a measure of geological time?
And, to what extent does the period of the submerged forests tie on
historical times with the Glacial Epoch?
All these questions are connected with the subject-matter of this
little book; but it is not written with the idea of showing how much
we know or pretend to know. Our main object is to draw attention
to a much neglected period in geological history and to suggest
directions in which further research is likely to be profitable. We
have, however, made out several points, and can give an approximate
answer to some of the questions.
It is quite clear that at the opening of the period with which
this volume deals, the greater part of England stood fully 70 feet
above its present level, for the oldest deposit we deal with is
a land-surface covered with oak-forest and lying 60 feet below
tide-level. The oaks cannot have flourished lower, but they may have
grown on a soil well above sea-level. Perhaps taking the whole of the
evidence into account, a subsidence of nearly 90 feet is the most
probable measure of the extent of the subsequent movement.
We do not yet know whether in England this movement was a depression
of the land or a rise of the sea; but the fact that the relative
levels seem to have been quite different in Scotland and in
Scandinavia seems to indicate that it was the land that moved, not
the sea.
We begin, therefore, with a period when the whole of the southern
part of the North Sea was an alluvial flat connecting Britain with
Holland and Denmark, and to some extent with France. The Isle of
Wight was connected with Hampshire, and the Channel Islands with
France. Probably the Isles of Scilly were islands even then, for the
channel between them and Cornwall is both deep and wide, though this
may possibly be due to tidal scour.
The animals and plants yet known from this lowest submerged forest
are disappointingly few; but the prevalence of the oak shows that
the climate was mild, and that we have no clear indication of
conditions approaching to those of the Glacial Epoch. In fact, in all
the submerged forests the fauna and flora seem poor and monotonous,
consisting essentially of living British species, with a few mammals
since locally exterminated by man, and all known to have a wide range
both in climate and latitude.
This in itself, however, is a point gained in the study of the
origin of our flora; for though the deficiency is no doubt largely
due to insufficient collecting, I am convinced that it is a true
characteristic of this period of transition. Much time has been spent
in examining and collecting the fossils of these submerged forests,
and various friends have also worked at them; but everywhere we seem
to get the same result, and many abandon the study because there
is so little to show for it. The deposits certainly contain a much
poorer fauna and flora than either the Pleistocene or the recent
alluvial strata.
If we consider the Britain of the submerged forests as having
lately emerged from a time when the climate was ungenial, we should
naturally expect to find among the first incomers after the change
only such animals and plants as have a wide climatic range or can
migrate freely. It is these species, and these only, which will be
living on the neighbouring lands; it is only an assemblage like
this that can stand the climatic alternations and relapses that are
likely to attend the transition. An assemblage consisting only of
species widely distributed in latitude is probably an assemblage that
has special means of dispersal—even if we do not happen yet to have
discovered these means.
These considerations should lead us to expect to find living, in any
country which has lately undergone a change of climate, a somewhat
peculiar assemblage, consisting mainly of hardy forms of wide range
in latitude, and not characteristically either northern or southern.
Mingled with them, we might expect a few survivors from the previous
warm or cold period. A hardy fauna and flora seem to characterise the
period of the submerged forests; but the absence or great scarcity of
characteristic survivors from a former period suggests that even the
lowest of these deposits is far removed from the Glacial Epoch. The
arctic species had already had time to die out, or had been crowded
out; but the time had not been sufficiently long for the incoming
of the southern forms which now characterise our southern counties.
Then, even less than now, had we reached a perfect adjustment of the
fauna and flora to the climatic conditions; this can only be brought
about by a constant invasion of species from all the surrounding
regions. Some hold their own, most cannot; but as time goes on, the
surviving assemblage consists more and more of species which have
been able to fight against the severe competition and colonize a new
country.
Garden experiments are of little use as tests of the capability of
any plant to survive in this country; the study of cornfield weeds
is no better. In both cases the cultivation of the land produces a
bare place on which a foreign introduction has as good a chance as
a native. But could this foreigner survive if the seed were dropped
on a natural moor or meadow? In this connexion it is noticeable that
great part of the rare British plants occur close to the coast,
opposite the part of the continent in which they are found, though
they are not maritime species. This is probably due to two different
causes, both acting in the same direction. In the first place most
of these local plants are obviously late comers, which have not yet
had time to spread inland or far. And, secondly, on the coast alone
do we find any considerable extent of natural bare land—practically
garden land—which does not at the same time consist of poor soil.
