shall apply the name " Period" as also sufficiently
convenient. It will be found that the different epochs
and periods described are in most cases distinguished
by a commencement and a termination, often not the
less interesting that each exhibits an occasional pas-
sage, both by mineral structure and fossil remains, into
the beds of the next succeeding one.
In describing the groups of fossils, however, it will
be necessary, in order to avoid repetition, that we
should as far as possible confine our attention in each
case to some group of animals or vegetables whose
remains are most characteristic of the particular
period which they are assumed to illustrate ; and for
the sake of convenience we shall often perhaps seem
to neglect, or pass by with very slight mention, those
which are nevertheless widely distributed in the rocks
of the period under consideration. This might lead
to some confusion, and even to wrong conclusions, if
it were not understood beforehand that such apparent
neglect is not without a reason.
In order to remedy this evil in some measure, I
have here appended a tabular view of the various pe-
riods, in the order in which they will be treated, and
with particular reference to the forms of organic life
most strikingly exhibited in each. By glancing the
eye over this table, the reader, however little ac-
quainted with the details of Geology, will at least be
enabled to recognize the plan, and will thus enter on
the descriptions with some general notion of their
bearing on the whole range of creation.
14
PICTURESQUE SKETCHES
1 1 1. The Modern Epoch.
TABULAR VIEW OF THE SUCCESSIVE GEOLOGICAL PERIODS.
10. The Period of the caverns and gravel; with
Carnivora, the Megaceros and other gigan-
tic ruminating animals, and the elephants
of Europe ; and of various gigantic animals
in Asia, America, Australia and New Zea-
land. (Newer Tertiary.')
9. The Period of various large animals of the
Middle Rhine valley, succeeded by that
of the mastodon and elephants in North
America, England, Northern Europe and
India. (Middk Tertiary.']
8. The Period of the pachyderms of the Paris
basin, and of the sub- tropical (?) fruits and
animals of the London and Hampshire
Basins. (Older Tertiary.)
7. The Periods of the Chalk and Greensand ;
during the deposit of which there was pro-
bably a deep sea, covering a large proportion
of the existing land.
6. The Periods of the gigantic land reptiles,
the flying reptiles, the gigantic crocodilian s,
and the first introduction of mammalian
animals. ( Wealden and Oolite.)
5. The Periods of the frog-like, bird-like, and
marine reptiles. (Lias and Trias.)
4. The Periods marked by the presence of vege-
tables and the first introduction of reptilian
animals. (Permian and Carboniferous.)
3. The Period of fishes. (Devonian.)
I. The Ancient Epoch.
2. The Period of invertebrated animals.
(Silurian.)
1. The Period antecedent to the introduction
of life.
II. The Middle Epoch.
OF CREATION. 15
THE FIRST OR ANCIENT EPOCH.
CHAPTER II.
THE PERIOD ANTECEDENT TO THE INTRODUCTION OF LIFE.
THE DEPOSIT OF NON-FOSSIL1FBROUS ROCKS.
JUDGING from the general appearance of the solar
system, and combining the result of astronomical ob-
servations on distant bodies in the universe with the
appearance presented by various rocks on the earth's
surface, it seems not unlikely that, at a very early
period of its history, our globe existed as an intensely
heated body in a fluid state, (the fluidity being the
result of igneous fusion,) and that it gradually cooled
at the surface, perhaps by exposure in space, con-
tracting in dimensions as it cooled and hardened.
In this manner, it may be, a succession of thin solid
crusts were formed, each in succession shrinking and
cracking, until at length, when a certain balance
was arrived at between the thickness of the crust,
the rate of cooling, and the amount of internal
heat, there would be left a rough uneven surface,
having many elevations and depressions, its tem-
perature being sufficiently reduced to allow of the ex-
istence of some such atmosphere as now surrounds
it, and also permit the permanent presence of water
16 PICTURESQUE SKETCHES
in a fluid state reposing in the hollows, and form-
ing seas, lakes, and oceans. During the whole of this
time, and until the existence of water in the liquid
state, and the establishment of a sea, and perhaps long
afterwards, it is likely that there were no living beings
on the earth ; because, so far as we know, neither ani-
mal nor vegetable can exist, and perform its functions,
at the temperature of water actually boiling,*
although, at a temperature not much short of that,
some small animalcules, and even some animals of
higher organization, would seem capable of enjoying
life. Thus, therefore, according to this view, and
the reader will understand that it is merely offered
as the most probable explanation of certain appear-
ances observed, the first period of the existence
of the earth as a planet was marked by a chaotic
state of igneous fusion, and characterised by fre-
quent disturbances of the surface consequent upon
cooling from such a state. Let us consider for a
moment what kind of rocks are exhibited to us when
we examine these earliest records of our globe, and
let us see also how far we are able to examine them.
