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THE WONDERS OF GEOLOGY.

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60. MUTATIONS IN THE RELATIVE LEVEL OF LAND AND SEA.—Of the reality of these changes in the relative level of the land and of the Northern Ocean, there cannot exist a doubt; but the mind is so accustomed to associate the idea of stability with the land, and of mutability with the sea, that it may be necessary to offer a few additional remarks on these highly interesting facts. As it is the property of all fluids to find their own level, it is obvious that if the level of the sea be elevated or depressed in any one part, that elevation or depression must influence the whole surface of the ocean, and the level therefore cannot be affected by local causes. But movements of the land may take place, and the effect extend over whole countries, as in South America,—or along lines of coast, as in Sussex,—or be confined to a single island,—or even to the area of a temple, as at Puzzuoli.*

But while the land is rising in the more northern latitudes, it appears to be sinking on the shores of the Mediterranean. Breislak mentions † that numerous remains of buildings are to be seen in the Gulf of Baiæ; ten columns of granite, at the foot of Monte Nuovo, are nearly covered by the sea, as are the ruins of a palace built by Tiberius in the island of Caprea. Thus while the level of the sea is becoming lower in the north, from the elevation of the land, it is *rising* in the Mediterranean, from the sinking of its coasts. Now, as all the parts of the ocean communicate, the water cannot permanently rise in one part and sink in another, but must rise and fall equally to maintain its level; we must therefore consider it as demonstrated, that these changes are solely dependent on the elevation and depression of the land. If we bear in mind the insignificance of the masses affected by these operations,

* See Playfair's admirable commentary on this geological problem, "Illustrations," p. 433.

† Playfair.

§ 61.

RETROSPECT.

119

as contrasted with the earth itself (see page 35), we may readily conceive that as fissures and inequalities are produced in the varnish of an artificial globe by heat and cold, in like manner the elevation of mountain chains, and the subsidence of whole continents, may be occasioned by the expansion or contraction of portions of the earth's crust, from sudden changes in the internal temperature of the globe.

61. RETROSPECT.—In this rapid sketch of the geological phenomena, which an examination of the surface of the earth presents to our notice, I have doubtless dwelt on several subjects familiar to many of my readers. But, as one of our ablest geologists* has remarked, “the teacher of Geology must suppose himself called on to answer questions, both concerning the facts of the science, and the inferences to be deduced therefrom; and his instructions will be so much the more successful as he takes these questions in the most natural order of their occurrence, and answers them most completely and satisfactorily. In doing this he is not at liberty to neglect even elementary truths, for if these were passed over in compliment to such as have made progress in the science, those for whose advantage he is especially interested, would be called to the unreasonable task of labouring without instruments, and of theorizing without intelligible data.”

From the vast field of inquiry over which our observations have extended, it may be useful to offer a brief summary of the leading principles that have been enunciated, and the facts on which they are founded. By the most profound investigations of which the human mind is capable, we learn that our earth is one of myriads of spherical bodies, revolving round certain luminaries; and that these bodies occur in every variety of condition, from that of a diffuse

* Professor John Phillips.

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THE WONDERS OF GEOLOGY.

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luminous vapour, to opaque solid globes like our own. All the materials of which the earth is composed may exist either in a solid, fluid, or gaseous state; and simply by a change of temperature, or by electro-chemical agency, every substance may undergo a transition from one state to the other. Water existing as ice, fluid, or vapour, and separable into two invisible gases, offers a familiar example of a body constantly exhibiting these transmutations; and mercury, of a metal which, though generally in a fluid state, becomes, when exposed to a very low temperature, a solid mass like silver. The relative position of land and water, and the inequalities on the surface of the earth, are subject to constant changes, which are regulated by certain fixed laws. The principal causes of the degradation of the land are atmospheric agencies, variations of temperature, the action of running water, and of icebergs, glaciers, &c., by which the disintegrated materials of the land are transported into the bed of the ocean. The mud, sand, and other detritus thus produced, are consolidated by certain chemical changes which are in constant activity, both on the land and in the depths of the ocean, and new rocks are thus in the progress of formation. But the conjoint effect of these operations is unremitting destruction of the surface of the land; and were there no conservative process, the whole of the dry land would disappear, and the earth be covered by one vast sheet of water. The globe, however, possesses an internal source of heat, and whether this exists as a central nucleus of high temperature, or as medial foci,— whether it be dependent on the assumed original nebulous state of the earth, or produced by chemical or electro-magnetic forces acting on the mineral substances contained in the interior of our planet,— does not affect the present inquiry. This internal heat, however induced, must occasion constant changes in the relative level of the land and water;

CT. I.

§ 61.

RETROSPECT.

121

elevating and depressing whole continents,—converting the bed of the sea into dry land,—and submerging the dry land into the abyss of the ocean. The volcano and the earthquake are the effects of its local and paroxysmal energies,—the quiet and insensible elevation and subsidence of the land, of its slow but certain operation. By this antagonist power the accumulation of the spoils of the land, which the rivers, waves, and currents have carried into the bed of the ocean, are again brought to the surface, and form the elements of new islands and continents; and by the organic remains discovered in the strata, we trace the nature of the countries whence these spoils were derived. In the deltas and estuaries of modern times,—in the detritus accumulating in the beds of the ocean,—in the recent tracts of limestone forming on the sea-shores,— beneath the cooled lava currents erupted from existing volcanoes,—the remains of man and of his works, and of the animals and plants which are his contemporaries, are found imbedded.

The dynamical effects of elevation appear to be referable to three great divisions :—1. The gradual rising of ridges through large spaces of the earth's crust, and the consequent production of longitudinal fissures and lines of volcanic vent; 2. The long-continued protrusion and eruption of igneous rocks along such lines of vent; and 3. Local eruptions and protrusions, producing valleys of elevation, dislocations of the strata, and other phenomena that terminate in ordinary volcanic action.

Such are the deductions derived from the phenomena which have been submitted to our examination. To the mind previously unacquainted with the elements of geology, I am ready to acknowledge that to attribute mutability to the rocks and the mountains, must appear as startling and incredible, as did the astronomical doctrines of Galileo to the people of his times; but the intelligent reader, who has

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THE WONDERS OF GEOLOGY.

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attentively considered the facts presented, even in this
brief survey, cannot, I conceive, refuse assent to the in-
ferences thus cautiously obtained. As we proceed in our
investigations, we shall find that from the earliest period of
the present physical condition of our planet, its surface has
undergone repeated modifications in the relative distribu-
tion of the water and the land; and as the rocks and
mountains and plains have been subjected to perpetual
mutation, the element which has hitherto been considered
as the type of mutability, can alone be regarded as having
suffered no change. This idea is finely embodied by Lord
Byron in the following sublime apostrophe to the Ocean,
with which I will conclude this discourse.

" Thy shores are empires, changed in all save thee—
Assyria, Greece, Rome, Carthage, what are they?
Thy waters wasted them while they were free,
And many a tyrant since; their shores obey
The stranger, slave, or savage; their decay
Has dried up realms to deserts:—not so thou,
Unchangeable, save to thy wild waves' play—
Time writes no wrinkle on thine azure brow—

*Such as Creation's dawn beheld, thou rollest now!*

CHILDE HAROLD, Canto iv.

LECTURE II.

1. Introductory. 2. Extinction of Animals. 3. Law of Extinction. 4. Animals extirpated by Human Agency. 5. Apterisy of New Zealand. 6. Moa of New Zealand. 7. Dodo of the Mauritius. 8. Irish Elk. 9. Epoch of Terrestrial Mammalia. 10. Fossil Mammalian Remains. 11. Comparative Anatomy. 12. Osteology of the Carnivora. 13. Osteology of the Herbivora. 14. Dental organs of the Rodentia. 15. General Inferences. 16. Fossil Elephants, &c. 17. Fossil Mammalia of the valley of the Thames. 18. Fossil Elephants of other parts of England. 19. Extinct Elephant or Mammoth in Ice. 20. Mammoths of the alluvial deposits of Russia. 21. Siberia and Russia in the Mammoth epoch. 22. Mastodon. 23. Mastodons of Ava. 24. Fossil Mammalia of the Sub-Himalayans. 25. Sub-Himalayah tertiary deposits. 26. Remarkable collocation of Fossil animals. 27. The Pampas. 28. The Sloth tribe. 29. Megatherium. 30. Mylodon. 31. Megalonyx. 32. Glyptodon. 33. Toxodon. 34. Fossil Hippopotamus, &c. 35. Dinotherium. 36. Fossil Carnivora in Caverns. 37. Cave of Gaylenreuth. 38. Förstershöhle, or Forest-cave. 39. Bone Caverns in England. 40. Diseased Bones found in Caverns. 41. Human Bones in Caverns. 42. Osseous Breccia. 43. The Rock of Gibraltar. 44. Osseous Breccia of Australia. 45. Retrospect.

1. INTRODUCTORY.—In the previous Lecture we took a comprehensive view of the actual physical condition of the surface of our planet, and of the nature and effects of the principal agents by which the land is disintegrated and renewed. We found in the modern fluviatile and marine deposits, that the remains of man, of works of art, and of existing species of animals and vegetables, were preserved. In every step of our progress, the grand law of nature, alternate decay and renovation, was exemplified in striking characters. Whether in the regions of eternal snow, or in torrid climes—in the rocks and mountains, or in the verdant plains—by the agency of heat, or by the effect of cold—of drought, or of moisture—of steam, or of vapour—by the abrasion of torrents and rivers—by inundations of the ocean—or by volcanic eruptions—still the work of destruc-

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THE WONDERS OF GEOLOGY.

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tion, in every varying character, was apparent. And on the other hand we perceived that amidst all these processes of decay and desolation, perpetual renovation was going on; and that Nature was repairing her ruins, and accumulating fresh materials for new islands and continents, and that innumerable living instruments were employed to consolidate, and build up the rocky fabric of the earth; and that even the most terrific of physical phenomena, the earthquake and the volcano, were but salutary provisions of the Supreme Cause, by which the harmony and integrity of our planet were maintained and perpetuated.

The occurrence of human skeletons in modern limestone —of coins and works of art in recent breccia—and the preservation of the bones of existing species of animals, and of the leaves and branches of vegetables, in the various deposits that are in progress of formation, incontestably prove that enduring memorials of the present state of animated nature will be transmitted to future ages. When the beds of the existing seas shall be elevated above the waters, and covered with woods and forests—when the deltas of our rivers shall be converted into fertile tracts, and become the sites of towns and cities—we cannot doubt that in the materials extracted for their edifices, the then existing races of mankind will discover indelible records of the physical history of our times, long after all traces of those stupendous works, upon which we vainly attempt to confer immortality, shall have disappeared.

But we must now proceed, and pass from the ephemeral productions of man, to the enduring monuments of nature—from the coins of brass and silver, to the imperishable medals on which the past events of the globe are inscribed—from the mouldering ruins of temples and palaces, to the examination of the mighty relics, which the ancient revolutions of the earth have entombed.

§ 3.

LAW OF EXTINCTION.

125

2. EXTINCTION OF ANIMALS.—Before we enter upon the geological history of the period immediately antecedent to the present, it will be necessary to notice one of the most remarkable facts which modern investigations have demonstrated, namely, the annihilation of numerous species and genera of animals and plants.

From the continual transmutations in the distribution of land and water, to which the earth's surface has been subjected, as indicated by our previous remarks, the destruction of some forms of animal life would seem to be a probable, if not inevitable, result; and such proves to have been the case. But not only has the extinction of certain races taken place; — a rigid examination of the fossil remains entombed in the various strata, demonstrates that other species, suited to peculiar states of the earth, have successively appeared, and played their part in the drama of life; and when the physical conditions of the lands and waters were altered, so as to be no longer adapted for the continuance of those types of animated nature, they in turn passed away, and were succeeded by new forms of organization.

The annihilation of whole tribes of animals and plants has no doubt depended on a variety of causes; and it is probable that in the earlier ages, an important agent in the extinction of many species, both terrestrial and aquatic, was the frequent oscillation in the relative position of the land and sea, and the consequent variations in atmospheric conditions.

3. LAW OF EXTINCTION.—But there is another consideration that bears upon this problem, and to which I must here briefly allude. It has been found that in countries where certain formations follow each other in tranquil and uninterrupted succession, the same restriction of particular fossils to special groups of strata, and the same disappearance of some species, and the first advent of others,

126

THE WONDERS OF GEOLOGY.

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as rigidly prevail as in England, where the strata have
been subjected to violent and repeated physical revolutions.

This is remarkably the case in Russia, where the Silu-
rian, Devonian, Carboniferous, and Permian systems of
rocks extend over immense regions, and are composed of
horizontal deposits of different ages, nearly all conformable
in position, and yet clearly separable from each other by
mineral characters and organic remains. Here then is
unequivocal proof, that some races of animals have disap-
peared and been succeeded by others, over enormously
extended areas, in which there has never been any great
physical catastrophe, nor the smallest eruption of plutonic
or volcanic matter.*

These facts naturally suggest the inquiry, whether the
continuance of species may not be governed by some natural
law, in like manner as is the duration of the life of the
individuals of any given species. May not some species,
for example, be so constituted as to continue but for a few
hundreds or thousands of years—others for ages—while
other organisms may be endowed with a perpetuity of
reproduction through all time? In this view of the subject,
species may have become extinct, simply because the pre-
destined term for the persistence of that peculiar form of
organism was expired; and this may have taken place
without any necessary relation to surrounding physical
conditions. In fine, may not the termination of the race,
like the death of the individuals, be the natural and inevi-
table result of their organization?

4. ANIMALS EXTIRPATED BY HUMAN AGENCY.—But
leaving for the present the further consideration of this

* "Geology of Russia," by Sir R. I. Murchison. These highly interesting results, which are entirely due to the labours of this eminent philosopher, have introduced a new and important element in all speculations relating to the cause of the extinction of species in the ancient geological periods.

§ 4. ANIMALS EXTIRPATED BY HUMAN AGENCY.

127

difficult problem, we pass to the examination of the effects
of human agency on the extinction of animals; and we
shall find conclusive evidence, that since Man became
the lord of the creation, his necessities and caprice have
occasioned the extirpation of many species of animals, of
which relics occur in the superficial alluvial deposits, asso-
ciated with those of contemporary species, but concerning
which both history and tradition are silent.

In this country, the beaver, wolf, hyena, bear, &c. are
examples of animals which, though exterminated in these
islands, still exist on the continent; while the Mammoth
and Irish Elk, of which numerous remains are found in our
alluvia and drift, have long since been obliterated from the
face of the earth. That the gradual extinction of many of
the existing species of animals will be effected by human
agency alone, cannot admit of question. In those animals
which supply fur, a remarkable proof of the immense de-
struction which is carried on, is stated in a late number of
the American Journal of Science. "Immediately after
South Georgia was explored by Captain Cook, in 1771,
the Americans commenced carrying seal-skins from thence
to China, where they obtained most exorbitant prices.
One million two hundred thousand skins have been taken
from that island alone, since that period; and nearly an
equal number from the Island of Desolation! The numbers
of the fur-seals killed in the South Shetland Isles (S. lat.
63°,) in 1821 and 1822, amounted to three hundred and
twenty thousand. This valuable animal is now almost
extinct in all these islands." From the most authentic
statements it appears certain that the fur trade must hence-
forward decline, since the advanced state of geographical
science shows that no new countries remain to be explored.
In North America the animals are slowly decreasing from
the persevering efforts, and the indiscriminate slaughter,
practised by the hunters, and by the appropriation to the

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THE WONDERS OF GEOLOGY.

LECT. II.

use of man, of those forests and rivers which once afforded them food and protection. They recede with the aborigines before the tide of civilization.

Before we proceed further in this argument, it will be interesting to notice a few of the links which connect the present "chain of being" with the past;—in other words, those species which are on the point of extinction, and others which have disappeared within a comparatively recent period.

5. THE APTERYX (*wingless bird*) OF NEW ZEALAND.—
The Apteryx, a bird peculiar to New Zealand, and belonging to a very limited group, of which the Ostrich is a well-known type, appears to be rapidly approaching extinction. It is of the size of a small turkey, of a chestnut-brown colour, the feathers being long, lanceolate, and hair-like, as in the Emu, but each plume has but a single shaft. It has a slightly-curved bill, with the nasal apertures at the apex,

LIGN 16.—THE APTERYX OF NEW ZEALAND.

not at the base, as in birds with a similar conformation of
beak, which is adapted for respiration while immersed in
mud or water. It has no visible wings; and in the skeleton
the bones of the arm are but very little developed. Its
habits are nocturnal, and it feeds on worms and insects.

§ 6.

THE MOA OF NEW ZEALAND.

It is very difficult to be obtained, and is hunted by torchlight by the natives for the sake of its skin, which is highly prized to ornament the dresses of their chiefs. It has become very rare, and must soon be exterminated, for its numbers are fast diminishing.*

6. THE MOA (*Dinornis* of Professor Owen,) OF NEW ZEALAND.—About eight years since a portion of a femur (thigh-bone) of large size was brought from New Zealand, and submitted to the examination of Professor Owen, who pronounced it to belong to a gigantic bird of the same family as the Apteryx. Subsequent discoveries have proved the correctness of this inference, and the numerous bones since received, establish the former existence in the islands of New Zealand, at no very distant period, of a tridactyle bird, resembling the Apteryx in its general conformation, but one-third larger than the African Ostrich. These bones were found in the alluvial mud of the rivers; the largest collection sent to England was obtained by the Rev. W. Williams, from Poverty Bay; the bones are in a very fine state of preservation, and resemble those found in our recent fluviatile clays and silt.

It seems probable that these remains are washed out of an ancient alluvial deposit, that forms the present river-channels: for I am informed by my son (Mr. Walter Martell, of Wellington, N. Z.) that he obtained bones from a potato-pit sunk by a native at some distance from any stream. If this be the case, these relics occupy the same relative geological position as those of the mammoth, horse, &c., that occur in the banks of the Thames.

It is remarkable that these bones were referred by the

* See Trans. Zoolog. Soc. of London, vol. ii. Another species of Apteryx has very recently been discovered in New Zealand; it is three feet high, and its eggs are as large as those of the Emu; it may possibly be a species of Moa.

K

130

THE WONDERS OF GEOLOGY.

LECT. II.

natives to a gigantic bird, which they deemed sacred, and called MOA, before these relics had been examined by any European, and when the New Zealanders could not have known of the existence of a bird larger than their own Apteryx. The native traditions assert the former abundance of these birds, and the existence of the race at the present time, within the hallowed and not to be violated precincts of Tongariro. But though, from the state of the bones, it is probable that the Moa (if extinct) was exterminated, like the Irish Elk, and the Dodo, by man, yet no trustworthy evidence has been obtained to prove that it was ever contemporary with the present inhabitants.*

The bones hitherto sent to this country belong to numerous individuals, and are referable to seven or more species, materially differing from each other in size. A considerable portion of the cranium has been obtained, and this approximates very nearly to the skull of the Dodo.

Thus we have certain evidence that the Islands of New Zealand (which are situated between the 30th and 50th degrees of south latitude, and are about 900 miles in length) were inhabited, at no very remote period, by numerous species of struthious (*Ostrich-like*) birds, some of much greater magnitude than any now known to exist; that these are extinct, and but one solitary and diminutive type of this wingless race, the Apteryx, remains; and this, in all probability, is destined to be speedily exterminated.

7. THE DODO (*Didus ineptus*).—A remarkable instance of the extirpation of a very peculiar type of organization is afforded by the Dodo, which has been annihilated, and become a denizen of the fossil kingdom, almost before our eyes. The Dodo was a terrestrial bird of the struthious

* For a full account of the Moa, see Professor Owen's Memoir in the Zoological Transactions; also my Medals of Creation, vol. ii. p. 816.

§ 7.

THE DODO.

family, larger than a turkey, of a dun colour on the back,
and marked on the breast like a cock pheasant; it abounded
in the Mauritius and adjacent islands. When those coun-
tries were first colonized by the Dutch, about two centuries
ago, the Dodo formed the principal food of the inhabitants;

LIGN. 17.—THE DODO.