The tumbled undercliffs of our coast are just the places to give a
foreign invader a chance; there only will it find patches of bare
good soil, full of small cracks in which a seed is hidden from birds.
If the view is correct, that a continuous growth of our flora, and
to some extent of our fauna, takes place through transportation to
our coasts, from which such species as can fight their way tend
more slowly to spread inland, it seems to account for the present
curious distribution of species, and this in a way that no continuous
land-connexion will do.
As we have pointed out in a former chapter, the land-connexion across
the North Sea was a wide alluvial plain and swampy delta. What use
could dry-soil plants make of such a bridge? It would be no easier
for them to cross than so much sea; and migrating mammals could
not greatly help in the dispersal, where so many rivers had to be
crossed. The aquatic species would be helped by such a connexion, and
it is curious to note that several of our most interesting aquatic
plants are confined to the eastern counties, which in post-glacial
times had direct connexion with the delta of the Rhine, and probably
with the Elbe.
Aquatic species, however, are not dependent on continuous waterways
for their dispersal; they have great facilities for overleaping
barriers and reaching isolated river-basins and lakes. Every dew-pond
on the downs after a few years’ existence contains aquatic plants and
mollusca, and a still larger number of species, including fish, will
be found in ancient flooded quarries or prehistoric dykes surrounding
some hill-fortification. If an aquatic plant is fairly common on the
continent near by, it is almost certain to occur in some isolated
pond or river in the part of Britain opposite.
Many of our peculiar mollusca and plants are limestone species,
which must have crossed over at a single leap, for no elevation or
depression will connect the various isolated limestone masses of
Britain. A post-glacial elevation would connect the North Downs with
the corresponding chalk-hills of France; but these Downs are isolated
by wide tracts of non-calcareous strata from the areas of Oolite
or Carboniferous limestone to which many of our limestone animals
and plants are now confined. There is also nothing in the present
distribution of our limestone species to suggest that any great
stream of migrants used this bridge of chalk-downs.
It may be asked, Why discuss these questions here, if all these
peculiar species are unknown in the submerged forests? In certain
cases negative evidence is of great value, and the deficient flora
of the submerged forests is a case in point. We find a striking
contrast between this ancient flora and the flora which flourished
when cultivation of the land had begun. The Roman deposits in Britain
yield many species which have not yet been found in the submerged
forests, and even the earlier Celtic deposits have already yielded a
few of them. To a large extent this difference is due to the agency
of man, intentional to a certain extent, but mainly accidental,
through the introduction of weeds and the preparation of the soil
for crops. It must not be forgotten that man not only introduced the
weeds, he prepared the land on which they could establish themselves,
and from thence spread to uncultivated ground where few botanists now
suspect that they are anything but “native.”
In days when the people of Britain were hunters, the only extensive
open country in the south and east seems to have been the chalk-downs
and the sandy heaths. These were not suitable for new additions to
the plant population, for the good land was all oak forest, the
barren heaths were unfavourable for any but heath plants, and the
alluvial flats were largely covered with sallow and alder. The open
downs were clothed with close turf, and until this was broken by
cultivation there would be little chance for migrants. It seems,
therefore, that to obtain a clear idea of the plant population of
this country before man’s influence could be felt, we must study
the flora of the submerged forests and of the associated alluvial
detritus washed from the uplands during the same period. Till this is
done more thoroughly, it is not much use to discuss what species are
“native” and what “introduced”; the submerged forest will yield the
answer to this question.
The next question we have put—What light do these submerged forests
throw on the antiquity of man in Britain, or on the race-problems of
Britain?—is a difficult one to answer in the present state of our
knowledge. Valuable evidence has been lost through the failure to
preserve most of the human remains that have been found; but both
Owen and Huxley recognised the peculiar type of the “river-drift
man.” Unfortunately few implements have been collected, and the
pieces of wood shaped by man, though recorded, have not been
preserved. One implement of polished stone has certainly been found
in the latest submerged land-surface, but it is not clear that
anything except flakes has been obtained in the older deposits.