In the first place, we often find, as the basis of all
other rocks in mountain chains, and throughout some
extensive tracts of country, a well-known rock called
granite; a rock whose structure is crystalline, and
which bears strong marks of having cooled slowly
from a state of intense heat. This rock is found in
all parts of the world, and sometimes in widely ex-
* This refers, of course, to the boiling temperature of water at the earth's
surface with the present atmosphere. There is no proof of any change in
the gaseous condition or pressure of the air, neither do we know what
would be the condition of the surface with a steam atmosphere.
OF CREATION. 17
tended masses. It generally exhibits its own charac-
teristic features with sufficient distinctness to leave no
doubt as to its nature; and it may be found in our own
island, as, for instance, in Cornwall, Wales, and Scot-
land ; and in other parts of Europe, as in the Scandi-
navian mountains, the Hartz, the range of mountains
separating Northern Germany from Bavaria and Bo-
hemia, in the Alps both of Switzerland and the Tyrol,
in the Pyrenees, and in the Carpathians. In Asia it
forms the centre of the Caucasus; it occupies a large
part of the Himalayan, Uralian, and Altai mountains ;
and is found also in Siberia. In Africa it appears
in Upper Egypt, in the Atlas mountains, and at
the Cape of Good Hope ; and it may be traced along
the Western part of the whole of the two Americas,
and appears again in the Southern islands and in
Australia.
A rock so universally extended might, almost for
that reason, be looked upon as the foundation and the
main solid frame- work of our globe. It must not be
lost sight of, however, that in many cases the granite
has been, if not formed, at least placed in its present
position, in a pasty or fluid state,'* long subsequent to
the early period of which we are now speaking ; and
thus, though we may safely consider the granite as
frequently the oldest rock, we should always remem-
ber that a material so widely extended and so im-
portant, may be elaborated and expelled from the
deep recesses of Nature's store-house at any time, and
even at the present day.
I shall not detain the reader any longer with an
* In either case the result of intense heat acting under enonnous
pressure.
18 PICTURESQUE SKETCHES
account of the rocks which have been called "Primi-
tive" but shall quit this subject with a remark which,
from the manner in which I have spoken of granite,
may perhaps be necessary. It is this : that there are
many kinds of granite and granitic rock, some of them
very different from ordinary granite in appearance,
and that there are also many other so-called primitive
rocks very different in structure ; but these varieties
do not prevent the account I have given from being
sufficiently accurate for my purpose, and I trust the
reader will not suppose, when he has read through
this little volume, that he has learnt everything in
Geology.
Next in order to the crystalline rocks, and almost
as widely extended, there are two or three others, often
themselves crystalline, but bearing evident marks of
what is called " mechanical structure," or, in other
words, of having been deposited from water. These
may be described as gneiss, mica-schist, and clay-slate."""
If we imagine common granite coarsely pounded, and
thrown into a vessel of water, it will arrange itself
at the bottom of the vessel in a condition very
much like that of gneiss, which is indeed nothing
else than stratified granite. If the water in which
the pounded rock is thrown is moving along at a
slow rate, and that part of the granite called felspar
happens to be somewhat decomposed, as it often
* Under this name " clay-slate," I only mean here to include those
slates, whether of distinctly crystalline structure or not, which present no
marks of having contained fossils. That there are such, no Geologist will,
I suppose, doubt ; but when the name clay-slate is given, as it is some-
times, to fossiliferous beds, they ought to be referred at once to the period
indicated by the kind of fossils discovered.
