THE PALÆOZOIC PERIOD.
“In His hand are the deep places of the earth.”—DAVID.
Trench, in his charming little book on the “Study of Words,” says of
words that they are “fossil poetry.” He adds, “Just as in some fossil,
curious and beautiful shapes of vegetable or animal life, the graceful
fern or finely vertebrated lizard, such as now it may be, have been
extinct for many thousands of years, are permanently bound up in the
stone, and rescued from that perishing which would otherwise have been
theirs; so in words are beautiful thoughts and images, the imagination
and the feeling of past ages, of men long since in their graves, of men
whose very names have perished—these, which would so easily have
perished too, are preserved and made safe for ever.”
Geology is the fossil poetry of the earth; such a poetry as those can
never dream of who in a pebble see a pebble and nothing more. But to
those who walk through this great and beautiful world intent upon
finding material for thought and reflection, there is no “picking up a
pebble by the wayside without finding all nature in connexion with it;”
and the most retired student, in search not simply of the picturesque or
of the beautiful, but of anything and everything that can minister to
his profounder worship of Him to whom belongeth both “the deep places of
the earth and the strength of the hills,” may say of his solitary
rambles:—
“There rolls the deep where grew the tree;—
O earth, what changes hast thou seen!
There where the long street roars, hath been
The stillness of the central sea.”[27]
We now enter upon the ancient life, or Palæozoic period of the earth’s
history, and proceed to examine the oldest forms of life, or the most
ancient organic remains found in the crust of the earth. As we do not
aim to _teach_ geology in this small work, but simply to place the chief
geological facts in such a light as to impart a _taste_ for the science,
the reader will not expect any minute details, which are more likely to
perplex than to assist the beginner. Let the reader dismiss from his
mind all that he has tried to remember about Upper and Lower Silurian
rocks, and the Upper and Lower Ludlow rocks, the Caradoc sandstone and
the Llandilo flags, and so on; let us simply say that one part of the
crust of the earth, supposed to be between 50,000 and 60,000 feet in
thickness,[28] is called the Silurian system, and constitutes a large
and interesting part of the Palæozoic period. The term Silurian was
given to this part of the earth’s crust in consequence of these rocks
being found chiefly in Wales, Devon, and Cornwall—parts of England once
inhabited by the Silures, who under Caractacus made so noble a stand
against the Romans.
In coming for the first time into contact with the organic remains of
pre-Adamite creations, it may be well to entreat the student to mark, as
he goes on, the very different and characteristic fossils of the several
formations through which we propose to travel. There will be little or
no difficulty in doing this, and its mastery will be of invaluable
service in our after researches. There is and there can be no royal road
to any kind of learning; all, therefore, that we propose to do is to
take a few of the big stones, boulders, &c., that have needlessly been
allowed to make the road rougher than necessary, out of the way, that
thus our companion traveller on this geologic route may feel that every
step of ground walked over is a real and solid acquisition. In marking
the characteristic fossils of each formation, let us suggest, in
passing, the vast amount of pleasure there is in going to a friend’s
house, and looking at the minerals or organic remains that may be in the
cabinet or on the mantel-shelf, and being able to take them up one by
one, and to say this is from the Silurian; that is from the
Carboniferous; this is from the Cretaceous, and that from the Wealden
formations, and so on. Why, it gives a magical feeling of delightful
interest to every object we see, and will always make a person a welcome
visitor with friends with whom, instead of talking scandal, he can talk
geology. Not long since the writer had a very pleasing illustration of
this. He had been lecturing on geology in a small agricultural village;
there was a good sprinkling of smock-frocks among the hearers, and he
said at the close of one of the lectures, “Now, very likely most of you
have got some stones, as you call them, at home on the chimneypiece;
perhaps you don’t know their names, or what they were before they became
stones; well, bring them next week, and we will do our best to name them
for you!” Next week, after the lecture, up came one, and then another,
and then a third, and so on; and diving their hands down into the old
orthodox agricultural pocket, brought out a variety of specimens, some
of them very good indeed, which had been “picked up” by them in the
course of their labour, and which, supposed to be “_rather kūrŭss_,” had
been carefully conveyed home. When these matters were given a “local
habitation and a name,” the delight of many was most gratifying.