(From a Painting in the British Museum.)

but as it unfortunately proved to be incapable of domesti-
cation, its numbers were soon diminished, and the species
insensibly disappeared. A live Dodo was exhibited in
London in 1638 as a great curiosity; and stuffed specimens
were preserved in the various museums of Europe: paint-
ings of the living animal are still extant in the Ashmolean
Museum at Oxford, and in the British Museum (see
*Lign.* 17). But the Dodo is now extinct; it is no longer
to be found in the isles where it once flourished, and even
all the stuffed specimens are destroyed. The only known
relics that remain, are the head and foot of an individual
in the Ashmolean, the leg of another in the British Museum,
and a skull in the museum at Copenhagen. To render this

K 2

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THE WONDERS OF GEOLOGY.

LECT. II.

illustration complete, some bones of the Dodo have been found in a tufaceous deposit, beneath a bed of lava, in the Isle of France, and in a cave in the Isle of Rodriguez; so that if the figures and remains of the recent birds above mentioned had not been preserved, these fossils would have constituted the only proof that such creatures had ever existed.

Thus it appears that of the few genera comprised in the remarkable family of birds, to which the Ostrich and Cassowary belong, no less than two have become extinct; one, the Dodo, within the last century and a half; the other, the Moa, at no very remote period; while a third, the Apteryx, will soon share the same fate.*

We pass on to the consideration of the extinct mammalia.

8. THE IRISH ELK, (Cervus megaceros, or Elk with great antlers.) The shell marls of Ireland contain the bones of an animal which, like the Dodo, was once contemporary with the human species, but is now extinct: the last individuals of the race having, in all probability, been destroyed by man. These remains commonly occur in the beds of marl beneath the peat-bogs, which are apparently like those of Scotland, the sites of ancient lakes, and bays. In Curragh, immense quantities of these bones lie within a small space; the skeletons appear to be entire, and are found with the skull elevated, and the antlers thrown back on the shoulders, as if a small herd of these Elks had sought for refuge in the marshes, and had sunk into the morass and been suffocated. Remains of the Elk occur also in marl

* The Struthionidæ are remarkably restricted in their geographical distribution. Thus the Ostrich inhabits Africa, and the Rheus, America; while the Dodo appears to have been limited to the Mauritius, and the Moa and Apteryx confined to New Zealand. See a highly interesting article on the Dodo in the Penny Cyclopedia.

§ 8.

THE IRISH ELK.

133

and gravel, in many parts of England, France, Germany,
and Italy, associated with recent species of river-shells.

This extinct creature far exceeded in magnitude any
living species of deer. The skeleton is upwards of ten
feet high from the ground to the highest point of the
antlers, which are palmated, and are from ten to fourteen
feet from one extremity to the other.* Skulls have been
found without horns, and are supposed to have belonged
to females; the average weight of the skull and antlers is
about seventy-five pounds. The bones are generally in a
fine state of preservation, of a dark brown colour, with
here and there a bluish incrustation of phosphate of iron,
like those of the deer from Lewes Levels. In some in-
stances they are in such a state of preservation that the
medullary cavities contain marrow having the appearance
of fresh suet, and which burns on the application of a
lighted taper. This Elk shed its horns, and probably, like
existing species, annually. The researches and observa-
tions of Professor Jameson, Mr. Weaver, and others, have
rendered it highly probable that this majestic creature
was coeval with man. A skull was discovered in Ger-
many, associated with urns and stone hatchets; and in the
county of Cork, a human body was exhumed from a
wet and marshy soil, beneath a bed of peat eleven feet
thick; the body was in good preservation, and enveloped
in a deer-skin covered with hair, which appeared to be
that of a gigantic Elk. A rib of this animal has been
found, in which there is a perforation evidently occasioned
by a pointed instrument while the creature was alive; for
there is an effusion of callus or new bony matter, which
could only have resulted from something remaining in the
wound for a considerable period; such an effect, indeed,
as would be produced by the head of an arrow or spear.†

* There is a fine skeleton of the Irish Elk in the British Museum.

† Jameson's Cuvier.

134

THE WONDERS OF GEOLOGY.

LECT. II.

There is, therefore, presumptive evidence that the last
individuals of the race were extirpated by the hunter-
tribes who first took possession of these islands.

Beds of gravel and sand, containing recent species of
marine shells with bones of the Irish Elk, have been ob-
served in the vicinity of Dublin, at an elevation of two
hundred feet above the level of the sea.* This extinct
quadruped, though found in peat-bogs and morasses of
comparatively very recent date, must therefore have been
an inhabitant of Ireland antecedently to some of the last
changes in the relative position of the land and water. The
discovery of a vast number of skeletons in the small area
of the Isle of Man, seems to indicate a great alteration in
the extent of land and sea; for it is difficult to conceive that
such herds of this gigantic race could exist in so limited
a district. It is therefore probable that the island was
separated from the main land at no remote geological
period, by subsidences commensurate with the elevations
of which Ireland affords such decisive evidence.

In the examples above described, we have an interesting
transition from the living to the lost types of animal exist-
ence. 1st, Species no longer inhabitants of the British
islands, but still living in other countries; 2dly, Animals
which have been exterminated within the last few cen-
turies; lastly, Species that have been utterly destroyed by
the early races of mankind.

9. EPOCH OF TERRESTRIAL MAMMALIA.—We must now
advance another step in the history of the past, and proceed
to the consideration of the geological phenomena presented
by the period immediately antecedent to the present, when
vast regions were inhabited by large herbivorous mammalia,
with which species of existing races were associated.
Thus while the present may be termed the *Modern* or

* By Dr. Scouler.

§ 9.

135

*Human Epoch*, that which forms the immediate subject of investigation may be designated the *Epoch of terrestrial mammalia*.

" When the traveller," says Cuvier, " passes over those
fertile plains, where the peaceful waters preserve, by their
regular course, an abundant vegetation, and the soil of
which is crowded by an extensive population, and enriched
by flourishing cities, which are never disturbed but by the
ravages of war, or the oppression of despotism, he is not
inclined to believe that nature has also had her intestine
wars, and that the surface of the globe has been overthrown
by various revolutions and catastrophes. But his opinions
change as he penetrates into that soil at present so peace-
ful; or as he ascends the hills which bound the plains.
His ideas expand, as it were, with the prospect; and so
soon as he ascends the more elevated chains, or follows the
beds of those torrents which descend from their summits,
he begins to comprehend the extent and grandeur of the
physical events of ages long past. Or if he examines the
quarries on the sides of the hills, or the cliffs which form
the boundaries of the ocean, he there sees, in the displace-
ment and contortion of the strata, and in the layers of
water-worn materials, teeming with the remains of animals
and plants, proofs that those tranquil plains, those smooth
unbroken downs, have once been at the bottom of the deep,
and have been lifted up from the bosom of the waters; and
everywhere he will find evidence that the sea and the land
have continually changed their place."*

In almost every part of the world, beneath the modern
alluvial soil, extensive beds of gravel, clay, and loam, are
found spread over the plains, or on the flanks of the moun-
tain chains, or on the crests of ranges of low elevation; and
in these accumulations of marine and fluviatile debris, are

* "Discours sur les Révolutions de la Surface du Globe."

136

THE WONDERS OF GEOLOGY.

LECT. II.

imbedded immense quantities of the bones of large mammalia. These belong principally to animals related to the elephant, as the mammoth, mastodon, &c., and to species of hippopotamus, rhinoceros, horse, ox, deer, &c.; and some are referable to extinct genera; while in caverns and fissures of rocks, more or less filled with loam and breccia, bones of tigers, boars, hyenas, and other carnivora, occur. Fossils of this kind exist in great abundance in various parts of Europe, Asia, and America; they are found alike in the tropical regions of India, and in the frozen plains of Siberia; and there are but few considerable districts in Great Britain in which some vestiges of this kind do not occur.

10. FOSSIL MAMMALIAN REMAINS.—For the convenience of study, Dr. Buckland classes these remains under five heads, namely:—

*First.* Bones of land animals, that were drifted into estuaries, and are associated with marine shells; such as those found in the Sub-Apennine formations; and in the beds of gravel, sand, &c. provincially termed *Crag*, in Norfolk and Suffolk; in loam and chalk conglomerate in the cliffs of Kent and Sussex; and in clay off Harwich and Herne Bay.

*Secondly.* Terrestrial quadrupeds, imbedded with fresh-water shells, in strata that have been formed during the same epoch as the above, at the bottom of fresh-water lakes and in the beds of rivers and deltas; such are the fossil bones of the lacustrine marls of the Val d'Arno; those in the valley of the Thames, &c.

*Thirdly.* Similar remains in superficial drift spread over the surface of rocks of all ages; as in beds of gravel near London; Petteridge Common in Surrey, &c.

*Fourthly.* Bones of carnivorous and herbivorous animals, accumulated in caverns and fissures of rocks, during the later period of the same epoch. The caves of Gay-

§ 10.

FOSSIL MAMMALIAN REMAINS.

lenreuth, Kirkdale, Kent's Hole near Torquay, &c. are
examples.

*Lastly.* Osseous breccias that occur in fissures of limestone on the shores of the Mediterranean, in the Ionian Isles, in the rock of Gibraltar, at Plymouth, in the Mendip hills, &c.*

Before directing your attention to the fossils before us,
which are from alluvial deposits of various ages and from
different localities, it will be necessary to review the leading
principles of the science which treats of the structure of
organized beings. Thus while in the preceding lecture we
referred to Astronomy to dissipate the obscurity which
shrouded the earliest physical condition of our planet, we
are now led to that important department of natural
knowledge termed *Comparative Anatomy*, to enable us to
determine the extinct forms of animal existence. I shall
therefore explain the mode of induction employed by the
scientific observer in the investigation of the fossil remains
of animals, and by which he is enabled to ascertain the
structure and economy of creatures, which have long since
disappeared from the face of the earth.

11. COMPARATIVE ANATOMY.—To a person uninstructed
in anatomical details, the specimens before us would appear
a confused medley of bones, and of osseous fragments im-
pacted in solid stone; and the only knowledge he could
derive from their examination would be the fact, that the
stone was once in the state of sand or mud, in which,
while soft, the bones had become imbedded. But in vain
would he seek for further information from these precious
historical monuments of Nature; to him they would prove
as unintelligible as were the hieroglyphics of Egypt, before
Young and Champollion explained their mysterious import.
It is only by an acquaintance with the structure of the living

* Dr. Buckland's Bridgwater Essay, p. 94.

138

THE WONDERS OF GEOLOGY.

LECT. II.

forms around us, and by acquiring an intimate knowledge
of their osseous framework or skeleton, that we can hope
to decipher the handwriting on the rock, obtain a clue to
guide us through the labyrinth of fossil anatomy, and con-
duct to those interesting results, which the genius of the
immortal Cuvier first taught us how to acquire. And here
it will be necessary to enter upon the consideration of those
admirable principles of the correlation of structure in
organized beings, that were first announced by that illus-
trious philosopher, and which form the basis of all palæ-
ontological knowledge.

The organs of every animal, observes Baron Cuvier, must
be regarded as forming a machine, the parts of which are
mutually dependent on each other, and exquisitely adapted
for the functions they are destined to perform; and such is
the intimate relation of the several organs, that any varia-
tion in one part, is constantly accompanied by a correspond-
ing modification in another. This correlation, or mutual
adaptation of the several parts of the animal fabric, is a law
of organic structure, which, like every other induction of
physical truth, has only been established by patient and
laborious investigation. It is by the knowledge of this law
that we are enabled to reassemble, as it were, the scattered
remains of the beings of a former state of the globe,—to
determine their place in the scale of animated nature,—
and to reason on their organization, habits, and economy,
with as much clearness and certainty, as if they were still
living and before us.

I will demonstrate this proposition by a few examples.
Of all the solid parts of the animal frame the most obviously
mechanical are the jaws and teeth; and as we know in each
instance the offices they are intended to perform, these
organs afford the most simple and striking illustration of
the principles above enunciated.

12. OSTEOLOGY OF THE CARNIVORA.—If we examine the

§ 12.

COMPARATIVE ANATOMY.

jaws of the skulls before us, those, for example, of a Bengal
Tiger (Lign. 18), and of a Cat (Lign. 19), we perceive that
there are cutting teeth in front, sharp fangs on the sides, and
molar, bruising, or crushing teeth, in the back part. The

LIGN. 18.—SKULL OF THE BENGAL TIGER.

molars rise into sharp lanciform points, and overlap each
other in the upper and lower jaw, like the edges of a pair
of shears; and the teeth are externally covered with a
thick crust of enamel. This is evidently an apparatus for
tearing and cutting flesh, or for cracking bones; but is
not suited for grinding the stalks or seeds of vegetables.
The jaws fit together by a transverse process or joint, which
moves in a corresponding depression in the skull, like a
hinge; they open and shut like shears, but admit of no
grinding motion; this, then, is such an articulation as is
adapted for a carnivorous animal; and every part of this
instrument is admirably fitted for its office.

But all these exquisite adjustments would be lost, were
there not levers and muscles to work the jaws,—were not
each portion of the animal frame adapted to all the other
parts,—and were not the instincts and appetites of the
animal such as are calculated to give to this apparatus its
appropriate movements.

Let us reverse the order of the argument,—let us assume
that the stomach of an animal be so organized as to be
fitted for the digestion of flesh only, and that flesh recent,—
we should find that its jaws would be so constructed as to

140

THE WONDERS OF GEOLOGY.

LECT. II.

fit them for devouring live prey,—the claws for seizing and tearing it,—the teeth for cutting and dividing it,—the whole

LIGN. 19.—SKULL OF A WILD CAT.

(Felis Canadensis.)

system of its powers of motion for pursuing and overtaking it,—the organs of sense for discovering it at a distance,— and the brain endowed with the instinct necessary for teaching the animal how to conceal itself, and lay snares for its victims. Such are the general relations of the structure of carnivorous animals, and which every being of this class must indispensably combine in its constitution, or its race cannot exist. But subordinate to these principles, are others connected with the nature and habits of the prey upon which the animal is intended to subsist, and thence result modifications of the details in the forms which arise from the general conditions. Thus, in order that the animal may have the power requisite to carry off its prey, there must be a certain degree of vigour in the muscles which elevate the head; and thence results a determinate form in the vertebræ or bones from which these muscles originate, and in the back of the skull in which they are inserted. That the paws may be able to seize their prey, there must be a certain degree of mobility in the toes, and

§ 13.

OSTEOLOGY OF THE HERBIVORA.

141

of strength in the claws, and a corresponding form in all the bones and muscles of the foot. It is unnecessary to extend these remarks, for it will easily be seen that similar conclusions may be drawn with regard to all the other parts of the animal.* In the Tiger and the Cat, (*Ligns.* 18, 19,) we have a familiar illustration of what has been advanced.

13. **OSTEOLOGY OF THE HERBIVORA.**—In animals which are destined to live on vegetables we have the same mutual relations; the sharp fangs of the teeth are wanting; the enamel is not all placed on the top of the teeth as in the carnivora, but arranged in deep vertical layers, alternating with bony matter; and this arrangement secures, in all states of the teeth, a rough grinding surface, as in the horse and the elephant. The flat molar teeth are not formed for

LIGN. 20.—SKULL OF THE HORSE.

cutting, but for mastication, and the jaws are loosely articulated together, so as to allow of a grinding movement; had the socket and corresponding part of the jaw been the same as in the tiger, the teeth could not have performed their office; in the skull of the horse (Lign. 20), this modification of structure is exemplified. Again, I might

* Consult Cuvier's "Discours sur les Révolutions;" "Leçons d'Anatomie Comparative;" "Ossemens Fossiles," &c.

142

THE WONDERS OF GEOLOGY.

LECT. II.

proceed in the argument, and show the adaptation of the
muscles of the head to the apparatus here described; and,
beginning with the jaw, review the whole animal frame,
and demonstrate how all its parts are alike wonderfully
constructed and fitted together, to perform the functions
necessary for the being to which it belongs.

In the Elephant, which has but four teeth in each jaw,
the deficiency of prehensile incisor teeth being supplied
by that wonderful instrument, the proboscis, or trunk, the
structure of the dental organs is still further modified.
The teeth of animals are formed of three distinct substances,
which are variously disposed in the different orders, accord-
ing to the habits and economy of the species. The nucleus, or
germ of the tooth, is a congeries of blood-vessels and nerves,
called the *pulp*, by which the calcareous hard parts are
elaborated. The pulp is surrounded by a covering of a very
dense substance, composed of phosphate of lime, with
albumen and gluten, termed dentine, or tooth-ivory, which
is permeated throughout by very minute tubes. The den-
tine is encased in a still harder material, called *enamel*. In
the teeth of man, and of the carnivora, the enamel covers the
entire external surface of the crown. There is a third sub-
stance, a coarse kind of dentine, of an opaque and yellowish
appearance, termed *crusta petrosa*, or cement, which, in
the Elephant and other herbivora, is interstratified with
the enamel and dentine. The intermixture of these three
dental elements—the tooth-ivory, cement, and enamel—is
apparent on the worn surfaces of the teeth of elephants ;
and it differs in the several recent and fossil species.*

In the African elephant, (*Lign.* 21, fig. 1,) the worn surface
of the molar teeth presents a series of lozenge-shaped lines of
enamel, having the dentine on the inner margin of the ridges,
and being surrounded by the *crusta petrosa*. In the Asiatic

* See "Medals of Creation," vol. ii. p. 837; "Teeth of Mammalia."

§ 14.

TEETH OF ELEPHANTS.

143

species (fig. 3) the enamel forms narrow transverse bands ;
and the tooth of the Mammoth, or fossil elephant, (fig. 2,)
has an analogous, but somewhat different distribution.

LIGN. 21.—GRINDING SURFACE OF TEETH OF ELEPHANTS.

Fig. 1. The worn surface of the crown of a tooth of the African Elephant. Fig. 2. Grinding surface of a tooth of the Mammoth, or fossil Elephant. Fig. 3. Grinding surface of the Asiatic Elephant.

The appearances shown in these horizontal sections of
the crown of the teeth, arise from the dentine being
disposed in parallel and vertical plates which have an im-
mediate investment of enamel, and are bound together by
an external layer of cement that envelopes the entire series,
which often consists of from twenty to thirty plates. By this
peculiar modification of structure, a rough grinding surface,
adapted for the mastication of vegetable food, is always
maintained, from the unequal wearing away of substances
of such different degrees of hardness.

14. DENTAL ORGANS OF THE RODENTIA, OR GNAWERS. —
In the jaws of an intermediate order of animals, we find
new modifications of the same apparatus. Thus the *Ro-*
*dentia*, or gnawers, have long sharp cutting teeth, like
nippers; it is by these instruments that the rat can speedily
gnaw a hole through a board, and the squirrel in a nut, in

144

THE WONDERS OF GEOLOGY.

LECT. II.

consequence of their exquisite adaptation for these operations. In the skull of the Squirrel (Lign. 22, fig. 2) the front teeth are of enormous size, as compared with the

LIGN. 22.—SKULL AND TEETH OF RODENTIA, OR GNAWERS.

Fig. 1. Inner side of the left lower jaw of a Florida rat, (Arvicola Floridana,) of the natural size.

2. Skull of the Squirrel.

3. Molar teeth of the upper jaw of a Florida rat, magnified; seen obliquely.

molar, and they lock together in such manner as to render a grinding movement impossible; a corresponding adjustment, therefore, takes place,—the lower jaw is so constructed as to work in the skull neither in a transverse nor in arotary direction, but lengthwise, like the action of a carpenter using his plane, the teeth moving backwards and forwards; as may be observed in the rabbit while eating its food. The enamel of the molar teeth, as for example in those of the Rat, (see Lign 22, fig. 3) is placed vertically and transverse to the jaw, so as to form an admirable grinding surface. But this is not the only variation of structure observable in these teeth. The incisors being implements of constant use, are renewed by continual growth, and there is a special provision for their support in a bent socket.

§ 15.

GENERAL INFERENCES.

