GEOLOGY
ON: PRINTED BY
NEW-STREET SQUARE
LOND
SPOTTISWOODE AND co.,
AND PARLIAMENT STREET
Ct
By SII
‘Veré scir
e’—PLa
PRINCIPLES OF GEOLOGY
OR THE
MODERN CHANGES OF THE EARTH
AND ITS INHABITANTS
CONSIDERED AS ILLUSTRATIVE OF GEOLOG
By SIR CHARLES LYELL, Barr. M.A, F.R.S
‘Veré scire est per causas scire ’"—BA
my rocks are oe primeval, es the daughters of Time ’—LiInN&US, Syst. Na
2
be k
the laws which direct
the
e the economy of el has been uniform, and her
e rivers and the rocks,
ston
» Stockholm, 1748, p. ¢
d all the rev Pe. of the glob
gs that 1 have aleted the Sater ‘al movem
inent ve been changed in all their cena
“The
ed. 5
Te
those Eiahses, and the ete to which they are subject, have bara invariably
laws are the eat thin
the s and the cont
e’—PLAYFAIR, Jllustrations of the Huttonian Theory, § 374
TENTH AND ENTIRELY REVISED EDITION
In Two VotumEs.—Vot. II
and Woodcuts
Illustrated with Maps, Plates
LONDON
JOHN MURRAY, ALBEMARLE STREET
me
1868
The right of translation is reserved
addit:
List 0
Vol;
Ninth
Edition,
PREFACE
for TENTH EDITION.
In the Preface to the First Volume I gave a list of the dates
of publication of the successive editions of this treatise, as
well as of my ‘ Elements of Geology’ and my ‘ Antiquity of
Man,’ and pointed out the relation of these two last works
to the ‘ Principles.’
In the same Preface I gave a list of the chief additions
then made for the first time; pointing out, so far as was
possible, the corresponding pages in the ninth edition; so
that readers already familiar with the earlier editions might
be able at once to refer to what was new.
I now subjoin a similar list of the chief alterations and
additions introduced for the first time into this tenth edition.
List of the Principal Additions and Corrections in the Second
Volume of the Tenth Edition of the ‘ ee of ae
“icin | tenth | Sava aa cia RUM
ean Edition, | . Additions and Corrections.
| Vol. AE
which I had first visited thirt y years before, in 1828.
| |
| |
424 | 47 | Of my re-examination in 1857 and 1858 8 of this volcano,
| h
‘eae
| ae Re . a double axis of age is Sane (p- 9)
)
| of some ancien valleys on Etna to the former structure
| of the none is considered (p. 40).
Ninth |
Edition. | |
Page
488
Chap.
XXXIV, |
mn
part
Tenth |=
maith,
Vo Hat |
Page
261
9Q9
283
PREFACE
TO THE TENTH EDITION.
Additions and Corrections.
| Eleven new woodcuts usta Sion XXVI, Shoe
| chiefly from my paper on Etna, communicated to the
| Royal Society in 1858.
| An account is here given of the changes produced by the
| recent eruption i in ans Gulf of Santorin in February 1866,
| with a bird’s-eye vi
| An account of the
re Pe upheaval and
ipelago, is given on the authority a Messrs. Hobe
| Walter 1 Mantel and I’, A. Weld. i
| of 9 feet n the rocks is described. map of the region
| Sona iy the same earthquake § 1s appende
earthquakes in Calabria in 1783 and
of the same.
corte in New Zealand in 1855, me
subsidence of land in
5/, the origin ae
ree ne
gr count is given of Mr. Robert Mallet’s
proposed Soa ie ae Sd atic
n the earth’s crust from which the shocks may proceed.
| | J i ae on the truncation of the cone of Papandayang in
|
|
|
|
nets observations made to determine whether a change
| is going on in the relative level of land and sea in
ae weden
| Messrs. Gw pee and Torell on shells of the Glacial
| Period in the begs ed, in Sweden
| The hypothesis of a change in the axis of rotation of the
| external shell e ane one considered as a possible cause
of change of cl
| This Thirty “eond Chaps
nee crys-
| aks anc ee were Be in the lower ke: of the
xpense a a central nucleus cooling
en up, now that oranite
is found to be of all ages, ire he e metamorphic rocks to
be altered sedimentary Bava implying the denudation
of a previously solidified crust.
| The Thirty-third Chapte been in great part recast.
| t is shown that the latest chemical observations on the
| products of fe j
ee to = continually lost by the planet by
ne fetid on in ta Space, may perhaps be restored by solar
magnetism in connection with electricity and chemical
| action
| | rie oreater part of this Thirty-fifth Cl hapter is new.
| objections originally urged against Lamarck’s the
transmutation — and his replies are considered.
question whether, if new species are created from time to
| time, their first appearance would have been witnessed
y y the naturalist, esti
Remarks are offered on the ‘V estiges
g
ninth | Ec
paition- i
X
mi hate
ated 4, ik
pre dy
Fe ebry 7 A
-apanday ang in
ether a mane
nd and sea i
of the Glacial
le
-otation of the
possible cause
re-written and
rphic rocks t0
he denudation
art recas
t e
an
ed ina ie
t by
the pl er olat
re - by ni
iD
Ninth
Edition. |
Page
| Edition.
| Vol It. |
Page
COR)
r &
Or Ha
co
ost
Co
‘Tenth |~ j
PREFACE TO THE TENTH EDITION.
Additions and Corrections.
of Creation,’ and on the eeseo of ‘ Natural Selection, as
advocated by Mr. C. Darwin and Mr. A. Wall }
change of opinion pr oduce d by Mr. Darwin’s work o
‘The Origin of Species’ is ae out, and Dr. H sates
views on the formation of specie n the vegetable world
by variation and selection are nbtie od.
This Thirty-sixth Chapter is for the most part new. It con-
tains an explanation of Mr. Darwin’s views on the for-
mation of new races by selection, both unconscious and
eee whethe xe eee or note under dome a
cation. octr t ‘Pax the manner
w ae dipalest die “a nw see reviv sae in the onepeaie
of cro s-breeds, is also alluded to. Likewise the fact that
aan parts of animals or ioe may be made to vary by
selection, while other parts of the same remain ve Me
‘aus ng hele of plants and animals is a ons sidered
on the en ee igin of s
This Thirty enth Cha he for the gee part new.
It treats of natural as sabia to artificial selection. The
ae of => to multiply bey ard ee meal
gole for life, an onditions on
ined.
R e, and
species are compared. It is shown that alternate gene-
ration will not explain the foie of origin of new species.
on the geographical distribution of
specie e-written. The six great provinces of
distinet _apecies ab ieee mammalia are chiefly dwelt
upon, agreement of the limitation of the species
ot ies sad ote, and even of the Ze eee animals
inte
Chapter iat on tl : eicrit ag ar
1
and corrections, fr fro
This woodcut of the Lemming or - “i Ma
from a specimen now living it in the Zoological Gardens of
London, has been substituted for a less ‘etetil x represent-
ation of the same animal given in former editions.
The Fortieth Chapter, on ne SGaiantied distribution and
oo of fish, testacea, insects and hee is for the
most part the same as in the ninth edition. But the
Pity ie additions and alterations have oe n mad
rmot, taken
immersed in salt water without injury, p- 391.
rown on source of the gulf-weed or sargassum, p. 392.
Darwin on seeds transported by birds, p.
The Forty-first Chapter is entirely new. It: ae of insular
floras and faunas considered with reference to the origin
isl
and Canaries, their volcanic origin an
Miocene bes are first treated of, and then the extent to
vill
Ninth
Edition
~ Page
663
Tenth |
Edition. |
Vol. II. }
PREFACE TO THE TENTH EDITION.
Additions and Corrections.
Page |
which the species of mammalia, birds, nips: land- a
and plants, agree or d with con
islands of the same archipelago, is shown to
mistake relation to the a re enjoyed by each class
of ¢ o the ocean. The bea ing of this relationship
on ae Shes ry of the origin of wieics by variation and
| ‘natural selection’ is pointe
| The Forty-second Chapter, on the extinction of Species, is
| re- A ae from the old edition with some fe
|
|
m
| na,
and 462. Mr. Tra on the spread of foreign plants j in
New Zealand, p. 45:
The whole ae this Forty-third Chapter, on man, considered
with re Se e to his origin and aes | distrbuto,
| is new, ith the exception of the first five
| The ‘antiquity of the more marked human a) and the
| geographical range with that of the
chief zoological provinces, is co
| igi ma.
theory of progressive development and of
Darwin’s okey of natural selection on the derivation of
from the inferior animals, i 1s treated of.
narine et s Bournemouth,
e south Sie of Rapes ase are
Ds: Dawson’s des
here
h is given, in retrospective chronological order,
of the remains of man and his works whi ch belong to to the
ages of Bronze and Stone. Implements of the Neolithic
Period—of the antecedent Rein- deer Period—and lastly of
1
oast of Hampshire and the Isle of Wie ech is oe :
The age of the ery in the upraised marine strata
Cagliar ari, on the south coast of pisdagien is , aie issed,
The F orty- -ninth Chapter is re-printed from the corre espond-
ing or concluding Chapter of the ninth edition, with some
tions in the n
} on the
fferent genera grow. Allusion is also made,
. 609, to the lar oe quantity of limestone in the oldest or
Pianieniae series of rocks in Canada.
CHARLES LYELL.
73 Hariry Street, Lonpon:
March 1, 1868.
External
Marine
Melting
Valleys
Voleanie ]
Barre
of Volea
Patthouak
SPherjo
ecieg at!
Cc
‘lations:
DY vari uti
A Variation ia
‘on of Species, i,
1€ few W audition
following: <i
He lena. } &, Dp. 452
foreign p| Plants in
man, considered
cal a Bes:
> pag
vith that of the
e as:
sed. The
opment “a ¥
ne derivation of
of,
3ournemouth,
Be
est on the Bay
yELL.
CONTENTS
THE SECOND VOLUME.
BOOK. Il.—continued.
CHAPTER XXVI.
ETNA.
External Physiognomy of Etna—Lateral Cones—Their successive Obliteration —
ine Strata at Base of Etna of Newer Pliocene Date—Oldest Volcanic Rocks
of same Date—Fossil Plants of Living Species in ancient Tuffs of Etna—Val
Del Bove on the Eastern Flank of Etna—Internal Structure of the Mountain
and Proofs of a Double Axis of Eruption—Want of Parallelism i in the ancient
the Great Cone—Eruptions of Etna of Historical Date—Erupti
Rossi, ae —Scenery of the Val Del Bov ee a of 1811 an aes That
of 1852—Changes which it has effected in the Val Del Bove—Cascades of Lava
in re = di Calanna—Inclined Lava of Cava Grando_F lood ene by the
D cier preserved by a Covering of Lava—Ancient
. : : . PAGE 1
Melting of Ice in 1755—Glac
Valleys of Etna—Antiquity of the Cone of Etna
CHAPTER XOeviil
VOLCANIC ERUPTIONS—concluded.
Voleanic Eruption i in Iceland in 1783—New Island thrown eee Currents of
Skaptar Jo ae in same Year—Their immense Vol ruption of Jorullo in
Mexico—Humboldt’s ee of the Convexity of the Plain of Malpais—Eruption
of ae n Java—Submarine Volcan os—Graham wae formed in 1831
—Voleanic ape aes —Submarine Eruptions in Mid Atl —The Canaries
t up in Lancerote, 1730-36— Santina and a ee Eruptions
—Barre Island in the ce of Bengal—Mud Volcanos—Mineral pe
of ee Products. ‘ 48
CHAPTER XXVIII.
EARTHQUAKES AND THEIR EFFECTS.
Earthquakes and their Effects—Deficiency of Ancient Accounts—Ordinary Atmo-
spheric Phenomena—Changes produced by Earthquakes in Modern Times
x CONTENTS OF THE SECOND VOLUME.
considered in Chronological Tl pene in New Z Zealand—Permanent
Upheaval and Bite be spes of Land—A. Fault produced in the Rocks —Earth-
quake in Syria, ee in Chili in ri and 1835—Isle of Santa
Maria pee ten Feet—Chili, 1822—Extent of Cor ntry. elevated —Ka arthquake
ie sie in 1819—Subsidence in the Delta of ii Tidus “Tak of Sumbawa in
15—Earthquake of Caraccas in 1812—Shocks at New Madrid in 1811 in the
PAGE 8()
ae of the Mississippi
CHAPTER XXIX.
EARTHQUAKES OF THE EIGHTEENTH CENTURY.
Earthquakes of the Eighteenth Century—Quito, 1797—Sicily, 1790— Calabria,
Fébruary 5, 1783—Shocks continued to the end of the Year 1786—Authorities
Ww ns an i
dual See in of Rett rangement of River Conrsec-—Landalipa “alam
transported entire to great Di stances—New Lakes—Funnel-shaped Hollows in
Alluvial Plains—Currents of Mud—Fall of Cliffs, and Shore near Scilla inun-
Movement—Number of Persons who a wee the Bax of 1783—
Concluding Remarks 112
CHART RRaexexsxe
EARTHQUAKES—continued.
Earthquake of Java, 1772—Truneation of a lof fty Cone—St. Domingo, 1770—
Li
on, 1775—Great Area over which the Shocks ce of the’
Sea—Proposed leper Bay, 1750—Permanent Elevation—
Peru, 1746—Java, 1699—Rivers obstructed by unum m
Sicily, 1693—Moluceas, 1693— Ta amaica, 1692—Large Tracts engulfed—Por
of Port Royal Sunk—Amount of Change in the last 170 years—Elevation oe
Subsidence of Land in phe of Baiz—Evidence of the same afforded by the
emple of Serapis . A : ; : .
CHAPTER XXXI.
ELEVATION AND SUBSIDENCE OF LAND WITHOUT EARTHQUAKES.
Changes in the relative Level of Land and Sea in Regions not Voleanic—Opinion
of Celsius that the Waters of the Baltie Sea and Northern Ocean were sinking
—Objections raised to his Opinion—Proofs of the Stability of the Sea Level in
the Baltic—Play fair’s Hypothesis that the Land was rising in Sweden—Opinion
of Von Buch—Marks cut on the Rocks—Survey of these in 1820—Signs of
Oscillations in Level—Fishing Hut buried under Marine Strata—Facility of
appreciating slight PORN hy of Level on the inner and outer Coast of Swe-
den—Snpposed Movement in opposite Directions in proceeding from the North
Intimate
rigin
Agency
i
CHA
was of i :
Doming? 1770-
of the.
CONTENTS OF THE SECOND VOLUME. xl
Cape Southwards to Scania—Change of Level on the West Coast near Gothen-
burg—-Geological Proofs of the great Oscillation of Level since the Glacial
Period at Uddevalla—Upraised Marine Deposits of the Western Coast of Swe-
den containing Shells of the Ocean, those on the Eastern Coast Shells of the
Baltic— Whether orway is now rising—Modern Subsidence in Part of Greenland
—Proofs afforded by these Movements of great Subterranean Changes pacr 180
CHAPTER XXXII.
CAUSES OF EARTHQUAKES AND VOLCANOS.
Intimate Connection between the Causes of Volcanos and Earthquakes—Supposec
Original State of Fusion of the Planet—lIts simultaneous and universal F luidity
not proved by its Spheroidal Figure—Attempt to calculate the Thickness of the
{otion—He
ally—No internal Tides of supposed
Central Fluid perceptible—Supposed ane ge of Axis of Earth’s Crust—Partial
Fluidity of ee dae Crust most consistent with Volcanic Phenomena of the
Past and Present—Abandonment of the Data by which the earlier Geologists
supported ve ce of the Pristine Fluidity of the Earth’s
of a continual Diminution of Terrestrial and Solar Heat Spisidekl
st—Woctrine
CHAPTER XXXIII.
CAUSES OF EARTHQUAKES AND VOLCANOS—continued.
mei) of Steam in Volcanic Eruptions—Geysers of Iceland—Expansive Power
of Liquid Gases—Access of Salt Water, Atmospheric Air, and Fresh Water to
the Voleanie Foci—How the successive Development of Voleanic Heat in the
Earth’s Crust causes it to resemble a Body cooling from a general State of
F pees lity i the Earth’s Seah teins and dre aaa considered
as Sources of Volcanic Heat—Chemical Action—Causes of Permanent Eleva-
tion ce “Subsidence of Land— ane of Dry Land, ne pesrvel—Respi
lation of Chapters xxi. and xxm. . : : : 214
BOOK III.
CHANGES OF THE ORGANIC WORLD NOW IN PROGRESS.
CHAPTER XXXIV.
LAMARCK ON THE TRANSMUTATION OF SPECIES.
Division of the Oecd of the Question, Whether Species have a
real Existence in Nature ¢ mportance of this Question in Geology—Sketch of
Lamarck’s Arguments in hae our of the Transmutation of Species, and his Con-
jectures respecting the Origin of existing Animals and Plants—His Theory of
the Transformation of the Orang- ~outang into the Human Species 244
Xil CONTENTS OF THE SECOND VOLUME.
CHAPTER XXXV.
THEORIES AS TO THE NATURE OF SPECIES, AND DARWIN ON NATURAL
SELECTION.
Objections urged against the Theory of Transmutation and Lamarck’s Replies—
Tummies of Animals and S eeds of Plants from Egyptian Tombs identical in
Cl
+
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ro
°
- ER
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6°
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of
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KB
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2
=]
A
ee
jm
ror)
n Question of
Species as heated of in the ‘ eee of Creation’—Mr. Alfred Wallace on the
Law which has regulated the Introduction of New tee —Mr. Darwin on
Natural Selection, and Mr. Wallace on the same—Darwin’s Origin of Species,
and the Change of Opinion which it effected—Dr. Hooker's Flora of Australia,
and his Views as to the Origin of Species by Variation .
CHAPTER XXXVI.
vARIATION OF PLANTS AND ANIMALS UNDER DOMESTICATION VIEWED AS
BEARING ON THE ORIGIN OF SPECIES.
