CLOSE OF THE POST-PLIOCENE, AND ADVENT OF MAN. (_Continued._)
Turning from these difficult questions of time, we may now look at the
assemblage of land-animals presented by the Post-glacial period. Here,
for the first time in the great series of continental elevations and
depressions, we find the newly-emerging land peopled with familiar
forms. Nearly all the modern European animals have left their bones in
the clays, gravels, and cavern deposits which belong to this period;
but with them are others either not now found within the limits of
temperate Europe, or altogether extinct. Thus the remarkable fact
comes out, that the uprising land was peopled at first with a more
abundant fauna then that which it now sustains, and that many species,
and among these some of the largest and most powerful, have been
weeded out, either before the advent of man or in the changes which
immediately succeeded that event. That in the Post-glacial period so
many noble animal species should have been overthrown in the struggle
for existence, without leaving any successors, at least in Europe, is
one of the most remarkable phenomena in the history of life on our
planet.
According to. Pictet,[AQ] the Post-glacial beds of Europe afford
ninety-eight species of mammals, of which fifty-seven still live
there, the remainder being either locally or wholly extinct. According
to Mr. Boyd Dawkins,[AR] in Great Britain about twelve Pliocene
species survived the Glacial period, and reappeared in the British
Islands in the Post-glacial. To these were added forty-one species
making in all fifty-three, whose remains are found in the gravels and
caves of the latter period. Of these, in the Modern period
twenty-eight, or rather more then one-half, survive, fourteen are
wholly extinct, and eleven are locally extinct.
[AQ] Palæontologie.
[AR] "Journal of Geological Society," and Palæontographical Society's
publications.
[Illustration: BRITAIN IN THE POST-PLIOCENE AGE. Musk-sheep,
Hippopotamus, Machairodus, Mammoth, Wooly Rhinoceros, Long-fronted Ox,
and Irish stag. The animals are taken from Mr. Waterhouse Hawkins's
picture, "Struggles of Life among British Animals of the Antediluvian
Times." London: 1853. The landscape is that of the later part of the
cold Post-pliocene period.]
Among the extinct beasts, were some of very remarkable character.
There were two or more species of elephant, which seem in this age to
have overspread, in vast herds, all the plains of Northern Europe and
Asia; and one of which we know, from the perfect specimen found
embedded in the frozen soil of Siberia, lived till a very modern
period; and was clothed with long hair and fur, fitting it for a cold
climate. There were also three or four species of rhinoceros, one of
which at least (the _R. Tichorhinus_) was clad with wool like the great
Siberian mammoth. With these was a huge hippopotamus (_H. major_), whose
head-quarters would, however, seem to have been farther south then
England, or which perhaps inhabited chiefly the swamps along the large
rivers running through areas now under the sea. The occurrence of such
an animal shows an abundant vegetation, and a climate so mild, that
the rivers were not covered with heavy ice in winter; for the
supposition that this old hippopotamus was a migratory animal seems
very unlikely. Another animal of this time, was the magnificent deer,
known as the Irish elk; and which perhaps had its principal abode on
the great plain which is now the Irish Sea. The terrible machairodus,
or cymetar-toothed tiger, was continued from the Pliocene; and in
addition to species of bear still living, there was a species of
gigantic size, probably now extinct, the cave bear. Evidences are
accumulating, to show that all or nearly all these survived until the
human period.