OF CREATION. 19
is, then the felspar (which is so truly clay, that
it makes the best possible material for the use of
the potteries,) and the thin shining plates of mica
will be carried farther by the water than the lumps
of white quartz or flint sand, which with the other two
ingredients made up the granite ; and the two former
will be deposited in layers, which, by passing a galvanic
current through them, would in time become mica-
schist. If the mica were absent, or if the clay were
deposited without it, owing to any cause, then a simi-
lar galvanic current would turn the deposit into some-
thing like clay-slate. These three mechanically ar-
ranged rocks are found abundantly, surrounding and
overlying the granite, as if they had been formed
from its broken and rough edges, worn away by the
waters of the first ocean, and afterwards deposited
at the bottom of the sea. In these rocks we have
arrived at a second period, still unmarked by life,
although apparently better fitted for sustaining it ;
our earth being then not merely a chaotic mass of
cracked and burnt rock, but having had superim-
posed upon that mass extensive and thick layers of
various materials ; these contain in their composition
most of the elements, both gaseous and solid, by
certain combinations of which living animals and
vegetables were enabled to perform their functions,
and render inanimate matter available for their dif-
ferent wants.
One of the most remarkable facts with regard to
these ancient deposited rocks, is their extraordinary
thickness in some localities. It is not difficult to
understand, that at a time when the granite and
granitic rocks were newly formed, and presented
20 PICTURESQUE SKETCHES
innumerable fractured edges in every direction, the
pounding action of moving water, especially if that
water was of a high temperature, might grind down
the exposed rock with extreme rapidity, and pro-
duce extensive deposits, rapidly filling up hollows
and depressions. But we can hardly suppose the ex-
istence of depressions so considerable as the thickness
of the gneiss and clay-slate would require ; and it is
far more reasonable to assume that a contraction of the
crust, the result of gradual cooling, produced a series
of wave-like motions in the earth's crust, alternately
elevating and depressing portions of the surface, and
sometimes producing a succession of elevations or de-
pressions on the same spot. However this may be, it
is certain that these old sedimentary rocks have been
not unfrequently altered so as to have become crys-
talline; and they are also very often cracked and
broken, the cracks being sometimes filled up with
rocks of a different kind, injected apparently in a
melted state, and sometimes with other materials,
also crystalline, and often containing a greater or less
proportion of metallic ore.
Thus do these lowest sedimentary strata, whose
vast antiquity is in many cases unquestionable, but
which sometimes, like the granite itself, have been
elaborated at later periods, occupy a definite place
among the rocks of which the earth's crust is made
up. They mark, it would appear, a strange and
dark passage from that state which we have con-
sidered chaotic, to a condition of more regular and
quiet deposit ; they are, however, with reference to
fossiliferous rocks, azoic, or lifeless; and they are also
as a class almost as widely spread, and as distinctly
OF CREATION. 21
universal, as the granitic rocks themselves. At the
end, therefore, of this our first period, we may suppose
that there existed a globe, whose surface exhibited al-
ternations of land and water; the land having in some
places as distinctly stratified an appearance as it has
at present, and the thick masses of strata resting on
huge bosses and peaks of granite and other igneous
rock : but all was then bare and desolate; not a moss
nor a lichen covered the naked skeleton of the globe ;
not a sea-weed floated in the broad ocean ; not a
trace existed even of the least highly organized ani-
mal or vegetable ; everything was still, and with the
stillness of absolute death. The earth was indeed pre-
pared, and the fiat of creation had gone forth; but
there was as yet no inhabitant, and no being endowed
with life had been introduced to perform its part in
the great mystery of Creation.
It must, however, be distinctly understood that this
view is strictly hypothetical, and is, after all, only one
means of explaining certain phenomena. So far as it
is an illustration of facts that have been observed, it
has its value, and may be received provisionally ; but,
so far as it is merely a theory of the earth, it is worth
neither more nor less than other different theories,
many of which were proposed by cosmogonists of
ancient date, and some have been put forth in our
own time by persons who have as little ground for
theorizing. I have chosen in the present case to
present it as a sketch, embodying many facts and re-
sults of observation, although the cause of the absence
of fossils in metamorphic rocks, and of the other ap-
pearances that have been observed, may undoubtedly
have been very different.