Domestic races, however Divergent, breed freely together—Remote ie
of some artificially formed Races— Bee: , both Unconscious and Metho
the Offspring of Cross becca HG le Origin of the Die Tee
Animal or Plant to vary while other Parts continue u red—Maize—Ca
bage—Are there any Limits to the Variability a Species ?—Obedience to
Man under Domestication often merely a new Adaptation of a Natural Instinct
ee do not revert to the exact Likeness of the Original Wild
How far do Domestic Races differ from Wild Species in their Capacity
to Inter-breed? — Hybridisation of Animals and Plants — He a
Plants not usually self- fertilised—Whethes the Distinctness of Species can be
tested by Hybridity—Tendency of different Races of Domestic Cat
ae to herd apart—Pallas on Domesticity eliminating Seiity Creation
of Growth 4 i fs : : y 284
CHAPTER XXXVII.
NATURAL SELECTON.
Natural as compared to Artificial Selection—Tendency in each Species to multi-
ply beyond the Means of Subsistence—Terms ‘Selection’ and ‘Survival of the
Fittest ’—Great Number and Variety of the Natural Conditions of Existence on
which the Constancy or Variation of a Species depends—Acclimatisation of
Species—The Intercrossing of slight Lniche beneficial. ee a in and in
injurious—Wild Hybrid Plants, and Opinions of Linneus on Protean Genera
—De Candolle on Wild Hybri ids—Hybridity will not account for Special In-
stincts—The Species of Polymorphous Genera more variable and comparatively
Modern—Alternate Generation does not explain the Origin of New Species 316
GeogtaPhl
ai “ee
Migration
—Migra
the Dist
ON TH
Geograph
seen fi
—Agel
Agency
tary ar
INSULA
Voleanic |
Conditi me
oth
ICATION VIEWD
S
r—Kemote Antiqi
scious s and Methoi:
articular Pars is
ize
iomest ic ‘ i
Corres
t i
erility
CONTENTS OF THE SECOND VOLUME. Xlil
CHAPTER XXXVIII.
ON THE GEOGRAPHICAL DISTRIBUTION OF SPECIES.
Geographical Distribution of Be ae. on Specific a ete of Quad-
rupeds of the Old and New. Worlds—Doctrine of ‘ Natural Barriers ’—Australian
Marsupials—Geo Easiest t aac of Extinct Fossil Rouc! % their nearest
allied Living Genera and Species—Geographical Provinces of Birds according to
Dr. Sate Se ead to Animals and Plants generall y—Neot: pee
egion — Nearetic—Palearctic—Ethiopian—Indian—Australian— Wallace
the Limits ‘ the Indian and Australian Regions in the Ma ay mate
pelago . . : : : : E
CHAPTER XXXIX.
ON THE MIGRATION AND DIFFUSION OF TERRESTRIAL ANIMALS.
Migration of Quadrupeds—Migratory Instincts—Drifting of Animals on Ice-Floes
—Mieration of Birds iat ion of pee eee Agency of Mar in
the Dispersion of Animals :
CHAPTER Xi,
ON THE GEOGRAPHICAL DISTRIBUTION AND MIGRATION OF SPECIES—
continued
aan es and Migration of Fish—Of Testac ea—Of Insects—Moths
300 ty
ants—Sargassv
alan of Animals in the Distribution of 1 Calais Seed of Man, both bees
tary and involuntary, in the Dispersion of Pla 369
CHAPTER XLI.
INSULAR FLORAS AND FAUNAS CONSIDERED WITH REFERENCE TO THE
ORIGIN OF SPECIES.
Volcanic Origin and Miocene Age of the Atlantic Islands—Islands once formed
have no rged, nor united with other eee ee
i De _ of 1e Oc cean
y,
the ie and other Species of ae are ants in the
m Ma i m Birds—From Insects—From Plants
—From eae san Number of Species of Landshells common to Madeir
and Porto Santo—Proportion of Species common to Madeira and the De iiss
—Contrast of the Testaceous Fauna of the British Isles and that of the Atlantic
Islands—Mode in which an Oceanic Island might become peopled with ae
shells—Variability of Species not greater in Islands than on Continents . 402
CHAPTER XLII.
EXTINCTION OF SPECIES.
Conditions which enable each Species of Plant to maintain its Ground against
others—Equilibrium in the Number of Species how preserved—Agency of
X1V CONTENTS OF THE SECOND VOLUME.
Insects in preserving this Equilibrium—Devastations caused by Locusts—Effect
of Omnivorous Animal s in preserving the Equilibrium of S ecies—Reciprocal
Bear in nto ee cre of Rein-deer imported into Iceland—Infiuence
of exterminating Species no Prerogative of Man—Concluding Remarks on
Extinct j : : é 3 5 : : PAGE 43
CHAPTER XLIII.
MAN CONSIDERED WITH REFERENCE TO HIS ORIGIN AND GEOGRAPHICAL
DISTRIBUTION.
ee Distribution of the Races of Man—Drifting of Canoes to vast Dis-
—Man, like other Species, has spread from a single Starting-point, or
veer ee Whether Man’s Bodily Frame became more stationary when his
Mind became more advanced—Great Antiquity of the more marked Human
Races—General Catpeiatint of their Range with the great Z ological Provinces
—American-Indian common to Neoarctic and Neotropical Regions—Man, an O
World Type—Marked Line of Separation between Malayan and Papuan Races
—Distinctness of Negro and European, and Question of the Multiple Origin of
—Six-fingered aniely of Man as bearing on the Mutability of his Organi-
Cot Rae of Supernumerary Digits when amputated—These Phenomena
referred by Darwin to Reversion—Whether Man has been degraded from a
higher or has risen from a lower Stage of Civilisation—Gradual Diminution
of the i atte of Languages and Races—Gaudry on Intermediate Forms be-
tween the Upper Mics and the Living Mammalia—Relationship of Miocene
and Living Quadrumana—Owen’s Classification of Mammalia according to
Cerebral Development—Progressive Advancement in Cerebral Capacity of the
Vertebrata—Improvement of Man’s Cerebral Conformation—Whether there is
any Fixed Law of Progress—Objections to Darwin’s Theory of Natural Selection
treat Step gained if Species are shown to be developed accord-
ing to the ordinary Laws of is tara ph of Reluctance to believe in
Man’ s Derivative Origin . 464
Sneidet ed.
CHAPTER XLIV.
ENCLOSING OF FOSSILS IN PEAT, BLOWN SAND, AND VOLCANIC EJECTIONS.
Division of the Subject—Imbedding of Organic Remains in Deposits on emerged
and—Growth of Peat—Site of Ancient Forests in Europe now occupied by
Peat—Bog Iron-Ore—Preservation of Animal Substances in Peat—Miring of
Quadrupeds— Sse of the Solw af loss—Imbedding of Organie Bodies A
Human Remains in Blown Sand—Great Dismal Swamp—Moving Sands 0
African Deserts—Buried Temple of Teedabat 4 in Egypt—Dried Careasses in aa
Fee of the Desert—Sand-dunes and Towns overwhelmed by Sand-floods—
abedding of Organic and other Remains in Voleanic Formations on the
499
“i
cjas forme
IMBE
Division oft
Dritting of Eq
’ Locust
EOGRAPHICy,
10€S to vast Dis.
tarting-point, or
ionary when his
marked Huma
ogical Provinces
s—Man, an Oli-
eloped 20°
2 to be “—_ :
1c ESECT joss
CONTENTS OF THE SECOND VOLUME. Xv
CHAPTER XLV.
BURYING OF FOSSILS IN ALLUVIAL DEPOSITS AND IN CAVES.
Fossils in Alluvium—Liffects of sudden Inundations—Terrestrial Anim: ils most
apa ium where Earthquakes prevail—Marine Allu-
of Landslips—Organic Remains in gemias and
Caves—Form and aaa of Hoheanens Their phan Origin—Closed
asins and Subterranean Rivers of the Morea—Katav —Formation of
Breccias with Red Cement—Human Remains imbedded in ee Schmerling
on Intermixture of Hum pe kien and Bones of Extinct Quadrupeds as
proving the former Co- Ge abhes of Man with those Lost Species —Bone-brec-
cias formed in Open Fissures and Caves . : PAGE 511
CHAPTER XLVI.
IMBEDDING OF ORGANIC REMAINS IN SUBAQUEOUS DEPOSITS.
Division of the Subject—Imbedding of Terrestrial eee and Plants—Increase d
Gravity of Wood sunk to great Depths in the Sea— Timber
the Mackenzie into Slave Lake an ue Sea—Floating Trees i in the
Mississippi—In the Gulf-stream—On the Coast of Iceland, Spitz der and
Labrador—Submarine Sera: sles on Coast of Hampshire and in Bay o
Fundy—Mineralisation of Plants—Imbedding of Insects— Of tiles—Bones
of Birds why ra alien ing 2 Terrestrial Quadrupeds by Riv loods—
Skeletons in recent Shell-marl— Imbedding of Mammiferous es in
Marine Stra 524
CHAPTER XLVII.
IMBEDDING OF THE REMAINS OF MAN AND HIS WORKS IN SUBAQUEOUS
STRATA
Drifting of Human Bodies to the Sea by River Inundations—How Human Corpses
—Number o
may be preserved in Recent Deposits—Fossil Skeletons of Men
Art—Chemical Changes
ley’s Arguments for the Recent
Post-tertiary Strata
CHAPTER XLVIII.
IMBEDDING OF AQUATIC SPECIES IN SUBAQUEOUS STRATA.
Inhumation of Freshwater Plants and Animals—Shell-marl—Fossilised Seed-
mene and Stems of Ch _— Deposits in 1 agua coher che ies
and ee Biata, a ade abstain of Marine Plants nd Animals
ded on o
the deep Sea—Burrowing Shells—Living Testacea found
Depths—Blending of Organic Remains of different Ages
VOL. II. a
Xvi CONTENTS OF THE SECOND VOLUME.
CHAPTER XLIX.
FORMATION OF CORAL REEFS.
Growth of Coral chiefly confined to Tropical Regions—Princip
building Zoophytes—Their Rate of Growth—Seldom
a
Craters—Mr. Darwin’s Theory of Subsidence in Explanation of Atolls, ane
ling and Barrier Reefs—Why the Windward Side of Atolls highest—Subsidence
explains why all Atolls are nearly on one Level—Alternate Areas of Eleva.
tion and Subsidenee—Origin of Openings into the Lago
goons— Size of Atolls and
Reefs—Objection to the Theory of Subsidence considered— ition, a
Structure, and Stratified Arrangement of Rocks now forming in Coral R roe
Lime whence derived—Supposed Increase of Cal
Epochs controverted—Concluding Remarks
eefs —
careous Matter in Modem Prare V.
5 : AGE 598
.
PratE V
Page 7
Page |
| following
Fig. 19
Wexford
in one he
Page 5
Page 6:
Gey
le!
STeatap Deni
s— }* -
“Maliiy, li,
eRe l Valea,
Atolls, Ens,
BNeSt— Sahai
“Teas of Elen,
78 Of Atolls ani
—Compositin
1 Coral Reef
Matter in Moden
PAGE jf}
LIST OF PLATES.
Directions to Binder.
Pratz V.—View looking up the Val del Bove, Etna To face Page 7
Pratt VI.—View of the Val del gle as seen from above, or
from the Crater of 18 To face Page 8
Prater VIT.—View of Bay of Baiz near Naples To face Page 176
ERRATA IN VOL, I.
Page 76, line 8 from foot, for ages read changes
Page 258.
following :—
Fig. 12.
For the explanation given of Figs. 11 and 12, substitute the
Here a point in St. George’s Channel midway between Pembroke and
Wexford is taken as a centre, and we behold the greatest quantity of land existing
in one hemisphere.
Fig. 11. Here the centre is the antipodal point to that taken in Fig. 12, and
we see the greatest quantity of water existing in one hemisphere.
Page 367, line 4 from foot, for (see above, p. 211), read (see above,
Page 534, line 8, for north-easterly read north-westerly
Page 578, line 3 from foot, Jor Perry read Perrey.
Page 585, line 9 from foot, Jor west read east
p. 248).
Page 590, line 3 from foot, for (p. 387) read (p. 586)
Page 592, line 18, for there is one, read there is no one
Page 680, line 20, for 72 read 71 B.c
PRINCIPLES
Poe 0LOG YX.
BOOK. Il.—continued.
CHAPTER XXVI.
ETNA.
EXTERNAL PHYSIOGNOMY OF ETNA—-LATERAL CONES—THEIR SUCCESSIVE OBLI-
TERATION—MARINE STRATA AT BASE OF ETNA OF NEWER PLIOCENE DATE—
ERUPTION—WANT OF PARALLELISM IN THE ANCIENT LAVAS—DIKES IN THE
VAL DEL BOVE, THEIR FORM AND COMPOSITION—TRUNCATIO F THE GREAT
CONE—ERUPTIONS OF ETNA OF HISTORICAL DATE—ERUPTION OF MONTI ROSSI
1669—SscENERY OF THE VAL DEL BOVE—ERUPTIONS OF 1811 anp 1 —THAT
COVERING OF LAVA—ANCIENT VALLEYS OF ETNA—-ANTIQUITY OF THE CONE OF
ETNA
EXTERNAL PHYSIOGNOMY oF ETN .4.—Next to Vesuvius, our
most authentic records relate to Etna, which rises near
the sea in solitary grandeur to the height of nearly 11,000.
feet.* The base of the cone is almost circular, and 87 English
miles in circumference; but if we include the whole district
x
by ¢
trigonometrically, that the
Etna was t. The Catanians,
disappointed thattheirmountainbad ost
¥
ne 2,000 feet oe assig
to it by Recupero, refuse 0 acquiesce
in the eee Afterwards, in 182
Sir J el, not being aware
Captain Simthis conclusions, determined
VOL. II.
In 1815, Captain Smyth ascertained,
heig f
areful barometrical measurement
that the height was 10, “ee is
singular agreem
eas obtained was spoken of by 7 Her schel
as ‘a happy accident ;’ but Dr. Wol-
laston remarked that ‘it was one
those accidents Meee would not have
happened to two fools
2 ETNA.
[Cu. Xxyy
over which its lavas extend, the circuit is probably twice ag
ereat.
The cone is divided by nature into three distinct zones,
called the fertile, the woody, and the desert regions, The
first of these, comprising the delightful country around the
skirts of the mountain, is well cultivated, thickly inhabited,
and covered with olives, vines, corn, and fruit trees. Higher
up, the woody region encircles the mountain—an extensiye
forest six or seven miles in width, affording pasturage fop
numerous flocks. The trees are of various species, the chest.
nut, oak, and pine being most luxuriant ; while in some tracts
are groves of cork and beech. Above the forest is the degert
region, a waste of black lava and scorie, which terminates
upwards in a kind of table-land, from which rises the principal
cone, 1,100 feet high, emitting continually steam and sul.
phureous vapours, and in the course of almost every century
several streams of lava.
Cones produced by lateral eruwption.—The most erand and
original feature in the physiognomy of Etna is the multitude
of minor cones which are distributed over its flanks, and
which are most abundant in the woody region. These,
although they appear but trifling irregularities when viewed
from a distance as subordinate parts of so imposing and
colossal a mountain, would, nevertheless, be deemed hills of
considerable altitude in almost any other region. Without
enumerating numerous monticules of ashes thrown out at
different points, there are about 200 of these secondary
voleanos as laid down in Von Waltershausen’s map within
a circuit twenty geographical miles in diameter having the
summit of Htnaasa centre. Outside of this circular area are
afew other modern cones of large size, such as the double
hill near Nicolosi, called Monti Rossi, formed in 1669, which
is 450 feet high, and two miles in circumference at its base.
Although.this hill somewhat exceeds in size Monte Nuovo, de-
scribed in the twenty-fourth chapter, it only ranks as a cone of
the second magnitude amongst those produced by the lateral
eruptions of Etna. Monte Minardo near Br onte, on the east
of the great volcano, is upwards of 700 feet in height.
On looking down from the lower borders of the desert
2 Pastry,
8 Species, the gi
While jn S0me b
> forest js the dy
Pe, Which erm;
h rises the pring
ally steam and
lmost Very cenh
1€ most granl
na is the milit
ver its flanks
ly region. Te
rities when TH
* so imposig!
be deemed ly
With
LATERAL CONES—OBLITERATION OF. 2
Cu. XXVI.] 3
region, these minor volcanos present us with one of the most
delightful and characteristic scenes in Kurope. They afford
every variety of height and size, and are arranged in beautiful
and picturesque groups. However uniform they may appear
when seen from the sea, or the plains below, nothing can be
more diversified than their shape when we look from above
into their craters, one side of which is generally broken down.
There are, indeed, few objects in nature more picturesque
than a wooded volcanic crater. The cones situated in the
higher parts of the forest zone are chiefly clothed with lofty
pines; while those at a lower elevation are adorned with
chestnuts, oaks, and beech trees.
Successive obliteration of these cones.—The history of the
eruptions of Etna, imperfect and interrupted as it is, affords
us, nevertheless, much insight into the manner in which a
large part of the mountain has successively attained its
present magnitude and internal structure. The cone from
which the eruptions at the summit now proceed, has more
than once been destroyed either by explosion or engulph-
ment, and has been as often reproduced. The great platform
(No. 2, Plate V. a, b, c, fig. 79) seems to have resulted
from the truncation of the ancient conical mountain, the
uppermost part of which has disappeared during a suc-
cession of such catastrophes, leaving a comparatively level
ground from which the modern cone now springs.
By far the greater number of eruptions proceed from the
great crater a fig. 79, and from lateral openings in the desert
region. When hills are thrown up lower down or in the middle
zone, and project beyond the general level, they gradually
lose their height during subsequent eruptions ; for when lava
descending from the upper parts of the mountain, encounters
any of these hills, the stream is divided, and flows round them
So as to elevate the gently sloping grounds from which they
rise. In this manner a deduction is often made at once of
twenty or thirty feet, or even more, from their height. Thus,
one of the minor cones, called Monte Peluso, was diminished
in altitude by a great lava stream which encircled it in 1844;
and another current has recently taken the same course —
yet this hill still remains 400 or 500 feet high.