Now, all this is only just the application of M. Cousin’s words in
relation to physical geography: “Give me the map of a country, its
configuration, its climate, its waters, its winds, and all its physical
geography; give me its natural productions, its flora and fauna, and I
pledge myself to tell you _à priori_ what the inhabitants of that
country will be, and what place that country will take in history, not
accidentally, but necessarily; not at a particular epoch, but at all
periods of time; in a word, the thought that country is formed to
represent.”
These remarks furnish us with a clue. Each formation has its own
peculiar and characteristic fossils, and these fossils are arranged with
as much care, and preserved as uninjured, as if they had been arranged
for a first-class museum. But before proceeding on this fossiliferous
tour, we may anticipate a question that may possibly be asked on the
threshold of our inquiries, and into which we propose going fully in the
sequel of this volume. It may be asked, “Were not these fossils placed
in the rocks by the Deluge?” To this, at present, we answer, that so
partial and limited was the character of the Deluge, being confined to
just so much of the earth as was inhabited by man, and so brief was its
duration, compared with the vast geological epochs we shall have to
consider, that we do not believe we have one single fossil that can be
referred to the Noachian deluge; and before we close, we trust it will
have been made evident to every careful reader that fossils, as records
of Noah’s flood, are an impossibility; and that the vast antiquity of
the globe, taken into connexion with the prevalence of death on a most
extensive scale, ages and ages previous to the creation of man, can
alone account for our innumerable treasures of the “deep places of the
earth.”
[Illustration:
1
]
The characteristic fossils of the Silurian system are entirely unique.
The trilobite may fairly be regarded as the prominent one; besides which
there are orthoceratites, and graptolites, some members of the
crinoidean family, with different kinds of corallines, and some other
names to be rendered familiar only by future further study. We shall
confine ourselves to those that our own recent researches have made us
familiar with. First, here is the trilobite. We need not perplex our
readers by any of the numerous subdivisions of this remarkable animal’s
nomenclature; that would defeat the purpose of this book. Any work on
geology will do this.[29] Here are three trilobites: one (1) by itself;
another, (2) imperfect in its bed or matrix, and a third (3) rolled up.
[Illustration]
This most remarkable crustacean possessed the power of rolling itself up
like the wood-louse or the hedgehog; and, reasoning by analogy, we
suppose this to have been its defence against its numerous enemies. It
is a very abundant fossil, found all over Europe, in some parts of
America, at the Cape of Good Hope, but never in more _recent strata_
than the Silurian. The hinder part of the body is covered with a
crescent-like shield, composed of segments like the joints of a
lobster’s tail; and two furrows divide it into three lobes, whence its
name.[30] Most remarkable are the eyes of this animal, and it is the
only specimen in the vestiges of ancient creations in which the eye,
that most delicate organization, is preserved; and if, as we believe,
this little creature was living and swimming about, now and then
fighting with some greater Cephalopodous mollusk, millions and millions
of years ago, then in this fact we have the real fossil poetry of
science, the romance of an ancient world which geology reveals to our
delighted and astonished minds. From Buckland’s Bridgewater Treatise we
give a drawing of the eyes of the trilobite; and in Buckland’s words we
add: “This point deserves peculiar consideration, as it affords the most
ancient, and almost the only example yet found in the fossil world, of
the preservation of parts so delicate as the visual organs of animals
that ceased to live many thousands, and perhaps millions of years ago.
We must regard these organs with feelings of no ordinary kind, when we
recollect we have before us the identical instruments of vision through
which the light of heaven was admitted to the sensorium of some of the
first created inhabitants of our planet.”[31]
[Illustration: Fossil]
But these are not the only fossils, or organic remains, to be found in
the clay, slates, &c., of the Silurian system. Passing by those we have
briefly indicated above, there are others of a highly interesting
character, concerning some of which we proceed to give a brief history.
Being in Cornwall a short time since, we made a visit to Polperro, a
romantic but out-of-the-way town on the south-west coast, for the
purpose of procuring some remains of fossil fish considered
characteristic of the Silurian system of Murchison, and which have been
recently discovered by Mr. Couch, an eminent local naturalist, in the
cliffs east and west of that town. We did not see Mr. Couch, but found
our way to a coast-guardsman, also a naturalist, whom we found to be a
most skilful bird and fish stuffer, and a ranger for objects of natural
history among the surrounding clay-slates and other rocks. William
Loughrin’s collection of Cornish curiosities will well repay any
traveller going out of the way twenty or thirty miles, and they will
find in him a fine specimen of an intelligent and noble class of men.