Still the stratigraphical relations seem to indicate that all these
deposits are of Neolithic age and later than the Palaeolithic
terraces. The relations of Palaeolithic to Neolithic are still very
obscure in this country, and the reason is perhaps to be sought in a
submergence which has tended to carry many of the transition deposits
beneath the sea-level, or has caused them to be silted up under more
modern alluvium. The lowest submerged forest requires careful search
before we can be certain of its true position in the sequence; but
it is seldom exposed, and then only in dock-excavations soon again
hidden.
Before we can attempt to answer the other questions, it is important
to get an estimate of the amount of time occupied in the formation
of these deposits, and of the lapse of time since the last of
them was formed. The newest of them belongs certainly to the age
of polished stone, and the earliest also probably comes within
the Neolithic period. We have already seen that within the period
represented by the submerged forests there has been a rise of the
sea-level, or depression of the land, to the extent of 80 feet,
perhaps a few feet more. If we can obtain some measure of the time
occupied in the formation of such a series of deposits, this should
give us some idea as to the length of the Neolithic period, and also
of the rate at which changes of the sea-level sometimes can take
place.
It is unfortunate that for these calculations so many of the factors
are of uncertain value. We may estimate from the present rate
of erosion of the coast the amount that has been lost since the
sea-level became stationary, or we may take the rate of accumulation
of sand-dunes or shingle-spits; or the rate at which our estuaries,
harbours, and broads are silting up. It all comes, however, to
this—no exact figures can be given; but so many rough calculations
lead to approximately the same date, that the date arrived at may
be trusted to give some idea of the length of the period which has
elapsed since the downward movement ceased.
Working backwards from the present day, step by step, archaeological
evidence gives an undoubted period of 2000 years, to the first
century B.C., during which no measurable change of sea-level has
taken place in the south of England.
To this must be added a few centuries for the growth of the marshes
on which Glastonbury and similar lake-dwellings were built, and
for the growth of various other marshes at present sea-level known
to be earlier than the Roman invasion. Also we must allow for the
accumulation of various shingle-spits and sand-dunes then already
partly formed.
In general, somewhere about one-third or one-half of this
accumulation seems to have taken place before the Roman invasion.
This adds another 1500 years; so that about 3500 years ago, we get
back to the beginning of the period of unchanging sea-level in which
we are still living, and begin to see evidence of earth movements
still in progress.
Whether this 3500 years will take us back to the beginning of the
Bronze Age in Britain is not yet proved; but so far we seem to
discover metals in the whole of the deposits formed whilst the
sea-level remained unchanged, and only stone weapons in even the
newest of the submerged forests. For the present, we may therefore
take it that the two changes nearly coincided. The use of metals
began in Britain about the time that the earth-movements ceased—that
is to say somewhere about 1600 B.C.
Whether this period of 3500 years will really take us back to the
commencement of the Bronze Age is doubtful, for Stonehenge had
already been built, and though only stone hammers seem to have been
there used, yet one slight streak of bronze or copper has been
noticed. Of course, there may have been a similar occasional use of
bronze at the time of the last submerged forest; but we have as yet
no evidence of this, and the possible correspondence in date between
Stonehenge and the last of the submerged forests remains merely a
suggestion.
Perhaps we may still find submerged stone-circles or other
antiquities of the age of Stonehenge beneath the sea-level; but
Stonehenge lies too high above the sea for it in itself to give any
clue as to a change of sea-level. We will only make one suggestion.
It is probable that when Stonehenge was built, a long arm of the
sea extended far up the Avon Valley, so that navigable water was
found not far from Stonehenge. There is in Stonehenge an inner
circle of smaller stones, not composed of the local greywethers but
consisting of large blocks of igneous rock of foreign origin. These
blocks, which are sufficiently large to be awkward for land-carriage,
have been said to be erratics gathered on Salisbury Plain, just as
the greywethers for the main circle were gathered; but there are
no erratics on Salisbury Plain. Large erratic blocks of similar
character occur, however, abundantly on the lowlands of Selsey Bill,
under the lee of the Isle of Wight. Probably a similar erratic-strewn
plain once fringed the coast on the west also, though on the exposed
side the part above the sea-level has now been entirely swept away by
the sea.
I would suggest that the Stonehenge erratics, instead of being
brought from any great distance, may have come from a wide plain at
the mouth of the Avon, then two or three miles further seaward. From
thence they were rafted far up the navigable fjord, not yet silted
up, and were only carried a short distance uphill. Igneous rocks such
as these, found in a country consisting essentially of chalk and
Tertiary strata, would be valuable and probably endowed with magic
properties, hence their employment in this inner circle.