B 2
There is a cone called Monte Nucilla near Nicolosi, roung
the base of which several successive currents have flowed,
and showers of ashes have fallen in historical times, till at
last, during an eruption in 1536, the surrounding plain wag
so raised, that the top of the cone alone was left projecting
above the general level. Monte Nero, situated above the
Grotta dell’ Capre, was in 1766 almost overflowed by a
current: and Monte Capreolo afforded, in the year 1669, a
Fig. 70. te
Aa
ae ee as
ALDMinuz eo ae
eee ae Licodia,z (dn ee.
ae a Rs: 3 :
ee : : GIS Gatonia
k - :
Plain Catania.
Hay un of Catani ]
i, = wa,
—— Sa <a <> —] _
aes aa! =&
View of Etna from the summit of the limestone platform of Primosole,
looking north
a. Highest oa | g. yas n of Cata
6. Montagnuo | h, 7. Dotted line oa sing the highes
c. Monte eae withsmaller lateral cones | hoe along which the marine pies: are
above. | occasionally seen. They reach a
d. Town we stipe su Mona | miles north of Catania, a — of ato 1 58
Argilla nd sandy bea. with murine ay —— feet above the level of the
shells ees all of living Mediterranea . Plain of Catania
ae and with associated and paepeeeates | Limestone sit atform of Primosole of the
ous volcanic rocks ew no Pliocene period.
| m a Motte a di Cneandeh
. Escarpment of stratified i So aia vol-
canic tuff, &c., north-west of Ca
curious example of one of the last stages of obliteration ; for
a lava stream, creeping along the top of a ridge which had
been built up by the continued superposition of successive
lavas, flowed directly into the crater, and nearly filled it.
The lava, therefore, of each new lateral cone tends to detract
from the relative height of lower cones above their base; 80
that the flanks of Etna, sloping with a gentle inclination,
envelope in succession a ereat multitude of minor volcanos,
while new ones spring up from time to time.
Marie strata and volcanic rocks of Htna of Newer Pliocene
date.—In the annexed outline of Etna and its environs, which
IT made in 1828 from the platform of tertiary limestone of
Primosole, the summit of the voleano is seen 24 geogra
OFertlon
the Year re
m of Primos
expressing the hiss
sey reach at (ait
a height of about?
level of the 5%
iy
smosole af
m of Primosole
ff
‘teratiols”
literal! Hf
Cu. XXVI.] MARINE STRATA OF NEWER PLIOCENE DATE. 5
phical miles distant in a straight line. At our feet lies
the alluvial plain of Catania (*) 6 miles broad, through
which the Simeto runs, and which is bounded on the north
by an undulating country e, e, composed for the most part
of a marine tertiary deposit of Newer Pliocene age.
The district composed of it near Catania which is provin-
cially called ‘Terra Forte,’ must have emerged from beneath
the sea at a period of very modern date geologically speaking ;
for not only are almost all the fossil shells included in the
clays of recent species, but the argillaceous beds themselves
are capped at the height of nearly 1,000 feet by two deposits,
in one of which near the sea all the shells are of living species,
while the other consists of rounded pebbles of limestone and
other rocks evidently once brought down from the interior by
the Simeto and deposited in its delta, which delta was after-
wards uplifted together with the subjacent clay as well as the
neighbouring mass of Etna and the sea-coast at its base.
In the old alluvium here adverted to the bones of elephants
and other extinct mammalia have been found at several
points. The line h, 7, expresses the level at which the
marine Newer Pliocene formation crops out irregularly from
beneath the modern streams of voleanic matter which are
gradually encroaching upon it and concealing it more and
more from view. Sometimes it cannot be traced higher than
600 feet, but at one place called Catira, 4 miles north of
Catania, the marine clays have been detected at the height
of 1,258 English feet above the level of the Mediterranean.
At that point and along the adjoining coast, as at Aci Castello
and at Trezza opposite the Cyclopean islands, and at Nizzeti
a mile and a half north-west of Trezza, the fossiliferous clays
are associated with contemporaneous basaltic and other
igneous products, the most ancient monuments of volcanic
action within the region of Etna. By these eruptions the
foundations of the great voleano may be said to have been
laid in the sea when the present site of Etna was a bay of the
Mediterranean. The fossil shells therefore found in these
clays are of great interest in settling the chronology of the
older part of the mountain. Out of 65 species which I
myself collected in 1828 M. Deshayes determined 4 to be
6 ETNA. [Cu. Xxyy.
extinct and the rest now common in the Mediterranean,
Phillippi obtained from the same district 76 species of
which only 3 were extinct, while a larger number (109
from Cefali in the suburbs of Catania yielded a proportion
of about 6 per cent. of extinct as compared to living species,
A still larger collection of 142 species of shells which Dy.
Aradas kindly lent to me in 1858 yielded 8 per cent, of
extinct species.* But these results are not so inconsistent
as they at first appear, because all the abundant species
(except Buccinum semistriatum, already mentioned as the only
extinct shell out of 100 found in the ancient tuffs of Somma)
are now living in the neighbouring sea, whereas nearly all
the lost species are so exceedingly rare that sometimes single
individuals of them have alone been found. Nevertheless I
regard the most ancient part of Etna as somewhat older than
the foundations of Vesuvius, and if I were asked what relation
the tertiary strata near Catania bear in point of age to our
British formations, I should answer that they are about
the age of the Norwich crag. In reference therefore to the
Glacial Period I consider the oldest eruptions of Etna as of
older date than the era of greatest cold in central and
northern Europe.
The reader must not suppose that the marine strata with
the associated basaltic rocks were first formed and then
raised to their present height above the level of the sea, and
that the great subaérial cone of Etna was a superstructure of
later date; for there is reason to believe that a general and
gradual upheaval of the foundations of Kitna, together with
the neighbouring country, was always going on during the
long period of supra-marine eruptions. And this slow upward
movement is probably still continuing, since raised beaches
or sands with littoral shells of living species often retaining
their colour are observed at the eastern base of Etna skirting
the shore, and there are also lines of inland cliff cut in the
tertiary strata and in the volcanic tuffs bearing witness to
successive alterations in the relative level of sea and land.
Fossil plants of living species in ancient tufis of Etna.—We
* See ‘Mode of Origin of Mount Etna,’ by the Author, Phil. Trans. Part II. for
1858, p. 778.
{S18 a
Undant
ned
Spee,
as the a
uits of Som,
Teas neath j
Metimes sins
Ney ertheles
hat older tha
1 what relatig
of age to ov
hey are abit
nerefore to th
of Etna asi
. central ani
ne strata mit
red and the
f the sea,
erstructutt!
’ general w
c ether yi
uring
1
mt
VNIA ‘HAOd Tad ‘IVA AHL dN YNIMOOT MIA
"A 098
wrna,
TuK VAL DEL novr,
VIEW LOOKING up
Cu. XXVI.] VAL DEL BOVE. 7
have rarely an opportunity of determining the exact nature
of the vegetation which covered the mountain when some
of the oldest showers of volcanic ashes were poured out ;
but there are some stratified tuffs at Fasano near Catania
replete ewith fossil leaves which throw some light on this
subject. I obtained several species of land-plants from these
tuffs which were determined by Professor Heer to belong to
species now living in Sicily. Among others were the sweet
bay, Laurus nobilis, the common myrtle, Myrtus communis,
and the Mastick tree, Pistachia lentiscus.
Val del Bove on the eastern flank of Etna.—Etna, when viewed
whether from the north or south, is of a very symmetrical
form, but on its eastern side it is intersected by a deep valley
called the Val del Bove, the head or upper part of which is
bounded by a precipice between 3,000 and 4,000 feet
high, which begins immediately below the eastern margin
of that highest platform which was before mentioned as
having been produced by the truncation of the great cone.
The annexed view, Plate V., taken from a drawing which I
made in November 1828, will give the reader some idea of
this precipice below the platform No. 2, which was at that
time covered with snow.
The great lava currents of 1811 and 1819 are seen pouring
down from the higher parts of the Val del Bove, overrunning
the forests of the great valley, and rising up in the foreground
on the left with a rugged surface, on which many hillocks
and depressions appear, such as often characterise a lava
current before it has ceased to flow as well as after its
consolidation.
The small cone, No. 7, was formed in 1811, and was still
smoking when I saw it in 1828. The other small volcano
to the left, from which vapour is issuing, was, I believe, one
of those formed in 1819.
The following are the names of some of the points indi-
cated in the sketch :—
1. Montagnuola. 5. Finoechio. 9. Musara.
2. Torre del Filosofo. 6. Capra. 10. Zocolaro.
8. Highest cone. 7. Cone of 1811. 11. Rocca di Calanna
4, Lepra, 8. Cima del Asino.
8 ETNA. [Cu. XXVI,
Description of Plate VI.—The second view (Pl. VI.) re.
presents the same valley as seen from above, or looking
directly down the Val del Bove, from the summit of the
principal crater formed in 1819. *
The circular form of the Val del Bove is well shown in thig
view (Pl. VI.). To the right and left are the lofty precipiceg
which form the southern and northern sides of the great
valley, and which are intersected by dikes projecting in the
manner afterwards to be described. In the distance appears
the ‘fertile region’ of Etna, extending like a great plain
along the sea-coast.
The spots particularly referred to in the plate are the
following :—
a. Cape ee in ess of which the | h. The great harbour of Syr
outline is seen in the distan | 4s adie city of Catania, near w ae is marked
b. The pr ube ory of ane on the | the cou ? the lay a whi flowed from the
pi coas | Monti Mate: in 1669, and dest d part of the
The rive pera | city.
id. The small village a Riposto. is The Lake of Lentin
e. Valley of Calann l. To the lets of ve view is the crater of
f. The town of A i Rea 1811 gies ae be ee
g. fs Sccchen tiled or oe araglioni,’ in the | m. Rock of aes also seen a WO393
Bay of Tre Plate III.
The Val del Bove is of truly magnificent dimensions, a
vast amphitheatre 4 or 5 miles in diameter, surrounded by
nearly vertical precipices, the loftiest being at the upper or
eastern end, where, as before stated, they are between 3,000
and 4,000 feet high, and the others on the north and south
side diminishing gradually from that height to 500 feet as
they extend eastward. The feature which first strikes the
geologist as distinguishing the boundary cliffs of this valley,
is the prodigious multitude of vertical dikes which are seen
in all directions traversing the volcanic beds. The circular
form of the great chasm, and the occurrence of so many
dikes, amounting perhaps to several thousands in number,
cannot fail to recall to the mind of everyone familiar with
Vesuvius the phenomena of the Atrio del Cavallo, although
* This view is taken from a sketch Vee
made by Mr. James Bridges, corrected in t
but I conceive that it would appear
ie face of the great pr sania near
which the smoke issuing from the coné
Tam unable to point out the No. 7 is made to terminate. There are
oe
occupy in the view represented in Plate
many ledges of rock on the face of that
precipice where eruptions have occurred.
i,
Piate V1.
*6ISIT JO URLVUO AHL NOU XO ‘TAOdVY WOU
Nogs SV ‘VNLO9 AOD Idd IVA AHL JO MOLA
(EDIE SS JEG
: fe eS ¥ q fa
: : |
<a f
ae ;
SES as
9 oso
Saas
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S=S==>=
LF a SF Se SS cf goa as" a ———— ae a or ee i ¥ dejan '
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PROOFS OF DOUBLE AXIS OF ERUPTION. 9
Cu. XXVI.]
the Val del Bove is on a scale as far exceeding that of Somma
as Etna surpasses Vesuvius in magnitude.
Internal structure of the mountain and proofs of a double axis
of eruption.—When I first examined Htna in 1828, I sup-
posed that the boundary walls of-the great amphitheatre dis-
played such an arrangement of the beds as showed that the
structure of that part of the mountain was very different
from that which the escarpment of Somma exhibits. I
imagined that the sloping away of the strata from a central
axis to all points of the compass, or what has been called the
quiquaversal dip, was wanting in the Val del Bove. But
when I revisited the same district in 1857-8,* I discovered
that the lower portion of the volcanic beds exposed to view in
the great precipices k, 7, at the head of the valley h, 7, k, of the
section fig. 72, page 12, dipped steeply to the west, and this
arrangement of the strata, together with that observed in the
other cliffs bounding the valley, can only be explained by
assuming that there was once a great centre of eruption at
or near the point in the annexed map (fig. 71) which I have
marked with a cross as indicating the axis of Trifoglietto.
The direction of the arrows a, b, c, d, e, f, 9, h, 7, indicate the
various points of the compass towards which the strata have
been observed to be inclined. I was accompanied in 1857 by
Signor G. G. Gemmellaro, when we made out this quaqua-
versal dip, and came to the opinion that the point marked
with a cross or the axis of Trifoglietto had been an ancient
centre of eruption.t
In confirmation of this theory, Baron 8. von Waltershausen
has observed that there is an ancient set of greenstone dikes,
thirteen or more in number, which radiate from the point or
axis alluded to and are seen traversing the surrounding
precipices. These greenstone dikes are distinguishable by
their mineral composition from those of more modern
doleritic lava which radiate from the present great centre of
eruption or the summit of Etna. This centre may be called,
from the modern name of the mountain, the axis of Mongi-
* See Paper on Mount Etna by the come to the same conclusion ; for that
Author, Phil. Trans. Part II. for 1858.
Iwas not then aware that Baron
S. Von Waltershausen had previously
part of his Atlas in which he announced
this opinion was not published till after
my return to England.
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Cu. XXVI_] PROOFS OF DOUBLE AXIS OF ERUPTION. 11
Description of Fig. 71.—(Map of Etna, p. 10).
Ground plan of the Val del gly ie the ie ue the beds on opposite sides of
s of Trifo eliet
rows a, b,c, d, ¢, f, 9, h, i,showing thedip , 6, dip in pha a a eee dir pr or at an
of the beds in niche directions from the angle of more than 20° to the we
centre of eruption or axis of Trifoglietto. i. Horizontal = ds in the gre: we precipice
Arrow showing the direction of the dip of above the Ser mnnicola, resting on beds of
beds in th sterna ( als n the rachyte and trachiti 0 tuft and conglomerate,
section fig. 72), where they are inclined 6° which last dip at angles of from 20° to 28°
south-east, whereas the beds in the lower parts N.W. as indicated by the arrow a.
of the same precipice as indicated by the arrow M. N. Line of section of fig. 72.
bello. In 1858, when I r paid a third visit to the Val del
Bove, I found that there was a great thickness of beds ((,
of Map fig. 71), in that part of the precipice between the
Piano del Lago and Giannicola, which are horizonta
perfectly reconcilable with the theory that the structure
of Mount Etna is due to its having been formed by the
pouring out of lava and scoriz from two great distinct centres
of eruption before alluded to, viz., that of Trifogletto and
that of Mongibello; the latter having eventually obtained
such an ascendancy as to overwhelm the products of the
former, and reduce the whole mountain to one symmetrical
cone, broken subsequently by the great chasm of the Val del
Bove on its eastern side, above described, a chasm of compa-
ratively modern date. The accompanying section will explain
the theory of the structure of Etna above alluded to, or the
hypothesis of a double axis by which all the dips in opposite
directions in the Val del Bove, apparently so complicated,
together with the horizontality of the beds immediately below
the edge of the Piano del Lago, are found to be resolv-
able into a very simple arrangement, such as is exemplified
in not a few of the great Javanese volcanos described by
Junghuhn. That author has particularly called attention to
the fact, that when there are two centres of eruption in the
same volcanic mountain, there is a certain area between them,
which he calls a saddle, where the beds of lava, or the
showers of ashes, are level or horizontal. Among other
instances he alludes to a saddle connecting the twin cones
of Gede and Panggerango which is 7,870 feet high. The
largest of the two cones, although truncated like Etna, is
9,226 feet high, and the lesser cone has a deep valley on one
i ie
ETNA. [Cu. XXyy,
14 \ ipe sa
Se ee side comparable to the Val oot
| ea 28 5, del Bove. In the case of ie des¢
aa | 238 Htna we are unable to do. a
\ & & - : = cide which of the two foe} © gal
2 : EB 5 A or B, fig. 72, gave vent to 7 Java
a Pa the earliest eruptions, but . noid]
3 usa é it is clear that after B (or t otati
. 2528 a2 the focus of Trifoglietto) 7 |
8 bi e qd was spent, the main ven} w 7
B ae . g of Mongibello continued iy eee
«85 2 E S* fall vigour, and over. pe on
zi 2 P ae 2% whelmed with its lavas a ab
Se : % a8 2 and scorize the minor cone i oe
ie ieee = ad, @ until it reduced the putters
o peoeea lope h, f, h. ared ba
“3 2388.» whole to one slop sds tring th
m Sek Ss Subsequently the chasm y Ze
E ee gee f called the Val del Bove, h less ree
2 tics Hse 4 k, was formed, chiefly I L a :
22 4 presume by explosions simi- upper
Bt ie: lar to those which are sup- — —-No hyp
2 2 posed in Vol. I. p. 630, to e ae
= & have removed the old cen- current,
‘ 2 tral portion of Somma be- phenom
a a 3 fore the modern cone of at this p
4 < 2 E ;. Vesuvius was built up. When
E < E 3 The arrangement of the Tgave th
zi : == «beds seen between k and i 88 it has
= 883 fe 79, ante ie Pated th
4 z 3 E ° 3 pice at the head of the 4 | outwards
! Bese del Bove, is of peculiar : Moun
z E : #3 eeological interest, ze “ Pi,
g gs a P especially the bo TMatio
\ fe : Ee . of those beds of lava ee | nou
\ E $$2222 are shaded with adark ee | Pe and
\ oe : = 3 2 = immediately below : tin | oe the
“\ a ae - se the entire absence they a Tate
Ey E Pee Es which they Se a - Nan
‘2 € “ < so" are strikingly contra in thet
: me S 2 eth lower ae Rpg
the Wai '
elle contin
_ and id
With its lr
e the minor iy
it reduced §
me slope b,j
itly the dha
Val del Bore
ormed, chiely
y explosions
e which ar
Vol. I. p ba)
wed the old
n of Sommal
nodern cone 1
vas built up
Cu. XXVI.] HORIZONTAL BEDS OF THE VAL DEL BOVE. 13
the same section in the Serra Giannicola, which are highly
inclined. In order to study the horizontal beds, I made
two descents of the great precipice at different points pre-
viously examined by very few geologists, and observed a re-
markable resemblance of one of the old lava currents with
the lava of 1669, which overflowed some level ground in
the neighbourbood of Catania, where there had been a rich
vegetation. The vegetable soil was there turned or burnt
into a layer of red-brick-coloured stone, reminding me of
the red bands which separate so many of the lavas in
Madeira. Midway between the top and bottom of the
great precipice, at a place called Teatro Grande, the ancient
lava current is seen, which had evidently cooled on a flat
surface, and the lower scoriaceous part of which reposed on
a red band of burnt soil, over which it had poured. Over-
lying the bottom scoriz was a central mass of stony lava no
less than forty feet thick, divided by vertical rents, so as to
be almost columnar, and above this again was the usual
* upper scoriaceous and highly vesicular division of the current.