The enamel is unequally distributed round the tooth, being very thin behind and thick in front, by which means the cutting edges are always preserved; for by the act of gnawing, the hinder part of the incisor wears away quicker than the fore part, and thus a sharp inclined edge, like that of an adze or chisel, is maintained, and which is the very form required in the economy of the animal. The teeth of the common rabbit or hare will exemplify these remarks.

15. GENERAL INFERENCES.—These are but a few instances of those admirable adaptations of means to ends, which are observable throughout the various classes of organized beings: but the limits of a single lecture will not admit of more examples, and it is, I trust, unnecessary to offer additional proofs, that the conclusions of geologists as to the nature of the ancient inhabitants of our globe, are not vague assumptions, as those unacquainted with the science might suppose, but the legitimate deductions of laborious and patient investigations. A few teeth and bones—sometimes but a single relic of this kind—are the elements by which the palæontologist is enabled, not only to restore the forms of creatures now banished from the face of the earth, but also to ascertain their habits and economy, and even arrive at positive conclusions respecting the nature of the country of which they were once the inhabitants. If we find the remains of animals which were herbivorous, it follows that there must have been a condition of nature calculated for the growth of vegetable productions for their subsistence; a suitable soil and climate, and a country diversified by hills, valleys, and plains, with streams and rivers to carry off the superfluous waters.

The same laws, under certain modifications, apply to other classes of beings. In birds, the form of the feet is modified according to the habits of the different orders. In the parrot, (*Lign. 22, fig. 3*) the claws are adapted to climb trees and perch on the branches; but in the eagle

L

146

THE WONDERS OF GEOLOGY.

LECT. II.

they are widely different, for its talons are constructed to
lacerate and tear its prey (fig. 4). The feet of aquatic
birds are formed like a paddle or oar, to enable them to

LIGN. 23.—DIFFERENT FORMS OF FEET IN BIRDS.

Fig. 1. Foot of the Heron; Fig. 2. of the Ostrich; Fig. 3. of the Parrot;
Fig. 4. of the Eagle; Fig. 5. of the Pelican.

make their way through the water (fig. 5); those of birds
that frequent marshes have a great expansion, like a tripod,
that they may move over the unstable surface of the morass
(fig. 1); while in species destined to inhabit sandy deserts,
as the Ostrich (fig. 2), the feet present a corresponding
modification of structure.

We perceive, therefore, that every vertebrated animal
has a solid and durable skeleton, or osseous support, formed
upon one general plan, but modified in almost endless
variety, in the relative magnitude, situation, and aspect of
the different parts, so as to adapt itself to the various habits

§ 16.

FOSSIL ELEPHANTS.

and functions of the diversified forms of animal life. In
short, that the Author of nature has by these changes varied
the same general fabric in innumerable ways, bestowed
upon it a thousand different instincts and passions, and
adapted it to every element and climate, and to every
possible variety of food and mode of existence; and it is
by a profound knowledge of these principles of the cor-
relation of the different parts of every organized creature,
that the scientific observer is enabled to reconstruct the
forms of extinct animals.

We may now enter upon that department of geology
called *Palæontology*, or the science which treats of the
fossil remains of the beings which inhabited our planet in
former ages.

16. FOSSIL ELEPHANTS, &c.—As the bones and teeth
are the least perishable parts of the animal structure, they
are in general the only indications of the characters of the
ancient mammalia. Occasionally very delicate parts, such
as the tunic of the eye, the membranes of the stomach, the
hair and integuments of the skin, &c. are preserved in a
fossil state, examples of which we shall hereafter adduce.
In the older rocks, the bones are generally mineralized,
and no longer possess the white and glossy appearance of
the recent skeleton; but those which occur in superficial
gravel, and in caverns, are commonly of a porous and
earthy character, like bones that have lost a portion of
their animal matter by being buried in a dry and loose
soil.

The fossil bones and teeth we have now to examine are
separable into two classes, namely, those which occur in the
gravel, marl, &c., of the drift and alluvial deposits, and
those buried in fissures and caverns. The former are
principally referable to herbivorous pachyderms and rumi-
nants; the latter to carnivora.

I will first take a brief review of the remains of the

L 2

148

THE WONDERS OF GEOLOGY.

LECT. II.

large herbivora, especially of those allied to the elephantine family, which occur in great abundance, and are very generally distributed throughout Europe, Asia, and America. In the earlier ages, these colossal bones were supposed to belong to gigantic races of mankind, and gave rise to the marvellous traditions of giants, so rife in every country in Europe; but we need not smile at the ignorance and credulity of our ancestors, for, not many years since, a fossil tooth of an elephant, found in digging a well in Brighton, was supposed to be a petrified cauliflower!

In Russia, and more especially in Siberia, the fossil bones of extinct species of Elephants, and other mammalia, are found throughout all the low lands, and in the sandy plains which extend from the borders of Europe to the nearest extreme point of America, and south and north from the base of the mountains of central Asia, to the shores of the Arctic sea. Within this space, which is almost equal in extent to the whole of Europe, fossil ivory is everywhere to be found; and the tusks are so numerous and well preserved, especially in Northern Russia, that thousands are annually collected, and form a lucrative article of commerce. In Siberia alone, the remains of a greater number of elephants have been discovered, than are supposed to exist at the present time all over the world.*

17. FOSSIL MAMMALIA OF THE VALLEY OF THE THAMES.
—It may appear astounding to some of my readers to treat of elephants, rhinoceroses, hippopotami, and gigantic elks,

* In 1844, a company of merchants was formed to collect teeth and tusks of mammoths from Siberia; for the fossil ivory was found to possess all the qualities of the recent, and at the same time was less liable to turn yellow. During the year, sixteen thousand pounds of jaws and tusks of mammoths were obtained, and these were sold at St. Petersburg, under the denomination of Siberian ivory, at prices from 30 to 100 per cent. above those of recent elephantine ivory.

§ 18.

FOSSIL ELEPHANTS OF THE THAMES.

149

as having formerly inhabited the country irrigated by the Thames; yet such was unquestionably the case at no very remote epoch, when probably the land of England was united to the Continent, and the river extended over a much larger area than it has occupied since many centuries before the Roman advent.

The banks of the Thames, and of its tributary streams, are in great part composed of an ancient alluvial silt or brick-earth, many yards in thickness, containing, in certain localities, mammalian bones in considerable abundance, with interspersions of existing species of land and river shells.* At Erith this deposit reaches to 40 feet above the river, and near Maidstone to 60 feet.

At Grays in Essex (opposite Gravesend) these deposits may be seen to advantage in sections exposed in the extensive brick-fields. The beds consist of—1. Gravel and sand; 2. Loamy sand and brick-earth; 3. Ferruginous sand, shells, and gravel; 4. The Chalk, which forms the foundation rock of the country. From this locality alone have been obtained numerous bones of the Elephant, Rhinoceros, Hippopotamus, Horse, Ox, Deer, Irish Elk, Vole, Bear, Hyena, and Monkey.

Scarcely any traces of trees or plants have been met with, yet it is obvious that the country which supported these large herbivora, must have had an abundant vegetation.

18. FOSSIL ELEPHANTS OF OTHER PARTS OF ENGLAND.
—Along the eastern coast of England, and off the mouth of the Thames, teeth, tusks, and bones of elephants and other mammalia, are often dredged up by the fishermen, having

* There is a species of Cyrena, supposed to be identical with one that now exists in Alexandria; and an Unio, of which the analogue lives in the lakes and rivers of Auvergne: neither are known as British species. See a highly interesting memoir on these deposits, and their fossil remains, by John Morris, Esq. (of Kensington), author of "A Catalogue of British Fossils," &c.; Mag. Nat. Hist. vol. ii. p. 539.

150

THE WONDERS OF GEOLOGY.

LECT. II.

been washed out of the alluvial deposits of the neighbour-
ing cliffs by the action of the sea; for the same kind of
drift and alluvial detritus is spread over the country
along the maritime districts of Essex, Suffolk, Norfolk, and
Yorkshire.

At Herne Bay, in the embouchure of the Thames, great
numbers of mammalian bones have been found; Walton in
Essex is still more prolific; and the late Mr. Woodward
informed me, that the elephants' teeth which had come
under his observation from the coast of Norfolk must have
belonged to more than 500 individuals.

On the western coast of Sussex, and in the neighbour-
hood of Arundel, Patcham, and Brighton, teeth and bones
of elephants have at different times been exhumed. At
Brighton the teeth are found in a deposit of water-worn
materials, consisting of loam, chalk, and broken flints,
resting on a bed of shingle covering the chalk.* In the
conglomerate, of which I have already spoken (p. 114), as
well as in the superincumbent deposits, teeth of elephants,
with teeth and bones of a species of deer, horse, and whale,
occur, and are associated with marine shells;† similar fossils
are found in deposits of a like character along the opposite
coast of France.

These elephantine remains are, in the opinion of Dr.
Falconer, referable to three species : but the greater number
belong to the Mammoth, or fossil Elephant of Siberia.

With these relics of extinct animals are found those
of many species which still inhabit England, as the Badger,
Otter, Polecat, Weasel; and of others which were contem-
porary with the earliest British tribes, as the Irish Elk,
Bear, Beaver, Wolf.‡

* See Geology of the South-East of England, p. 32.

† Medals of Creation, vol. ii. p. 824, for an account of the discovery of the fossil jaw of a Whale in Brighton Cliffs.

‡ In the fenny district of Cambridgeshire, these and other mam-

§ 19.

MAMMOTH IMBEDDED IN ICE.

151

19. EXTINCT ELEPHANT, OR MAMMOTH,* IN ICE.—There are but two species of existing Elephants, namely, the African, which ranges as far south as the Cape of Good Hope, and the Asiatic, which is limited to within 31° north latitude. Yet the remains not only of one, but of several extinct species of this family, occur all over Europe and North America, and are imbedded in frozen gravel and drift in 72° north latitude. They even abound in ice-cliffs on the north-west angle of the American Continent, near to Behring's Straits.

The occurrence of innumerable relics of huge extinct herbivorous mammalia, over vast regions of the icy zone, where but few forms of animal life can now subsist, is a fact of so much interest in every point of view, as to

LIGN. 24.—MAMMOTH, OR ELEPHAS PRIMIGENIUS; FOUND IMBEDDED IN FROZEN GRAVEL IN SIBERIA.

(Twelve feet high, and sixteen feet long.)

demand our earnest attention. For not only are the bones
and tusks found in a beautiful state of preservation, but

malian remains have been found. See Professor Owen's History of
British Mammals; and my Medals of Creation, vol. ii.

* A Russian term applied to the fossil Elephant.

152

THE WONDERS OF GEOLOGY.

LECT. II.

sometimes even the entire body, with the flesh and skin, as fresh as if but recently imbedded.

In 1774, near Vilhoui, the carcass of a rhinoceros was taken from the frozen sand, where it must have been concealed for ages, the soil of that region being always frozen to within a few inches of the surface. This specimen was a complete natural mummy, part of the skin being still covered with long hairs, and forming a warmer covering than that of the African rhinoceros.

The discovery of a Mammoth under similar circumstances, is yet more interesting. Towards the close of the last century, 1799, a Tungusian fisherman observed in a cliff of ice and gravel, on the banks of the river Lena, a shapeless mass, the nature of which he was unable to determine. In the course of the next year it was more visible, and on the third a large tusk was seen projecting from the ice-cliff, and at length became detached. On the fifth year, an early thaw set in, and the entire carcass of a mammoth was exposed, and at length fell upon the ground. It was twelve feet high, and about sixteen feet in length; the tusks were nine feet long. The flesh was in such a state of preservation, that it was devoured as it lay by wolves and bears, and the hunters fed their dogs with the remains. The skin was covered with hair consisting of black bristles, thicker than horsehair, and fifteen inches in length; of wool of a reddish brown, and hair of a fawn colour; and with a mane on the neck. Upwards of 30lbs. of hair were collected; some specimens of which are preserved in the Hunterian Museum of the College of Surgeons. The ears remained dry and shrivelled; the brain and even the capsule of the eye were preserved! the bones and part of the integuments, and a considerable quantity of the hair, are in the Museum of Natural History at St. Petersburgh. The accompanying sketch (Lign. 24) represents the specimen in its present state.

§ 19.

MAMMOTHS OF SIBERIA.

153

The tusks are curved forward and upward. The teeth differ from those of the two living species of Elephants, in the disposition of the plates of dentine (see p. 142), and also in their internal microscopic structure; the configuration of the skull is likewise peculiar; and these discrepancies, together with the hairy and woolly skin, led Baron Cuvier to consider the species as having been adapted to exist in a colder climate than the living types. But that eminent philosopher also assumed, from the preservation of the bodies of these animals in ice, and the present low temperature and sterile condition of that part of Siberia where these remains abound, that a sudden change of climate had taken place, and continued, by which the race was destroyed, and entombed in the frozen soil.

Playfair, with that profound sagacity which characterized all his speculations on geological phenomena, first suggested the idea, "that the power of living in a different climate, and of enduring greater degrees of heat or of cold, and of subsisting on a different kind of food," may have been longed to the extinct Elephants found in Siberia; "for though one species," he remarks, "may now be confined to the southern parts of Asia, another may have been able to endure the severe climates of the north: and the same may be true of the rhinoceros, buffalo, &c. These animals may have lived farther to the south than where their remains are actually found, among the valleys between the great ranges of mountains that bound Siberia on that side. We must observe, too, that they may have migrated with the seasons, and by that means avoided the rigorous winters of the high latitudes."* And more recently, Mr. Lyell, extending these views, suggested that a large region of Central Asia, perhaps the southern half of Siberia, might, during the Mammoth period, have possessed a climate mild

* Playfair's Illustrations of the Huttonian Theory, Edinburgh edition of 1822, vol. i. p. 465. Dr. Fleming also supported these views.

154

THE WONDERS OF GEOLOGY.

LECT. II.

enough to support a vegetation fit for the sustenance of the
fossil species; and reasoning upon the present physical
geography of the country, that the whole tract from the
Ural mountains to the sea, had been upraised, like Sweden
(p. 116); and that the refrigeration of the north-east of
Asia, and its present condition, were the result. These
opinions have been confirmed by the recent investigations of
Sir R. Murchison, which are so important, both in a geo-
logical and palæontological point of view, that I must offer
a concise sketch of the facts and observations which bear
upon this question.

20. MAMMOTHS OF THE ALLUVIAL DEPOSITS OF RUSSIA.—
Premising, that with the remains of the Mammoth and Rhi-
noceros, there occasionally occur bones of a gigantic Beaver
(*Trogontherium*), Bear, Elk, Ox, and a remarkable extinct
pachyderm (*Elasmotherium*), we will first describe the na-
ture of the deposits in which these relics are imbedded.

There is a great analogy in the geological character of
the detritus composing the alluvial mammalian beds of
Russia and those of our own island; both have evidently
been formed under similar circumstances in river deltas, and
in estuaries, and off sea-shores, in water of moderate depth;
they are in fact drifted materials that were brought down
by currents and streams, from the dry lands inhabited by
the animals whose remains they contain: and by the sub-
sequent elevation of the coasts these littoral deposits have
been raised to their present level.

In Siberia, the mammoth's remains are found in alluvial
detritus in the flat northern tracts, or near the mouths of
the great rivers. Even in all the central and southern
parts of European Russia, from there being no high ridges
of elevation, and consequently no coarse local detritus as on
the flanks of the Ural mountains, the Mammoth alluvium
assumes the same aspect as in the distant plains of Siberia,
where it is equally removed from disturbing causes.

§ 21.

MAMMOTH EPOCH.

155

A section exposed in an abrupt cliff on the sea of Azof, at Taganrog, will explain the usual character of the deposits :*—

1. Tertiary newer miocene limestone: forming the base of the cliff: 20 feet.

2. Band of finely laminated sands, full of shells, specifically identical with those that inhabit the adjacent river Don.

3. Clay drift, containing numerous bones and teeth of the Mammoth: 50 feet.

From the nature of this drift, and its distribution at various levels, Sir R. Murchison infers that the greater part of this low continent, unlike the Ural and higher portions of Siberia, was not dry land during the existence of the Mammoths, nor in the period immediately antecedent to our own; but was in the same subaqueous condition as the low lands of Northern Siberia, when the bones were transported into the then existing estuaries and bays.

21. SIBERIA AND RUSSIA IN THE MAMMOTH EPOCH.— These observations of Sir R. Murchison clearly prove, that the mammoths cannot have inhabited the northernmost tracts of Siberia in which their remains are imbedded, for the wide and low tracts of that sterile region were beneath the sea at the period when these extinct animals existed; the bones and carcasses must, therefore, have drifted thither, and probably from a considerable distance. The mammalian remains do not occur on the elevated chains of hills; and from the physical structure of the region, it is probable that not only the Ural and Altai mountains, but also their northern ridges and terraces, which include more than half of Siberia, were covered with forests in some parts, and with brushwood steppes in others; and herds of mammoths may have migrated thence in the summer season, (which is even now intensely hot,) to the

* Geol. Russ. vol. i. p. 502.

156

THE WONDERS OF GEOLOGY.

LECT. II.

embouchures of the great streams, and the borders of the
then Arctic sea. Sir R. Murchison proceeds to remark that—

“A former terrestrial surface, on which the great quadrupeds lived for ages, and the rupture and diminution of adjacent lakes, coincident with some of the last elevations of the Ural chain, will best explain the condition in which the remains of mammoths are left buried on the edges of the uplifted ridges of the Ural, as well as in the low lands and great estuaries farthest removed from them.

“As we advance into the plains of Siberia, or descend into the valleys of the Tobol and the Obe, the bones are in greater quantities and in a better state of preservation; and the farther the Siberian rivers are followed to their mouths, the more do the mammalian remains increase, until at length whole skeletons, and even carcasses, are found. The single fact of the very wide diffusion of mammoth bones over enormous regions, in itself indicates that those creatures had long been inhabitants of such countries, living and dying there for ages; whilst their final destruction may have resulted from aqueous debacles dependent on oscillations of the land, the elevation of mountain chains, and the formation of much local detritus.

“The Siberian mammoth, having a close coating of wool and much shaggy hair, seems to have been adapted to inhabit the regions of northern Europe and Asia; and the elevation of large tracts of land in Siberia, by laying dry the low shores and estuaries into which their bones had been washed, would necessarily render the climate more intensely cold. The intimate structure of the teeth in the mammoth differs from that of the Asiatic and African elephant, and is supposed by Professor Owen to indicate that the extinct creature lived on coarser ligneous tissue of trees and shrubs, that may have constituted forests, extending even into the promontories of the icy sea, where the physical events which elevated the Ural mountains to their present altitude, and left the coasts with no vegetable support but the moss and lichens for the rein-deer, with which the mammoths were once contemporary.”*

22. THE MASTODON.—In various parts of North America,
there are marshy tracts abounding in salt and brackish
waters, that are frequented by deer, and other animals;

* From a masterly review of the phenomena relating to this subject, by Sir R. I. Murchison,—“Geology of Russia,” vol. i. chap. xix.

§ 22.

THE MASTODON.

a circumstance from which these swamps have acquired the American name of *Lick*. In these morasses vast quantities of bones and several entire skeletons of elephants and other gigantic quadrupeds have been discovered. The spot most celebrated for these remains in Kentucky, is called Big-bone Lick, which is situated to the south-east of the Ohio, in the midst of a group of low hills, and is traversed by a small stream of brackish water. The bottom consists of black fetid mud, intermingled with sand and vegetable matter; and in this bog, bones occur in abundance. Some of them are referable to the mammoth; but others, as you may observe from the specimens before us, belonged to a creature not less gigantic, but with very distinct characters. These teeth are composed of dentine and enamel; and the latter is spread over the crown of the tooth, which, before it is

LIGN. 25.—TOOTH OF THE GREAT MASTODON, FROM THE BANKS OF THE HUDSON; WEIGHT 4lbs; ONE-THIRD NATURAL SIZE LINEAR.

(Mastodon giganteus.)

worn by use, is divided into several transverse tubercles, or processes, each of which is subdivided into two obtuse points, these transverse ridges not being filled up with

158

THE WONDERS OF GEOLOGY.