Our next enquiry must be into the length of time represented by
the series of submerged forests and associated deposits described
in the foregoing pages. The newest of them belongs certainly to
the age of polished stone, and the earliest also probably comes
within the Neolithic Period. Within the period represented by the
submerged forests, we have seen that there has been a change of the
sea-level to the extent of 80 feet, or perhaps rather more. If we can
obtain some measure of the time occupied, this should give us some
approximate idea as to the length of the Neolithic period, and of
the rate at which changes of the sea-level can take place.
The first point to be considered is the length of time occupied by
the growth of the series of submerged forests. On first examining,
or reading accounts of, deposits of this sort one obtains a vague
impression of long periods, during which mighty oaks flourished.
Both the movements of submergence and the intervening periods of
vegetable growth seem to require great lapses of time. On closer
study, however, the evidence seems scarcely to support this view,
for estuarine silts are deposits of exceptionally rapid growth, and
one finds that the usual characteristic of a “submerged forest” is
that it shows indications of only a single generation of trees. The
trees also are usually small, except where the submerged forest rests
directly on deposits of much earlier date, or on solid rock.
It should be remembered that the large oak trees which are often
found in the lowest land-surface at any particular place do not
necessarily belong to any one special stage of the submergence.
These same trees may have grown continuously above tide-marks
during several successive stages, until at last the upward creeping
water rose sufficiently to reach this part of the forest. The large
well-grown oaks seen in Mount’s Bay and various other places are, as
far as I have seen, all rooted on ancient gravels, solid rock, or
boulder clay, not on beds of silt.
We cannot speak confidently as to the time needed to form each thin
layer of vegetable soil, marsh peat, or estuarine silt. On comparing
the submerged land-surfaces, however, with similar accumulations
formed within known periods, such as marsh soils grown behind ancient
embankments, or forest-growth over flats silted up at known dates,
we can learn something. No one of the land-surfaces alternating with
the silts would necessarily require more than a century or two for
its formation. Brushwood and swamp growth are the characteristic
features of these deposits, and such growth accumulates and decays
very rapidly. Possibly trees of older growth may still be found, but
I have not succeeded in discovering a tree more than a century old in
any one of the marsh deposits alternating with the estuarine silts.
Oaks of three centuries may be observed rooted in the older deposits;
but this, as above explained, is another matter.
It is useless to pretend to any exact calculations as to the time
needed for the formation of these alternating strata of estuarine
silt and marsh-soil; but looking at the whole of the evidence without
bias either way, it seems that an allowance of 1000, or at most
1500, years would be ample time to allow. A period of 1500 years may
therefore be taken to cover the whole of the changes which took
place during the period of gradual submergence.
If this is approximately correct, the date at which the submergence
began was only 5000 years ago, or about 3000 B.C. The estimate may
have to be modified as we obtain better evidence; but it is as well
to realize clearly that we are not dealing with a long period, of
great geological antiquity; we are dealing with times when the
Egyptian, Babylonian, and Minoan civilizations flourished. Northern
Europe was then probably barbarous, and metals had not come into use;
but the amber trade of the Baltic was probably in full swing. Rumours
of any great disaster, such as the submergence of thousands of square
miles and the displacement of large populations might spread far and
wide along the trade routes. Is it possible that thus originated some
of the stories of the deluge?
We will not now pursue this enquiry; but it is well to bear in mind
the probability that here geology, archaeology, and history meet and
overlap. Any day one of our submerged forests may yield some article
of Egyptian manufacture of known date, such as a scarab, which has
passed from hand to hand along the ancient trade routes, till it
reached a country still living in the Stone Age, where its only use
would be in magic. But it might now serve to give us a definite date
for one of these submerged forests. It might happen to have been
lost with some of the stone implements, or with one of the human
skeletons, apparently belonging to persons drowned, for no trace of
a grave is ever mentioned. A find of this sort is no more improbable
than the discovery of a useless modern revolver in a bag of stone
and bone tools belonging to some Esquimaux far beyond the reach of
ordinary civilized races.