No hypothesis, except that of the double axis, can give even
a plausible explanation of the position of this powerful
current, which must have cooled on a flat surface. But the
phenomena are quite reconcilable with the former existence
at this point of a saddle between the cones.
When treating of Vesuvius, in the first volume, p. 633,
I gave the reader an account of the theory of elevation craters
as it has been called, to which some geologists have attri-
buted the high inclination of the lavas of Somma, which dip
outwards in all directions from a central axis. The structure
of Mount Etna has been referred by the same school to a
similar movement of upheaval, which caused all the volcanic
formations previously horizontal to be suddenly uplifted into
a mountain mass, so as to assume a conical form, the beds of
lava and scorie being made to dip away in all directions
from the axis of upheaval. Even if it were true that the
alternate scoriaceous and stony beds exhibited a quaquaversal
dip, many unanswerable objections might be offered to the
above-mentioned hypothesis. Among others, I may mention
the impossibility of imagining that so large a proportion of the
14 ETNA. [Cu XXVT
dikes of different ages should be so nearly vertical ag they
are found to be. But as I have dwelt so long on thig subject
on a former occasion, I will merely say here, in favour of the
theory of eruption as opposed to that of upheaval, that one
cone formed by eruption may and often does embrace and bury
a contiguous cone of older date and of similar origin ; whereag
a cone of upheaval, even if we grant that the voleanic forces
ever give rise to such a structure, cannot be conceived to
envelope an older cone.
Want of parallelism in the ancient lavas.
It will be useful,
however, to point out in detail some features in the shape
ise fo.
Stony layers in the northern escarpment of the Val del Bove in the Serra di Cerrita,
part of the Concazze (see Map, fig. 71), where the precipice is 1,000 feet high,
a. Vertical section of rock 40 feet.
b 3eds to the westward in the same
seek
d. Same bed as a thinning out westward to
> Ce > r
plane as the thickest part o
d
a thickness of 4 or 5 feet at a distance of a
few hundred yards from a. .
|
|
.
and structure of the beds which are intersected in the cliffs
of the Val del Bove, in order to show that they are not uni-
form in thickness, and that they by no means preserve every-
where that perfect parallelism to each other which has been
ascribed to them. They present, it is true, to the eye, a
great appearance of regularity when viewed as a whole and
from a distance, but when
more closely inspected, they
are found to be variable,
both in thickness and in
their dip, as much so as we
: a have any right to expect m
en pee ta oars the Com currents which have lowed
of the Val del Bove. down. the sides of a steeply
Vertical distance from a to b about 60 fect. In- sloping cone like Htna from
coherent tufts
beds here figured. “some opening at or near the
summit. The annexed dia-
erams will explain the appearance of the lavas and scorie
at many points in the north and south walls of the Val del
Bove, where they are laid open to view in vertical sections.
cluding,
have bee
T may
cones lai
gin . 3 Wh,
he Vv Oleanie
: sb | Meeting
Ut Will beg
res in the g
ted in the
hey are nott
3 preserve ere
which has lé
» to the ef
a, whol?
France, but w
: inspect rf
ye Vi
as
‘in seacliffs in Ma-
deira, and their andca
within 12 a 14 feet of each other at the two extremities of the
same.
Cu. XXVI.] STRATA AND BEDS OF THE VAL DEL BOVE. 15
As the continuity of many of the beds in the boundary
cliffs of the Val del Bove has been thought by some to be
opposed to the theory
of their having flowed
in succession one over
the other down the
sloping sides of a
ereat cone, I may re-
mark, that provided
we behold a section
running in the same
direction as the ori-
ginal course of the
currents, we have
every reason to ex-
pect them to be con-
tinuous for several
miles. As to their
dip, even if it amount
to 20° or 30°, there
is no reason for con-
Beds of doleritic lava and scorie in the Serra del
Solfizio, south side of the Val del Bov
Gee Let eee 1 See Popisciy a ods (Nae aa : .:
a. i y g LOS
£44 1 £ 4 f ¥
g
5 feet thick.
c. Bed of similar cca ials, but coarser, thinning out at d.
asaltic lava, 3 feet in its eo eates st = ckness, ae
Hieiie at an angle wr z° (or 17° steeper than
Jj. Fragmentary scoriaceous bed 10. ns et thick, having a
similar dip with i Bthees which underlie it.
cluding, as I shall show in the sequel, that they may not
have been originally inclined at such high angles.
I may here remark,
cones laid open by
the grand sections
exhibited in the
cliffs of the Val
del Bove
distinctly to be
seen in some in-
land ravines and
absence in the Val
del Bove implies
that I saw no signs of buried lateral
° Such “= -¥ ut
; Srp oe jae
buried cones are
Curvatures of lava in the hill of Zoccolaro, at the eastern
extremity of the Serra del Solfizio
ee beds of lava varying in thickness from 4 to 6 feet,
a, 0b,
ne or a oc agi matter
b
ins out a
Wak apart in the middle of this section, and come
that the great period of lateral eruptions was subsequent
in date to the origin of that valley.
16 ETNA. [Cx, XXVI.
Dikes in the Val del Bove.—I have already alluded to a set
of dikes of greenstone or diorite, observed by Waltershausep,
to converge in the supposed centre of eruption or axis of
Trifoglietto (see p. 11). A much greater number of dikeg
or vertical walls of lava radiate from the modern centre of
eruption, or that of Mongibello. They consist chiefly of
dolerite or greystone, intermediate between trachyte and
basalt,—the trachi-dolerites of some geologists. They vary
i EO
pets. Ne ea rr tea
Zp iY
ZA
——— _
Ly
——
Dikes at the base of the Serra del Solfizio, Etna.
in breadth from 2 to 20 feet and upwards, and usually
project from the face of the cliffs, as represented in the
annexed drawing (fig. 77). They consist of harder materials
than the strata which they traverse, and therefore waste
away less rapidly under the influence of that repeated con-
gelation and thawing to which the rocks in this zone of
Etna are exposed. The dikes are, for the most part, vertical,
but sometimes they run in a tortuous course through the
tuffs and breccias, as represented in fig. 78.
The dikes are most numerous near the head of the Val del
that they stoy
their vertical «
ind do not @
mere of a date
We know n
lave been pot
We perceive th
Tina have aly
On. XXVI.] DIKES IN THE VAL DEL BOVE. 17
Bove, or near the two ancient centres of eruption before alluded
to as the axes of Trifoglietto and Mongibello. They continue
to abound throughout that zone of the mountain where
lateral eruptions are frequent, but below that level they
become extremely rare, as in the valley of Calanna, for
example, in which the section of the Val del Bove is continued.
Still lower in the same easterly direction, as in the valley of
San Giacomo for example, none occur. The rarity or ab-
sence of dikes as we recede from the great centres of eruption,
is precisely what we might have expected if the vertical
fissures now filled with
solid rock were once
the channels which
gave passage to lava
currents. Some of the
dikes blend at their
termination upwards
with currents of lava, so
that they stop short in
their vertical direction,
and do not cut through the higher currents of lava which
were of a date posterior to the dikes.
We know not how large a quantity of modern lava may
have been poured into the bottom of the Val del Bove, yet
we perceive that eruptions breaking forth near the centre of
Etna have already made no small progress in filling up this
great hollow. Even within the memory of persons now
living, the rocks of Musara and Capra have, as before stated,
lost much of their height and picturesque grandeur by the
piling up of recent lavas round their base, and the great
chasm has intercepted many streams which would otherwise
have deluged the fertile region below. The volcanic forces
are now labouring, therefore, to repair the breach caused pro-
bably by one or more paroxysmal eruptions of ancient date
on one side of the great cone; and unless their energy should
decline, or a new sinking take place, they may in time efface
this inequality. In that event, the restored portion will
always be unconformable to the more ancient part, yet it
will consist, like it, of alternating beds of lava and scorie,
VOL. I. C
= ——~ SS
P= = SSS SSS
aS Sos PSSSSS8
Tortuous veins of la
18 ETNA. [Cu, XXVIL
which, with all their irregularities, will have a general] slope
from the centre and summit of Etna towards the sea,
Origin of the Val del Bove.—It will be seen by the idea]
section given in fig. 72, p. 12, that I suppose the modern
centre of eruption (that of Mongibello, A,) to have over-
whelmed the ancient lateral cone formed by B, so as to reduce
the whole mountain to a symmetrical form, the present valley
k, i, h having then no existence. In what manner thig
enormous gulf was formed has been a fertile subject of con-
jecture. So late as the year 1822, as we shall see in the
next chapter, during a violent earthquake and volcanic erup-
tion in Java, one side of the mountain called Galongoon,
which was covered by a dense forest, became an enormous
gulf in the form of a semicircle. The new cavity was about
midway between the summit and the plain, and surrounded
by steep rocks.
It will be shown that in that instance vast quantities of
boiling water and mud were thrown up like a waterspout,
and great blocks of basalt were projected to a distance of
7 miles, and ashes and lapilli of the size of nuts as far
as 40 miles. Numerous villages 24 miles distant from the
centre of eruption were completely buried, implying that the
solid matter ejected by the explosive power of steam was
voluminous enough to account for the formation of the new
cavity, vast as were its dimensions.
It will be also seen in the thirtieth chapter, that in the
year 1772, Papandayang, the largest volcano in the island
of Java, lost 4,000 feet of its height, at the same time that
40 villages, spread over an area 14 miles in length and 6m
breadth, were destroyed. According to the earlier accounts
they were engulphed, and the truncation of the cone was attri-
buted to subsidence; but the subsequent investigations of
Junghuhn about seventy years after the explosion have shown
that the villages were overwhelmed by volcanic sand and
scoria, under which they now lie buried ; and it cannot be
doubted that the loss of height of the great cone, attributed
to subsidence, was caused in great part at least by explosion.
The summit of Carguairazo, one of the loftiest of the Andes
of Quito is said to have ‘fallen in’ on July 19, 1698, and
———
shal] Neg y
nd voleani: :
alled Cala
ime an enon
Cavity Was dh
» and sumu
rast quantita
ke a water
to a distant
» of nuts a!
distant fro’
mplying tht
or of steal!
of the?
ration
Cu. XXVI_] TRUNCATION OF GREAT CONE. 19
another cone of still greater altitude in the same chain, called
Capac Urcu, was, according to tradition, truncated a short
time before the conquest of America by the Spaniards. It is
possible that when the lava is rising to the summit of such
cones the foundations of parts of the volcanic structure may
be undermined and melted, so that one part after another of
the walls of the highest crater may sink down before the
principal escape of gas and the ejection of scoriz takes place.
In the year 1792 a small circular tract called the Cisterna
(see Map, fig. 71), situated on the edge of the platform from
which the highest cone of Etna rises, sank down to the depth
of about 40 feet, leaving a chasm on all sides of which a
vertical section is now seen of alternating stony lavas and
scorie. It is conceivable, therefore, that parts of the area
of the Val del Bove may, in like manner, have fallen in
during earthquakes; but I think it probable that by far the
greater portion of the huge cavity was caused by explosions
of pent-up vapours escaping from subterranean fissures,
during one or more lateral eruptions connected perhaps with
a temporary revival of the ancient focus of eruption which I
have called the axis of Trifoglietto.
Eruptions of Kina of historical date.—Truncation of the great
cone.—What I have hitherto said of the first existence of
Etna as a submarine volcano, the building up of the sub-
aérial part of the mountain by the pouring out of lava and
scoriz from two principal centres, the accompanying general
upheaval of the whole mass above the level of the sea, and
the probable origin of the Val del Bove, has been entirely
founded on geological inferences from the internal structure
of the mountain.
We may next turn to history and enquire what changes
are recorded to have taken place since the volcano was an
object of interest to the civilised world.
Ktna appears to have been in activity from the earliest
times of tradition; for Diodorus Siculus mentions an eruption
which caused a district to be deserted by the Sicani before
the Trojan war. Thucydides informs us, that in the sixth
year of the Peloponnesian War, or in the spring of the year
425 B.c., a lava stream ravaged the environs of Catania, and
CeZ
20 ETNA [Cu. XX}
this he says was the third eruption which had happened in
Sicily since the colonisation of that island by the Greeks
The second of the three eruptions alluded to by the historian
took place in the year 475 B.C., and was that so poetically
described by Pindar, two years afterwards, in his first
Pythian ode :—
KL@V
A’ ovpavia suvEexet
Nigdoeoo’ Aitva, TaveTes
Xuovos okeras TLOnva..
In these and the seven verses which follow, a graphic de-
scription is given of Etna, such as it appeared five centuries
—— 7
Gilli
Truncated appearance of the summit of Etna on the north-west side, as seen from
near Bronte.—From Sartorius von Waltershausen’s Atlas, plate 2.
a. Modern cone. 6,c. Margin of highest platform. d. Minor cones.
before the Christian era, and such as it has been seen when
in eruption in modern times. The poet is only making 4
passing allusion to the Sicilian voleano, as the mountain
under which Typheeus lay buried, yet by a few touches of his
master hand every striking feature of the scene has been
faithfully portrayed. We are told of ‘the snowy Btma, the
pillar of heaven—the nurse of everlasting frost, in whose deep
caverns lie concealed the fountains of unapproachable fire—
a stream of eddying smoke by day—a bright and ruddy flame
* Book iii., at the end.
j
graphic te
1Ve Centura
Cu. XXVI.] CHANGES IN APPEARANCE OF MOUNTAIN. 24
by night; and burning rocks rolled down with loud uproar
into the sea.’
Alessi in his history of Etna refers to Seneca, who, in the
first century of our era reminds Lucillius that mount Etna
had in his time lost so much of its height that it could be no
longer seen by boatmen from certain points whence it had
been previously visible. At a much later period, Falcando
relates that the lofty summit of Etna had fallen in in 1179,
and it was destroyed, according to Fazzello, for the third time
in 1329. Again it was engulphed for the fourth time in
1444, and finally the whole top of the mountain fell in in
1669.* The result of these and previous truncations may
well have produced the form of a truncated cone, represented
in the accompanying drawing (fig. 79).
Eruption of 1669. Monti Rossi formed.—The ereat eruption
last alluded to of 1669, deserves particular attention as the
first noticed by scientific observers. An earthquake had
levelled to the ground al! the houses in Nicolosi, a town
situated near the lower margin of the woody region, about
20 miles from the summit of Etna, and 10 from the sea
at Catania. Two gulfs then opened near that town, from
whence sand and scorie were thrown up in such quantity,
that in the course of three or four months, a double cone was
formed, called Monti Rossi (or Monte Rosso) about 450 feet
high. But the most extraordinary phenomenon occurred at
the commencement of the convulsion in the plain of S. Lio.
A fissure six feet broad, and of unknown depth, opened with
a loud crash, and ran in a somewhat tortuous course to
within a mile of the summit of Etna. Its direction was
from north to south, and its length 12 miles. It emitted a
most vivid light. Five other parallel fissures of consider-
able length afterwards opened one after the other, and
emitted vapour, and gave out bellowing sounds which were
heard at the distance of 40 miles. This case seems to
present the geologist with an illustration of the manner in
which those continuous dikes of vertical porphyry were
formed, which are seen to traverse some of the older lavas of
Ktna; for the light emitted from the great rent of 8. Lio
* Alessi, Storia critica dell’ Eruz. dell’ Etna, p. 149,
appears to indicate that the fissure was filled to a certain
height with incandescent lava, probably to the height of tit
orifice not far from Monti Rossi, which at that time opened
and poured out a lava current. When the melted mattey in
such a rent has cooled, it must become a solid wall or dike,
intersecting the older rocks of which the mountain ig coyy_
posed; similar rents have been observed during subsequent
eruptions, as in 1832, when they radiated in various directions
from the centre of the voleano. It has been remarked by M,
Elie de Beaumont, that such star-shaped fractures may
indicate a slight upheaval of the whole of Etna. They may
Minor cones on the flanks of Etna.
1. Monti Rossi, near Nicolosi, formed in 1669. 2. Monpileri.
’ I
be the signs of the stretching of the mass, which may thus
be raised gradually by a force from below.*
The lava current of 1669, before alluded to, soon reached
in its course a minor cone called Monpileri, at the base of
which it entered a subterranean erotto, communicating with
a suite of those caverns which are so common in the lavas of
Ktna. Here it appears to have melted down some of the
vaulted foundations of the cone, so that the whole of that hill
became slightly depressed and traversed by numerous opel
fissures. | y Recy
Part of Catania destroyed.—The lava, after overflowing Of aneie
fourteen towns and villages, some having a population of
*§
va , . . hi
* Mém. pour servir, &c., tom. iv. p. 116. t Rey
PaCtures ly
. They Tay
Gu. XXVL] RATE OF ADVANCE OF LAVA STREAM. 23
between 3,000 and 4,000 inhabitants, arrived at length at
the walls of Catania. These had been purposely raised
to protect the city; but the burning flood accumulated
till it rose to the top of the rampart, which was 60 feet in
height, and then it fell in a fiery cascade and overwhelmed
part of the city. The wall, however, was not thrown down,
but was discovered long afterwards, by excavations made in
the rock by the Prince of Biscari; so that the traveller may
now see the solid lava curling over the top of the rampart as
if still in the very act of falling.