LECT. II.

cement, as in the elephant; from this form of the crown
of the tooth the animal to which it belonged has received
the name of MASTODON, signifying mammillary tooth. These
teeth have no relation whatever to those of the carnivora; for
though they have an external investment of enamel as in
the teeth of the tiger, they are destitute of the longitudinal,
serrated, cutting edge; and in those which are worn, the pro-
tuberances become truncated into a lozenge form. This
structure is fitted for the grinding and mastication of tough
and hard vegetable substances. The bones and teeth of the
mastodon have been found throughout the plains of North
America, from north of Lake Erie to as far south as
Charleston in South Carolina; they have also been dis-
covered on the Continent, and in the Crag of England, and
in several parts of India. Here are examples from the banks
of the Ohio and Hudson; and from Big-bone Lick; one
of these is a perfect tooth of a young animal; but this
specimen must have belonged to a very old one, for the
grinding surface is worn almost flat by use.

These remains are found in marl, beneath peat bogs, at
moderate depths, and with no marks of attrition; it is
therefore evident that the animals lived and died in the
country where their relics are entombed.

In the suburbs of Rochester (U. S.) many bones of
Mastodons were dug up from a bed of clay which con-
tained numerous shells of existing river species (pla-
norbis, valvata, limnea, cyclas, &c.). The skeletons of
the great mastodon found in the bogs of Louisiana were
in a vertical position, as if they had sunk in the mire; and
one discovered imbedded in black earth, in New Jersey,
forty miles to the south of New York, was in the same
position, the head being on a level with the surface of the
soil. There is now an entire skeleton of the mastodon in
the British Museum. From this specimen it appears that
the great mastodon of the Ohio was not unlike the elephant
in its general outline, though somewhat longer and thicker.

§ 23.

MASTODONS FROM AVA.

159

It had a trunk or proboscis, tusks, which curved upward, and four molar teeth in each jaw, but no incisors.

But another remarkable peculiarity, and which entirely separates the mastodon from the elephant, is that the young animal had a pair of tusks, placed horizontally in the lower jaw, and of these tusks, one only became developed, and that in the adult male; both were early shed in the female.* In the midst of a collection of mastodon bones imbedded in mud, a mass of small branches, grass, and leaves, in a half bruised state, and a species of reed, common in Virginia, were discovered; the whole appeared to have been enveloped in a sac, probably the stomach of the animal. In another instance, traces of the proboscis were observed. The tusks are composed of ivory, and vary somewhat in the direction and degree of their curvature. The bones of this colossal quadruped are found remarkably fresh and well preserved, and are generally impregnated with iron. No living instance of this creature is on record, and there can be no doubt that its race has long since been extinct. The Indians believe that men of equally gigantic proportions were coeval with the mastodon, and that the Great Spirit destroyed both with his thunder.† There are several species, some of which have been found in North America only, and others in Europe. Baron Humboldt discovered a tooth of the mastodon near the volcano of Imbaburra, at an elevation of 1,200 fathoms. In England, a few teeth have been found in the Norwich Crag; these belong to a species named Mastodon angustidens (narrow-toothed).‡

23. MASTODONS FROM AVA.—I have now to call your attention to the fossil remains of several species of mas-

* Professor Owen.

† Cuvier. Oss. Foss.

‡ The British Museum now contains an unrivalled collection of the fossil remains of mastodons and mammoths from North and South America, and India.

160

THE WONDERS OF GEOLOGY.

LECT. II.

todons which, from the structure of the teeth, fill up, as it
were, the interval that separates the mastodon from the
elephant; one of these was in consequence named by Mr.
Clift, *Mastodon elephantoides*, (Lign. 26, fig. 2.) These

LIGN. 26.—FOSSIL TEETH OF THE ELEPHANT AND MASTODON.

(One-sixth the diameter of the originals.)

Fig. 1. Tooth of the *Elephas primigenius*, from Big-bone Lick.

2. Tooth of the *Mastodon elephantoides*, from near Ava.

teeth present very peculiar characters; for while in their
general appearance they resemble those of the mastodons
already described, the crown of the tooth is deeply ridged,
and the dentine and enamel are invested with so large a
portion of cement, as to give the worn surface of the crown,
the aspect of the molars of the true elephant.

The specimens before us, consisting of teeth and bones
of mastodons, elephants, hippopotami, rhinoceroses, horses,
tapirs, antelopes, gavials, fresh-water turtles, &c. and
silicified wood, are part of an extensive collection formed
about twenty years since by Mr. Craufurd, on his mission
to Ava. In descending the river Irawaddi, his steam-boat,
owing to the shallowness of the water, ran aground between
Prome and Ava, about 20° north latitude, near some petro-
leum wells, where the bank of the river presented a cliff

§ 24. FOSSIL MAMMALIA, &c. OF THE SUB-HIMALAYAHS.

161

80 feet high; and on the strand were observed masses of petrified wood, and vast quantities of bones. The adjacent country is formed of low, sterile sand-hills, intersected by ravines, with beds of gravel, which are here and there cemented into a conglomerate by iron and carbonate of lime. Scattered over the surface, in some instances lying loose in the sand, and in others half buried, were masses of silicified wood, and fragments of bones, which had become exposed, from the removal of the sand by the winds and rains. The bones are more or less invested with a hard crust, which is a concretion formed by the consolidation of loose sand from ferruginous and calcareous infiltrations. The natives who assisted Mr. Craufurd's party in collecting these remains, believed them to be the bones of giants that had warred against Vishnu, by whom they were destroyed.

24. FOSSIL MAMMALIA, &c. OF THE SUB-HIMALAYAHS.
—But the number of these transitional or intermediate links of elephantine forms, has been greatly increased by the accession made to our knowledge of the fossil fauna of India, by the labours of Major Proby Cautley, and Dr. Falconer, who, with energy and perseverance beyond all praise, formed, and brought to Europe, an immense collection of these mammalian remains. The following extract from the prospectus of a work now in the course of publication by these eminent naturalists, will convey some idea of the richness and interest of their discoveries:—

> "The fossil Fauna of the Sewalik range of hills, skirting the southern base of the Himalayahs, has proved more abundant in genera and species of mammalia than that of any other region yet explored. As a general expression of the leading features, it may be stated, that it appears to have been composed of representative forms of all ages, from the oldest of the tertiary period down to the modern; and of all the geographical divisions of the Old Continent, grouped together into one comprehensive Fauna. Of the forms contained in it may be enumerated, in the *Pachydermata*, several species of Mastodon and Elephant,

M

162

THE WONDERS OF GEOLOGY.

LECT. II

Hippopotamus, Rhinoceros, Anoplotherium, Sus, and three species of Equus; in the *Ruminantia*, the colossal genus Sivatherium, peculiar to India, with species of Camelus, Camelopardalis, Bos, Cervus, and Antelope; in the *Carnivora*, species of most of the great types, together with several remarkable undescribed genera; in the *Rodentia*, several species; in the *Quadrumana*, several species; in the *Reptilia*, a Gigantic Tortoise (*Colossochelys*), with species of Emys and Trionyx, and several forms of Crocodile. To these may be added the fossil remains of struthious and other Birds, Fishes, Crustacea, and Mollusca.” *

25. **SUB-HIMALAYAH TERTIARY DEPOSITS.**—The deposits from which these remains were obtained resemble those of Ava, and consist of concretionary grit, conglomerate, sandstone, and loam; they are spread over the flanks of a range of hills belonging to the Sub-Himalayan mountains, between the river Sutlej and the Ganges. These hills, which are called Sewalik (from Siva, an Indian deity), rise to an altitude of from one to three thousand feet above the level of the sea. The alluvial deposits extend about 200 miles in length, and seven in width, and dip to the north at an angle of 25°; wherever gulleys or fissures expose sections of the beds, abundance of fossil bones appear.† Lignite, and trunks of dicotyledonous trees occur; a few land and freshwater shells of existing species, are the only vestiges of mollusca that have been observed. Remains of several species of river-fish, some related to the recent Silurus, have been obtained.

The immense collection of these fossils in the British Museum, renders any detailed description unnecessary, and I will only dwell on a few of the most important particulars.

The remains of the Elephants and mastodontoid animals,

* “*Fauna Antiqua Sivaliensis*, or the Fossil Zoology of the Sewalik Hills, in the north of India, by Hugh Falconer, M. D. and Major P. T. Cautley.”

† See an interesting Memoir by Major Cautley; Geol. Trans. 2d Series, vol. v. p. 267.

§ 26. REMARKABLE COLLOCATION OF FOSSIL ANIMALS.

comprise perfect specimens of skulls, and jaws, of gigantic size. The tusks of one example are 9 feet 6 inches long, and 27 inches in circumference at the base.*

26. REMARKABLE COLLOCATION OF FOSSIL ANIMALS.--- But this collection is invested with the highest interest, not solely on account of the number and variety of the specimens, but, also, for the extraordinary assemblage of animals which it presents. In the Sub-Himalayans we have entombed in the same rocky sepulchre, bones of the most ancient extinct races of mammalia, with species and genera which still inhabit India! Palæotheria, Anoplotheria, Dinotheria, Mastodons, Elephants, Giraffes, Hippopotami, Rhinoceroses, Horses, Camels, Antelopes, and even Monkeys; Struthious Birds, and Crocodilian and Chelonian rep tiles. To this concise enumeration must be added several genera previously unknown; large rodents, and insectivora, &c.

Among these marvellous relics of the past, are the skull and bones of an animal named *Sivatherium* (from the Indian deity *Siva*), that requires a passing notice. This creature forms, as it were, a link between the ruminants and the large pachyderms. It was larger than a rhinoceros, had four horns, and was furnished with a proboscis; thus combining the horns of a ruminant with the characters of a pachyderm. When living, it must have resembled an immense antelope, or gnu, with a short and thick head, and an elevated cranium crested with two pairs of horns; the front pair were small, and the hinder large, and set quite behind, as in the aurochs; with the face and figure of the

* These fossils are so admirably cleared from the hard rock with which they were incrusted (a task of no little labour, and requiring great skill), that I cannot forbear recommending to the notice of any collectors who may require such aid, the person by whom they were chiselled out—*James Dew*, 25, *Harrison Street, Gray's Inn Road*.

M 2

164

THE WONDERS OF GEOLOGY.

LECT. II.

rhinoceros, it had small lateral eyes, great lips, and a nasal
proboscis.

Among the reptilian remains are skulls and bones of a
Gangetic Crocodile or Gavial, and of a land Turtle, which
cannot be distinguished from those of species still living in
India. But the most extraordinary discovery is that of
bones, and portions of the carapace, of a Tortoise of gigantic
dimensions; it has been aptly named *Colossochelys Atlas*:
the length of this reptile exceeded *twelve feet*.

27. THE PAMPAS.—The Pampas, those vast plains in South America, which present a sea of waving grass for 900 miles, are principally composed of alluvial loam and sand containing freshwater and marine shells, and were once, like Lewes Levels, a gulf, or arm of the sea. In these alluvial deposits, bones of enormous extinct mammalia have frequently been discovered. Towards the close of the last century, an almost perfect skeleton of a gigantic animal (*Megatherium*), was dug up, at a considerable depth, in a bed of clay, on the banks of the river Luxor, about four leagues W.S.W. of Buenos Ayres. This skeleton was sent, in 1789, to the museum at Madrid, where it now remains. It is described and figured by Cuvier, under the name of *Megatherium*.

In 1832, Sir Woodbine Parish, with considerable labour and expense, collected many bones of a similar creature from the Salado; having actually diverted for a time the river from its course, that he might disinter these remains; these he afterwards presented to the Museum of the Royal College of Surgeons of England.

Since that time relics of several other remarkable forms
of extinct mammalia have been discovered; a few of these
we will here briefly describe.

The Pampas, observes Mr. Darwin, may be regarded as
one vast sepulchre of these lost quadrupeds. The deposits
in which the bones occur are as follow :—

§ 28.

THE SLOTH TRIBE.

165

1. Clay, sand, and limestone, containing marine shells and shark's teeth, forming the substratum.

2. Indurated marl.

3. Red clayey earth with calcareous concretions and bones of terrestrial animals.

This section demonstrates that a bay of salt-water was gradually encroached upon, and at length became the bed of a muddy estuary, into which floated the carcases of the animals which then inhabited the neighbouring dry land. It is in the upper deposits that the teeth and bones of the Megatherium, Mylodon, and other gigantic animals of the Sloth tribe, Armadillo, Mastodon, Horse, &c. are imbedded.*

28. THE SLOTH TRIBE.—The most remarkable of the fossil bones discovered in the Pampas, belong to several extinct colossal animals of the *Edentata*;† an order, of which the Armadillos, Sloths, and Ant-eaters are the living representatives. But as the extinct forms differ greatly from the existing ones, in their gigantic proportions, short massy extremities, and thick and strong tail, their mode of life must have been very dissimilar. To impart a clear perception of the peculiar modification of structure which these extinct beings present, it will be necessary to offer some remarks on the existing types—the Sloths.

The Sloths are arranged by naturalists in a tribe termed *tardigrada*, from their feeble power of progression on the surface of the land; for the same reason they are called *Paresseux* by the French, whence the English name, *Sloth*. They are of slender form and small size: the largest species is but little larger than a cat. They have long toes, and nails which fold up, so as to enable the animal to walk, in the same way as if our fingers were folded under the palms

* Mr. Darwin, Appendix to Beechey's Voyage.

† So named from having no teeth in the front of the jaws.

166

THE WONDERS OF GEOLOGY.

LECT. II.

of the hands; but which are not capable of being retracted
into a sheath, as in the feline tribes. The arms are double
the length of the legs, and, from the construction of the
limbs, the animal, when it walks, or rather crawls on the
ground, is obliged to drag itself along on its elbows. But
these creatures are destined to inhabit trees; their proper
element is on the branches, and they can pass from bough
to bough, and from tree to tree, with a rapidity which soon
enables them to lose themselves in the depths of the forests.
They live on the leaves and the young shoots, and unless
disturbed, never quit a tree till they have stripped off
every leaf. To avoid the labour of a descent, they drop to
the ground, previously coiling themselves into a round ball,
in which state, while attached to the branch, they may be
taken alive. Thus the habits and economy of the sloth
point out the necessity for a peculiarity in the structure of
its claws. The monkey leaps and swings himself from tree
to tree, and catches at will the branches or the trunk; but
the sloths do not grasp; their claws are mere hooks to hang
by, and their great strength is in their arms. They never
unfix one set of hooks until they have caught a secure hold
with the other, thus hanging by their arms and legs, while
their bodies are pendant; and they sleep in the same po-
sition. The bones of the arm are constructed to suit these
conditions. The humerus has a long internal condyle for
the origin of large muscles to move the enormous claws; and
there is an opening for the passage of the principal nerves
and blood-vessels, to protect them from the pressure to which
they would be exposed from the powerful muscular action:
and the radius (one of the bones of the fore-arm) is con-
structed to allow of a free rotatory motion to the limb. In
the extinct Sloths a similar conformation is maintained,
but somewhat modified to suit the different physical con-
ditions under which they existed. There are three genera
well established from the fossil remains: the names assigned

§ 29.

THE MEGATHERIUM.

167

to them refer to some striking character; as *Megalonyx*,
from the enormous size of the claw:—*Megatherium*, or
enormous wild animal, from its colossal proportions:—
*Mylodon*, or molar-tooth animal, from the peculiarity of
its dental organs.

29. THE MEGATHERIUM.—This creature was seven feet high, and nine long, and therefore larger than the largest rhinoceros; but this comparison by no means conveys a proper idea of its bulk, since its proportions are perfectly colossal, the thigh-bone being three times as large as that of the elephant, and the pelvis, or haunch-bone, twice the breadth. It possessed no incisor teeth, and the grinders, which are seven inches long, are of a prismatic form, and, like those of the Sloth, composed of dentine and cement.* They are so formed, that the crown always presents two cutting, wedge-shaped, salient angles. As in an adze, a plate of steel is placed between two of iron, so as to project in a line, in like manner these teeth have in the centre a cylinder of ivory, which is protected by a plate of denser structure, and an external coating of cement; they are, therefore, admirably adapted for cutting and bruising vegetable substances. The entire fore-foot is about a yard in length, and armed with strong claws. The pelvis measures five feet in width, and the sacral aperture of the spinal marrow is one foot in circumference! This enormous size was suitable to the habits of an animal requiring to maintain an upright posture for a considerable time, while employing its fore feet in digging up roots, or in severing and pulling down the young trees and branches, which doubtless constituted the food of this colossal creature.

The *Megatherium* was intermediate between the Sloths,
Armadillos, and Ant-eaters; for while in its skull and

* See Professor Owen's "Odontography," vol. i. p. 338.

168

THE WONDERS OF GEOLOGY.

LECT. II.

shoulders it resembled the former, its legs and feet pre-
sented an admixture of the characters of the latter.

30. THE MYLODON.—This creature was nearly as large as the Hippopotamus, but shorter. Its hinder extremities are relatively short, and the feet are placed at right angles with the legs, and are as long as the thigh-bones. The tail is remarkably thick and strong, and as long as the hinder extremities. The pelvis is very massive and solid. The ribs are as stout and broad as in the elephant. The fore-legs, or arms, are connected to the sternum by powerful clavicles, and are so constructed as to admit of unrestrained motion in every direction. The toes are five in number on each fore foot, and four on the hinder; the two external toes are unarmed, the others have powerful curved nails or claws. This creature had claws and hoofs on the same foot, and therefore connects the two great groups of recent animals, the *ungulata* and *unguiculata*.

The skull is long, narrow, and smaller than that of the
ox; it terminates in a flat or truncated muzzle. The bones
of the upper part of the cranium are of enormous thick-
ness, large air-cells being interposed between the inner
and outer table. The teeth, which are implanted in very
deep sockets, are of the same form and size throughout,
and closely resemble in structure those of the Megatherium,
but the surface of the crown when worn is flat; there are
four on each side in the lower, and five in the upper jaw.*

There is a magnificent skeleton of this creature in the Hunterian Museum; it is as perfect as if the animal had recently been buried, and the bones dug up entire. It is eleven feet long, from the muzzle to the extremity of the tail.†

* See Medals of Creation, vol. ii. pp. 845—847.

† See a Memoir on the " Skeleton of an extinct gigantic Sloth (Mylodon robustus)," by Professor Owen. 1 vol. 4to. with plates.
1842.

§ 31.

MYLODON AND MEGALONYX.

169

The Mylodon, like the Megatherium, was a vegetable feeder, and probably browsed on the shrubs and branches of trees. The arms are especially adapted for grasping and wrenching; and though no trees could support the weight of this enormous creature, there is nothing to forbid the supposition that with its hinder feet it could clasp the trunk of a large tree, and with its fore feet climb to a sufficient height to seize and wrench off the branches.

31. THE MEGALONYX.—An enormous curved ungueal phalanx or claw-bone, and several bones of the arm and sternum, of an animal related to the Sloths, were found many years since in Big-bone Cave, one of the numerous saltpetre caverns which occur in the states of Kentucky, Tennessee, and Virginia. Some of these caves extend many miles under ground, passing beneath hills, valleys, and even rivers. In these subterranean retreats are sometimes found Indian mummies, which are simply desiccated human bodies, in a fine state of preservation; bones of existing species of mammalia, and of mastodons, mammoths, and rarely, of extinct gigantic sloths, also occur.*

The remains of the Megalonyx were first described by President Jefferson; and the claw-bones, the largest of which was nearly seven inches long, excited especial attention, from the supposition that they belonged to a carnivorous animal of marvellous size. But Cuvier, in an admirable memoir, proved that they were referable to an extinct form of the Edentata. I will endeavour briefly to explain how this beautiful induction was established.

The paws both of the canine and feline tribes are armed with claws; in the former the nails are thick and coarse, as in the dog, wolf, &c., and will bear the friction and pressure

* See Dr. Harlan's Medical and Physical Researches, 1 vol. 8vo.
Philadelphia, 1845: p. 319.

170

THE WONDERS OF GEOLOGY.