22
PICTURESQUE SKETCHES
It is not, indeed, till we advance one step further,
and consider the condition of the earth, by comparing
what we know of its inhabitants with our speculations
concerning the position of land then existing above
the water, that we can arrive at conclusions at all
satisfactory.
The additional facts made known by studying the
remains of animals and vegetables found in the vari-
ous rocks, give a new aspect even to the form of the
speculation ; and we shall soon perceive how far this
view of the earliest condition of the globe is probable,
when we study the first known results of creative
power in reference to organic beings.
OF CREATION. 23
CHAPTER III.
THE PERIOD'OF THE EXISTENCE OF INVERTEBRATED ANIMALS AS THE
MOST HIGHLY ORGANIZED INHABITANTS OF THE SEA. THE SILU-
RIAN ROCKS.
WRAPPING round the igneous rocks of Cumberland
and the lake district, ranging over a considerable part
of the north-east of Ireland, occupying a large portion
of South Wales, and present almost everywhere in
North Wales, there are found a great number of sedi-
mentary rocks of various kinds, covering the gneiss,
mica schist, or clay slate, and covered up in South
Wales by a series of coarse red conglomerates or beds
of pudding-stone. These sedimentary rocks are ex-
panded sometimes to a thickness of many thousand
feet, and they form a remarkable and natural group,
which may be conveniently sub-divided into two
parts, the lower being by far the most considerable
in vertical thickness, but the upper containing a
greater number and variety of the fossil remains of
animals.
In the British Islands, and very generally in other
countries, this lower group of rocks consists of a gray-
ish-coloured sandy stone, often slaty or flaggy, and
containing much clayey matter, sometimes including
poor bands of limestone, and not unfrequently exhi-
biting, in the partings between two beds, a number of
imperfect remains of shells and other organic sub-
24 PICTURESQUE SKETCHES
stances. From its frequently assuming the appear-
ance of clay slate, and being indistinguishable from
that rock except by the presence of fossils, it may be
supposed that the materials of which it is for the
most part formed were obtained from older, and
probably from igneous, rocks pounded still more
finely at the bottom of water, and forming fresh com-
binations, often marked by the presence of sand ob-
tained from the quartz of the granite, and also oc-
casionally distinguished by the presence of mica.
In those parts of England and Wales in which these
rocks have been discovered, they have been found to
exhibit indications of very extensive disturbance, and,
in some cases, seem to have been deposited alternately
with great masses of igneous rock poured out like lava
from a volcano, but erupted through the bed of the
ocean, and soon covered up with new deposits. Be-
sides disturbances of this kind, these same rocks have
in North Wales been subjected to so much squeezing,
under a great pressure from above, that they are twist-
ed into folds repeated several times, just as a number
of pieces of cloth might be thrown into wave-like folds
if squeezed by lateral pressure, with a heavy weight
resting upon the upper surface. No description, how-
ever, can at all do justice to the singular complica-
tion thus introduced into the huge masses of hard and
tough rock. In one place the strata are snapped
asunder and displaced, in another they are bent
nearly double like sheets of paper. Here the slaty
beds are contorted into the most strange and violent
curves; there, the opposite cliffs of a narrow glen
exhibit them torn asunder like fragments of soft wood
or semi-tenacious paste.
OF CREATION. 25
Nor should it be supposed that such appearances
are confined to the slaty and tough beds of this
particular period. They are as common in the older
schists, and in the gneiss, as in these strata, and they
appear again in the similar rocks of the next newer
period ; but there is this difference observable in the
case of England, namely, that the disturbances seem
either to have diminished in intensity, or to hlive
produced a smaller effect at each later time, while
they are nowhere more remarkable than in the case
of the lower silurian strata of North Wales and
Cumberland.*
In these ancient beds, so greatly altered by me-
chanical violence from their original condition, often
deposited amidst much disturbance, and presenting so
many analogies with the earlier and non-fossiliferous
stratified rocks, we find for the first time distinct
marks of the existence of beings endowed with life.
We naturally turn with considerable interest to
inquire concerning the nature of the inhabitants of
our globe, as exhibited by their remains in these
rocks ; and in doing so, we find, that, although the
conditions were, in some respects, very different, and
the animals often unlike existing species, there is yet
sufficient analogy to enable us to determine with con-
siderable certainty the nature of the groups of species
living in the sea at that early period.