This great current performed the first 13 miles of its
course in 20 days, or at the rate of 162 feet per hour, but
required 23 days for the last two miles, giving a velocity
of only 22 feet per hour; and we learn from Dolomieu
that the stream moved during part of its course at the rate
of 1,500 feet an hour, and in others took several days to
cover a few yards.* When it entered the sea it was still
600 yards broad, and 40 feet deep. It covered some ter-
ritories in the environs of Catania, which had never before
been visited by the lavas of Etna. While moving on, its
surface was in general a mass of solid rock; and its mode
of advancing, as is usual with lava streams, was by the
occasional fissuring of the solid walls. A gentleman of
Catania, named Pappalardo, desiring to secure the city
from the approach of the threatening torrent, went out with
a party of 50 men whom he had dressed in skins to pro-
tect them from the heat, and- armed with iron crows and
hooks. They broke open one of the solid walls which flanked
the current near Belpasso, and immediately forth issued a
rivulet of melted matter which took the direction of Paterné ;
but the inhabitants of that town, being alarmed for their
safety, took up arms and put a stop to further operations.t
As another illustration of the solidity of the walls of an
advancing lava stream, I may mention an adventure related
by Recupero, who, in 1766, had ascended a small hill formed
of ancient voleanic matter, to behold the slow and gradual
* See Prof. J. D. Forbes, Phil. Trans., 1846, p. 155, on Velocity of Lava.
{ Ferrara, Deseriz, della Etna, p. 108.
24 ETNA. [Cu, XXVI.
approach of a fiery current, 23 miles broad; when sud.
denly two small threads of liquid matter issuing from
crevice detached themselves from the main stream, and ran
rapidly towards the hill. He and his guide had just time t)
escape when they saw the hill, which was 50 feet in height,
surrounded, and in a quarter of an hour melted down into the
burning mass, so as to flow on with it. 15 t0
But it must not be supposed that this complete fusion of yet &
rocky matter coming in contact with lava is of universal, o; kt
even common occurrence. It probably happens when fresh | posed
portions of incandescent matter come successively in contact Che
with fusible materials. In many of the dikes which intersect The (
the tuffs and lavas of Etna, there is scarcely any perceptible parts
alteration effected by heat on the edges of the horizontal my fi
beds, in contact with the vertical and more crystalline mags, striki
On the site of Monpileri, one of the towns overflowed in the of th
ereat eruption above described, an excavation was made in
1704; and by immense labour the workmen reached, at the
depth of 35 feet, the gate of the principal church, where
there were three statues, held in high veneration. One D
of these, together with a bell, some money, and other articles, who
were extracted in a good state of preservation from beneath to hi
a great arch formed by the lava. It seems very extra- ' as
ordinary that any works of art, not encased with tuff, like islanc
those in Herculaneum, should have escaped fusion in hollow Th
spaces left open in this lava current, which was so hot at alread
Catania eight years after it had entered the town, thatitwas | and q
impossible to hold the hand in some of the crevices. tiles
Subterranean caverns on Htna.—Mention was made of the a pan
entrance of a lava stream into a subterranean erotto, whereby highes
the foundations of a hill were partly undermined. Such mount
underground passages are among the most curious features Bove,
on Etna, and may perhaps be caused by the sudden con- Visible
version into steam of lakes or streams of water overwhelmed mn the
by a fiery current. Great volumes of vapour thus produced the gm
may force their way through liquid lava already coated over throyy,
externally with a solid crust, and may cause the sides of
such passages as they harden to assume a very irregular
outline. Near Nicolosi, not far from Monti Rossi, one of the Va
nat time;
q
In heioti
WD into th
z fusion af
nlversal, a
When fre}
in COntag
- Intersa
perceptibk
horizontd
lline mags,
wed in the
S made in
ed, at the
ch, wher
Cu. XXVI.]. CHANGES PRODUCED BY MODERN ERUPTIONS. 25
these great openings may be seen, called the Fossa della
Palomba, 625 feet in circumference at its mouth, and 78
deep.. After reaching the bottom of this, we enter another
dark cavity, and then others in succession, sometimes de-
scending precipices by means of ladders. At length the
vaults terminate ina great gallery 90 feet long, and from
15 to 50 broad, beyond which there is still a passage, never
yet explored; so that the extent of these caverns remains
unknown. The walls and roofs of these great vaults are com-
posed of rough bristling scoriz, of the most fantastic forms.
Changes produced by modern eruptions in the Val del Bove.—
The change which had taken place in the aspect of several
parts of Etna, but especially in the Val del Bove, between
my first and second visits, or between 1825 and 1857, was very
striking. That deep chasm is called in the provincial dialect
of the peasants, ‘ Val di Bué,’ for here the herdsman
—— in reducta valle mugientium
Prospectat errantes greges.
Dr. Buckland was, I believe, the first English geologist
who examined this valley with attention, and I am indebted
to him for having described it to me, before I visited Sicily,
as more worthy of attention than any single spot in that
island, or perhaps in Europe.
The views, Plates V. and VI. above described, p. 7, have
already given the reader some idea of the scenery, looking up
and down the vast amphitheatre, which is between 4 and 5
miles in diameter. The accompanying view, fig. 81, is part of
a panoramic sketch, which I made from the summit of the
highest cone on December 1, 1828. Every part of the
mountain was then free from clouds, except the Val del
Bove, some of the upper precipices of which, alone, were
visible with their large vertical and projecting dikes as seen
in the drawing. The crater nearest the foreground and
the small cone adjoining, were among those which had been
thrown up during the eruptions of 1810 and 1811, or eighteen
years before my visit.
The lavas which were poured out from near the head of
the Val del Bove in those years, and subsequently in 1819,
26 ETNA. [Cu. XXvI,
flowed between some isolated rocks, called Finocchio, Capra,
and Musara, which are remnants of the old cone of Etna, not
destroyed | at the time when the Val del Bove was formed.
The position of these is pointed out at numbers 5, 6, and 9
in Plate V. Their height had already been much reduced by
the flowing round them of the currents of 1811 and 1819,
and in 1857 I found that the lavas of 1852 had still farther
diminished their importance. When I first saw them as I
b)
View from the summit of Etna into the Val del Bove.
ascended the valley, I compared them to the Trosachs in
the Highlands of Scotland which
Like giants stand
To sentinel enchanted land ;
though I remarked that the stern and severe grandeur of the
scenery which they adorned, was not such as would be
selected by a poet for a vale of ‘enchantment.’ The character
of the scene would accord far better with Milton’s picture of
the infernal world; and if we imagine ourselves to behold in
nd 181
hem as I
Cu. XXVI.] DESOLATE ASPECT OF THE REGION. D7
motion, in the darkness of the night, one of those fiery
currents which have so often traversed the great valley, we
may well recall
——yon dreary plain, forlorn and wild,
The seat.of desolation, void of ight,
Save what the glimmering of these livid flames
Casts pale and dreadful.
The strips of green herbage and forest land, which have
here and there escaped the burning lavas, serve, by contrast,
to heighten the desolation of the scene. When first I visited
the valley, nine years after the eruption of 1819, I saw
hundreds of trees, or rather the white skeletons of trees, on
the borders of the black lava, the trunks and branches being
Fig. 82.
ah
as
; Hi \ h My
Mall lh
fl r | Hy
2 !
rfl
Vie; if
wt, Mie
i Wan wtilhet Gee <A
WO BAY
thy
Wes mga (a> 3 Cpt ii 4, Gh
DIE D BPiNy ie i
We fe oF Tx ee yw, yy, eal
annniWw sated bp aed Do
View of the rocks Finocchio, Capra, and Musara, Val del Bove.
all leafless, and deprived of their bark by the scorching heat
emitted from the melted rock; an image recalling those
beautiful lines:—
s when heayen’s fire
Hath seath’d the forest oaks, or mountain pines,
With singed top their stately growth, though bare,
Stands on the blasted heath.
An unusual silence prevails throughout this region; for
there are no torrents dashing from the rocks, nor any move-
ment of running water in this valley, such as may almost
invariably be heard in mountainous regions. Every drop of
water that falls from the heavens, or flows from the melting
28 ETNA. (Cu. XXyyq,
ice and snow, is instantly absorbed by the porous lava; ang
such is the dearth of springs, that the herdsman is compelleq
to supply his flocks, during the hot season, from storeg of
snow laid up in hollows of the mountain during winter,
Late in the autumn, when the sun is shining, both on the
higher and lower parts of Etna, and on every other part of
Sicily, clouds of fleecy vapour often fill the Val del Bove, ang
are sometimes partially dispersed along the face of the lofty
precipices, causing the black outlines of the dikes to stand
out in picturesque relief. About midday, when the vapours
begin to rise, the changes of scene are varied in the highest
degree, different rocks being unveiled and hidden by turng,
and the summit of Etna often breaking through the clouds
for a moment with its dazzling snows, and being then ag
suddenly withdrawn from the view.
Eruptions of 1811 and 1819—I have alluded to the streams
of lava which were poured forth in 1811 and 1819. Gem-
mellaro, who witnessed these eruptions, informs us that the
great crater in 1811 first testified by its loud detonations,
that a column of lava had ascended to near the summit of
the mountain. A violent shock was then felt, and a stream
broke out from the side of the cone, at no great distance
from its apex. Shortly after this had ceased to flow, a
second stream burst forth at another opening, considerably
below the first; then a third still lower, and so on till seven
different issues had been thus successively formed, all lying
upon the same straight line. It has been supposed that
this line was a perpendicular rent in the internal framework
of the mountain, which rent was probably not produced at
one shock, but prolonged successively downwards, by the
weight, pressure, and intense heat of the internal column
of lava, as its surface subsided by gradual discharge through
each vent.*
In 1819 three large mouths or caverns opened very near
those which were formed in the eruptions of 1811, from
which flames, red-hot cinders, and sand were thrown up with
loud explosions. A few minutes afterwards another mouth
opened below, from which flames and smoke issued; and
* Serope on Voleanos, p. 160.
k
the Vapoy,
1 the highs
n by tam
vu)
©S tO sty)
of
h the clini
ing then y
the strean
819. Gen.
us that tl
detonation,
e summit i
nd a streal
at distant
to flow, }
Cw. XXVI.] ERUPTION OF AUGUST 1862. } 99
finally a fifth, lower still, whence a torrent of lava flowed,
which spread itself with great velocity over the Val del Bove.
When it arrived at the precipice called the Salto della
Giumenta at the head of the valley of Calanna, it poured
over in a cascade, and made an inconceivable crash as it was
dashed against the bottom. So immense was the column of
dust it raised by the abrasion of the tufaceous hill over which
the hardened mass descended, that the Catanians were in
ereat alarm, supposing a new eruption to have burst out in
the woody region, exceeding in violence that near the summit
of Etna.
Mr. Scrope observed this current in the year 1819, slowly
advancing down a considerable slope, at the rate of about a
yard an hour, nine months after its emission. The lower
stratum being arrested by the resistance of the ground, the
upper or central’ part gradually protruded itself, and, being
unsupported, fell down. This inits turn was covered by a
mass of more liquid lava, which swelled over it from above.
The current had all the appearance of a huge heap of rough
and large cinders rolling over and over upon itself by the
effect of an extremely slow propulsion from behind. The con-
traction of the crust as it solidified, and the friction of the
scoriform cakes against’ one another, produced a crackling
sound. Within the crevices a dull red heat might be seen
by night, and vapour issuing in considerable quantity was
visible by day.*
Eruption of August. 1852.—Of all the recorded eruptions
of Etna, with the exception of that of 1669 already men-
tioned, that which began in August 1852 and continued till
May of the following year, was the most remarkable for the
volume of lava which was poured out. In the annexed wood-
cut, fig. 83, [have given the outline of the two cones (marked
1852 in the Map, fig. 71) from which in that year the lava
issued, and in fig. 84 the course of the great stream is
pointed out as it flowed from those cones b, c, through the
Val del Bove, and beyond to Milo in one direction, or to the
left, and to Zafarana on the right. Scorize were thrown up
from the highest crater, and the largest of the two cones ¢,
* Serope on Volcanos, p. 102.
30 ETNA. [Cu XX
formed together with b at the base of the great precipice at
the head of the Val del Bove was about 500 feet high on
its eastern side at the end of 16 days. So great wag tie
expanse of molten matter that the whole valley when seen by
Dr. Giuseppe Gemmellaro at the end of August was like a seq
of fire. In September it reached the Salto della Giumenta
before mentioned. In its descent over the precipice jt
sounded as if metallic and glassy substances were bein
broken. The lava streams d d’, which poured out till the
latter part of November, were about 2 miles broad and 6
long. They continued to issue with some intermissions for
more than nine months until May 1853. The depth of
single streams was from 8 to 16 feet, but when piled over
:
Fig. ee
The two cones formed in the Val del Bove by the eruption of 1852.
la Grande
A. Lower part of
Gi i cone called Centenario.
6. Upper or western cone.
c. Lower to)
d. Commencement of current of lava of 1852,
one another they were from 30 to 50 feet thick, and at one
point near the Portella or lower entrance of the valley of
Calanna they seemed to me to have attained a thickness of
150 feet.
An unusual event, and one of no small oeological interest,
occurred some weeks after May 27th, when to all appearance
the flowing of lava had entirely ceased, and when all the
currents had become encrusted over with so firm a covering
of scoriz that the inhabitants could walk upon them with
safety. Within a certain area six or seven hundred yards in
diameter, and situated between Zafarana and Ballo, all the
fruit-trees and vines were struck dead as if by lightning.
The ground exhaled no hot gases,and the vegetation did
not suffer in the space intervening between the parched-up
area and the recent lava, which was only a few hundred
yards distant. Dr. Giuseppe Gemmellaro has suggested, as
the most natural explanation of the
phenomenon, that the
lava had gradually made its w
ay through underground pas-
© till the
ud and §
sions for
depth ¢f
ed over
$52.
0.
f lava of 1852.
d at one |
valley of
kness of
interest,
ITS APPEARANCE IN 1858. 31
Cu. XXVIL.]
sages, until coming beneath the fields alluded to, it dried up
the roots of the plants by its heat. It is well known (see
above, p. 24) that vaults and tunnels abound in many of
the modern lavas of Etna, and such empty spaces must some-
times at subsequent periods unavoidably become filled with
fused matter, which may then solidify under considerable
pressure, giving rise to masses of crystalline rock or some-
times perhaps to tortuous veins like those represented in
fig. 78, p. 17, and offering a perplexing problem to a geo-
logist who might obtain a section of them without having any
clue to the peculiar conditions under which they originated.*
Fig. 84.
Course of the lava currents through the Val del Bove in 1852-3,
as seen from above
a. Par la Grande : oe ig i
ge fig . Concs
e. Sto Finoochi Bas eae ae ‘folate.
f. Roc
In 1858 I found the surface of this lava of 1853 still giving
out columns of white steam from numerous fumeroles espe-
cially after heavy rains. Near Zafarana its surface is divided
into longitudinal ridges rising from 30 to 70 feet above
the bottom of the intervening and parallel depressions.
It was a melancholy sight to behold pastures which T had
seen verdant in 1828 in the valley of Calanna black and
desolate, and the region above so deluged with the sterilising
products of the late eruption that there had ceased to be
a picturesque contrast between tracts of the old forest and
dark strips of modern lava. The larger part of the great
valley had become one monotonous desert no longer support-
ing any cattle, nothing to justify its original name, and with
scarcely a living creature to be seen, though a few goats were
* Etna Paper, p. 22.
32 ETNA. [Cu. XXVI.
still driven up to browse on some shrubby knolls which haq
escaped the general devastation. After passing several days
without seeing even a goat, the footmarks of a wolf imprinteq
at one point on some loose volcanic sand quite surprised
me and made me enquire where they could still find any prey,
I crossed on foot a part of the new lava-field, in company
with Signor G. G. Gemmellaro, to the rock called Finocchio,
which in 1828 I had reached easily on mule-back. There
was now no foot-path leading to it, and we found the black
scoriaceous crust of the lava of 1852 bent into exceedingly
sharp, longitudinal ridges, separated by narrow interspaces,
from 20 to 40 feet deep, the sides of each ridge sloping
at angles of from 20° to 40° but seeming at some points
to be absolutely vertical. On the crests of each ridge were
fragments of scoriform lava, sometimes tabular, and stick-
ing up edgeways, like sheets of broken ice on a Canadian
river, where an obstruction or ‘jam’ has stopped the floating
masses. More frequently the projecting portions of the
superficial crust assumed the forms of gigantic madrepores,
or of various animals, such as dogs and deer, or still oftener
the heads of elks with branching horns. The surface often
resembled, in all but colour, the descriptions given of coral
reefs ; and at one moment when my foot slipped, I had an
opportunity of knowing that the stony asperities could tear
the flesh of my hands as readily as real corals. The stones
on the top and sides of most of the ridges were so loose, that
no sooner was one of them set a-rolling, than it started a
number of others, until a continuous avalanche poured down
into the trough below; but as we had to zigzag our way up
each steep ascent, there was little danger of one of us being
just under his companion when the torrent came down. Now
and then our direct march was arrested by a ridge, rendered
impassable by its steepness or the incoherence of the stony
fragments forming its crust, which obliged us to make a long
circuit, often with our backs turned towards our goal, the
hill of Finocchio. The manner in which detached blocks of
various shapes and sizes were occasionally poised one upon
another, on very narrow ridges, made us marvel that high
winds had not blown them down. T climbed up to some of
ions of th
madrepores,
still oftener
urface often
ven of con!
d, I hada
s could teat
Cu, XXVI.] ANCIENT LAVA CURRENTS CONFORMABLE. 33
them, to ascertain that they were not soldered on to the mass
of scoriz below; but I found them free to move and only
holding on by the slight inequalities of their surface.
When at length we reached Finocchio we found it standing
like a rocky islet submerged up to its middle in lavas of
different ages, and with the fresh current of 1852 near its
base. The relief afforded to the eye by that oasis was very
great; and although the day was cloudy, the green turf
enlivened by the flowers of a yellow ragwort, looked dazzling
by contrast with the dark surrounding desert, and the
autumnal crocus (colchicum autumnale), also in full bloom,
seemed more than ever beautiful.