In this connexion it might be worth while systematically to dredge
the Dogger Bank, in order to see whether any implements made by man
can be found there. The alluvial deposits are there so free from
stones that if any at all are found in them they may probably show
human workmanship. The Dogger Bank may have remained an island long
after great part of the bed of the North Sea had been submerged, for
the Bank now forms a submerged plateau. It may even have lasted into
fairly recent times, the final destruction of the island being due
to the planing away of the upper part of the soft alluvial strata
through the attacks of the sea and of boring molluscs. _Pholas_ is
now actively attacking the hard peat-beds at a depth of more than
10 fathoms, and is rapidly destroying this accumulation of moorlog,
wherever the tidal scour is sufficient to lay it bare.
BIBLIOGRAPHY
BRÖGGER, W. C. Om de Senglaciale og Postglaciale Nivåforandringer
i Kristianiafeltet (Molluskfaunan). _Norges geol. undersögelse._
1900-1.
COLENSO, J. W. A Description of Happy-Union Tin Stream-Work at
Pentuan. _Trans. R. Geol. Soc. Cornwall_, vol. IV, 1832, p. 30.
[GODWIN-]AUSTEN, R. A. C. On the Valley of the English Channel.
_Quart. Journ. Geol. Soc._ vol. VI, 1849, p. 69.
GODWIN-AUSTEN, R. A. C. On the Newer Tertiary Deposits of the
Sussex Coast. _Quart. Journ. Geol. Soc._ vol. XIII, 1856, p. 40.
HENWOOD, W. J. On some of the Deposits of Stream Tin-Ore in
Cornwall, with remarks on the Theory of that Formation. _Trans. R.
Geol. Soc. Cornwall_, vol. IV, 1832, p. 57.
HOLMES, T. V. Excursion to Tilbury Docks, May 17, 1884. Record of
Excursion, _Geol. Assoc._ p. 182.
—— Notes on the Geological Position of the Human Skeleton lately
found at the Tilbury Docks, Essex. _Trans. Essex Field Club_, vol.
IV, 1884, p. 135.
KEITH, Prof. A. Ancient Types of Man. London, 1911.
LORIÉ, Dr J. Contributions à la Géologie des Pays-Bas. V. Les Dunes
intérieures, les Tourbières basses et les Oscillations du Sol.
_Archives Teyler_, Sér. II, t. III, 5^{me} Partie. 1890.
MILLER, S. H., and S. B. J. SKERTCHLY. The Fenland past and
present. 8vo. London, 1878.
MORTON, G. H. Local Historical, Post-glacial and Pre-glacial
Geology. _Proc. Liverpool Geol. Soc._ 1887-8.
MUNTHE, H. Studier öfver Gottlands Senkvartära Historia. _Sveriges
Geol. Undersökning._ 1910.
OWEN, Sir R. Antiquity of Man. _Proc. Roy. Soc._ vol. XXXVI, 1883,
p. 136; and more fully in his _Antiquity of Man as deduced from the
Discovery of a Human Skeleton at Tilbury_. 8vo. London, 1884.
POTTER, C. Observations on the Geology and Archaeology of the
Cheshire Shore. _Trans. Hist. Soc. Lancashire and Cheshire._ 1876.
PRESTWICH, Sir J. Geology. Vol. II. Oxford, 1888.
PREVOST, Dr E. W. and others. The Peat and Forest Bed at
Westbury-on-Severn. _Proc. Cotteswold Field Club_, vol. XIV, 1901,
p. 15.
RASHLEIGH, P. An Account of the Alluvial Depositions at Sandrycock.
_Trans. R. Geol. Soc. Cornwall_, vol. II, 1822, p. 281.
READE, T. M. The Geology and Physics of the Post-glacial Period,
as shown in the Deposits and Organic Remains in Lancashire and
Cheshire. _Proc. Liverpool Geol. Soc._ vol. II, session xiii,
1871-2, p. 36.
—— Glacial and Post-glacial features of the Lower Valley of the
River Lune and its estuary. _Proc. Liverpool Geol. Soc._ vol. IX,
session xliii, 1902, p. 163.
REID, C. On the Relation of the present Plant Population of the
British Isles to the Glacial Epoch. _Rep. Brit. Assoc. for 1911_,
p. 573.
—— The Island of Ictis. _Archaeologia_, vol. LIX, 1905.
—— On the former Connexion of the Isle of Wight with the Mainland.
_Rep. Brit. Assoc. for 1911_, p. 384.
REID, C. The Geology of the country around Southampton. _Mem.
Geological Survey_, 1902.