The first thing that strikes the geological natural-
ist, in looking over the numerous fossils obtained from
* The evidence of great disturbance observable in these beds in the
British Islands does not extend to Russia and Scandinavia, where they
also occur. Here, and in other parts of the world, they have been less
disturbed, but their general character is the same.
C
26 PICTURESQUE SKETCHES
the great series of the lower silurian rocks, is the ap-
parent want of fishes, and, indeed, of all vertebrated
animals. We find everywhere abundant proof that
these great thicknesses of mud and sand, with occa-
sional bands of imperfect limestone, were formed at
the bottom of water, and at various depths ; some,
in all probability, in shallow water near land, and
others in the deepest recesses of the ocean ; but no-
where throughout their wide spread in all parts
of the world have they yet yielded the smallest
fragment that could be referred to a fish. It is,
therefore, pretty clear, either that fishes had not then
been created, or that the conditions for their develop-
ment were so unfavourable that they were extreme-
ly rare, and formed no important group among the
inhabitants of the sea, in places where other organic
remains, often found in newer formations accompany-
ing fishes, are very abundant. The animals we do find
consist of certain sea- weeds, called Graptolites* the
habitation, probably, of compound creatures, )* which
seem scarcely to deserve the name of animals ; of other
polyps of somewhat higher organization, building those
singular and lasting monuments, the coral-reefs ; of
animals removed yet another step in advance, and
called Crinoids J , and of a singular and extensive
group of crustacean animals, known by the name of
Trilobites. They also include a considerable group
* Graptolites, ypairroQ (graptos), written upon ; \iQoQ (lithos), a
stone from their appearance.
-J- Allied to the recent family of Sertularida.
$ Crinoids, tcpivog (crinos), a lily ; eidog (eidos), resembling. Lily-
shaped animals.
Trilobites, three-lobed, so called from their shape.
OF CREATION.
27
of bivalve shells belonging to animals of low organiza-
tion, and allied to the Terebratula; of a few other
shells, both bivalve and univalve ; and, last of all, of
a number of the many-chambered shells of a carnivo-
rous animal * like the cuttle-fish, a creature of high
and complicated organization among the Inverte-
brata, and which seems to have been introduced
among the very earliest of the species intended to
people the primaeval seas. All these animals must
have been to a certain extent contemporaneous ; and
it is worth while to remark, concerning them, that
they exhibit some instances of very imperfect, and
some of the most perfect, development of the great
kingdom of nature to which they belong. In the
older beds, at least until the termination of the first
great epoch, the silurian, there seem, indeed, only
to have been introduced successive modifications
and additional species of the invertebrated type ; and
not till its close did the fishes appear, as if preparing
the way for the next period, marked by the preva-
lence of these more highly organized beings.
As the animals of the newer differ so little from
those of the older portion of the first period, at least
in points which admit of general description, I shall
not describe them separately ; but, having already of-
fered a few remarks on the mineral structure of the
rocks, I shall proceed at once to explain in succession
those groups which are most interesting and characte-
ristic. In this way I hope to communicate something
like a distinct notion of the results of geological inves-
tigation with regard to the first inhabitants of the
earth, and not only show the general fact, that impor-
* OrthroceratiteS) and several allied forms.
c 2
28 PICTURESQUE SKETCHES
tant changes must have since taken place in the con-
dition of the sea-bottom, but also explain the nature
of some of those changes.
According to the actual constitution of things, the
soft substance of the bodies of animals consists chiefly
of carbon in combination with gases (oxygen, hydro-
gen, and nitrogen) ; and the more solid parts, whether
forming a bony skeleton, or a yet harder external
case, or internal framework of stone, are composed of
salts of lime with little admixture of other material,
especially in the invertebrated animals. The presence
of carbon, lime, and these gases, therefore, in sufficient
abundance under favourable circumstances of tempe-
rature and in a condition to combine with other ele-
ments, is all that is required to enable animals once
created to carry on the functions of life.*
Of such substances, those existing in a gaseous
state were, no doubt, sufficiently abundant during