LECT. II.

incident to a long chase; but in the cat tribe, they are
curved and sharp, and these qualities are preserved by
a particular mechanism. The last bone which supports
the claw is placed laterally to the penultimate bone of the
phalanx, and is so joined to it, that an elastic ligament
draws it back, and raises the sharp extremity of the claw
upwards; and the proximal, or nearest extremity of the
farthest bone, presses the ground in the ordinary running
of the animal, while the claw is retracted into a sheath:
but when the creature makes a spring and strikes, the
claws are uncased by the action of the flexors or bending
tendons. In the Bengal tiger, the claws are so sharp and
strong, and the arms so powerful, that they have been
known to fracture the skull of a man, by a single touch
from the animal in the act of leaping over him. A cat
affords a familiar illustration of this peculiarity of struc-
ture; when pleased, its claws are retracted, and when angry
they are thrown out.

In the claw of the Megalonyx there is no such lateral
provision for its retraction, and the point could not have
been raised vertically, as in the cat, so as to have permitted
it to touch the ground without injury. The articulating
surface is double, that is, there is a ridge or spine in the
middle, and it must, therefore, have moved like a hinge.
The bones of the arm present a corresponding configuration
with those of the sloth; the humerus is perforated for the
passage of the blood vessels, and the radius is constructed
for rotation.

The Megalonyx resembled the Megatherium in its gene-
ral character, configuration, and habits, but was one-third
smaller than that gigantic creature.*

* Casts of all the bones and teeth of the Megalonyx that are in the Museum of Philadelphia, were presented to me by Dr. S. G. Morton of that city, and are now in the British Museum, in the same case with the models of the bones of the Megatherium.

§ 34.

THE TOXODON.

32. THE GLYPTODON, — so named from the deeply-grooved teeth, — was an animal allied to the armadillos, and possessed a carapace, or coat of mail, formed of polygonal bony plates united by suture, which constituted an impenetrable covering over the upper part of the body. The plates of this bony integument were not disposed in rings as in the armadillo, but were articulated to each other, and formed a tesselated cylinder, or rather arch; the tail was inclosed in a case of this kind, like a sword in its scabbard.*

Such were the gigantic Edentata that inhabited the dry land of South America at a comparatively modern period; and it is worthy of especial remark, that though these beings have long been extinct, sloths, ant-eaters, and armadillos, but of diminutive size, are still the characteristic animals of that country.

33. THE TOXODON.—The bones of several other extinct quadrupeds have been found with the relics of the gigantic sloths and armadillos. Among these are the skull and teeth of an animal of large size, named by Professor Owen, *Toxodon*, from the singularly curved form of its molar teeth. The skull is twenty-eight inches long, and sixteen broad, and presents a blending of the osteological characters of the several natural orders of the rodentia, ruminantia, and cetacea.

The MACRAUCHENIA, another extinct pachyderm, found in Patagonia, unites in a remarkable degree the structure of the Camel and Tapir; it must have somewhat resembled the Llama, but had a neck surpassing in length that of any other animal, except the Giraffe.†

34. FOSSIL HIPPOPOTAMUS, RHINOCEROS, HORSE, &c.—
With the remains of the mammoth, elephant, and other

* A splendid specimen of the bony cuirass of the Glyptodon is in the Museum of the College of Surgeons.

† An elaborate account of the extinct animals of South America, by Professor Owen, will be found in the "Natural History of the Voyage of the Beagle," by Mr. Darwin.

172

THE WONDERS OF GEOLOGY.

LECT. II.

large mammalia, teeth and bones of several species of hippopotamus, horse, elk, ox, and auroch, are very commonly associated in the alluvial deposits of Europe. In the Vale of Arno, in Italy, immense quantities of the teeth and bones of hippopotami are found; on the table before us are specimens from that locality; as well as molars and incisors of a young animal from Huntingdonshire; and tusks, teeth, and bones, dug up in alluvial marl, at Southbourn, in Sussex. Among the fossils sent me by Major Cautley, from India, are several fine portions of jaws, with teeth, belonging to another species, the *H. Sivaliensis*. Several extinct species have been determined by Baron Cuvier, one of which was not more than half the size of the common Hippopotamus.

The bones and teeth of the Rhinoceros are frequently associated with those of the fossil elephant; and in this country they occur in superficial gravel and loam. I have obtained specimens from a bed of gravel, on Petteridge Common, in Surrey; and from loam at the *Wish*, near Southbourn, in Sussex.

The most extraordinary and interesting fact, relating to the Rhinoceros in a fossil state, is the discovery of the entire carcass, covered with its skin, in frozen sand, on the banks of the Wilaji, in Siberia, as previously mentioned (p. 152). The head was extremely large, and sustained two very long horns; it had no incisors; the body and limbs were covered with brown hair; the general form of the animal was lower and more compact than the living species.

The teeth and bones of one or more species of Horse, occur very constantly with those of the other large extinct pachyderms. In these examples of the conglomerated shingle from Brighton cliffs (see p. 114), the coffin, pastern, and cannon bones, as they are termed, of a small species, about the size of a Shetland pony, are imbedded; in some

§ 35.

THE DINOTHERIUM

173

instances the cavities of the long bones are filled with crys-
tallized carbonate of lime.

In addition to those already mentioned, the deposits
now under examination, contain vestiges of other lost
forms of mammalia. The fossil remains of an animal re-
sembling the Musk-ox were found with elephants' bones in
Siberia; of an extinct species of Fallow-deer in Scania; of
Roe-buck and Reindeer* in France; and of gigantic Oxen,
Aurochs,† Deer, &c. in our own country. It is worthy of
remark, that the fossil pachyderms, such as the elephant,
rhinoceros, &c. belong to genera which are now restricted
to torrid climes, while the ruminants resemble those which
at the present time are natives of northern latitudes.

35. THE DINOTHERIUM. ‡—I shall conclude this notice of the fossil mammalia, with an account of a gigantic creature, whose bones occur with those of the mastodon, elephant, and the other terrestrial quadrupeds, previously described.

In various parts of the south of France large molar teeth,
resembling in form and structure those of tapirs, have
occasionally been found; they are described by Cuvier
under the name of the " *Gigantic Tapir.*" Subsequent
discoveries in Bavaria, Austria, and particularly at Ep-
pelsheim, about twelve leagues south of Mayence, have
thrown light on the osteology of the original, which
appears to have been an aquatic animal of great size.
The most extraordinary deviation from ordinary types

* In the alluvial loam filling up fissures in the tertiary limestone, at Binstead, Isle of Wight, I discovered the skull of a reindeer, in 1846. See my Geology of the Isle of Wight, p. 104.

† The Auroch is a species of wild bull or buffalo, distinct from the common ox. The horns of the fossil ox are sometimes of enormous size: Mr. Parkinson had a pair in which the length of each horn was 2 feet 7 inches.

‡ *Dinos*, terrible; *therion*, a wild beast.

174

THE WONDERS OF GEOLOGY.

LECT. II.

consists in a pair of curved tusks, which are fixed in the lower jaw, and directed downwards. From the structure of the anterior portion of the cranium, and the disposition of the nasal fossæ, it is supposed that the creature had a proboscis; it possessed no incisor teeth with which to seize its food, and the jaws could not even close together in front; the lower jaw is four feet in length. The tusks resemble

LIGN. 27.—RESTORED FIGURE OF THE DINOTHERIUM.

those of the Walrus, and were probably weapons of defence. This drawing, (Lign. 27,) from a restoration by M. Kaup, an eminent German naturalist, to whose researches we are indebted for the important discoveries at Eppelsheim, represents the supposed form of the original creature. It has been assumed that the Dinotherium was nearly related to the hippopotamus, and formed a link between the cetacea and pachyderms; but it seems more probable that it was an herbivorous cetacean related to the Lamantins.

36. FOSSIL CARNIVORA IN CAVERNS.—We have now briefly reviewed the extinct population of a remote period of our globe,—those enormous terrestrial mammalia, the mastodons, mammoths, &c., that lie buried in the alluvial and superficial strata. We pass to the consideration of

§ 37.

CAVE OF GAYLENREUTH.

a phenomenon not less interesting—the occurrence of im-
mense quantities of bones of many species of carnivora in
fissures and caverns. In the former discourse I alluded to
the chasms which occur in certain limestone rocks, and
described the process by which their roofs, floors, and
walls become lined with stalactites and stalagmites (p. 78).
Some of these hollows have evidently been occasioned by
the destruction of the softer portions of the rock, by the
erosion of subterranean streams and rivers: others are so
extensive, and present such decided marks of angular
fracture, as to leave no doubt that they are rents produced
by earthquakes. The occurrence of bones of land animals
in such chasms might reasonably be expected.

The caves that admitted of easy access from without, and
which contain large quantities of bones of but a few species
of carnivora, may for a while have been tenanted by species
whose habits lead them to retire into secret recesses; and
if there were open fissures, kids, deer, &c. may have
fallen in, and their bones have become enveloped in
calcareous incrustations. But the bones and teeth of
herbivora and carnivora, that are promiscuously inter-
mingled in loam and clay at the bottom of fissures and
caves, have evidently been drifted in, while the land was
under water.

37. CAVE OF GAYLENREUTH.—For many centuries,
certain caverns in Germany have been celebrated for their
osseous treasures, particularly those in Franconia: the
most remarkable is that of Gaylenreuth, which lies to the
north-west of the village, on the left bank of the river
Wiesent.* The entrance (*Lign. 28, a*), which is about seven
feet high, is in the face of a perpendicular rock, and leads to
a series of chambers from fifteen to twenty feet high,

* See Medals of Creation, vol. ii. p. 869, for an interesting account of the present state of some of these caves, by my friend Major Willoughby Montagu.

176

THE WONDERS OF GEOLOGY.

LECT. II.

and several hundred feet in extent, terminating in a deep chasm (b), which, however, has not escaped the ravages of visitors. This cavern is perfectly dark, and the icicles, and pillars of stalactite, reflected by the torches which it is necessary to use, present a highly picturesque effect. The floor is literally paved with bones and fossil teeth; and the pillars and corbels of stalactite also contain osseous remains.

LIGN. 28.—VERTICAL SECTION OF THE CAVE OF GAYLENREUTH.
a, The entrance of the cave; b, one of the deep recesses.

A graphic description of this cave was published by M. Esper, in the middle of the last century; at that period, the innermost recesses contained waggon loads of bones and teeth; some imbedded in the rock, and others in the loose earth.

The bones are in general scattered and broken, but not rolled; they are lighter and less solid than recent bones, and are often incrusted with stalactite. Through the kindness of the Earl of Enniskillen, and Sir P. M. de G.

§ 38.

FOSSIL BEARS OF THE CAVERNS.

177

Egerton, I am able to illustrate these remarks by an
extensive suite of specimens, exhumed from the deepest
recess in the cavern, by these distinguished geologists. But
the most interesting relic in my possession is a remark-
ably perfect skull of a bear, which belonged to my late
friend Mr. Parkinson, the author of that delightful work,
*“The Organic Remains of a Former World.”*

Cuvier, who examined a very large collection of bones
from Gaylenreuth, determined that at least three-fourths of
the osseous contents of the caverns belonged to bears;
and the remaining portion to hyenas, tigers, wolves, foxes,
gluttons, weasels, and other small carnivora. Most of the
bones which are referable to bears, belong to two extinct
species. The largest has the skull more prominent in front
than any living species, and is called *Ursus spelæus*, or bear
of the caverns; the other has a flat forehead, and is named
*Ursus priscus*. The Hyena was allied to the spotted hyena
of the Cape, but differed in the form of its teeth and head.
Bones of the elephant and rhinoceros are also said to have
been discovered, together with those of existing animals,
and fragments of sepulchral urns of high antiquity.†

38. FÖRSTERSHÖHLE (*Forest Cavern*). — This cavern,
which is situated in the same part of Germany, is remark-
able for the beauty of its stalactites and sparry incrustations;
it varies in height from ten to thirty feet, and its greatest
width is about ten yards. In the side vaults or recesses,
which descend, at an angle of about forty-five degrees, into
the main chamber, the stalagmite has formed the appearance

* Their Royal Highnesses the Princes George of Cumberland and Cambridge, when inspecting my collection at Lewes, a few years since, pointed out the skull and bones of the *Ursus spelæus* as resembling some fossils that had been exhumed from a fissure in limestone, in the kingdom of Hanover.

† See Medals of Creation, vol. ii. p. 853, for further details relating to the fossil carnivora.

N

178

THE WONDERS OF GEOLOGY.

LECT. II.

of cascades of pure alabaster, the waves of which seem to be rushing out at the bottom, to pour themselves into the stagnant lake of the same substance which covers the floor. The roof has been corroded into deep cavities, which are separated by partitions of every conceivable form and tenuity, giving it the appearance of the richly fretted gothic roof of a chapel, with pendent corbels. Beautiful stalactites depending from these projections, reach almost to the floor, and contribute by their delicacy and transparency to throw additional richness over the scene.

It is certainly, as M. Cuvier remarks, a most extraordinary fact, that caves, spread over an extent of two hundred leagues, should have the same osseous contents. The relative proportions of the different species are computed to be as follow :—three-fourths belong to bears—two-thirds of the remainder to hyenas—and a small number to the tiger or lion, and to the wolf or dog ; rolled pebbles of a greyish blue marble are the only extraneous materials found with the bones. The singular assemblage of species whose recent types are widely separated geographically, which some of these caves present, is very remarkable. Thus in one cavern, animals allied to the spotted hyena of the Cape of Good Hope, are associated with the remains of others related to the glutton, which inhabits Lapland ; and in another, bones of the rhinoceros with those of the reindeer.

Numerous caves containing osseous remains are scattered over the continents of Europe and America; and in Australia, fossil bones referable to animals of different genera, are found, under similar conditions. In the Brazils there are also numerous ossiferous caverns presenting the same general character. These bones belong, for the most part, to genera which still inhabit South America. It is worthy of especial notice, that the bones of a species of horse occur in these accumulations; for when the Spaniards invaded the country, horses were unknown to the inhabitants, who,

§ 39.

BONE CAVERNS IN ENGLAND.

179

upon seeing a Spaniard on horseback, actually supposed
that the man and horse were but one animal. At the
present time, herds of wild horses, the descendants of those
introduced by the Spaniards, are distributed over the vast
plains of South America. "It is a marvellous event in the
history of animals," observes Mr. Darwin, "that a native
kind should have disappeared, and be succeeded in after
ages by countless herds introduced by the agency of man."*

39. BONE CAVERNS IN ENGLAND.—In England, caves
and fissures containing bones of bears, wolves, and other
carnivora, in every respect analogous to those of Germany

4 feet.

LIGN. 29.—SECTION OF THE ENTRANCE TO KIRKDALE CAVE.

(From Dr. Buckland's *Reliq. Diluv.*)

A. Mud covering the floor of the cave to the depth of one foot, and concealing the bones.

B. Stalagmite containing bones, formed before the mud was introduced.

C. Stalagmite formed over the mud.

D. Insulated stalagmite on the surface of the mud.

E. E. Stalactites dependent from the roof.

above described, have been discovered and explored. The
Dean of Westminster, in his beautiful work, the *Reliquiæ
Diluvianæ*, has noticed several of the most important

* *Voyage of the Adventure and Beagle.*

N 2

180

THE WONDERS OF GEOLOGY.

LECT. II.

assemblages of this kind; of these the cave of Kirkdale, in
consequence of the highly interesting disquisition on its
contents by Dr. Buckland, is the most celebrated.

In the summer of 1821, a deep fissure or chasm was discovered near Kirkdale, about twenty-five miles NN.E. of York, in a bank about sixty feet above the level of a small valley, and near a public road. Some workmen who were quarrying stone, cut across the narrow mouth of a chasm which had been choked up with rubbish, and overgrown with grass and bushes; and which, from this cause, as well as from its inaccessible situation, had hitherto escaped observation. The entrance was so small that a person could only enter in a bent position; and the passage was exceedingly irregular in its dimensions, varying from two to seven feet in breadth, and from two to fourteen feet in height, its greatest length being 245 feet. The cave was divided into several smaller cavities, which were nearly closed by sparry concretions; these occurred where the roof was intersected by fissures, and continued for a few feet, but were gradually lost in the superincumbent limestone; they were thickly lined with stalactites. The true floor was only seen near the entrance, for in the interior the whole was covered with a bed of hardened mud or clay, about a foot in average thickness. The surface was perfectly smooth and level when the cave was first opened, except where stalagmites had formed upon it by infiltration from the roof. Where stalactitic matter incrusted the sides, it also extended over the bottom like a thin coat of ice; and therefore must have been deposited since the mud was introduced. This mud or clay was filled with fragments of bones belonging to a great variety of animals; and some of the bones exhibited marks of having been gnawed. From many corroborative circumstances these appearances were supposed, by the distinguished author, to have been occasioned by hyenas. The bones thus preyed

§ 39.

KIRKDALE CAVE.

upon belong to the tiger, bear, wolf, fox, weasel, elephant,
rhinoceros, hippopotamus, horse, ox, and deer. Bones of a
species of hare or rabbit, water-rat, and mouse, with frag-
ments of the skeletons of ravens, pigeons, larks, and ducks,
were imbedded with these remains.

From these facts Dr. Buckland inferred that the cave
had been inhabited by hyenas for a considerable period, and
that many of the remains found there, were of species which
had been carried in, and devoured by those animals, and
that in some instances the hyenas preyed upon each other;

LIGN. 30.—THE LEFT SIDE OF THE LOWER JAW OF A HYENA, FROM KIRKDALE CAVE.

the gnawed portions of elephants' bones seem to show that
occasionally the large mammalia also served as food. It is
probable that many of the smaller animals were drifted in
by currents, or fell into the chasm, through fissures now
closed up by stalactitical incrustations.

KENT'S CAVE, near Torquay in Devonshire, Oreston
Cave near Plymouth, and Banwell Cave in the Mendip
Hills, are well known for the abundance and variety of the
fossil bones imbedded in alluvial drift, with which they are
partly filled.*

* In the south-east of England but one instance is known; a fissure in the sand-rock at Boughton Quarries, near Maidstone, contained the jaw and some bones of a hyena, which are now in the Museum at Oxford.

182

THE WONDERS OF GEOLOGY.

LECT. II.

Of these, the first named has been the most productive in objects of interest; probably from the diligent research carried on for many years by several local collectors. A very fine and extensive series obtained by the late Rev. J. MacEnery, of Torquay, is now in the British Museum. It comprises skulls and bones of all the species of carnivora usually met with in such recesses; and also the skull and teeth of a species of Badger, Otter, Pole-cat, Ermine, &c. Among these are a most remarkable canine tooth, six inches long, and an incisor, of a feline animal larger than the Tiger (*Machairodus latidens*); the edges of these teeth are serrated, and the canine is very like in form the tooth of one of the Wealden reptiles (the Megalosaurus). The teeth of another species occur in the caves of Germany; and a skull with teeth, has lately been found in Auvergne. This extraordinary animal was originally named *Ursus cultridens* by Cuvier, who supposed it to have been an extinct species of Bear.*

But this cave is invested with additional interest on another account, which I will here briefly explain. The principal fissure extends 600 feet in length, and there are several lesser lateral ones. The lower part of the cave is filled up to a thickness of 20 feet, with reddish sandy loam full of fossil bones. This is covered by a layer of stalagmite, from one to four feet thick, which forms the floor of the cave. Upon this is a slight covering of earthy matter, with here and there patches of charcoal; a few human bones, and fragments of coarse ancient pottery, have been observed. Upon breaking through the sparry floor the ossiferous earth is exposed; and, *imbedded with the fossil bones*, several flint knives, arrow and spear heads, have been discovered. These stone instruments are of the same kind as those found in the tumuli of the early British tribes, and unquestionably belong to the same period. This fact has given rise to much curious speculation, but the arguments I shall presently bring forward, when speaking of a similar collocation of works of art, and human bones, with those of the extinct cavern animals, will, I conceive, show that the data hitherto obtained, do not warrant the inference, that these relics were contemporary. Kent's Hole, Banwell Cave, and all the ossiferous caves I have examined in England, appear to have been mere rents or fissures in limestone rocks, which were filled with drift, while submerged in shallow water; and the carcases of land animals may have been floated in by the subaqueous currents. As the bones, though broken, are rarely waterworn, and the fragments even retain their sharp edges, the bones must have been more or less protected by

* See British Fossil Mammalia, p. 174.