—— The Geology of Holderness. _Mem. Geological Survey._
—— The Origin of the British Flora. 8vo. London, 1899.
ROGERS, INKERMANN. On the Submerged Forest at Westward Ho! Bideford
Bay. _Trans. Devon. Assoc._ vol. XL, 1908, p. 249.
SHORE, T. W., and J. W. ELWES. The New Dock Excavation at
Southampton. _Proc. Hampshire Field Club_, 1889, p. 43.
SHORE, T. W. Hampshire Mudlands and other Alluviums. _Proc.
Hampshire Field Club_, 1893, p. 181.
SKERTCHLY, S. B. J. Geology of the Fenland. _Mem. Geological
Survey_, 1877.
SPURRELL, F. C. J. Early Sites and Embankments on the Margins of
the Thames Estuary. _Archaeological Journ._ 1885.
—— On the Estuary of the Thames and its Alluvium. _Proc. Geol.
Assoc._ vol. XI, 1889, p. 210.
STATHER, J. W. Shelly Clay Dredged from the Dogger Bank. _Quart.
Journ. Geol. Soc._ vol. LXVIII, 1912, p. 324.
STRAHAN, A. On submerged Land-surfaces at Barry, Glamorganshire.
With notes on the Fauna and Flora by CLEMENT REID. _Quart. Journ.
Geol. Soc._ vol. LII, 1896, pp. 474-489.
TYLOR, A. On Quaternary Gravels. _Quart. Journ. Geol. Soc._ vol.
XXV, 1869, p. 57.
WHITAKER, W. The Geology of London and of part of the Thames
Valley. _Mem. Geol. Survey_, 1889, 2 vols.
WHITEHEAD, H., and H. H. GOODCHILD. Some Notes on “Moorlog,”
a peaty deposit from the Dogger Bank in the North Sea. _Essex
Naturalist_, vol. XVI, 1909, p. 51.
WORTH, R. H. Evidences of Glaciation in Devonshire. _Trans. Devon.
Assoc._ vol. XXX, 1898, p. 378.
INDEX
Alder, 1, 8, 16, 32, 64, 112
Alternations of freshwater and marine strata, 4, 7, 16, 29, 35, 44,
51, 57, 94-97
Amberley Wild Brook, 73
Amsterdam, 48
Anchor-ice, 89
Aquatic plants, dispersal of, 110
Archaeological evidence, 61, 115-117, 121
Atlantic waves, effect of, 85, 86
Baltic, 49
Barry Docks, 52-57, 59
Base-level planes, 22, 37, 38, 80, 87, 88
Baynes, D., 13-17
Bay of Biscay, 86, 103-105
Bear, 2
Beaver, 2, 35, 44
Belle Ile, 104
Bideford Bay, 61, 62
Birch, arctic, 46
—— white, 46
Blakeney, 29
Boar, 2, 35
Boats, 99, 102, 103
Bog-bean, 45
Bone needles, 54
Brétignolles, 104
Bridgwater Levels, 60
Bristol Channel, 58-61
Broads, 23-26, 114
Brögger, W. C., 122
Bronze age, 115, 116, 120
Caesar’s invasion, 65, 66, 75
Canoes, 99, 102, 103
Cardiff, 57
Carne, J., 102
Carnon stream-works, 98, 99
Cattewater, 84, 88
Causeway, submerged, 97, 100
Celtic shorthorn, 63, 96
Champion, G. C., 46
Channel Islands, 68, 86, 103, 106
Channels, shifting of, 6, 21, 36, 37, 91, 93, 102
Chara-marl, 8
Charcoal below submerged forest, 97
Chatteris, 30, 35
Cheshire, 50, 51, frontispiece
Chichester Harbour, 76, 77
Clacton, 21, 23, 30, 31
Climatic changes, 10, 46, 66-68, 104, 107, 108
Clyde-beds, 50
Coast-erosion, 114
Colenso, J. W., 91-97, 122
Compression of alluvial strata, 3, 4, 16
Continental platform, origin of the, 69, 70
Coracles, 99
_Corbicula fluminalis_, 11, 23, 31, 35, 37, 74
Cornel, 55