The manner in which pieces of loose scorie had often rolled
down in great numbers from the ridges into the troughs of
the lava serves to show to what an extent superficial inequa-
lities may be reduced, or even effaced, when fresh currents
overflow older ones. This may partly account for the regu-
larity and parallelism of the successive stony lavas with their
upper and under scorie in the escarpments of the Val del
Bove; but the chief reason why those ancient currents are
for the most part so conformable to each other is, I believe,
the steepness of the slope down which they descended; the
lofty and sharp ridges above described being characteristic of
lavas flowing on more level ground or down slightly inclined
planes. When they descend very steep slopes the very
moderate thickness which they attain is alone sufficient to
preclude the possible formation of undulations like those just
described, which are from 10 to 30 feet or more in height.
Cascades of lava at Salto della Giwmenta.—Some very
instructive examples are to be seen at various points on
Mount Etna of the external form and internal structure
assumed by currents of lava of known date which have flowed
down very steep slopes. To one of these, which was precipi-
tated in 1819 down a precipice which forms the head of the
valley of Calanna, allusion has already been made, page 29.
This precipice, called the Salto della Giumenta, is about 400
feet high and several hundred wide. In the annexed drawing,
fig. 85, which I made in 1828, it is seen in profile with a
branch of the lava of 1819 a, flowing over it. Fig. 86 is a front
OT. it, D
34 ETNA.
[Cu. XXV].
view of the same, which I sketched in1858, when a much more
copious stream of melted matter (part of the current of 1852)
Fig. 85.
Modern lavas, as they are in 1828, 5, Mepecndiee the precipice called the Salto,
at the head of the valley of Calanna, and flowing round the hill of that name,
called Salto ig Giumenta, and flowing
thr nse 2 val
of a ‘aad 1819 flowing round the
. Zoccol
= Monte aL ceseiiie
C. ches in at the head of the Valley of
a a of were
ae of 1819 descending the precipice
had cascaded down the same height and overflowed the plain
below. The greater part, however, of the same current ¢, like
Till of price Fig. 86.
Hill of Caianna
Lava of 1852 aan down the precipice called Salto della Giumenta.
a, a. Portions of the face of the precipice sacle which had
composed of rocks like those of Zoccolaro an . Lava of 1852 which meee over the
Cc aan which have not been concealed by the pr ecipice
modern lavas.
os va oO 1819 w weet = we down and en-
crusted the face of the precipic
——>b. Same lava ae and the pro-
montory of Calanna, ase WwW ith the lava of
he same lava overflowing the level plain
of the Vv ley bas Ce ul ann a
', Same '
Pe peter pats of the older currents °
1811 and 18
7+he promonto ry
Jigs
fog
¥
ee «
) called the Sup
1 of that nam
enta, and foiy
9 flowing round t
ed the phi
wrrent ¢, lik
Cu. XXVI.] INCLINED LAVA OF CAVA GRANDE. 35
its predecessors of 1811 and 1819, turned round the promon-
tory formed by the Hill of Calanna, and moving right onwards
has been piled up on the left side of the Valley of Calanna so
as to heighten its boundary wall without flowing down into it.
Both the lavas of 1819 and 1852 had been covered origi-
nally in every part where they congealed on the face of the
steep precipice with the usual scoriaceous crust. But this
crust, about three feet thick, had been washed off by rain
at several places, and had exposed to view a solid and con-
tinuous stony layer below. The rock is somewhat vesicular,
and contains crystals of felspar, augite, and olivine, with
some titaniferous iron. As itis inclined at angles of from
35° to 50°, it affords a striking refutation of the doctrine that
stony layers can only consolidate on slopes of from 3° to 5°.
Inclined lava of Cava Grande.—Among other examples
attesting the erroneousness of the notion just alluded to, I
may call attention to another cascade of lava the internal
structure of which is still more clearly exposed to view. On
the eastern flank of Etna, north of Milo, is a deep and
narrow gulley called the Cava Grande (see Map, fig. 71),
which, although usually dry, has been entirely excavated
through successive beds of ancient lava and scorize by the
waters of occasional floods, which cascade over a perpen-
dicular precipice of a horseshoe form, at the upper end of
the ravine. The torrent is gradually cutting its way back-
wards, and thus adding to the length of the narrow valley.
I witnessed, October 1857, several avalanches of sand and
stones loosened from the terminal cliff by the heavy rains of
the preceding day. The boundary walls of the opposite sides
of the Cava Grande are 220 feet high, in part vertical, in
part sloping at angles of between 38° and 65°.
In the year 1689, a lava stream descended from the Val
del Bove in a direction nearly parallel to the Cava Grande,
but a portion of its left side was precipitated into the ravine
in the manner represented at a’ a’ a’ in figure 87.
In addition to the retrogressive excavation of the head of
the ravine caused by the torrent before mentioned, the steep
boundary precipices are also undergoing constant waste, by
which means a clear vertical section of the interior structure
D2
36 ETNA.
of the current @’
diagrams, figs. 87 and 88.
este
qm up ae
MED Se
all AS 2
2 waagiitees
Highly inclined lava of Cava Grande.
ips stream of lava of 1689 flowing
cast
a',a . Branch of ee same lava cascading
nor ee ards int avine ca se d the Cava
Grande with a mean inclinat ion 5°
scoriaceous part of
. Solid layer of stony lava from 2% to 5
Nee ©
[Cu. Xxyy
is exposed to view as shown in the
It is evident that when the lay,
y OT et
ile gall Patna g:
Vda 7
ons
(p lig
y! TM opepitne Ente
TAT Caralaa iy
<9 bs i ie ‘cease ~
RT
i Poe io Sy
WES ake Fs
ie ae
ae
~“ OZ Wor
From a sketch made October 1857,
feet thick, a at an eet of 35° and at
. Sco ming the base of the
mbponat a’, a’, and underlying the stony layerc.
e, f. Cliffco ie 10 ancient lava currents
f Etna, appearing horizontal, b
fact inclined at 7° to the east, or towards the
sea
reached the edge of the precipice, fragments of the solid
crust with much loose scorie first rolled down, producing a
talus by which the general slope of the cliff was reduced to
Fir = 88.
Supposed north and south section of the rocks at the Cava Grande near the head
the ravine.
a. Lava of 1689 with lofty parallel east
aN west ridges
b, c, d, e, 7. Same as in fig. 87.
.
Ca. XXVI.] FLOOD OF 1755 IN THE VAL DEL BOVE, 37
an angle of between 30° and 35°. Near the top, however, at
e, part of the lava consolidated at an angle of 47°, the stony
layer c being there only 24 feet thick, whereas it has twice
that thickness where it is less inclined (viz. at 35°) below.
The rock formed on this steep slope is as compact as our
ordinary ancient trap-rocks, and has the same specific
gravity as commonly belongs to them. It contains crystals
of felspar, and a small quantity of olivine. It is divided by
a few joints at right angles to the cooling surfaces.
Flood of 1755 wn the Val del Bove-—Before I allude to the
action of running water in excavating ravines on the flanks
of Htna, it may be well to mention the only instance on
record of a great body of water having passed from the
higher region of the mountain through the Val del Bove.
This occurred in the year 1755. An eruption had taken
place at the summit of the voleano, in the month of March,
a season when the top of the mountain was covered with
snow. ‘The Canon Recupero, a good observer, and a man of
great sagacity, was commissioned by Charles of Bourbon,
king of Naples, to report on the nature and cause of the
catastrophe. He accordingly visited the Val del Bove in the
month of June, three months after the event, and found that
the channel of the recent flood, nearly two miles broad, was
still strewed over with sand and fragments of rock to the
depth of 34 feet.
The volume of water in a length of one mile he estimated
at 16,000,000 cubic feet, and he says that it ran at the
rate of a mile in a minute and a half for the first twelve
miles. At the upper end of the Val del Bove, all the pre-
existing inequalities of the ground, for a space of two miles
in length, and one in breadth, were perfectly levelled up and
made quite even, and the marks of the passage of the flood
were traceable from thence up the great precipice (or Balzo
di Trifoglietto), to the Piano del Lago, or highest platform.
Recupero, in his report, maintains that if all the snow on
Etna, which he affirms is never more than four feet deep
(some chasms we presume excepted), were melted in one
instant, which no current of lava could accomplish, it would
not have supplied such a volume of water. He came therefore
38 ETNA.
[Cu. Xxyq.
to the somewhat startling conclusion, that the watey was
vomited forth by the crater itself, and was driven out from
some reservoir in the interior of the mountain.*
It seems to me very unlikely that the Canon, who wag on
the ground within three months of the date of the catas-
trophe, could have been mistaken in regard to the region
whence the waters came. His conclusions on that head seem
to have been legitimately deduced from the fact that the
wreck of the inundation was traceable continuously from the
sea-shore at Riposto up to the highest cone or its immediate
neighbourhood. I am, therefore, inclined to suspect that at
the time of the eruption of 1755 there was upon the summit
of Htna, not only the winter’s snow of that year, but many
older layers of ice alternating with volcanic sand and lava,
at the foot or in the flanks of the cone, which were suddenly
melted by the permeation through them of hot vapours, and
the injection into them of melted matter.
Glacier preserved by a covering of lava.—I stated in 1828,+
that I ascertained the fact of the existence of a glacier under
lava near the Casa Inglese, on the SE. side of the highest
cone, and that it had been quarried during the previous
summer, affording a supply of ice to the Catanians, at the
close of an unusually hot season. On returning thirty years
afterwards (September 1858), I found the same mass of ice,
of unknown extent and thickness, still unmelted. It had
been quarried only five years before, to the depth of four feet
on the very same spot. My guide told me that he had seen
this mass of solid ice, the bottom of which they did not
reach, and that it was overlaid by ten feet of sand, and the
sand again by lava.
Signor Mario Gemmellaro had satisfied himself in 1828, that
nothing but the subsequent flowing of the lava over the snow
could account for the position of the glacier. We may
suppose that, at the commencement of the eruption, a deep
mass of drift snow had been covered by volcanic sand
showered down upon it before the descent of the lava. A
dense stratum of this fine dust mixed with scorie is well
* Recupero, Storia dell’ Etna, p- 86.
{ Principles of Geology, 1st edition, p- 369.
apours, aul
din 18}
acier unl
the highs
Cu. XXVLJ EXISTENCE OF ICE UNDER LAVA. 39
known to be an extremely bad conductor of heat; and the
shepherds in the higher regions of Htna are accustomed to
provide water for their flocks during summer, by strewing a
layer of volcanic sand a few inches thick over the snow,
which effectually prevents the heat of the sun from pene-
trating.
Suppose the mass of snow to have been preserved from
liquefaction until the lower part of the lava had consolidated,
we may then readily conceive that a glacier thus protected,
at the height of 10,000 feet above the level of the sea,
would endure as long as the snows of Mont Blanc, unless
melted by volcanic heat from below. When I first visited
the summit of the highest cone in the beginning of winter
(December Ist, 1828), I found the crevices in the interior
encrusted with thick ice, and in some cases hot vapours were
actually streaming out between masses of ice and the rugged
and steep walls of the crater. Paradoxical, therefore, as it
may appear, we cannot doubt that a great mass of ice was
preserved from melting, by the singular accident of a current
of lava flowing over it.
If, then, glaciers may endure for a series of years under
volcanic sand and lava, the store of water which Recupero
speculated upon as contained somewhere in the interior of the
mountain, seems sufficiently accounted for. I am also now dis-
posed to attach more importance than when I first wrote on
this subject, to the tales of the mountaineers, which Recupero
thought worth recording. They related to him that the
water was boiling, that it was as salt as the sea, and that
it brought down with it sea-shells to the coast. Now it will
be seen that the hypothesis above suggested would very
naturally account for the water being hot, and it may have
been impregnated with saline matter exhaled from fumeroles
on the sides of the cone or from the crater itself during the
eruption, and these exhalations without giving to it the com-
position of sea-water, may have taken away its freshness. As
to the story of the marine shells, if the flood, after issuing
from the Val del Bove, cut deeply through the superficial
lava or the alluvium between Milo and Giarre, it may have
reached some of the beds of the subjacent Newer Pliocene
40 ETNA.
[Cu. XXyy.
clay, at the height of 1,000 or 1,200 feet above the
washing out of it fossil shells of living species stron
to bear transportation as far as Riposto.
Ancient valleys of Htna.—The action of voleanos ig, ag we
have already seen, characteristically intermittent even when
they are in a phase of frequent eruption ; but we have s00d
reason to believe that if their history could be known for
thousands of years, we should find that there are very long
periods, during which they le dormant, and then have their
fires resuscitated. From Junghuhn’s account of the numerous
cones of Java it appears that these volcanos are subject to
protracted periods of inaction, during which valleys, deepen-
ing as they descend, are eroded by running water on all their
sides ; at length a paroxysmal outburst occurs, by which part
of the cone is destroyed, and then lavas again pour out from
time to time. Mr. Dana, in his account of the great cones
of the Sandwich Islands, states, that the comparative length
of the periods during which any one of them has been at
rest may be estimated by the depth and size of the valleys
which furrow their sides; but the time which such denuda-
tion may have occupied has often been so vast that we cannot
attempt, with our present knowledge, to form any conjecture
as to its duration.
From what was said of Vesuvius in the last chapter, the
reader is aware that until the year 79 of our era, it had
all the characters of an extinct voleano. The only part of
the exterior of the ancient cone which still retains that
physiognomy by which the whole of it must have been cha-
racterised before the renewal of its volcanic activity, is the
northern side, scarcely ever visited by travellers, and which
we have described as being intersected by numerous deep
ravines, radiating as from a central axis towards all points of
the compass. On ascending several of these ravines, we have
seen that they terminate abruptly in perpendicular precipices
from 60 to 300 feet in height, where in the rainy season
there are waterfalls.* Above the head of such precipices
shallow valleys continue upwards to the crest of the boundary
Sea,
§ enough
wall of the Atrio del Cavallo, and no doubt were once con-—
* See Vol. I. p. 634.
Cz. XXVI.] PROBABLE ORIGIN OF THE MOUNTAIN. 4]
tinued to near the summit of the old cone of Somma, before
that mountain was truncated in the year 79.
In like manner I conceive that, long before the historical
era, Mount Etna may have been furrowed on all sides by
valleys during a long interval of comparative rest, or, perhaps,
a total suspension of eruptions.
The vast deposits of alluvial matter, more than 100 feet
thick, which are seen along the coast eastward of the Val del
Bove, between Giarre and Mangano, and which may some-
times be traced up to the height of 400 feet, attest the
enormous amount of erosion which the eastern flanks of
Htna have undergone at a remote period.
At length one or more paroxysmal outbreaks, to which the
Val del Bove may have owed its origin, ushered in a period
of renewed activity to which the lateral cones are principally
due. The lavas pouring out successively on the northern,
western, and southern flanks obliterated all the ancient
valleys on those three sides, and would have done the same
on the eastern flank of the cone had they not been inter-
cepted in their course by that huge chasm, the Val del Bove,
which they have already, in great part, filled up. Three
valleys or ravines, which have escaped obliteration, deserve
notice as bearing the same relation to the margin of the Val
del Bove which the valleys on the north of Vesuvius (those of
the Casa dell’ Acqua and others, described at page 634,
Vol. I.) bear to the Atrio del Cavallo. These three valleys
on the south-east side of Etna are the Valle del Tripodo, the
Valle dei Zappini, and the Valle di Calanna, the position of
which will be seen in the Map, fig. 71, p.10. The first of them,
the Valle del Tripodo, although not difficult of access from
Zafarana, is scarcely ever visited by travellers. It is a beau-
tiful, wooded-alpine ravine down which a torrent flows. On
reaching the head of this ravine, or the col which divides it
from the Val del Bove, a truly splendid view is obtained of
all the grand features of that vast amphitheatre before de-
scribed. Although the col is no less than 7,000 feet high
above the level of the sea, it forms the lowest part of a
deep notch in the southern escarpment of the Val del Bove
or the Serra del Solfizio. (See Map, fig. 71.) The depth of the
42 ETNA.
(Cx. XxXyy,
gap must be great as it enables an observer, looking at Etna
from a vessel at sea off Aci Castello, to get a view of the Va]
del Bove through the opening. This notch is a section of a
ravine of denudation once continuous with the Valle del
Tripodo, which furrowed the old cone before the Val de]
Bove was formed.
The second valley, called ‘dei Zappini,’ runs parallel to the
former, and is similar in its geological features though legs
grand. ‘The torrents that drain both of them are swallowed
up at their lower end in the holes and grottoes of the ereat
lava current of 1792, which, flowing down from a different
and higher part of Etna, crossed the channels of these
torrents and blocked up the ravines in which they flow.
The third valley, that of Calanna before alluded to, is the
most interesting because at its upper end we find the preci-
pice before described, figs. 85 and 86, p. 34, over which the
modern lavas of 1819 and 1852 have cascaded. There can
be no doubt that this precipice, the Salto della Giumenta, was
the site of a waterfall when a river flowed down from the
ancient cone, before the origin of the Val del Bove. The
space between the hills of Zoccolaro and Calanna indicates
the place of the upper valley, while the Salto was formed by
the river cutting its way backwards after the manner of the
stream in the Cava Grande before described, p. 35, or of the
retrograding torrents of Vesuvius, or, to compare small things
with great, the river Niagara at its falls.
If Vesuvius continues to be as active as it has been for the
last eighteen centuries, its lavas may one day top the crest
of the Atrio and cascade over the precipices at the head of
the Casa del’ Acqua and the Fosso di Cancharoni, in the same
way as the Htnean streams of 1819 and 1852 have cascaded
down the Salto della Giumenta.
Antiquity of the cone of Etna.—It was before remarked (Vol.