If we turn now to those animals which are only locally extinct, we
meet with some strange, and at first sight puzzling anomalies. Some of
these are creatures now limited to climates much colder then that of
Britain. Others now belong to warmer climates. Conspicuous among the
former are the musk-sheep, the elk, the reindeer, the glutton, and the
lemming. Among the latter, we see the panther, the lion, and the Cape
hyena. That animals now so widely separated as the musk-sheep of
Arctic America and the hyena of South Africa, could ever have
inhabited the same forests, seems a dream of the wildest fancy. Yet it
is not difficult to find a probable solution of the mystery. In North
America, at the present day, the puma, or American lion, comes up to
the same latitudes with the caribou, or reindeer, and moose; and in
Asia, the tiger extends its migrations into the abodes of boreal
animals in the plains of Siberia. Even in Europe, within the historic
period, the reindeer inhabited the forests of Germany; and the lion
extended its range nearly as far northward. The explanation lies in
the co-existence of a densely wooded country with a temperate climate;
the forests affording to southern animals shelter from the cold or
winter; and equally to the northern animals protection from the heat
of summer. Hence our wonder at this association of animals of diverse
habitudes as to climate, is merely a prejudice arising from the
present exceptional condition of Europe. Still it is possible that
changes unfavourable to some of these animals, were in progress before
the arrival of man, with his clearings and forest fires and other
disturbing agencies. Even in America, the megalonyx, or gigantic
sloth, the mammoth, the mastodon, the fossil horse, and many other
creatures, disappeared before the Modern period; and on both
continents the great Post-glacial subsidence or deluge may have swept
away some of the species. Such a supposition seems necessary to
account for the phenomena of the gravel and cave deposits of England,
and Cope has recently suggested it in explanation of similar
storehouses of fossil animals in America.[AS]
[AS] Proceedings of the American Philosophical Society, April 1871.
Among the many pictures which this fertile subject calls up, perhaps
none is more curious then that presented by the Post-glacial cavern
deposits. We may close our survey of this period with the exploration
of one of these strange repositories; and may select Kent's Hole at
Torquay, so carefully excavated and illumined with the magnesium light
of scientific inquiry by Mr. Pengelly and a committee of the British
Association.
The somewhat extensive and ramifying cavern of Kent's Hole is an
irregular excavation, evidently due partly to fissures in limestone
rock, and partly to the erosive action of water enlarging such
fissures into chambers and galleries. At what time it was originally
cut we do not know, but it must have existed as a cavern at the close
of the Pliocene or beginning of the Post-pliocene period, since which
time it has been receiving a series of deposits which have quite
filled up some of its smaller branches.
First and lowest, according to Mr. Pengelly, is a "breccia" or mass of
broken and rounded stones, with hardened red clay filling the
interstices. Most of the stones are of the rock which forms the roof
and walls of the cave, but many, especially the rounded ones, are from
more distant parts of the surrounding country. In this mass, the depth
of which is unknown, are numerous bones, all of one kind of animal,
the cave bear, a creature which seems to have lived in Western Europe
from the close of the Pliocene down to the modern period. It must have
been one of the earliest and most permanent tenants of Kent's Hole at
a time when its lower chambers were still filled with water. Next
above the breccia is a floor of "stalagmite" or stony carbonate of
lime, deposited from the drippings of the roof, and in some places
three feet thick. This also contains bones of the cave bear, deposited
when there was less access of water to the cavern. Mr. Pengelly infers
the existence of man at this time from a single flint flake and a
single flint chip found in these beds; but mere flakes and chips of
flint are too often natural to warrant such a conclusion. After the
old stalagmite floor above mentioned was formed, the cave again
received deposits of muddy water and stones; but now a change occurs
in the remains embedded. This stony clay, or "cave earth" has yielded
an immense quantity of teeth and bones, including those of the
elephant, rhinoceros, horse, hyena, cave bear, reindeer, and Irish
elk. With these were found weapons of chipped flint, and harpoons,
needles, and bodkins of bone, precisely similar to those of the North
American Indians and other rude races. The "cave earth" is four feet
or more in thickness, It is not stratified, and contains many fallen
fragments of rock, rounded stones, and broken pieces of stalagmite. It
also has patches of the excrement of hyenas, which the explorers
suppose to indicate the temporary residence of these animals; and in
one spot, near the top, is a limited layer of burnt wood, with remains
which indicate the cooking and eating of repasts of animal food by
man. It is clear that when this bed was formed the cavern was liable
to be inundated with muddy water, carrying stones and other heavy
objects, and breaking up in places the old stalagmite floor. One of
the most puzzling features, especially to those who take an
exclusively uniformitarian view, is, that the entrance of water-borne
mud and stones implies a level of the bottom of the water in the
neighbouring valleys of about 100 feet above its present height. The
cave earth is covered by a second crust of stalagmite, less dense and
thick then that below, and containing only a few bones, which are of
the same general character with those below, but include a fragment of
a human jaw with teeth. Evidently, when this stalagmite was formed,
the influx of water-borne materials had ceased, or nearly so; but
whether the animals previously occupying the country still continued
in it, or only accidental bones, etc., were introduced into the cave
or lifted from the bed below, does not appear.