Cornwall, 80-105
_Cotoneaster Pyracantha_, 74
Cromer Forest-bed, 11, 22, 23, 39
Cultivation, effects of, 111, 112
Dart, 98
Dartmoor, 82, 83, 89
Dates, 26, 114-121
Dead Sea depressions, 5
Dee, 51
Deformation of shore-lines, 38, 49
Deluge, 2, 66, 81, 120
Denmark, 48, 106
Depression, extent of, 8, 17, 20, 22, 26, 38, 47-49, 51, 56, 57, 68,
73, 75, 88, 93, 94, 106
Devonport, 6, 83, 90
Dispersal of plants, 108, 109-112
Dogger Bank, 17, 18, 39-49, 69, 121, 124
Domestic animals, 63, 96
Dove Point, 50, 51, frontispiece
Dunge Ness, 71
Eccles Church, 27, 28
Elbe, 40, 110
Elder, 16
Elevation of the land, former, 8, 17, 20, 22, 26, 38, 47-49, 51, 56,
57, 68, 73, 75, 106
Elwes, J. W., 124
Ely, 30, 34
English Channel, 64-79
Estuaries, silting-up of, 25, 26, 114
Fal, 98
Fareham, 76
Fen-deposits, 30-36, 44, 45
Fenland, 4, 30-37
Flint-implements, 21, 35, 54, 62, 74, 113
Flora, changes of the, 9, 10, 110
—— of the submerged forests, 63, 64, 104, 105, 107, 108
Formby, 52
France, 103-106
Gadeceau, E., 104
Gannel, 98
Geographical distribution, 60, 110
Glacial epoch, 10, 23, 36, 67, 68, 83, 87, 89, 90, 94, 107, 108
Glamorgan, 52-57
Glastonbury Levels, 60-62, 115
Godwin-Austen, R. A. C., 122
Gold-dust, 92
Goodchild, H. H., 42, 124
Goodwin Sands, 66, 70
Gothland, 49
Gravesend, 17
Grays, 20, 23, 30, 31, 37
Hamoaze, 84, 85, 88
Hampshire, 74-79, 106
Happisburgh, 39
Happy Union, 92-97
Harbours, origin of, 77, 78
—— silting-up of, 98, 99, 114
Harwich, 22
Hastings, 71
Hawthorn, 55
Hazel, 1, 8, 9, 46, 55, 98, 101, 102
Henwood, W. J., 98, 123
Heysham, 50
Holderness, 38, 44
Holland, 4, 44, 48, 49, 106
Holmes, T. V., 123
Horse Sand Fort, 74
Human remains, 9, 10, 13-15, 17, 18, 52, 62, 96-99, 113, 121
Humber, 20, 35-38, 88
Huxley, Prof. T., 13, 15, 113
Implements, stone, 21, 35, 54, 62, 74, 113
—— wooden, 96, 113
Intermittent depression, 35, 51
Ireland, 49
Irish elk, 21
—— Sea, 80
Isle of Man, 50
—— Wight, 75, 76, 106, 117
Keith, Prof. A., 13, 15, 122
Kent, 65-70
Kessingland, 23
King, Rev. S. W., 27
King’s Lynn, 6
Laira Viaduct, 88
Lancashire, 50, 51
Landes, 104
Land’s End, 100
Landslips, 3
Langer Fort, 22
Langston Harbour, 76, 77
Leasowe, 50, 51, frontispiece
Lewes, 73
Lincolnshire, 35
London, 12, 19
Lorié, Dr. J., 122
Lost Lyonesse, 100
Lowestoft, 23, 26
Lyell, Sir C., 27, 91
Mammoth, 15, 21, 35
Man, remains of, 9, 10, 13-15, 17, 18, 52, 62, 96-99, 113, 121
Man’s influence on our flora, 112
Marazion, 101-103
March, 30, 31, 35, 37
Marine erosion, 84-86
Mersey, 51, 52
Migration of species, 10, 108-112
Miller, S. H., 122
Moorlog, 41, 43, 44, 47
Morton, G. H., 123
Mosses, formation of, 35
Mount’s Bay, 100, 101, 118
Munthe, Dr H., 49, 123
_Najas marina_, 53
Nar Valley Beds, 31, 35
Neolithic, 21, 35, 38, 53, 62, 74, 75, 79, 113-115, 118
Noah’s Woods, 1, 66
Noman Fort, 75
Norfolk broads, 23, 24-26, 49
North Sea, 17, 38-49, 67, 68, 80, 106, 110, 121