§ 40.

DISEASED BONES FOUND IN CAVES.

183

muscles and skin: the extreme freshness of many of them (especially in Banwell Cave) supports this opinion. Upon the elevation of the land, these fissures were raised above the water, and gradually drained, during which period the formation of stalactite commenced from the percolation of water through the superincumbent beds of limestone. When Kent's Cave was accessible, and before the formation of the floor of stalagmite, some of the wandering tribes of the early Britons may have prowled into the recess, or occasionally sought shelter there; and stone implements, bones, or any hard substances, left in the cave, would soon sink a few feet in the soft ossiferous mud, and become hermetically sealed up, as it were, by the stalagmitic deposit.

From what has been stated, we learn that our wastes and forests were once inhabited by extinct herbivora and carnivora, belonging to genera of which the recent species are almost entirely restricted to southern climates; that some of the caves were tenanted by successive generations of bears, wolves, &c.; that the hyenas, according to their peculiar habits, dragged into their dens the creatures which they killed or found dead, and devoured them at their leisure;—that subsequently all these races were annihilated except the few allied species which still inhabit the European continent and islands. In England, the only living representatives of the three families of carnivora which swarmed in these latitudes during the Mammoth period, are the *Fox*, of the dog tribe; the *Wild Cat*, of the feline order; and the *Badger*, of the bear tribe.*

40. DISEASED BONES OF CARNIVORA FOUND IN CAVES.—
Among the bones found in the caves of Germany are many
in a condition which must have resulted from accident or
disease. In some there has been a formation of new bony
matter to repair fractures; in others there is anchylosis, or
adhesion of the joints from inflammation: while in some
the effects of caries, or decay of the bones, the result of
tedious and painful diseases, are apparent. Others have a

* British Fossil Mammalia.

184

THE WONDERS OF GEOLOGY.

LECT. II.

light and spongy character, and are very fragile, which must have arisen from a want of energy in the nutritive system, in consequence of a scrofulous affection.*

41. HUMAN BONES, AND WORKS OF ART IN CAVERNS.—
Not only in the caverns of England, but also in those of France and Germany, human bones, and fragments of ancient pottery, have been found. As mankind, in an uncivilized state, commonly inhabit caves, traces of their having occupied recesses, which had previously been the retreat of wild animals, might be expected. But as bones of extinct species occurred with these relics of man, it was assumed that they were coeval with each other; more accurate observations have, however, rendered it probable that the human remains were introduced at a later period. We have historical proof that the early inhabitants of Europe often resided, or sought shelter in caves. Thus Florus records, that Cæsar ordered the inhabitants of Aquitania to be inclosed and suffocated in the caverns to which they had fled for safety.† Many tribes of the Celtic race occupied these subterranean retreats, not only as a refuge in time of war, but also for shelter from cold, and as magazines for their corn, and for the produce of the chase, and as places of concealment for the animals they had domesticated. The bones of such of these people as perished, or were buried in the caverns, would become blended with the mud, gravel, and debris of the animals already entombed; and a stalagmitic paste might in some places be formed by the infiltration of water, as at Bize, and cement the whole into a solid aggregate. In concretionary masses of stone of this kind, containing bones of the bear, and

* Professor Walther, on the antiquity of diseases of bones; see Professor Jameson's Cuvier's Theory of the Earth. Edin. 1827.

† A horrible and atrocious cruelty, which the French, of the nineteenth century, have not scrupled to perpetrate in Algeria!

## § 42. OSSEOUS BRECCIA, OR BONE-CONGLOMERATE.

other extinct species, human bones, fragments of pottery, terrestrial shells, and bones of animals of modern times, may therefore be associated.* Such are the contents of numerous caves, and this explanation shows how they may have been accumulated.†

42. OSSEOUS BRECCIA, OR BONE-CONGLOMERATE.—The facts we shall next examine are even more extraordinary than those already described; for the fossil remains are not imbedded in gravel or clay, or collected together in caves, but occur in fissures of limestone, over an area of many hundred leagues, and in rocks and islands very remote from each other. The limestone presents but little variety, the substance in which the fossils are enveloped is everywhere the same, and the bones belong, with few exceptions, to similar species of animals. The rocks in which they occur have been shattered in every direction, and the fissures are filled, more or less completely, with what geologists term an osseous or bone-breccia; that is, an aggregation of bones held together by a calcareous cement or paste, in the same manner as the conglomerated shingle near Brighton (p. 79); or, to exemplify its nature by a still more familiar illustration, the mixture of mortar, pebbles, &c. which is employed in masonry, and called concrete.

This cement is of a reddish brown colour, and much resembles common brick, while the bones are beautifully white, and in many instances have their cavities lined with spar. In some examples the bones have undergone but little change; in others, the cells of the cancellated structure are filled with calcareous matter. The specimen before us

* Memoir by M. Desnoyer.

† The femur of the Bear is so like the human thigh-bone, as to be readily mistaken, without due caution; see Prof. Owen; British Mammalia, p. 96: in which the distinctive characters of each are pointed out.

186

THE WONDERS OF GEOLOGY.

LECT. II.

(Lign. 31) is from Gibraltar, and contains two teeth, and fragments of bone, of a ruminant. The breccia in which the teeth are imbedded is now a compact limestone; it is of a

LIGN. 31.—TEETH OF A RUMINANT IN OSSEOUS BRECCIA, FROM GIBRALTAR.

dull red colour, mottled with white, and susceptible of a good polish. This osseous breccia occurs on the northern shores of the Mediterranean; in the rock of Gibraltar; at Cette, Nice, and Antibes; in Dalmatia, and in the isles of Cerigo, Corsica, &c.; and in Sicily, Sardinia, and many parts of Germany. Each of these localities presents highly interesting examples of the objects of our present inquiry.

43. THE ROCK OF GIBRALTER.—As the rock of Gibraltar, so well known from its historical and political importance, affords a good illustration of the phenomena under review, I shall, for the sake of brevity, confine my observations to that celebrated spot. Gibraltar is situated on the Spanish side of the Mediterranean, being united to the main land by a narrow isthmus, which is a mere bank of consolidated sand, about three-fourths of a mile broad, and only eight or ten feet above the level of the sea. The rock stands on the western extremity of the area in which the osseous breccia occurs, and its greatest altitude is about 1,350

§ 43.

THE ROCK OF GIBRALTAR.

187

feet. It is in great part composed of strata of compact, bluish-grey marble, of the oolitic period, which like most extensive limestone masses is cavernous. The principal cavern, called St. Michael's, contains stalagmites and stalactites, which when polished are of great beauty. The fissures intersecting the rock, as well as those in some of the caves, are partially filled up with a calcareous concretion, of a reddish-brown colour, which in some parts is a mere earthy mass, but in others is highly indurated. The bones are commonly in a broken state, and but seldom water-worn; and the fragments of limestone with which the fissures abound, are also angular, and have evidently, like the bones, fallen into the crevices at different periods, and been gradually incrusted and conglomerated by calcareous infiltrations. Snails and other land shells of the existing species of the country often occur impacted in the solid breccia; and as the stalactitic concretion is constantly going on, some masses contain recent terrestrial shells unmixed with bones.

The cementing material is very similar in the different localities where the breccia has been observed; namely, at Cette, Nice, Antibes, &c. in Dalmatia and Sardinia. The animal remains of the breccia are referable to several species, some of which are recent and others probably extinct, of deer, antelope, rabbit, rat, mouse, &c. Bones of birds and of lizards have been discovered at Cette; and of lemmings,* and of the *lagomys*,† which now only exists in Siberia: it is but rarely that traces of carnivora are observed.‡

No one can fail being struck with surprise at the occurrence of these isolated, yet analogous phenomena, which

* Lapland marmot.

† Signifying rat, or tailless hare; a small animal which forms a link between the hare and the rat.

‡ See an interesting memoir in the Geology of the Environs of Nice, by Sir H. De la Beche: Geol. Trans. vol. iii. p. 171.

188

THE WONDERS OF GEOLOGY.

LECT. II.

surround the great basin of the Mediterranean;—rocks of a uniform character, fissured and broken, their rents filled up with similar materials, and with the remains of the same species of animals. The occurrence of species, either extinct, or no longer inhabiting the same latitudes (as the *lagomys*), refers the period of the existence of these animals to the epoch of the mammoths and mastodons; and the absence of marine remains, and of the usual abrading effects of water, show that the breccia was formed on dry land, and not beneath the sea. The rational explanation of these facts, appears to be that which assumes the original union of these distant rocks and islands into a continent, or large island, that, like Calabria, was subject to repeated visitations of earthquakes; and that the animals which inhabited the country fell into the fissures thus produced, and were preserved by the calcareous infiltrations that were constantly in progress. Subsequent convulsions severed the country into rocks and insular masses, of which catastrophes the osseous conglomerates are the physical and only records.

44. OSSEOUS BRECCIA OF AUSTRALIA.—Caves and fissures, filled with osseous breccia, of the same nature as that above described, have also been discovered in New Holland, to the westward of Sydney, near the banks of the Macquarrie river; and it is not a little remarkable, that even the red ochreous colour of the European conglomerates prevails; the bones, however, belong to animals wholly distinct from any noticed in the preceding examples. Some of them are of living, others of extinct species, but almost all are referable to marsupial animals, as the *Kangaroo*, *Wombat*, *Dasyurus*, &c. A portion of a large bone, found in a cave, is said to belong to the hippopotamus, and another fragment to the mastodon, but this requires confirmation; it is, however, a subject worthy of attention, since the kangaroo is the largest animal now

§ 45.

RETROSPECT.

189

known in those regions. The fact that the fossil animals hitherto discovered are marsupial, that is, belong to mammalia which carry their young in a pouch—a type of organization which is the peculiar feature of the existing Australian fauna—is of great interest, for it proves that the present zoological character of the country has prevailed from a very remote period.

45. RETROSPECT.—I must now bring to a close this survey of the ancient superficial deposits—those accumulations of alluvial debris, which, taken as a whole, are referable to a far more remote period than those which strictly belong to the human epoch; although the ancient pass by insensible gradations into those of comparatively recent origin.

In the former discourse I found it necessary to refer to the discoveries of Astronomy, to elucidate the earliest physical conditions of our planet; in the present I have summoned comparative anatomy to our aid, and have endeavoured to point out the mode of induction pursued by the palæontologist, in his inquiries into the fossil remains of animal organization, and by which he is enabled to call forth from their rocky sepulchres, the beings of past ages, and, like the fabled sorcerer, give form and animation to the inhabitants of the tomb.

From the facts that have been reviewed in the course of this Lecture, the following inferences result.

*First*—that the extinction of certain forms of animal organization has extended throughout the period comprehended in our present researches. We have traced its influence from the partial extirpation of certain existing forms, to the entire annihilation of many species and genera that once were contemporary with man; as well as to those which lived, and became extinct, antecedent to all traces of the human race.

*Secondly*—that while in the modern marine and fluviatile

190

THE WONDERS OF GEOLOGY.

LECT. II.

deposits, the remains of existing species of animals, and of man and his works, are entombed,—in the ancient alluvial sediments, those of large extinct mammalia are chiefly imbedded, and no vestiges of human remains have been discovered.

*Thirdly*—that the bones principally belong to extinct mammalia, related to the elephant, hippopotamus, sloth, horse, deer, &c.; and to the bear, hyena, tiger, and other carnivora; and with these are associated the remains of recent species.

*Fourthly*—that in the period immediately antecedent to the present state of the earth's surface, the dry land teemed with large herbivorous animals, which roamed through the primeval forests, unmolested, save by beasts of prey. Numerous species and entire genera have since been swept away from the face of the earth,—some by physical revolutions, others by a gradual decadence,—while many have been exterminated by man.

*Lastly*—that the various deposits in which these fossils are imbedded, whether formed in the beds of lakes, rivers, or estuaries, have been elevated above the level of the waters and become dry land, at a comparatively recent period, and now constitute fertile countries, supporting busy communities of the human race.

I have thus endeavoured to interpret one chapter in the ancient physical history of our planet, and explain the records of one epoch in geological chronology. We have entered upon the confines of the past, and already we find ourselves surrounded by an innumerable population of unknown types of being,—not as dim and shadowy phantoms of the imagination, but in all the reality of form and structure, and bearing the impress of the mighty changes of which they constitute the imperishable memorials. We

§ 45.

RETROSPECT.

191

have witnessed the effects of repeated changes in the relative
level of the land and water,—have seen that our present
plains and valleys were submerged beneath the ocean, at a
period when large mammalia, apparently unrestricted by
existing geographical limits, were inhabitants of regions
which are now no more;—and we have obtained additional
proof that—

> New worlds are still emerging from the deep,
> The old descending in their turn to rise!

Even in this early stage of our progress, we have con-
clusive evidence of the extinction of whole tribes of ani-
mals, alike admirably adapted to the conditions in which
they were placed, as the races which have survived. And
it is most gratifying to the geologist to find, that this fact,
which but a few years since was received with hesitation
by most, and condemned and rejected by many, is now
adduced by the moralist and divine, as affording new and
striking proofs of the wisdom and overruling providence
of the Eternal.*

* See Dr. Buckland's Bridgewater Essay.

LECTURE III.

<table>
  <tbody>
    <tr>
      <td>1.</td>
      <td>Introductory.</td>
      <td>2.</td>
      <td>Mineral composition of Rocks.</td>
      <td>3.</td>
      <td>Crystallization.</td>
      <td>4.</td>
      <td>Stratification.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>5.</td>
      <td>Displaced Strata.</td>
      <td>6.</td>
      <td>Veins and Faults.</td>
      <td>7.</td>
      <td>Chronological Synopsis of the Strata.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>8.</td>
      <td>Geology of England.</td>
      <td>9.</td>
      <td>Alluvium and Drift of the Modern Epoch.</td>
      <td>10.</td>
      <td>Erratic Boulders.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>11.</td>
      <td>Tertiary Formations.</td>
      <td>12.</td>
      <td>Classification of the Tertiary.</td>
      <td>13.</td>
      <td>Fossil Shells.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>14.</td>
      <td>Lithological Characters of the Tertiary.</td>
      <td>15.</td>
      <td>Subdivisions of the Tertiary System.</td>
      <td>16.</td>
      <td>Pliocene Deposits.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>17.</td>
      <td>Miocene; the Crag.</td>
      <td>18.</td>
      <td>Eocene, or Lower Tertiary.</td>
      <td>19.</td>
      <td>The Paris Basin.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>20.</td>
      <td>The London Basin.</td>
      <td>21.</td>
      <td>The Isle of Sheppey.</td>
      <td>22.</td>
      <td>Bagshot Sand.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>23.</td>
      <td>Phenomena of Springs.</td>
      <td>24.</td>
      <td>Artesian Wells.</td>
      <td>25.</td>
      <td>The Hampshire Basin.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>26.</td>
      <td>Alum Bay.</td>
      <td>27.</td>
      <td>London Clay of Hampshire.</td>
      <td>28.</td>
      <td>Freshwater Tertiary of the Isle of Wight.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>29.</td>
      <td>Organic Remains of the Eocene Strata.</td>
      <td>30.</td>
      <td>Amber.</td>
      <td>31.</td>
      <td>Zoophytes of the Tertiary.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>32.</td>
      <td>Shells of the Tertiary.</td>
      <td>33.</td>
      <td>Fossil Nautilus.</td>
      <td>34.</td>
      <td>Nummulites.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>35.</td>
      <td>Rotaliæ.</td>
      <td>36.</td>
      <td>Crustaceans and Fishes.</td>
      <td>37.</td>
      <td>Tertiary Reptiles.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>38.</td>
      <td>Tertiary Birds.</td>
      <td>39.</td>
      <td>Fossil Mammalia of Paris.</td>
      <td>40.</td>
      <td>Palæotheria and Anoplotheria.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>41.</td>
      <td>Fossil Monkeys.</td>
      <td>42.</td>
      <td>Tertiary Deposits of Aix.</td>
      <td>43.</td>
      <td>Fossil Insects.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>44.</td>
      <td>Fossil Fox of Cèningen.</td>
      <td>45.</td>
      <td>Fossil Fishes of Monte Bolca.</td>
      <td>46.</td>
      <td>Tertiary Volcanoes of France.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>47.</td>
      <td>Extinct Volcanoes of Auvergne.</td>
      <td>48.</td>
      <td>Crater of the Puy de Come.</td>
      <td>49.</td>
      <td>Mont Dore.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>50.</td>
      <td>Lacustrine Strata of Auvergne.</td>
      <td>51.</td>
      <td>Successive Epochs of Mammalia.</td>
      <td>52.</td>
      <td>Survey of Geological Phenomena.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>53.</td>
      <td>Excavation of Valleys by running Water.</td>
      <td>54.</td>
      <td>Extinct Volcanoes of the Rhine.</td>
      <td>55.</td>
      <td>Brown Coal Deposits; the Loess.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>56.</td>
      <td>Tertiary of Europe and North America.</td>
      <td>57.</td>
      <td>Altered Tertiary of the Andes.</td>
      <td>58.</td>
      <td>Saliferous Deposits.</td>
    </tr>
    <tr>
      <td></td>
      <td></td>
      <td>59.</td>
      <td>Retrospect.</td>
      <td>60.</td>
      <td>Concluding Remarks.</td>
      <td></td>
      <td></td>
    </tr>
  </tbody>
</table>

1. INTRODUCTORY.—Although it is my object in these Lectures to present a general view of the philosophy of Geology, and render the examination of geological phenomena subservient to an exposition of the laws which the Divine Author of all things has established for the renovation, maintenance, and government of the organic and inorganic kingdoms of Nature, I must enter somewhat in detail on the nature and distribution of the materials of which the crust of the earth is composed. For based as Geology is upon observations of the various physical changes which are now taking place on the surface of

§ 1.

INTRODUCTORY REMARKS.

193

our globe, and on investigations of the natural records of
similar changes in periods antecedent to all human history
and tradition, the minerals and fossils are the alphabet, the
rocks and mountains the volume, by which the student of
this interesting department of science must learn its im-
portant lessons. But to those who cannot examine Nature
in her secret recesses, or accompany an experienced teacher
to the valleys, or the mountain-tops, lectures illustrated by
specimens and drawings, afford, perhaps, the best substi-
tute for the more efficient and interesting mode of in-
struction.

That we may obtain a clear and comprehensive view of
the vast field of inquiry that lies before us, artificial classi-
fications are necessary in this, as in other departments of
science; and without assuming that the arrangement in
which the various deposits are grouped by modern geologists,
may not require considerable modification as new facts are
brought to light, I will place before you a tabular view
of the formations, or systems of deposits, in their pre-
sumed chronological order. At the same time it must be
borne in mind, that all arrangements of this kind necessarily
involve arbitrary distinctions; and that it may, possibly,
hereafter appear, that we have in some instances classed as
general, what are but local phenomena; and have grouped
together in one system, strata, which farther investigations
may show to be distinct formations, separated from each
other by vast periods of time. It must too be admitted,
that there are not in nature those strict lines of demarcation
between one system of strata and another, which, for the
convenience of study, have been adopted. For though
the limits of certain formations may be clearly defined
in one region, in other and distant countries there may
be an insensible passage from one system to the other.
In short, both in the organic and inorganic kingdoms
of nature, in proportion as our knowledge is increased,

O

194

THE WONDERS OF GEOLOGY.

LECT. III.

and our views enlarged, the harmony and unity of nature become more and more manifest; the apparent breaks in the chain of causation exist only in our imperfect conceptions. These considerations will not, however, affect those leading principles of Geology which it is my present endeavour to render familiar to the intelligent but unscientific inquirer.

In pursuance of this object we will first take a general view of the nature of the mineral substances which enter into the composition of the crust of the earth, and briefly notice the laws which regulate the deposition of sedimentary detritus in the beds of rivers, and in the depths of the ocean.