The next bed marks a new change. It is a layer of black mould from
three to ten inches thick. Its microscopic structure does not seem to
have been examined; but it is probably a forest soil, introduced by
growth, by water, by wind, and by ingress of animals, at a time when
the cave was nearly in its present state, and the surrounding country
densely wooded. This bed contains bones of animals, all of them
modern, and works of art ranging from the old British times before the
Roman invasion up to the porter-bottles and dropped halfpence of
modern visitors. Lastly, in and upon the black mould are many fallen
blocks from the roof of the cave.
There can be no doubt that this cave and the neighbouring one of
Brixham have done very much to impress the minds of British geologists
with ideas of the great antiquity of man, and they have, more then any
other Post-glacial monuments, shown the persistence of some animals
now extinct up to the human age. Of precise data for determining time,
they have, however, given nothing. The only measures which seed to
have been applied, namely, the rate of growth of stalagmite and the
rate of erosion of the neighbouring valleys, are, from the very
sequence of the deposits, obviously worthless; and the only apparently
available constant measure, namely, the fall of blocks from the roof,
seems not yet to have been applied. We are therefore quite uncertain
as to the number of centuries involved in the filling of this cave,
and must remain so until a surer system of calculation is adopted. We
may, however, attempt to sketch the series of events which it
indicates.
The animals found in Kent's Hole are all "Post-glacial." They
therefore inhabited the country after it rose from the great Glacial
submergence. Perhaps the first colonists of the coasts of Devonshire
in this period were the cave bears, migrating on floating ice, and
subsisting, like the Arctic bear, and the black bears of Anticosti, on
fish, and on the garbage cast up by the sea. They found Kent's Hole a
sea-side cavern, with perhaps some of its galleries still full of
water, and filling with, breccia, with which the bones of dead bears
became mixed. As the land rose, these creatures for the most part
betook themselves to lower levels, and in process of time the cavern
stood upon a hill-side, perhaps several hundreds of feet above the
sea; and the mountain torrents, their beds not yet emptied of glacial
detritus, washed into it stones and mud and carcases of animals of
many species which had now swarmed across the plains elevated out of
the sea, and multiplied in the land. This was the time of the cave
earth; and before its deposit was completed, though how long before, a
confused and often-disturbed bed of this kind cannot tell, man himself
seems to have been added to the inhabitants of the British land. In
pursuit of game he sometimes ascended the valleys beyond the cavern,
or even penetrated into its outer chambers; or perhaps there were even
in those days rude and savage hill-men, inhabiting the forests and
warring with the more cultivated denizens of plains below, which are
now deep under the waters. Their weapons, lost in hunting, or buried
in the flesh of wounded animals which crept to the streams to assuage
their thirst, are those found in the cave earth. The absence of human
bones may merely show that the mighty hunters of those days were too
hardy, athletic, and intelligent, often to perish from accidental
causes, and that they did not use this cavern for a place of burial.
But the land again subsided. The valley of that now nameless river, of
which the Rhine the themes, and the Severn may have alike been
tributaries, disappeared under the sea; and some tribe, driven from
the lower lands, took refuge in this cave, now again near the
encroaching waves, and left there the remains of their last repasts
ere they were driven farther inland or engulfed in the waters. For a
time the cavern may have been wholly submerged, and the charcoal of
the extinguished fires became covered with its thin coating of clay.