I. p. 91) that confined notions in regard to the quantity of
past time have tended, more than any other prepossessions,
to retard the progress of sound theoretical views in geology;
the inadequacy of our conceptions of the earth’s antiquity
having cramped the freedom of our speculations in this
science, very much in the same way as a belief in the exist-
(Cay, |
Zatp | |
of they {
‘Ctoy af
» a |
Vall dy
le Val dg ‘
lel tp the |
ough leg |
Cua. XXVI.] PROBABLE AGE OF THE MOUNTAIN. 43
ence of a vaulted firmament once retarded the progress of
astronomy. It was not until Descartes assumed the indefinite
extent of the celestial spaces, and removed the supposed
boundaries of the universe, that just opinions began to be
entertained of the relative distances of the heavenly bodies ;
and until we habituate ourselves to contemplate the possi-
bility of an indefinite lapse of ages having been comprised
within each of the modern periods of the earth’s history, we
shall be in danger of forming most erroneous and partial
views in geology.
If history had bequeathed to us a faithful record of the
eruptions of Etna, and 100 other of the principal active
volcanos of the globe, during the last 3,000 years,—if we had
an exact account of the volume of lava and matter ejected
during that period, and the times of their production,—we
might, perhaps, be able to form: a correct estimate of the
average rate of the growth of a volcanic cone. For we might
thus obtain a mean result by the comparison of the eruptions
of so great a number of vents, however irregular might be
the development of the igneous action in any one of them, if
contemplated singly during a brief period.
It would be necessary to balance protracted periods of in-
action against the occasional outburst of paroxysmal explo-
sions. Sometimes we should have evidence of a repose of
Seventeen centuries, like that which was interposed in Ischia,
between the end of the fourth century B. c. and the beginning
of the fourteenth century of our era.* Occasionally a tre-
mendous eruption like that of Jorullo or that of Papandayang
and others alluded to at page 11, would be recorded, giving
rise at once to a new mountain, or to the truncation of an
ancient cone, or to some vast lateral cavity like the Val del
Bove. But the comparative rarity of such catastrophes
exalts our conception of the great duration of the intervals
of rest which occur between eras of paroxysmal violence.
If we desire to approximate to the age of Etna, we ought
first to obtain some data in regard to the thickness of matter
which has been added during the historical era, and then
endeavour to estimate the time required for the accumulation
* See Vol. I. p. 606.
44 ETNA.
(Cu. XXyq.
of such alternating lavas and beds of sand and scorie ag are
superimposed upon each other in the Val del Bove; after.
wards we should try to deduce, from observations on Other
volcanos, the more or less rapid increase of burning moun-
tains in all the different stages of their growth.
Although it is possible that some of the ancient eruptions
of which the products are seen in the walls of the Val do]
Bove were on as grand a scale as those of our own time or
even grander, yet we should in vain seek for evidence that
any one of those ancient currents equalled in volume the
lavas of 1669 or those of 1852.
There is a considerable analogy between the mode of in-
crease of a volcanic cone and that of trees of exogenous growth,
These trees augment, both in height and diameter, by the
successive application externally of cone upon cone of new
ligneous matter; so that if we make a transverse section
near the base of the trunk, we intersect a much greater
number of layers than nearer to the summit. When branches
occasionally shoot out from the trunk, they first pierce the
bark, and then, after growing to a certain size, if they
chance to be broken off, they may become inclosed in the
body of the tree, as it augments in size, forming knots in
the wood, which are themselves composed of layers of ligneous
matter, cone within cone.
In like manner, a voleaniec mountain consists, as we have
seen, of a succession of conical masses enveloping others,
while lateral cones, having a similar internal structure, often
project in the first instance, like branches from the surface
of the main cone, and then becoming buried again, are hidden
like the knots of a tree.
We can aseertain the age of an oak or pine by counting
the number of concentric rines of annual growth seen in a
transverse section near the base, so that we may know the
date at which the seedling began to vegetate. The Baobab-
tree of Senegal (Adansonia digitata) is supposed to exceed
almost any other in longevity. Adanson inferred that one
which he measured, and found to be thirty feet in diameter,
had attained the age of 5,150 years. Having made an.
incision to a certain depth, he first counted 300 rings
STUD tion
Val del
de of ip.
ig growth,
r, by the
1@ of ney
e section
Cu. XXVI.] ITS GREAT ANTIQUITY. 45
of annual growth, and observed what thickness the tree
had gained in that period. The average rate of growth of
younger trees, of the same species, was then ascertained, and
the calculation made according to a supposed mean rate of
increase. De Candolle considers it not improbable that the
celebrated Taxodium of Chapultepec, in Mexico (Cupressus
disticha Linn.), which is 117 feet in circumference, may be
more aged.
It is, however, impossible, until more data are collected
respecting the average intensity of the volcanic action, to
make anything like an approximation to the age of a cone
like Etna; because, in this case, each successive envelope of
lava and scorie is not of simultaneous growth round the
mountain, like the layers of wood round a tree, and therefore
affords us no corresponding and definite measure of time.
Hach conical envelope is made up of a great number of dis-
tinct lava currents and showers of sand and scorie differing
in width and depth, and also the results of intermittent
action exceedingly variable as to intensity and frequency of
recurrence. Yet we cannot fail to form the most exalted
conception of the antiquity of this mountain, when we con-
sider that its base is about 90 miles in circumference; so
that it would require 90 flows of lava, each a mile in
breadth at their termination, to raise the present foot of the
volcano as much as the average height of one lava current.
The injection of several thousand dikes into the mass of
matter previously accumulated, is more comparable, as M. E.
de Beaumont has hinted, to the endogenous growth of a tree
implying the stretching outwards and perhaps upwards also
ofthe mountain. But observations within the historical era
are too imperfect to enable us to decide whether the moun-
tain has gained or lost in altitude at those periods when new
fissures have been formed and filled.
Of the 80 most conspicuous minor cones which adorn the
flanks of Etna, only one of the largest, Monti Rossi, has been
produced within the times of authentic history. Even this
hill, thrown up in the year 1669, although 450 feet in height,
only ranks as a cone of second magnitude. Monte Minardo,
near Bronte, rises, even now, to the height of 750 feet,
46 ETNA. [oxy oF
although its original base has been elevated by more modern “
lavas and ejections. It must also be remembered, that of the ot
small number of lava streams which are poured forth in a a
century, one only is estimated to issue from the summit of | i
Ktna for every two that proceed from the sides. Noy do all | : e
the lateral eruptions give rise to such hills ag would he we
reckoned amongst the 200 lateral cones before alluded to We °
: - ; ’ Mon
p- 2, as laid down in Waltershausen’s map. Some of them ht
produce merely insignificant monticules, which are goon after wi
overwhelmed by showers of ashes proceeding from higher bs
vents. bi
How many years, then, must we not suppose to have been bi
expended in the formation of all the minor cones? Tf we o
could strip off from Etna the whole of those now visible, be
together with the lavas and scorize that have been poured out ills
from them, and from the highest crater, during the period Sl
of their growth, the diminution of the entire mass would be -
extremely slight: Etna might lose, perhaps, several miles in
diameter at its base, but the aspect of the woody region Be:
would not be essentially changed, because other minor cones, .
now concealed, would be recalled as it were into existence by .
the removal of the lava and ejected matter under which they bi
now lie buried. As to the height of the mountain during _
the early stages of the phase of lateral eruptions, it may have We
been much greater before its summit was truncated than it 10
is now, even if we make allowance for a slight accession of a
height due to the gradual upheaval of the whole mass above Bes,
the level of the sea, as testified by the raised beaches on the and
coast before described. neg
To attempt to estimate the number of centuries which have
elapsed since the first submarine eruptions began would be
idle, because there may have been periods of tranquillity
such as that in which the ancient valleys were excavated,
enduring perhaps for tens of thousands of years, and then
followed by paroxysmal outbursts like that to which the
Val del Bove may have owed its origin.
No general deluge can have occurred in the forest zone of
Etna since the lateral cones were thrown up. For few, if
any, of these heaps of loose scorix could fail to have been
Would
ludeg ty
OF then
‘00D afte
M higher,
Cu. XXVL] ITS GREAT ANTIQUITY. 47
swept away by a great flood, and all of them would have ex-
hibited some signs of its denuding action. To some, perhaps,
it may appear that hills of such incoherent materials cannot
be of very great antiquity, because the mere action of the
atmosphere must, in the course of several thousand years,
have obliterated their original forms. But there is no
weight in this objection; for although the steep slopes of
Monti Rossi, being still bare and composed in great part of
light scorie and fine volcanic sand, have been acted upon both
by wind and rain within the memory of persons now living,
yet the older hills have been protected from waste ever since
they have been covered with trees and herbage. Even before
dense vegetation has been established, such is the porosity
of their component materials, that almost all the rain which
falls upon them is instantly absorbed; and for the same
reason that the rivers on Etna have a subterranean course,
there are no rills descending the sides of the minor cones.
In conclusion, I may remind the reader that, however vast
may be the lapse of ages which we require for the growth of
a mountain like Etna, there has been ample time for its pas-
sage through every phase of its development. Its foundations
were laid in the sea, in the Newer Pliocene period—that sea
in which the shells of Aci Castello and Trezza flourished.
We have seen at p. 6 that the events of the Glacial Period,
though they may have occupied several hundred thousand
years, do not reach back to an era when the assemblage of
marine testacea differed as much as those of Aci Castello
and Trezza differ from the fauna now characterising the
neighbouring parts of the Mediterranean.
CHAPTER XXVIII.
VOLCANIC ERUPTIONS—conceluded.
VOLCANIC ERUPTION IN ICELAND IN 1783—NEW ISLAND THROWN UP—nrayaA
OF THE PLAIN OF MALPAIS—ERUPTION OF GALONGOON IN JAVA J
VOLCANOS—GRAHAM ISLAND, FORMED IN 1831—vorcaNnIc ARCHIPELAGOS—
ARREN
ISLAND IN THE BAY OF BENGAL——-MUD VOLCANOS—MINERAL COMPOSITION OF
VOLCANIC PRODUCTS.
VOLCANIC ERUPTIONS IN IcELAND.—With the exception of
Etna and Vesuvius, the most complete chronological records
of a series of eruptions are those of Iceland, for their history
reaches as far back as the ninth century of our era; and,
from the beginning of the twelfth century, there is clear
evidence that, during the whole period, there has never been
an interval of more than forty, and very rarely one of twenty
years, without either an eruption or a great earthquake. So
intense is the energy of the volcanic action in this region,
that some eruptions of Hecla have lasted six years without
ceasing. Earthquakes have often shaken the whole island
at once, causing great changes in the interior, such as the
sinking down of hills, the rending of mountains, the desertion
by rivers of their channels, and the appearance of new lakes.*
New islands have often been thrown up near the coast, some
of which still exist; while others have disappeared, either by
substdences or the action of the waves.
In the interval between eruptions, innumerable hot springs
afford vent to the subterranean heat, and solfataras discharge
copious streams of inflammable matter. The volcanos im
different parts of this island are observed, like those of the
* Von Hoff, vol. ii. p. 393.
OSITION OF
‘ception
~al recor |
pir history
era; aul |
e is cleat
ever bea
of twell!
ake, 9
Ca. XXVIL] ERUPTIONS OF SKAPTAR JOKUL, 49
Phlegrean Fields, to be in activity by turns, one vent often
y
a
serving for a time as a safety-valve to the rest. Many cones
‘are often thrown up in one eruption, and in this case they
take a linear direction, running generally from north-east to
south-west, from the north-eastern part of the island, where
the volcano Krabla lies, to the promontory Reykianas.
Great eruption of Skaptar Jokul in 1783.—New island thrown
wp.—The convulsions of the year 1783 appear to have been
more tremendous than any recorded in the modern annals of
Iceland; and the original Danish narrative of the catastrophe,
drawn up in great detail, has since been substantiated by
several English travellers, particularly in regard to the pro-
digious extent of country laid waste, and the volume of lava
produced.* About a month previous to the eruption of
Skaptar Jokul on the mainland, presently to be mentioned, a
submarine volcano burst forth in the sea in lat. 63° 25/ N.,
long. 23° 44’ W., at a distance of 30 miles in a south-west
direction from Cape Reykianas, and ejected so much pumice,
that the ocean was covered with that substance to the dis-
tance of 150 miles, and ships were considerably impeded in
their course. A new island was formed, from which fire,
smoke, and pumice were emitted at different points. This
island was claimed by his Danish Majesty, who denominated
it Nye, or the New Island; but before a year had elapsed,
the sea resumed its ancient domain, and nothing was left but
a reef of rocks from 5 to 30 fathoms under water.
Earthquakes which had long been felt in Iceland, became
violent on June 11, 1783, when Skaptar Jokul, distant nearly
200 miles from Ny6e, threw out a torrent of lava which
flowed down into the Skapta, and completely dried it up.
The channel of the river was between high rocks, in many
places from 400 to 600 feet in depth, and near 200 in breadth.
* The first narrative of the eruption and length of the lava currents, by re-
Was drawn up by Stephenson, then Chief ference to the MS. of Mr. Paulson, who
Justice in Iceland, appointed commis- visited the tract in 1794, and examined
erat by the ing of Denmark for _ the lava with attention. (Journal of a
amage done to the Residence in Iceland, &c., p. 229.) Some
that relief might be affordedto of the principal facts are also corro-
oe € Henderson was enabled borated by Sir William | Hooker, in his
be Cet some of the measurements ‘Tour in Iceland,’ vol. ii. p. 128
Biven by Stephenson, of the depth, width,
OL. II, K
50 VOLCANIC ERUPTIONS IN ICELAND,
[Cu XXyyyp
Not only did the lava fill up this great defile to the b
but it overflowed the adjacent fields to a considerable e
The burning flood, on issuing from the confined rocky gorge,’
was then arrested for some time by a deep lake, which for.
merly existed in the course of the river, between Skaptarda]
and Aa, which it entirely filled. The current then advanced
again, and reaching some ancient lava full of subterraneong
caverns, some of them apparently filled with water, melted
parts of the rock and blew up others, throwing large frag.
ments to the height of 150 feet into the air. On June 18,
another ejection of liquid lava rushed from the volcano, which
flowed down with amazing velocity over the surface of the
first stream. By the damming up of the mouths of some of
the tributaries of the Skapta, many villages were completely
overflowed with water, and thus great destruction of property
was caused. The lava, after flowing for several days, was
precipitated down a tremendous cataract called Stapafoss,
where it filled a profound abyss, which that great waterfall
had been hollowing out for ages, and after this, the fiery
current again continued its course.
On August 3, fresh floods of lava still pouring from the
volcano, a new branch was sent off in a different direction ;
for the channel of the Skapta was now so entirely choked up,
and every opening to the west and north was so obstructed,
that the melted matter was forced to take a new course, so
that it ran in a south-east direction, and discharged itself
into the bed of the river Hverfisfliot, where a scene of de-
struction scarcely inferior to the former was occasioned.
These Icelandic lavas (like the ancient streams which are
met with in Auvergne, and other provinces of Central
France), are stated by Stephenson to have accumulated to
a prodigious depth in narrow rocky gorges; but when
they came to wide alluvial plains, they spread themselves
out into broad burning lakes, sometimes from 12 to
miles wide, and 100 feet deep. When the ‘fiery lake’
which filled up the lower portion of the valley of the Skapta
had been augmented by new supplies, the lava flowed up
the course of the river to the foot of the hills from whence
the Skapta takes its rise. This affords a parallel case to one
rink,
xtent,
ano, Which
ace of thy
of some ¢
complete;
f proper
days, wa
Stapafie,
t waterfall |
the fie
from tle
directio1;
Cu, XXVIL] IMMENSE VOLUME OF THE LAVA. 51
which can be shown to have happened at a remote era in the
voleanic region of the Vivarais in France, where lava issued
from the cone of Thueyts, and while one branch ran down,
another more powerful stream flowed up, the channel of the
river Ardéche.
The sides of the valley of the Skapté present superb ranges
of basaltic columns of older lavas, resembling those which
are laid open in the valleys descending from Mont Dor in
Auvergne, where more modern lava currents, on a scale very
inferior in magnitude to those of Iceland, have also usurped
the beds of the existing rivers. The eruption of Skaptar
Jokul did not entirely cease till the end of two years ; and
when Mr. Paulson visited the tract eleven years afterwards
in 1794, he found columns of smoke (or vapour) still rising
from parts of the lava, and several rents filled with hot
water.*
Although the population of Iceland was very much scattered,
and did not exceed 50,000, no less than twenty villages were
destroyed, besides those inundated by water; and more than
9,000 human beings perished, together with an immense
number of cattle, partly by the depredations of the lava,
partly by the noxious vapours which impregnated the air,
and, in part, by the famine caused by showers of ashes
throughout the island, and the desertion of the coasts by the
fish.
Immense volume of the lava.—But the extraordinary volume
of melted matter produced in this eruption deserves the
particular attention of the geologist. Of the two branches,
which flowed in nearly opposite directions, the greatest was
50, and the lesser 45 miles in length. The extreme breadth
which the Skapt’ branch attained in the low countries
defiles it sometimes amounted to 600. Professor Bischoff
1, that the mass of lava brought up from
by this single eruption ‘surpassed
mM magnitude the bulk of Mont Blane’+ But a more
* Henderson’s Journal, &e., p. 228.
t Jameson's Phil. Journ. vol. xxvi. p. 291.
E 2
52 ANCIENT AND MODERN LAVAS COMPARED. [Cz xxyp
distinct idea will be formed of the dimensiong of the two
streams, if we consider how striking a feature they would
now form in the geology of England, had they been poured
out on the bottom of the sea after the deposition, and before
the elevation of our secondary and tertiary rocks, The
same causes which have excavated valleys through parts of
our marine strata, once continuous, might have acted with
equal force on the igneous rocks, leaving, at the same time
a sufficient portion undestroyed to enable us to discover
their former extent. Let us, then, imagine the termination
of the Skapta branch of lava to rest on the escarpment of the
inferior and middle oolite, where it commands the vale of
Gloucester. The great platform might be 100 feet thick,
and from 10 to 15 miles broad, exceeding any which can be
found in Central France. We may also suppose great tabular
masses to occur at intervals, capping the summit of the Cots-
wold Hills between Gloucester and Oxford, by Northleach,
Burford, and other towns. The wide valley of the Oxford clay
would then occasion an interruption for many miles ; but the
same rocks might recur on the summit of Cumnor and Shot-
over Hills, and all the other oolitic eminences of that district,
On the chalk of Berkshire, other tabular masses, 6 or 7 miles
wide, might again be found; and, lastly, crowning the
highest sands of Highgate and Hampstead, we might behold
some remnants of the current 500 or 600 feet in thickness,
causing those hills to rival, or even to surpass, in height,
Salisbury Craigs and Arthur’s Seat.