Norway, 49
Oak, 1, 8, 16, 19, 32, 34, 54-57, 62, 71, 94-96, 101, 102, 106, 107,
119, 120
—— cut by man, 97
_Osmunda_, 1, 52
Ouse, 6
Owen, Sir R., 13, 15, 18, 113, 123
Oysters on submerged trees, 94, 95
Palaeolithic, 15, 21, 22, 113
Pegwell Bay, 65
Pentuan, 92-97, 99, 100, 122
Penzance, 101
Pepys, S., 19
Pevensey Level, 71
_Pholas_, erosion caused by, 43, 121
Piles below a submerged forest, 97, 100
Pine, 32, 34, 35, 79
Plane of marine denudation, 22
Plym, 82
Plymouth Sound, 83-88, 90, 98
Polished stone implements, 54, 113
Pollen-grains in submerged peat, 45
Poole Harbour, 79
Portsmouth Harbour, 76, 77
Potter, C., 123
Potter Heigham, 26
Prestwich, Sir J., 26, 123
Prevost, Dr E. W., 123
Raised beaches, 38, 50
Rashleigh, P., 123
Reade, T. M., 50, 51, 123
Reindeer, 44, 79
Rhine, 18, 40, 67, 110
Ribble, 51
River-drift man, 15
—— ice, 89
Roadway, submerged, 28, 100
Rogers, I., 61, 62, 124
Roman period, 3, 16, 61, 63, 65, 75, 101, 111, 115
Romney Marsh, 70, 71
Rostock, 49
_Ruppia_, 46
St Austell River, 92-98
St Michael’s Mount, 100, 101
Saltash, 88
Sand-dunes, 3-5, 26, 27, 47, 114
Sangatte, 68
Scandinavia, 49, 106
Scilly, 100, 106
Scotland, 38, 49, 50, 106
_Scrobicularia_-clay, 7, 19, 53, 96
Sea-level, changes of, 3, 4, 8, 17-20, 22, 26, 38, 47, 48, 51, 57,
68, 73, 75, 106, 114
Selsey, 74, 117
Severn Tunnel, 59
Sheep, 63
Shell-marl, 8
Sherringham, 22
Shingle-beach, protection afforded by, 3-5
—— spits, growth of, 26, 114
Shore, T. W., 79, 124
Silting-up, rate of, 25, 26
Skertchly, S. B. J., 31, 122, 124
Solent, 74-76
Somerset, 60, 61
Southampton Water, 74, 76, 79
South Downs, 72
Southwold, 22
Spithead, 74-77
Spurrell, F. C. J., 13, 15-18, 124
Stather, J. W., 124
Stonehenge, 116
Storrie, J., 53, 54
Strahan, Dr A., 52-57, 124
Strait of Dover, 65-70
Stream-tin works, 80, 81, 90-102, 123, 124
Submarine erosion, 69, 84-86, 121
Submerged forest, definition of, 11
Submergence, extent of the, 8, 17, 20, 22, 26, 38, 47-49, 51, 56, 57,
68, 73, 75, 88, 93, 94, 106
Sussex, 65, 68, 71-74
Sweden, 49
Tamar, 82, 84, 85
Tavy, 82, 88
Thames, 11-19, 20, 21, 29, 38, 40, 51, 52, 84, 88, 122, 124
Thaws and floods, 89
Tidal scour, 69, 85, 86
—— wave deadened by obstructions, 4, 5, 28, 29
Tides of the Bristol Channel, 56
Tilbury, 13-19
Time, 114-121
Tin stream-works, 80, 81, 90-102, 123, 124
Trees growing below high-water level, 4, 5, 8
—— rooted into rock, 4
—— succession of, 8, 32
Tyler, A., 124
Vegetable remains, decay of, 4
Vine, 105
Virgin, Wheal, 97
Walrus, 44
Wash, 29, 30
Waves, effect of, 85, 86
Wealden axis, 72
Weeds, introduction of, 112
Welsch, Prof. J., 104
Westward Ho, 61-64
Weybourn, 29
Whitaker, W., 13, 15, 16, 124
Whitehead, H., 42, 124
Wolf, 2, 35
Wood, implements of, 9, 96, 97, 113
Worth, R. H., 124
Yarmouth, Isle of Wight, 75
—— Norfolk, 26, 28
Yew, 19, 32
CAMBRIDGE: PRINTED BY JOHN CLAY, M.A. AT THE UNIVERSITY PRESS