But ere long it re-emerged to form part of an island, long barren and
desolate; and the valleys having been cut deeper by the receding
waters, it no longer received muddy deposits, and the crust formed by
drippings from its roof contained only bones and pebbles washed by
rains or occasional land floods from its own clay deposits. Finally,
the modern forests overspread the land, and were tenanted by the
modern animals. Man returned to use the cavern again as a place of
refuge or habitation, and to leave there the relics contained in the
black earth. This seems at present the only intelligible history of
this curious cave and others resembling it; though, when we consider
the imperfection of the results obtained even by a large amount of
labour, and the difficult and confused character of the deposits in
this and similar caves, too much value should not be attached to such
histories, which may at any time be contradicted or modified by new
facts or different explanations of those already known. The time
involved depends very much, as already stated, on the question whether
we regard the Post-glacial subsidence and re-elevation as somewhat
sudden, or as occupying long ages at the slow rate at which some
parts of our continents are now rising or sinking.[AT]
[AT] Another element in this is also the question raised by Dawkins,
Geikie, and others as to subdivisions of the Post-glacial period and
intermissions of the Glacial cold. After careful consideration of
these views, however, I cannot consider them as of much importance.
Such are the glimpses, obscure though stimulating to the imagination,
which geology can give of the circumstances attending the appearance
of man in Western Europe. How far we are from being able to account
for his origin, or to give its circumstances and relative dates for
the whole world, the reader will readily understand. Still it is
something to know that there is an intelligible meeting-place of the
later geological ages and the age of man, and that it is one inviting
to many and hopeful researches. It is curious also to find that the
few monuments disinterred by geology, the antediluvian record of Holy
Scripture, and the golden age of heathen tradition, seem alike to
point to similar physical conditions, and to that simple state of the
arts of life in which "gold and wampum and flint stones"[AU]
constituted the chief material treasures of the earliest tribes of
men. They also point to the immeasurable elevation, then as now, of
man over his brute rivals for the dominion of the earth. To the
naturalist this subject opens up most inviting yet most difficult
paths of research, to be entered on with caution and reverence,
rather then in the bold and dashing spirit of many modern attempts.
The Christian, on his part, may feel satisfied that the scattered
monumental relics of the caves and gravels will tell no story very
different from that which he has long believed on other evidence, nor
anything inconsistent with those views of man's heavenly origin and
destiny which have been the most precious inheritance of the greatest
and best minds of every age, from that early pre-historic period when
men, "palaeolithic" men, no doubt, began to "invoke the name of
Jehovah," the coming Saviour, down to those times when life and
immortality are brought to light, for all who will see, by the Saviour
already come.
[AU] So I read the "gold, bedolah, and shoham" of the description of
Eden in Genesis ii.--the oldest literary record of the stone age.
In completing this series of pictures, I wish emphatically to insist
on the imperfection of the sketches which I have been able to present,
and which are less, in comparison with the grand march of the creative
work, even as now imperfectly known to science, then the roughest
pencilling of a child when compared with a finished picture. If they
have any popular value, it will be in presenting such a broad general
view of a great subject as may induce further study to fill up the
details. If they have any scientific value, it will be in removing the
minds of British students for a little from the too exclusive study of
their own limited marginal area, which has been to them too much the
"celestial empire" around which all other countries must be arranged,
and in divesting the subject of the special colouring given to it by
certain prominent cliques and parties.
Geology as a science is at present in a peculiar and somewhat
exceptional state. Under the influence of a few men of commanding
genius belonging to the generation now passing away, it has made so
gigantic conquests that its armies have broken up into bands of
specialists, little better then scientific banditti, liable to be
beaten in detail, and prone to commit outrages on common sense and
good taste, which bring their otherwise good cause into disrepute. The
leaders of these bands are, many of them, good soldiers, but few of
them fitted to be general officers, and none of them able to reunite
our scattered detachments. We need larger minds, of broader culture
and wider sympathies, to organise and rule the lands which we have
subdued, and to lead on to further conquests.