2. MINERAL COMPOSITION OF ROCKS.—Every substance is composed of atoms of inconceivable minuteness, held together by a principle termed attraction or cohesion, and which is probably a modification of that influence, which, as it exists under certain conditions in inorganic substances, is called electricity, galvanism, or magnetism; and in organized beings, nervous influence.* The different states of solidity, fluidity, and vapour, in which every material body may exist, were exemplified in a former lecture, and we need only remark, that of the substances, which in the present state of chemical knowledge are considered simple or elementary, about sixteen constitute, in their various combinations, by far the largest amount of all organic and inorganic matter. Of these, eight are non-metallic; viz. *oxygen, hydrogen, nitrogen, carbon, sulphur, chlorine, fluorine, and phosphorus*; the four first are almost always found in combination. *Oxygen* constitutes one-fifth part of the atmosphere, and eight-ninths in weight of water, and a large proportion of every kind of rock. *Hydrogen* makes up the remaining portion of water; and *Nitrogen*

* See a masterly “Essay on the Correlation of Physical Forces,” by W. B. Grove, Esq. F.R.S. London, 1846.

§ 3.

CRYSTALLIZATION.

four-fifths of the atmosphere. *Carbon* is the chief constituent of animal and vegetable structures, and is only found pure in the diamond.

There are also six metallic bases of alkalies and earths; namely, *silicon*, which, when united with an equivalent of oxygen, forms quartz, or flint, the basis of nearly half the rocks that compose the crust of the earth; *aluminum*, *potassium*, *sodium*, *magnesium*, and *calcium*; and two, the oxides of which are neither earths nor alkalies, namely, *iron* and *manganese*. The principal remaining metallic substances, viz. *copper*, *lead*, *zinc*, *arsenic*, *silver*, *gold*, &c. are comparatively unimportant in a geological point of view.

The sedimentary rocks are in a great measure composed either of lime, silex, or argillaceous earth; and accordingly as these substances predominate, the masses possess, what in mineralogical language is called a *cleavage*, or peculiar fracture, which is distinct in each. Thus, if I take this piece of flint and break it at random, it presents a glassy or *conchoidal* fracture, and every fragment has a sharp cutting edge; and subdivide it as I may, each portion retains the same character: but if I break this block of chalk, the edge is not sharp, but blunt and dull, exhibiting what is termed an *earthy* fracture. Again, if I shiver to pieces by a blow of a hammer this calcareous spar, every fragment partakes, more or less distinctly, of a rhomboidal form; so true is the remark, that we cannot break a stone but in nature's joinings.

3. CRYSTALLIZATION.—Crystallization may be defined a methodical arrangement of the particles of matter according to fixed laws.* For example—there are nearly 500 varieties

* The definite or mathematical proportions in which substances unite, both as to weight and volume, is a subject of the highest interest, but which does not come within the scope of the present inquiry.

02

196

THE WONDERS OF GEOLOGY.

LECT. III.

of crystallized carbonate of lime, each crystal being composed of millions of atoms of the same compound substances, and having one invariable primary form—that of a rhomboid. Mechanical division is incapable of altering this arrangement; break the fragments as we may, we can only separate them into a rhomboidal figure; nor can this condition be altered except by chemical decomposition. If we pursue the investigation we find by analysis, that every atom of these crystals consists of lime and carbonic acid, each of which is made up of innumerable molecules. “Lime and carbonic acid are also themselves compounds, lime consisting of a metal called calcium and oxygen; and carbonic acid, of carbon and oxygen. Thus these ultimate particles of calcium, carbon, and oxygen, form the indivisible atoms into which all the secondary crystals of lime may be reduced.”*

4. **STRATIFICATION.**—Having previously shown that the disintegration and solution of the most refractory, and apparently indestructible substances, may take place from the conjoined effects of mechanical and chemical agency, we proceed to the consideration of the manner in which the debris of the ancient lands, and the accumulations in the seas, have been converted into the rocks and strata that form the existing islands and continents. The formation of beach and sand, and the deposition of mud and clay in layers or strata, and the subsequent consolidation of these materials into rocks, have already been explained. And here let me remind you, that *strata* are successive layers of detritus spread over each other in such manner, as to allow of the partial consolidation of one bed, before the deposition of another upon it; and a rock is said to be *stratified*, when it presents the appearance of such divisions. Chalk cliffs, and sandstone and limestone quarries, afford illus-

* Dr. Buckland's Bridgwater Essay.

§ 4.

STRATIFICATION.

197

trations of this structure. The original direction of these layers must have been more or less horizontal, for this obvious reason, that in their fluid state they would find their own level, and spread over the surface of the basin into which they flowed; and although they might partake of the inequalities of the depressions in which they were deposited, yet this cause would not affect their general distribution. The strata when accumulated in very thin layers, resembling the seams formed by the leaves of a closed book, are termed *laminæ*; a character that commonly prevails in fluviatile or river deposits: thus the shales, clays, and sandstones, of Tilgate Forest are laminated, and often bear the impress of the waves which have flowed over them (see p. 60).

The contemporaneous beds formed in the same oceanic basin, though often maintaining a general character over very extensive areas, must nevertheless vary considerably. At the present moment, the rivers flowing from different latitudes into the existing seas, must necessarily be producing in the same marine basin accumulations of a very dissimilar character; and the distribution of the detritus, must be greatly modified by the agency of those powerful currents, to which allusion has already been made (p. 70). These elements of variation in the deposits that may be formed contemporaneously within the same ocean bed, serve to explain the origin of similar discrepancies in the contents of the ancient seas. Thus the same system, or formation, may consist of strata containing exclusively marine shells, corals, fishes, &c. intercalated with layers of clays and sands, abounding in lacustrine shells, and plants, and the remains of terrestrial animals and vegetables: the former being strictly of marine, and the latter of fluvio-marine origin; in other words, consisting of deposits brought into the sea by river currents loaded with the detritus of the land.

198

THE WONDERS OF GEOLOGY.

LECT. III.

The oolitic system of Yorkshire affords examples of these alternations of marine and fluvio-marine strata.

5. DISPLACED STRATA.—But though the sedimentary strata have originally been deposited in horizontal layers, yet this arrangement has subsequently been disturbed by expansive internal forces, which have occasioned the elevation of some areas and the depression of others, by which the strata have been broken up, and thrown into every direction, from a slight degree of inclination, to a vertical position.

It will therefore be requisite in this place to explain a few scientific terms which are frequently employed to express these phenomena; for though it is my wish to abstain as much as possible from technical language, it cannot in all cases be avoided without incurring inconvenient circumlocution. Parallel layers or strata, placed horizontally upon each other, as a, b, c, d, in the annexed

LIGN. 32.—ILLUSTRATIVE OF STRATIFICATION.

a, b, c, d, Horizontal strata in a conformable position, resting unconformably on the inclined strata, 1, 2, 3, 4.

1, 2, 3, 4, Strata in an inclined position, and severed and displaced by a fault, f.

diagram (Lign. 32), are said to be conformable; but when strata are superimposed on others which lie in a different

§ 6, 7.

VEINS AND VAULTS.

199

direction, as the series a, b, c, d, on the beds 1, 2, 3, 4,—
as if a set of horizontal volumes were placed flat on the
inclined edges of another series of books,—they are termed
*unconformable*.

6. VEINS AND FAULTS.—But the strata have not only suffered change of position, they have also been rent and broken, and are traversed by cracks or fissures, which in some instances are filled with bones, pebbles, and stalacti- tical concretions (p. 78), and in others with mineral mat- ter, and veins of metalliferous ores. The term *fault* is applied to those fractures and displacements which are accompanied with the subsidence of one part of a mass, and the elevation of another. This is exemplified in the section of the carboniferous strata represented in *Lign*. 32, in which the layers, or seams of coal (1, 2, 3, 4), have been shifted to a higher level on the left hand, though both sides of the rock remain in apposition; *f*, marks the line of fault. Strata, in fact, may be compared with the layers of masonry in a building; beds of clay representing the mortar, and those of harder rocks the courses of brick or stone; while the fissures, veins, and faults, are analogous to the cracks, sinkings, and displacements, produced by the settling of different portions of the edifice after its erection.

7. CHRONOLOGICAL ARRANGEMENT OF THE STRATA.—In the alluvial beds of gravel, sand, and marl, containing the remains of the large herbivorous mammalia, which formed the principal subject of the previous discourse, but few indications of regular stratification are observable; the deposits for the most part consisting of materials that have been transported by rivers or currents, or drifted by ice- bergs, and accumulated in estuaries and bays, or spread along the shallows of sea-coasts. The vast series of ancient deposits we are about to examine, are on the contrary composed of regularly stratified rocks, with occasional

200

THE WONDERS OF GEOLOGY.

LECT. III.

interspersions of fluviatile and alluvial debris, and intrusions of volcanic matter.

It is necessary to premise, that there are three elements of classification applicable to stratified rocks; namely, 1st, their mineral structure; 2dly, their order of superposition; and 3dly, the nature of the organic remains which they contain: the following arrangement is in accordance with these principles. The terms by which the formations and their subdivisions are designated, express the predominant characters by which they are distinguished.

## A CHRONOLOGICAL SYNOPSIS OF THE PRINCIPAL ROCKS AND STRATA.

*(Commencing with the uppermost or newest deposits.)*

### Fossiliferous Strata.

#### I. THE HUMAN or MODERN EPOCH.—ALLUVIUM or DRIFT;
comprising the superficial deposits described in the previous Lecture, and which are characterized by the remains of *Man*, and of animals and plants, contemporaneous with the human race.

*Observations*.—To this epoch belong those superficial accumulations of alluvial debris, and of drifted gravel, sand, boulders, &c., of rocks of all ages, in which, with shells, and bones of existing species of animals, are associated those of the Mammoth, Irish Elk, and other extirpated genera; together with the remains of the more ancient extinct mammalia, that occur in caverns and fissures of various rocks. The line of demarcation between the most ancient beds of this epoch, and the most modern of the following, cannot be strictly defined; and the separation can only be regarded as conventional. In Europe, the elevation of the Alps appears to have been the grand physical event which marked the close of the tertiary period; for in all deposits of later age, existing species have been met with.

#### II. THE TERTIARY EPOCH.—An extensive series comprising many isolated groups of marine, fluvio-marine, and

§ 7.

CHRONOLOGICAL SYNOPSIS.

201

lacustrine deposits, containing remains of animals and vegetables of all the existing orders and families, and many genera and species; and with these are associated numerous extinct species and genera of mammalia, reptiles, fishes, mollusks, &c.

*Observations*.—The formations of this epoch are assemblages of marine, fluvio-marine, and lacustrine strata, either isolated or alternating, and occupying extensive but defined areas. These beds consist of detritus, accumulated during long periods, in bays, gulfs, deltas, and lakes, and in the depths of the ocean. Intrusions of lava currents, scoriæ, and other volcanic products, occur in many of the tertiary formations. The zoological character of this period is the prevalence of terrestrial mammalia.

### III. THE SECONDARY EPOCH.
—An immense series of marine strata, with intercalations of fluvio-marine deposits, and one extensive delta. The most striking zoological characters of this epoch are the almost entire absence of warm-blooded animals, and the abundance of terrestrial and aquatic reptiles. The aggregate thickness of the strata is many thousand feet. The following are the principal subdivisions of the formations comprised in this class.

#### 1. THE CRETACEOUS (or Chalk) FORMATION.
—Marine strata, with but few interspersions of terrestrial or fluviatile debris. In England, the white limestone, termed Chalk, forms the upper strata; marls and clays the medial; and clays, sands, and sandstones, the lower portion of the series. The strata abound in the remains of extinct species of zoophytes, mollusca, echinoderms, fishes, and reptiles. Drifted wood, and some marine plants are, with but few exceptions, the only vegetable exuviae.

*Observations*.—The strata comprehended in the term *Cretaceous Formation*, though differing essentially in their lithological constituents, so far correspond in the nature of their organic remains, as to prove that the whole were formed under the same general conditions; in other words, that the sea and land, and their inhabitants, underwent no essential change during the vast periods in which these deposits were

202

THE WONDERS OF GEOLOGY.

LECT. III.

accumulated; the entire series therefore constitutes, in geological
language, but one formation. With but a very few exceptions, no
vestiges of existing species of animals have been detected.

2. THE WEALDEN FORMATION.—A series of fluviatile deposits of great thickness and extent, with scarcely any interpolations whatever of marine detritus. The lithological characters are, alternations of clays, limestones, sands, and sandstones, with beds of freshwater shells and crustaceans. The peculiar organic features are the abundance of the remains of enormous land and aquatic reptiles, river shells, and crustaceans; and coniferous trees, cycadeous plants, ferns, and other terrestrial vegetables.

*Observations*.—This remarkable series presents the most unequivocal example of an ancient delta, or assemblage of fluviatile deposits, hitherto observed. The strata exhibit throughout the character of river detritus, that has been accumulated in a vast inland lake, which received the drainage of an extensive country, and had but a restricted communication with the ocean. The Wealden extends over the whole of the south-east of England, and a great part of the north of Germany.

3. THE JURASSIC or OOLITIC FORMATION.—A formation of great thickness and extent, consisting of several groups of marine limestones and clays, which abound in extinct marine shells, corals, crinoidea, crustaceans, fishes, and reptiles; with intercalations of fluvio-marine strata, in which are remains of terrestrial reptiles, insects, and plants; and of two *genera of small extinct mammalia*. Layers and beds of coal, and lignite, of considerable extent, occur in some parts of the system.

4. THE LIAS.—Marine clays, shales, and limestones full of shells, crinoidea, crustaceans, fishes, and extinct reptiles; with fluvio-marine beds, containing lignite, trunks and leaves of coniferous trees, and cycadeous plants.

*Observations*.—The Oolite and Lias, though conveniently distinguished by certain species of shells, &c., must be regarded as but one natural series or group of deposits, formed in the bed of an ocean of great extent, into which numerous streams transported the debris of

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203

the land, and its inhabitants. Two genera of marine reptiles, *Ichthyosaurus* and *Plesiosaurus*, swarmed in the Liassic and Oolitic ocean, and their remains abound throughout the system.

5. **THE TRIASSIC (New Red) FORMATION.**—A group of variegated, blue, yellow, and red marls, abounding in gypsum and salt; with sandstones, limestones, and conglomerates, for the most part coloured red by peroxide of iron. Fossils are not abundant, but some peculiar shells, corals, crinoidea, reptiles, and coniferous plants, characterize the series, which is of marine formation.

*Observations*.—This group is the grand depository of rock salt in England. In Germany the strata form a triple series (whence the name *Triassic*) of variegated marls, limestones, and sandstones, which contains peculiar fossil remains. The separation of these deposits from the following has been made in consequence of certain genera and species of animals, which abound in the more ancient rocks, being entirely absent in the Triassic, and all the subsequent formations; and also from some genera, especially of Batrachian and other reptiles, appearing for the first time in strata of this age. The Triassic is therefore, at present, regarded as the lowermost, or base line, of the formations comprised in the secondary epoch; the faunas and floras of the older strata being entirely distinct.

#### IV. THE PALÆOZOIC EPOCH.
— Under this general term are comprised all the ancient fossiliferous strata, the organic remains of which, as the name indicates, belong almost exclusively to species or genera that are wanting in all the newer formations.

6. **THE PERMIAN (Magnesian Limestone) FORMATION.**—
A series of marine strata, consisting of limestones charged with a large proportion of magnesia, red marls, conglomerates, and slates. These contain peculiar shells, fishes, and reptiles.

*Observations*.—This group of deposits was formerly named the *Lower New Red*, or *Magnesian Limestone*; but, as either of these terms is ambiguous, that of Permian (first suggested by Sir R. Murchison, from the large development of the series in the ancient kingdom of Permia in Russia) is now generally adopted. In this group are

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included all the deposits that intervene between the Triassic above, and the Carboniferous systems below; and these contain but one type of animal and vegetable life. Remains of reptiles occur, and are the most ancient, or earliest, of this class of animals.

7. THE CARBONIFEROUS FORMATION.—Sandstones, grits, shales, clays, and layers of ironstone, alternating with beds of coal, form the upper series;—limestone and flagstone, with layers and nodules of chert, abounding in marine shells, crinoidea, and corals, constitute the lower division of this extensive group of deposits; the total thickness of which is many thousand feet. The coal strata are remarkable for the abundance and peculiarity of the terrestrial trees and plants, of which they are almost wholly constituted; remains of insects, fishes, and crustaceans of an extinct family have been found in this formation.

*Observations*.—These strata, so interesting to the botanist from the richness and peculiarity of their fossil flora, and to mankind in general for the inexhaustible supply of fuel which they yield, appear for the most part to have been deposited in salt water; for the beds of coal are generally associated with marine shells, corals, &c.; and there are only a few local intercalations of layers of fresh water shells. The flora of the coal is the most striking feature of this system of deposits.

8. THE DEVONIAN (Old Red) FORMATION.—An assemblage of quartzose grits, sandstones, marls, and conglomerates, largely charged with peroxide of iron, which imparts to the whole a dull red colour; with beds of coralline marble, and laminated micaceous sandstones; this formation was formerly, from its colour, denominated the Old Red sandstone. Shells, corals, fishes, crustaceans, and cephalopoda, of peculiar species and genera, are the prevailing and characteristic organic remains.

*Observations*.—The term Devonian, which has been substituted for that of Old Red Sandstone, as being more precise, is derived from the geographical development of this group of rocks in Devonshire, England. The red conglomerates, which constitute a well marked lithological character, consist of water-worn fragments of slate with

§ 7.

CHRONOLOGICAL SYNOPSIS.

205

quartz pebbles, cemented together by red sand and marl, and have
evidently resulted from the destruction of ancient slate rocks; they are
in many instances mixed up with volcanic ashes and scoriae. Beautiful
coralline marbles occur in South Devonshire, and in some localities
fishes of a very remarkable conformation, belonging to genera unknown
in any other system.

9. **THE SILURIAN FORMATION.**—Marine limestones, sandstones, shales, and calcareous flagstones, abounding in shells, cephalopoda, corals, and crustaceans, (especially of the extinct family of Trilobites,) of peculiar types, constitute this important and extensive system of marine deposits. A few traces of fuci are the only known vegetable remains.

*Observations*.—This system (which was first established by Sir R. Murchison) is entirely of marine origin, and many beds are aggregations of corals, shells, &c. cemented together by calcareous matter. The organic remains are numerous, and afford characters by which the system is conveniently subdivided into two groups; but only one general organic type prevails throughout. The lowermost beds contain but very few fossils, and insensibly pass into sedimentary deposits, in which no traces of organic existence have yet been discovered.

10. **THE CUMBRIAN (Schistose) FORMATION.**—A largely developed series of slate rocks, and conglomerates, several thousand yards in thickness; the uppermost beds contain a few shells and corals, which are not distinguishable from Lower Silurian species.

*Observations*.—This system includes all the sedimentary deposits between the lowermost of the Silurian and the uppermost of the ancient metamorphic rocks. It has been named by Professor Sedgwick *Cambrian*, and *Cumbrian*, from the large development of the strata in Wales and Cumberland. But as no assemblage of organic remains specifically distinct from the fossils of the Silurian has been detected, a zoological line of separation cannot at present be drawn between the lower Silurian and the Cambrian deposits. Until characteristic fossils be met with, the group, therefore, as a distinct system, rests on the geological position and lithological characters of the strata so largely developed in Cumberland. Future researches will, in all probability, lead to the discovery of peculiar organisms, more ancient than the Silurian types.

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THE WONDERS OF GEOLOGY.

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## Hypogene Rocks.

### I. METAMORPHIC; or stratified crystalline rocks.

*Observations.*—These rocks are presumed to be sedimentary deposits, that have been metamorphosed or changed in mineral structure from long exposure to a high temperature under great pressure; by which their constituent substances have passed into new combinations, and all traces of any organic remains they may have contained entirely obliterated. The name *Hypogene*, or *nether-formed* rocks, (suggested by Mr. Lyell,*) refers to the condition under which these rocks are supposed to have originated. They are subdivided into two groups:

1. *Mica-schist system*; comprising mica-slate, quartz rock, hornblende-schist, and crystalline limestone.