Below we give some specimens from the Polperro slate. No. 1 might be
taken for impressions of sea-weed, so remarkably does it resemble the
sea-weed thrown up on our beaches; but it is generally conceded that
this is merely a crystallization of oxydized matter, such as may often
be found in connexion with manganese.
[Illustration:
No. 1.
]
No. 2 is the Bellerophon,[32] a shell which we shall afterwards find in
the mountain limestone, but which is rare in connexion with the Silurian
rocks.
[Illustration:
No. 2. BELLEROPHON, a shell which seems to have been abundant.
]
[Illustration:
No. 3. REMAINS OF VEGETABLE TEXTURE.
]
No. 3 we know not how to describe. We are not certain what organic
remains these are; so far as we have been able to examine them, they
appear to us the remains of succulent vegetables, (?) probably the
thick, soft stems of sea-weed, that may once have reposed in quiescence
on the mud of which these slates are composed, and afterwards have been
crushed by the superposition of mud and shale, until in the course of
ages, by upheaval and depression, they have become a second time
visitants of our atmosphere, and now expose themselves to our study and
speculations.
[Illustration:
No. 3. (Portion magnified two natural sizes.)
]
[Illustration:
No. 4. CORALLINE. (Natural size.)
]
Here is one more form of life of this ancient period; it is evidently a
coralline, which we also procured at Polperro.
Let us suppose our readers to have made themselves familiar with these
organic remains, simply as characteristic and illustrative of this
formation; they will easily find their way into other traces and
remnants of ancient life in the Silurian epoch. How absurd must seem the
development hypothesis to those who rightly ponder these old, old
vestiges! It seems to us a very idle idea to suppose that a trilobite
could develop itself into a bird, or a monkey, or by any series of happy
accidents, could become a man;[33] yet such has been the theory of those
who overlook what some writer on geology, whose name we forget, has
expressed strongly in these words: “There is no fact which has been
demonstrated more completely to the satisfaction of every man of real
science, than that there is no known power in nature capable of creating
a new species of animal, or of transmuting one species into another.”
We close this chapter on the Silurian system in the eloquent words of
Professor Sedgwick: “The elevation of the faunas of successive periods
was not made by transmutation, but by creative additions, and it is by
watching these additions that we get some insight into nature’s true
historical progress. Judging by our evidence—and what else have we to
judge by?—there was a time when Cephalopods were the highest type of
animal life. _They_ were then the Primates of this world, and,
corresponding to their office and position, some of them were of noble
structure and gigantic size. But these creatures were degraded from
their rank at the head of Nature, and _Fishes_ next took the lead; and
they did not rise up in nature in some degenerate form, as if they were
only the transmuted progeny of the Cephalopods, but they started into
life in the very highest _ichthyic_ type ever reached.
“Following our history chronologically, _Reptiles_ next took the lead,
and, with some evanescent exceptions, they flourished during the
countless ages of the secondary period as the lords and despots of the
world: and they had an organic perfection corresponding to their exalted
rank in Nature’s kingdom; for their highest orders were not merely great
in strength and stature, but were anatomically raised far above any
forms of the Reptile class now living in the earth. This class, however,
was in its turn to lose its rank. _Mammals_ were added next (near the
commencement of the tertiary period), and seem to have been added
suddenly. Some of the early extinct forms of this class, which we now
know only by ransacking the ancient catacombs of Nature, were powerful
and gigantic, and we believe well fitted for the place they filled. But
they in turn were to be degraded from their place in Nature, and she
became what she now is by the addition of man. By this last addition she
became more exalted than before. Man stands by himself, the despotic
lord of the living world; not so great in organic strength as many of
the despots that went before him in Nature’s chronicle, but raised far
above them all by a higher development of brain, by a framework that
fits him for the operations of mechanical skill, by superadded reason,
by a social instinct of combinations, by a prescience that leads him to
act prospectively, by a conscience that makes him amenable to law, by
conceptions that transcend the narrow limits of his vision, by hopes
that have no full fruition here, by an inborn capacity of rising from
individual facts to the apprehension of general laws, by a conception of
a cause for all the phenomena of sense, and lastly, by a consequent
belief in the God of nature:—such is the history of nature.”[34]
[Illustration:
LANDS END, CORNWALL.
]