In the present state of natural science in Britain, this evil is
perhaps to be remedied only by providing a wider and deeper culture
for our young men. Few of our present workers have enjoyed that
thorough training in mental as well as physical science, which is
necessary to enable men even of great powers to take large and lofty
views of the scheme of nature. Hence we often find men who are fair
workers in limited departments, reasoning most illogically, taking
narrow and local views, elevating the exception into the rule, led
away by baseless metaphysical subtleties, quarrelling with men who
look at their specialties from a different point of view, and even
striving and plotting for the advancement of their own hobbies. Such
defects certainly mar much of the scientific work now being done. In
the more advanced walks of scientific research, they are to some
extent neutralised by that free discussion which true science always
fosters; though even here they sometimes vexatiously arrest the
progress of truth, or open floodgates of error which it may require
much labour to close. But in public lectures and popular publications
they run riot, and are stimulated by the mistaken opposition of
narrow-minded good men, by the love of the new and sensational, and by
the rivalry of men struggling for place and position. To launch a
clever and startling fallacy which will float for a week and stir up a
hard fight, seems almost as great a triumph as the discovery of an
important fact or law; and the honest student is distracted with the
multitude of doctrines, and hustled aside by the crowd of ambitious
groundlings.
The only remedy in the case is a higher and more general scientific
education; and yet I do not wonder that many good men object to this,
simply because of the difficulty of finding honest and competent
teachers, themselves well grounded in their subjects, and free from
that too common insanity of specialists and half-educated men, which
impels them to run amuck at everything that does not depend on their
own methods of research. This is a difficulty which can be met in our
time only by the general good sense and right feeling of the
community taking a firm hold of the matter, and insisting on the
organization and extension of the higher scientific education, as well
as that of a more elementary character, under the management of able
and sane men. Yet even if not so counteracted, present follies will
pass away, and a new and better state of natural science will arise in
the future, by its own internal development. Science cannot long
successfully isolate itself from God. Its life lies in the fact that
it is the exponent of the plans and works of the great Creative Will.
It must, in spite of itself, serve His purposes, by dispelling
blighting ignorance and superstition, by lighting the way to
successive triumphs of human skill over the powers of nature, and by
guarding men from the evils that flow from infringement of natural
laws. And it cannot fail, as it approaches nearer to the boundaries of
that which may be known by finite minds, to be humbled by the
contemplation of the infinite, and to recognise therein that
intelligence of which the human mind is but the image and shadow.
It may be that theologians also are needed who shall be fit to take
the place of Moses to our generation, in teaching it again the very
elements of natural theology; but let them not look upon science as a
cold and godless demon, holding forth to the world a poisoned cup
cunningly compounded of truth and falsehood; but rather as the natural
ally and associate of the gospel of salvation. The matter is so put in
one of those visions which close the canon of revelation, when the
prophet sees a mighty angel having the "everlasting gospel to preach;"
but he begins his proclamation by calling on men to "worship Him _that
made heaven and earth and the sea and the fountains of waters_." Men
must know God as the Creator even before they seek Him as a benefactor
and redeemer. Thus religion must go hand in hand with all true and
honest science. In this way only may we look forward to a time when a
more exact and large-minded science shall be in perfect accord with a
more pure and spiritual Christianity, when the natural and the
spiritual shall be seen to be the necessary complements of each other,
and when we shall hear no more of reconciliations between science and
theology, because there will be no quarrels to reconcile. Already,
even in the present chaos of scientific and religious opinion,
indications can be seen by the observant, that the Divine Spirit of
order is breathing on the mass, and will evolve from it new and
beautiful worlds of mental and spiritual existence.