2. *Gneiss system*; layers of gneiss, quartz rock, syenite, &c., alternating with clay-slate, and mica-schist.

*Observations.*—The *mica-schist* is a slaty rock, composed of mica and quartz, and often passes insensibly into clay-slate. *Gneiss* is formed of mica, quartz, and felspar, has a laminated structure, and often occurs in distinct layers, or strata.

### II. PLUTONIC; or amorphous crystalline rocks.

*Granitic System*; comprising *Granite*, *Porphyry*, and certain Trap rocks.

*Observations.*—The well known rock, termed granite, which, like gneiss, is composed of mica, quartz, and felspar, is not stratified or disposed in layers, but occurs either in amorphous masses protruded through newer rocks, or in dikes and veins, which often traverse strata of all ages. The traps, porphyries, &c., included in this system, have the character of mineral masses, which have been rendered crystalline by intense fusion, under great pressure, in the depths of the earth.

## Volcanic Rocks.

1. *Trap, Basalt, Tuff, Toadstone, and Obsidian*, or *glassy lava*:—products erupted from ancient volcanoes.

* From ὑπο, under, and γινομαι, to be born; see "Elements of Geology," p. 20.

§ 8.

GEOLOGY OF ENGLAND.

207

2. Lava, Scoriæ, Pumice, Ashes, &c.:—products of modern dormant and active sub-aerial volcanoes.

*Observations*.—In this class are placed the mineral productions of fire, or subterranean heat, ejected from beneath the surface, through fissures or rents, whether in ancient or modern times. These igneous materials are of all ages; they traverse alike the hypogene rocks, and the sedimentary strata, as well as the most recent deposits.

LIGN. 32.*—DIAGRAM OF THE RELATIVE POSITION OF THE ROCKS AND STRATA IN ENGLAND.

1. Tertiary strata.

2. Secondary.

3. Palæozoic.

4. Older Palæozoic.

5. Metamorphic rocks.

6. Plutonic (granitic) rocks.

8. GEOLOGY OF ENGLAND.—By an inspection of the Geological Map of England, *Plate I.*, it will be seen that the principal formations successively appear on the surface, somewhat in their true chronological order (*Lign. 32*%), as we pass from the eastern or south-eastern part of the Island to the west or north-west; as, for example, from the coast of Suffolk to Cardigan Bay, or from London to Liverpool. Thus, the Tertiary deposits are spread along the eastern and south-eastern maritime districts; and in proceeding in a north-westerly direction, we successively travel over the Cretaceous, Oolitic, Triassic, Carboniferous, Devonian, Silurian, and Cumbrian systems; and, lastly, metamorphic and primary rocks appear.

This distribution of the strata has imparted a peculiar character to the physical geography of England. The Alpine or mountainous districts, which extend north and south along the western portion of England and Wales, from Cornwall to Cumberland, are formed by the elevated

208

THE WONDERS OF GEOLOGY.

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masses of the metamorphic, Cambrian, and Silurian rocks. These are succeeded by a band of the carboniferous and triassic strata, with a few intrusions of metamorphic and plutonic rocks, that stretches from the coast of Devonshire, through the midland counties by Leicestershire and Derbyshire, to Newcastle. On the south-east of this tract the oolitic and cretaceous formations, chiefly made up of argillaceous and calcareous deposits, constitute a diversified agricultural district, which extends from the southern shores of Dorset and Hants, to the coast of Yorkshire. The Wealden is exposed in the area between the ranges of the north and south downs of Kent and Sussex. The Tertiary overlie the uppermost secondary strata; they occupy the eastern and south-eastern maritime districts, and form the area on which stands the metropolis of England; they are covered in many places by the drift and alluvial debris, which contain mammalian remains.

After this comprehensive view of the leading characters of the principal rocks and strata of which the present islands and continents are composed, we proceed to a more particular examination of the several formations in their natural sequence, or order of superposition.

## 9. DRIFT AND ALLUVIUM OF THE MODERN EPOCH.
When explaining, in the previous Lecture, the circumstances under which the remains of terrestrial quadrupeds occur in the superficial deposits, the nature and origin of those beds were briefly described. It is necessary, in this place, to offer a few remarks on the phenomena presented by the drift and other alluvial accumulations of the modern epoch.

The drift and alluvium consist of beds of loam, sand, and gravel, variously distributed; being, in some instances, spread over extensive areas; in others, forming mounds, ridges, and hills of low elevation; in others cresting the summits of abrupt and lofty escarpments: sometimes radiating, as it

§ 10.

ERRATIC BOULDERS.

209

were, in broad streams from mountain chains; in others constituting a series of terraces and platforms, as if originating in gradual and successive elevations of a sea-coast. The composition of these deposits is as various as their origin. They are generally made up of the detritus of rocks of all ages, promiscuously intermingled, and varying in lithological composition from fine earth and sand, gravel, and pebbles, to large boulders, and rocks many tons in weight. They sometimes consist of the debris of the strata of the adjacent country, but more frequently of rocks that are situated in very remote regions.

It will be apparent to the intelligent reader, that deposits varying so much in mineral characters and structure, must belong to very different epochs, and have been accumulated under very dissimilar conditions. Some are unquestionably ancient shingles or sea-beaches (see p. 113): others are sheets of detritus that have been formed along shallow coast-lines, or on the borders of rivers, lakes, deltas, and estuaries: others consist of ridges and mounds of debris heaped up by sudden deluges, or powerful floods that have swept over low tracts of country, or by subaqueous currents, or waves of translation: and others have been produced by the agency of frozen water, either as floating icebergs, or as glaciers. By the nature and state of the shells, bones, and other organic remains, when present, and of the gravel, pebbles, boulders, &c. of which the accumulation of drift or alluvium may consist, the origin of the materials, and the age and character of the deposit, may be more or less satisfactorily determined.*

10. ERRATIC BOULDERS.—But there is another class of phenomena which must not be passed over without comment. In many countries rounded and angular boulders of

* Mr. Lyell's "Principles of Geology" should be consulted for a full exposition of this subject.

P

210

THE WONDERS OF GEOLOGY.

LECT. III.

great size are very abundant, either imbedded in the allu-
vial sands and gravel, or spread over them. Vast areas,
literally covered with boulders, occur in many parts of
Europe; enormous masses of stone lying exposed on the
surface of the ground, as bare as when left by the retiring
waters, and appearing as—

"Huge rocks and mounds confus'dly hurl'd,
The fragments of an earlier world."

Many of these boulders are of such magnitude, as more
properly to be termed rocks; being from twenty to forty
feet high, and weighing many hundred tons.*

Connected with the boulders, and beds of drifted gravel
and other coarse detritus, is the occurrence of deep grooves,
furrows, striae, and scratches, on the upper surface of many
rocks, and on the sides of such as flank narrow gorges and
valleys, or form the slopes of hills and other inclined planes;
appearances manifestly resulting from the passage of peb-
bles, grit, boulders, and angular fragments of hard stone,
over exposed surfaces of rocks and strata; in some instances
by the action of currents and floods, in others by glaciers
and floating ice. In some countries the boulders are not far
distant from their parent rocks, and their course and origin
may be readily traced; but throughout a great part of
Europe, Asia, and America, these waterworn masses
must have been derived from very remote regions; and
they are distributed in such manner, as to show that
their transport could not have taken place under the

* There is a large boulder in the plain near Mount Sinai, which
monkish legends identify with the rock of Horeb, whence Moses, by a
stroke of his rod, miraculously raised a stream of water for the parching
Israelites. It is a block of granite, nearly twenty feet square, which
has probably been derived from the neighbouring mountain.—
Mr. Greenough's "Critical Examination of the First Principles of
Geology:" a work abounding in facts and comments of the highest
interest.

§ 10.

ERRATIC BOULDERS.

211

existing geographical distribution of the land and water, but must have been effected when the present dry land was beneath the sea, and subaqueous currents and icebergs were in active operation. By the former, the accumulations of sand, mud, and gravel may have been deposited; and by the latter, the blocks, however large, may have been detached and transported from their parent rocks to the distant regions they now occupy.* The general course of the drift and erratic boulders in the northern parts of Europe and America, appears to have been from the north and northwest towards the south-east; as if the materials had been brought by polar currents from the northern to the southern regions; hence the term "northern drift" is often employed to designate the alluvium and boulders which belong to this category.

Over vast regions of the north of Europe, in Poland, Russia, &c. erratic boulders, chiefly of crystalline and palæozoic rocks, are profusely scattered over the beds of alluvial debris, and upon the exposed surfaces of the older strata. In Sweden, these phenomena are strikingly displayed. The transported blocks occur in clusters, on mounds and ridges of sandy loam termed *osar*, sometimes at a height of from 200 to 300 feet above the adjacent plains. The origin of these widely spread erratic boulders is the granitic and palæozoic rocks of Scandinavia. The recent travels and investigations of Sir R. Murchison have afforded a satisfactory solution of this problem. It appears that at a very remote period, the granitic rocks of Scandinavia were upheaved, and their pinnacles split and shattered to pieces, by the expansive effect of ice; and the fragments and detritus that were carried into the sea by the action of glaciers and

* The power of icebergs in transporting blocks and immense quantities of earthy materials, is graphically elucidated in Mr. Lyell's Principles of Geology, and Sir R. Murchison's Silurian System; see also several memoirs in the American Journal of Science.

P 2

212

THE WONDERS OF GEOLOGY.

LECT. III.

torrents, were urged on by subaqueous currents, and large masses transported by ice-floes during the summer season, and deposited on the sea bottom hundreds of miles to the southward. These submarine deposits, covered here and there by erratic boulders dropped by the melted icebergs, were subsequently elevated above the waters, and now constitute the vast plains of Russia and other parts of northern Europe; the transported blocks remaining as durable monuments of the physical changes which converted the ocean-bed into dry land.*

In England there are no tracts covered by boulders of such magnitude as to be comparable with the instances above adduced; but the same phenomena are observable on a smaller scale, in various districts. Boulders of the granites, porphyries, syenites, and slaty rocks of the Cumberland mountains, are dispersed northward towards Carlisle, southward towards the bay of Morecombe, and eastward to the foot of the Pennine chain. They may be traced from Lancaster "at intervals through the comparatively low country of Preston and Manchester, lying between the sea and the Yorkshire and Derbyshire hills, to the valley of the Trent, the plains of Cheshire and Staffordshire, and the vale of the Severn, where they occur of considerable magnitude."† The quartz rocks of the Lickey Hills, between Birmingham and Bromsgrove, in Worcestershire, have yielded immense beds of pebbles, which are thickly spread to the south and east, and even into the valleys of the Evenlode, Cherwell, and Thames, and into the gorge of the chalk downs as far as Reading.‡

* See "Geology of Russia," for a full consideration of the "Scandinavian Drift," and the phenomena connected therewith.

† Professor John Phillips's "Treatise of Geology."

‡ See "A Description of the Quartz Rock of the Lickey Hill in Worcestershire, and of the strata immediately surrounding it;" by the Rev. Dr. Buckland.—*Geol. Trans.* vol. v. p. 506. This is a masterly

§ 11.

THE TERTIARY FORMATIONS.

213

In some of the examples quoted, the surface of the
country is not unfavourable to the passage of such materials
as compose the drift, if urged on by floods or sudden rushes
of water; and if it be assumed that the Cumberland moun-
tains were of sufficient altitude, during the boulder period,
to accumulate glaciers, the torrents produced by the melting
of the ice in the summer seasons, would account for some of
these beds of transport. But in many instances the physical
configuration of the surface forbids this interpretation; and
the subaqueous condition of the country, and the action of
currents, waves of translation, and ice-floes, offer the most
satisfactory explanation of the phenomena.*

11. THE TERTIARY FORMATIONS.—We now enter upon
the consideration of the Tertiary Formations, — those
ancient deposits of seas, rivers, and lakes, which belong
to the period immediately antecedent to that which is
marked by the prevalence of existing species of quadru-
peds, and of extinct elephantine forms, as the Mammoth,
Mastodon, &c. and subsequent to the deposition of the
uppermost secondary formation, the Chalk.

The discoveries of MM. Cuvier and Brongniart, about
thirty years since, in the immediate vicinity of Paris, first
review of some of the principal examples of drift in that part of
England. The young geologist in perusing this memoir must, how-
ever, bear in mind, that the facts so graphically described, do not afford
any evidence of a recent universal deluge; a hypothesis maintained
by the most eminent geologists of that period (1821).

* Our limits will not admit of any further notice of the erratic blocks of England; but it may interest the reader to know that there is a very instructive example of a ridge of drift, probably deposited by an ice-floe, in the immediate vicinity of London, namely, Muswell Hill, beyond Highgate; which is capped with an alluvial bed of pebbles, boulders, and fossils of rocks of all ages, from the chalk to below the carboniferous limestone inclusive. The collections of Mr. Wetherell and Mr. Toulmin Smith, of Highgate, contain characteristic fossils of the oolite, lias, mountain limestone, &c., with blocks and pebbles of granite, gneiss, and other primary rocks, all obtained from Muswell Hill.

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THE WONDERS OF GEOLOGY.

LECT. III.

directed attention to the important series of strata now dis-
tinguished by the name of *Tertiary* (see p. 201). The
fossil extinct pachyderms, whose bones abound in the
gypsum quarries of Montmartre, were by the genius of
Cuvier recalled, as it were, into existence, and the philo-
sophers of Europe saw with astonishment, whole tribes of
unknown and extraordinary types of being, disinterred
from rocks and mountains, which had previously been
considered as destitute of scientific interest. Analogous
strata, some of a marine, and others of a lacustrine and
fluviatile character, were soon found to be spread over
many parts of the continents of Europe and America;
forming a series so extensive, and requiring such a lapse
of time for its production, that the Chalk, hitherto regarded
as comparatively of modern origin, is carried back to a
period incalculably remote. The tertiary system may be
said to constitute a series of strata which unites the
present organic kingdoms with the past; for while the most
ancient contain species related to forms that occur in the
secondary formations, the most recent insensibly glide into
the modern deposits, and abound in fossil remains of recent
species of animals and plants, associated with many that
are not now known to exist.

Mr. Lyell has adopted a classification of the tertiary
strata, founded on the relative proportion of recent and
extinct species of animals, which any given series of beds
may contain; and as shells occur in most of the strata in
great abundance, and in good preservation, he has selected
these types of animal organization, as the distinctive charac-
ters of the principal subdivisions. Though in the present
state of our knowledge this method is of great utility, it
will probably require considerable modification; and, per-
haps, must hereafter be altogether abandoned; for it cannot
be doubted, that strata in which no recent species have yet
been found, may yield them to more diligent and extended

§ 12.

CLASSIFICATION OF THE TERTIARY.

215

researches; and the relative proportions of recent and extinct organisms, may be found to occur in a very different ratio, from that which is assumed as the basis of this arrangement.*

12. CLASSIFICATION OF THE TERTIARY.—According to this system the tertiary strata form three principal groups, each characterized by the relative proportion of the recent and extinct species of shells; and a nomenclature has been

* This anticipation is already in some measure confirmed; for existing species have been found in the most ancient tertiary deposits: and several secondary shells, fishes, &c. in tertiary strata, and even living in the present seas. An eminent Italian naturalist (Dr. A. Philippi), in an elaborate review of the mollusca of the South of Italy in reference to the shells of the tertiary period, has come to the following conclusion:—"That the tertiary formations of Southern Italy will not admit of any chronological subdivisions, for we cannot "trace the limits which separate the tertiary from the diluvial, nor "the diluvial from the existing period; neither can we make use of "the terms eocene, miocene, and pliocene, with reference to the South "Italian deposits, so far as these expressions refer to a per centage of "extinct to existing species; and we would suggest that such terms "are also uncertain and arbitrary with regard to other districts."—*Philippi: Proceed. Geol. Soc. Feb. 1846.*

Immediately after the last tertiary deposits, the modern period begins, when all the now European species first appear: the cavern animals and some of the large pachyderms, are referable to the earliest age of this era. Inundations, more or less local, occasioned by the elevation of some tracts of dry land, and the subsidence and submergence of others, filled up the caverns and destroyed the races of carnivora.

In the diluvial gravel in the Canton of Geneva, there have been found bones of many species of animals which still inhabit the surrounding country; as for example, the mole, fox, sheep, ox, pig, rat, mouse, green frog, lizard, &c. These remains occur beneath distinctly stratified beds of gravel, at a depth of ten feet below the cultivated soil. These animals must therefore have been indigenous to this part of Europe, when the deposition of the diluvium was going on, and prove the continuance of species uninfluenced by those geological changes which occasioned the last elevation of the land.—*M. Pictet on the Diluvial Deposits of the Canton of Geneva.*

216

THE WONDERS OF GEOLOGY.

LECT. III.

adopted expressive of the characters upon which the classification is founded. These divisions are as follow :—

1. THE PLIOCENE (*signifying more new or recent*).—Tertiary strata, in which the shells are for the most part recent; containing about ten per cent. of extinct species; these beds are subdivided into the newer and older *pliocene*.

2. THE MIOCENE (*denoting less recent*) :—containing a small proportion, about twenty per cent., of recent species of shells.

3. EOCENE (*signifying the dawn of recent, in allusion to the first appearance of recent species*) :—containing very few recent species; not more than three or four per cent.

The marine are in many instances associated with freshwater deposits, and the general characters of the system are alternations of marine with lacustrine strata. The districts occupied by these beds in Europe, are exceedingly variable in extent, as Mr. Lyell has shown in a very ingenious map of the tertiary seas ;* and it appears certain, that during the tertiary epoch, there were large areas alternately the sites of freshwater lakes and inland seas, and that these transitions were dependent on oscillations in the relative level of the land and water.

13. FOSSIL SHELLS.—The geological evidence afforded by fossil remains has already been exemplified; but our remarks have hitherto in a great measure been restricted to the relics of terrestrial quadrupeds. The shells of molusca, however, from their durability, often escape obliteration under circumstances in which all traces of the higher orders of animals are lost, and they become, therefore, of the utmost importance in the speculations of the geologist. In loose sandy strata, they often occur in a high degree of perfection; in mud and clay, in a fragile state; in some instances they are silicified; and many limestones are wholly composed of shells, cemented together by calca-

* Principles of Geology, vol. i. p. 214.

§ 13.

FOSSIL SHELLS.

217

reous spar. Molluscous animals* are divided into *mollusca*, properly so called, which are covered with a single shell, as snails, periwinkles, &c. ; and *conchifera*,† having a shell with two valves, as oysters, scallops, &c. The former are of a higher organization than the latter, having eyes, and a distinct nervous system; the latter have neither eyes nor head, and are therefore called *acephala*.‡ Some genera are herbivorous, living exclusively on vegetables; others are carnivorous; and many have a retractile proboscis, furnished with a rasp, by which they can perforate wood, shells, stone, and other substances. The shells of the carnivorous testacea are also generally provided with a channelled or grooved beak, for the reception of the fleshy syphon by which the sea water is conveyed to the respiratory organs (*Lign.* 38, *fig.* 3, 4, 5); while the herbivorous have the opening of the shell entire (*Lign.* 39, *fig.* 3, 5, 6, 7). Some tribes are exclusively marine, others can only live in freshwater, while many are restricted to the brackish waters of estuaries. Their geographical distribution is alike various: certain highly organized forms (the *Cephalopoda*) inhabit deep waters only, and are provided with an apparatus by which they can rise to the surface; while others are littoral, that is, live in the shallows along the sea coasts; many exist in quiet, others in turbulent waters; some are gregarious, like the oyster, while others occur singly or in small groups. All these varieties of condition are more or less strongly impressed on their shelly coverings, which may be regarded as their external skeletons; and the experienced conchologist is generally enabled, by the peculiar characters of the shell, at once to determine the economy and habits of the animal, and consequently the physical conditions in

* Soft-bodied animals.

† Shell-bearing animals.

‡ Having no head.

§ Medals of Creation, vol. i. chap. 12, p. 363.