The distance between the extreme points here indicated
would not exceed 90 miles in a direct line; and we might
then add, at the distance of nearly 200 miles from London,
along the coast of Dorsetshire and Devonshire, for example,
a great mass of igneous rocks, to represent the submarine
reef of the island of Nyéde. An eminent French writer
declared in 1829 that all geological phenomena took place
in ancient times on a scale of magnitude a hundredfold
greater than those which are witnessed in our days, but it
would be difficult to point out a mass of igneous rock of
ancient date (distinctly referable to a single eruption) which
Cu, XXVIL] ERUPTION OF JORULLO, A.D, 1759, 53
would even rival in volume the matter poured out from
Skaptar Jokul in 1783.
Eruption of Jorullo im 1759.—As another example of the
stupendous scale of modern volcanic eruptions, I may mention
that of Jorullo in Mexico, in 1759. The great region to which
this mountain belongs has already been described. The plain
of Malpais forms part of an elevated platform, between 2,000
and 3,000 feet above the level of the sea, and is bounded by
hills composed of basalt, trachyte, and volcanic tuff, clearly
indicating that the country had previously, though probably
at a remote period, been the theatre of igneous action. From
the era of the discovery of the New World to the middle of
the last century, the district had remained undisturbed, and
the space, now the site of the volcano, which is 36 leagues
distant from the nearest sea, was occupied by fertile fields of
sugar-cane and indigo, and watered by the two brooks
Cuitimba and San Pedro. In the month of J une, 1759,
hollow sounds of an alarming nature were heard, and
earthquakes succeeded each other for two months, until, at
the end of September, flames issued from the ground, and
fragments of burning rocks were thrown to prodigious
heights. Six volcanic cones, composed of scoriz and frag-
mentary lava, were formed on the line of a chasm which ran
in the direction from NNE. to SSW. The least of these
cones was 300 feet in height; and Jorullo, the central
volcano, was elevated 1,600 feet above the level of the plain.
Tt sent forth great streams of basaltic lava, containing
included fragments of granitic rocks, and its ejections did not
cease till the month of February, 1760.*
Humboldt visited the country more than forty years after
this occurrence, and was informed by the Indians, that when
they returned, long after the catastrophe, to the plain, they
found the ground uninhabitable from the excessive heat:
When he himself visited the place, there appeared, around the
base of the cones, and spreading from them, as from a centre,
over an extent of four square miles, a mass of matter of a
Convex form, about 550 feet high at its junction with the cones,
* Daubeny on Volcanos, p. 337.
54 CONVEXITY OF THE PLAIN OF MALPAIS, [Cu. XXvqq
and gradually sloping from them in all directions towards the
plain. This mass was still in a heated state, the tempe-
rature in the fissures being on the decrease from year to year,
but in 1780 it was still sufficient to ight a cigar at the depth
of a few inches. On this slightly convex protuberance, the
slope of which must form an angle of about 6° with the
horizon, were thousands of flattish conical mounds, from ¢
to 9 feet high, which, as well as large fissures traversing
the plain, acted as fumeroles, giving out clouds of sulphurous
acid and hot aqueous vapour. The two small rivers before
mentioned disappeared during the eruption, losing themselves
1g. 89
6
eee ee ‘
<<
+ 1 £ POF.
+ =) 5
a. Summit of Jorullo. b, c. Inclined pl
below the eastern extremity of the plain, and reappearing as
hot springs at its western limit.
Cause of the convexity of the plain of Malpais.—Humboldt
attributed the convexity of the plain to inflation from below;
supposing the ground, for four square miles in extent, to
have risen up in the shape of a bladder to the elevation of
550 feet above the plain in the highest part. But Mr. Serope
has suggested that the phenomena may be accounted for far
more naturally, by supposing that lava flowing simultaneously
from the different orifices, and principally from Jorullo,
united into a sort of pool or lake. As they were poured forth
on a surface previously flat, they would, if their liquidity was
not very great, remain thickest and deepest near their source,
and diminish in bulk from thence towards the limits of the
space which they covered. Fresh supplies were probably
emitted successively during the course of an eruption which
lasted more than half a year ; and some of these, resting 0
those first emitted, might only spread to a small distance
_ from the foot of the cone, where they would necessarily
accumulate to a great height. The average slope of the
great dome-shaped volcanos of the Sandwich Islands, formed
almost exclusively of lava, with scarce any scorie, is betwee? -
° ° . . .
6° 380’ and 7° 46’, so that the inclination of the convex mass
around Jorullo, if we adopt Mr. Serope’s explanation (see
Cu. XXVII.] CONVEXITY OF THE PLAIN OF MALPAIS. 4)
fig. 89), is quite in accordance with the known laws which
govern the flow of lava.
The showers, also, of loose and pulverulent matter from the
six craters, and principally from Jorullo, would be composed
of heavier and more bulky particles near the cones, and
would raise the ground at their base, where, mixing with
rain, they might have given rise to the stratum of black clay,
which is described as covering the lava. The small conical
mounds (called ‘ hornitos,’ or little ovens) may resemble those
five or six small hillocks which existed in 1823 on the
Vesuvian lava, and sent forth columns of vapour, having been
produced by the disengagement of elastic fluids heaving up
small dome-shaped masses of lava. The fissures mentioned
by Humboldt as of frequent occurrence, are such as might
naturally accompany the consolidation of a thick bed of lava,
contracting as it congeals; and the disappearance of rivers
is the usual result of the occupation of the lower part of a
valley or plain by lava, of which there are many beautiful
examples in the old lava currents of Auvergne. The heat of
the ‘hornitos’ is stated to have diminished from the first ;
and Mr. Bullock, who visited the spot many years after
Humboldt, found the temperature of the hot spring very low
—a fact which seems clearly to indicate the gradual conge-
lation of a subjacent bed of lava, which from its immense
thickness may have been enabled to retain its heat for half
acentury. The reader may be reminded, that when we thus
Suppose the lava near the volcano to have been, together
with the ejected ashes, more than 500 feet in depth, we
merely assign a thickness which the current of Skaptar Jokul
attained in some places in 1783.
Hollow sound of the plain when struck.—Another argument
adduced in support of the theory of inflation from below, was,
the hollow sound made by the steps of a horse upon the
plain; which, however, proves nothing more than that the
materials of which the convex mass is composed are light and
Porous. The sound called ‘rimbombo’ by the Italians is
very commonly returned by made ground when struck sharply ;
and has been observed not only on the sides of Vesuvius and
other voleanic cones where there is a cavity below, but in
56 VOLCANIC ERUPTIONS IN JAVA. [Cu. XXvqq.
such regions as the Campagna di Roma, composed in a
great measure of tuff and porous volcanic rocks. The rever-
beration, however, may perhaps be assisted by grottos and
caverns, for these may be as numerous in the lavas of J orullo
as in many of those of Htna; but their existence would lend
no countenance to the hypothesis of a great arched cavity,
four square miles in extent, and in the centre 550 feet
high.*
No recent eruptions of Jorullo.—In a former edition I stated
that I had been informed by Captain Vetch, that in 1819 a
tower at Guadalaxara was thrown down by an earthquake,
and that ashes, supposed to have come from J orullo, fell at
the same time at Guanaxuato, a town situated 140 English
miles from the volcano. But Mr. Burkhardt, a German
director of mines, who examined Jorullo in 1827, ascertained
that there had been no eruption there since Humboldt’s visit
in 1803. He went to the bottom of the crater, and observed
a slight evolution of sulphurous acid vapours, but the
‘hornitos ’ had entirely ceased to send forth steam. During
the twenty-four years intervening between his visit and that
of Humboldt, vegetation had made great progress on the
flanks of the new hills, the rich soil of the surrounding
country was once more covered with luxuriant crops of
sugar-cane and indigo, and there was an abundant growth of
natural underwood on all the uncultivated tracts.
Galongoon, Java, 1822.—The mountain of Galongoon (or
Galung Gung) was in 1822 covered by a dense forest, and
situated in a fruitful and thickly-peopled part of Java.
There was a circular hollow at its summit, but no tradition
existed of any former eruption. In J uly, 1822, the waters of
the river Kunir, one of those which flowed from its flanks,
became for a time hot and turbid. On October 8 following,
a loud explosion was heard, the earth shook, and immense
columns of hot water and boiling mud, mixed with burning
brimstone, ashes, and lapilli, of the size of nuts, were projected
from the mountain like a water-spout, with such prodigious
violence that large quantities fell beyond the river Tandoi,
* See Serope on Voleanos, p. 267.
T Leonhard and Bronn’s Neues Jahrbuch, 1836, p. 36.
Cu, XXVII.] ERUPTIONS OF GALONGOON, JAVA, IN 1829. 57
which is40 miles distant. Every valley within the range of this
eruption became filled with a burning torrent, and the rivers,
swollen with hot water and mud, overflowed their banks, and
carried away great numbers of the people, who were en-
deavouring to escape, and the bodies of cattle, wild beasts,
and birds. A space of 24 miles between the mountain and
the river Tandoi was covered to such a depth with bluish mud
that people were buried in their houses, and not a trace of
the numerous villages and plantations throughout that extent
was visible. Within this space the bodies of those who
perished were buried in mud and concealed, but near the
limits of the volcanic action they were exposed, and strewed
over the ground in great numbers, partly boiled and partly
burnt.
It was remarked, that the boiling mud and cinders were
projected with such violence from the mountain, that while
many remote villages were utterly destroyed and buried,
others much nearer the volcano were scarcely injured.
The first eruption lasted nearly five hours, and on the
following days the rain fell in torrents, and the rivers, densely
charged with mud, deluged the country far and wide. At
the end of four days (October 12th), a second eruption
occurred more violent than the first, in which hot water and
mud were again vomited, and great blocks of basalt were
thrown to the distance of 7 miles from the volcano.
There was at the same time a violent earthquake, and in
one account it is stated that the face of the mountain was
utterly changed, its summit broken down, and one side,
which had been covered with trees, became an enormous
gulf in the form of a semicircle. This cavity was about
midway between the summit and the plain, and surrounded
by steep rocks, said to be newly heaped up during the erup-
tion. New hills and valleys are said to have been formed,
and the rivers Banjarang and Wulan changed their course,
and in one night (October 12th) 2,000 persons were killed.
he first intimation which the inhabitants of Bandong
received of this calamity on October 8th, was the news that
the river Wulna was bearing down into the sea the dead
bodies of men, and the carcasses of stags, rhinoceroses, tigers,
58 SUBMARINE VOLCANOS. (Cw. XXVIT.
and other animals. The Dutch painter Payen determined
to travel from thence to the volcano, and he found that the
quantity of the ashes diminished as he approached the bage
of the mountain. He alludes to the altered form of the
mountain after the 12th, but does not describe the new semi-
circular gulf on its side.
The official accounts state that 114 villages were destroyed,
and above 4,000 persons killed.*
Submarine volcanos.—Although we have every reason to
believe that volcanic eruptions as well as earthquakes are
common in the bed of the sea, it was not to be expected that
many opportunities would occur to scientific observers of
witnessing the phenomena. The crews of vessels have some-
times reported that they have seen in different places sul-
phurous smoke, flame, jets of water, and steam, rising up
from the sea, or they have observed the waters greatly dis-
coloured, and in a state of violent agitation as if boiling,
New shoals have also been encountered, or a reef of rocks
just emerging above the surface, where previously there was
always supposed to have been deep water. On some few
occasions the gradual formation of an island by submarine
eruption has been observed, as that of Sabrina, in the year
1811, off St. Michael’s in the Azores. The throwing up of
ashes in that case, and the formation of a cone about 300
feet in height, with a crater in the centre, closely resembled
the phenomena usually accompanying a volcanic eruption on
land. Sabrina was soon washed away by the waves. Pre-
vious eruptions in the same part of the sea were recorded
to have happened in 1691 and 1720. The rise of Nyée,
also, a small island off the coast of Iceland, in 1783, has
already been alluded to; and another voleanic isle was pro-
duced by an eruption near Reikiavig, on the same coast, in
Graham Island,t 1831.—We have still more recent and
* Van der Boon Mesch, de Incendiis ft Journ. de Géol. tome i.
Montium Javee, &e. Lugd. Bat. 1826; t In a former edition, I selected the
and Official Report of the President, name of Sciacea out of seven which had
7 Js ‘ ny 7 * = a 3
Baron Van der Capellen; ulso, Von heen proposed; but the Roy al and
Ruch, Hes Canar., p. 424, Geographical Societies have nowadopted
Cu. XXVII.] GRAHAM ISLAND. 59
minute information respecting the appearance, in 1831, of a
new voleanic island in the Mediterranean, between the
SW. coast of Sicily and that projecting part of the African
coast where ancient Carthage stood. The site of the island
was not any part of the great shoal, or bank, called ‘ Nerita,’
as was first asserted, but a spot where Captain W. H. Smyth
had found, in his survey a few years before, a depth of more
than 100 fathoms’ water.*
The position of the island (lat. 37° 1’ 30” N., long. 12° 42’
15” EH.) was about 30 miles SW. of Sciacca, in Sicily, and
33 miles NE. of the Island of Pantellaria.t On June
28, about a fortnight before the eruption was visible, Sir
| ie gt
Fig. 90. |
yy, 2 eS We es
"pila ee
Form of the cliffs of Graham Island, as seen from SSE., distant one mile,
7th August, 1831.
Pulteney Malcolm, in passing over the spot in his ship, felt
the shocks of an earthquake, as if he had struck on a sand-
bank; and the same shocks were felt on the west coast of
Sicily, in a direction from SW. to NE. About J uly 10,
John Corrao, the captain of a Sicilian vessel, reported that,
as he passed near the place, he saw a column of water like
a water-spout 60 feet high, and 800 yards in circumference,
rising from the sea, and soon afterwards a dense steam in its
place, which ascended to the height of 1,800 feet. The
Same Corrao, on his return from Girgenti, on July 18, found
@ small island, 12 feet high with a crater in its centre, ejecting
volcanic matter, and immense columns of vapour; the sea
Graham Island ; @name given byCapt. scarcely ever been outdone even in the
Senhouse, R.N., the first who succeeded annals of zoology and botany.
m landing on it, e seven rival * Phil. Trans. 1832, p. 255.
names are Nerita, Ferdinanda, Hotham, ft Journ. of Roy. Geograph. Soc.
hake Corrao, Sciacca, Julia. As 1830-31.
® isle was visible for only about three { Phil. Trans., part ii., 1832, reduced
oh , this is an instance of a wanton from drawings by Captain Wodehouse,
Multiplication of Synonyms which has’ R.N.
60 GRAHAM ISLAND. [Cx. Xxvqy
around being covered with floating cinders and dead fish.
The scoriz were of a chocolate colour, and the water which
boiled in the circular basin was of a dingy red. The eruption
|
|
Fig. 91.
oP ee mE
7 Pp fit
"
\y
View of the interior of Graham Island, 29th Sept. 1831.
continued with great violence to the end of the same month;
at which time the island was visited by several persons, and
among others by Capt. Swinburne, R. N., and M. Hoffmann,
Fig. 92.
Graham Island, 29th Sept. 1831,*
the Prussian geologist. It was then from 50 to 90 feet in
height, and 3 of a mile in circumference. By August 4 it
became, Scans to some accounts, above 200 feet high,
* In the annexed sketch (fig. 92), am informed by M. Prevost that these
drawn by M. Joinville, who « accompanied —_ lines were not intended by the artist to
evost, the beds seem to slope
towards the centre of the crater; but I
alOh Jey
represent the dip of the beds.
3
Cu, XXVIL] GRAHAM ISLAND IN 1831. 61
and 8 miles in circumference ; after which it began to di-
minish in size by the action of the waves, and was only 2
miles round on August 25; and on September 3, when it
was carefully examined by Captain Wodehouse, only 2 ofa
mile in circumference ; its greatest height being then 107 feet.
At this time the crater was about 780 feet in circumference.
On September 29, when it was visited by Mons. OC. Prevost,
its circumference was reduced to about 700 yards. It was
composed entirely of incoherent ejected matter, SCoriee,
pumice, and lapilli, forming regular strata, some of which
are described as having been parallel to the steep inward
slope of the crater, while the rest were inclined outwards,
like those of Vesuvius.* When the arrangement of the
ejected materials has been determined by their falling con-
tinually on two steep slopes, that of the external cone and
that of the crater, which is always a hollow inverted cone, a
Pet 2Z2-——_
transverse section would probably resemble that given in the
annexed figure (93). But when I visited Vesuvius, in 1828,
I saw no beds of scoriz inclined towards the axis of the cone.
(See fig. 67, Vol. I. p. 631.) Such may have once existed ; but
the explosions or subsidences, or whatever causes produced
the great crater of 1822, had possibly destroyed them.
Few of the pieces of stone thrown out from Graham Island
exceeded a foot in diameter. Some fragments of dolomitic
limestone were intermixed ; but these were the only non-
volcanic substances. During the month of August, there
Cceurred on the S.W. side of the new island a violent ebul-
lition and agitation of the sea, accompanied by the constant
ascension of a column of dense white steam, indicating the
existence of a second vent at no great depth from the surface.
Towards the close of October, no vestige of the crater re-
Mained, and the island was nearly levelled with the surface
of the ocean, with the exception, at one point, of a small
monticule of sand and scorie. It was reported that, at the
* See Memoir by M.C. Prevost, Ann. des Sci. Nat. tom. xxiy.
62 GRAHAM ISLAND, (Cu. XXVI
commencement of the year following (1832), there wag a
depth of 150 feet where the island had been: but this
account was quite erroneous; for in the early part of that
year Captain Swinburne found a shoal and discoloured water
there, and towards the end of 1853 a dangerous reef existed
of an oval figure, about 3 of a mile in extent. In the centre
was a black rock, of the diameter of about 26 fathoms, from
9 to 11 feet under water; and round this rock are banks of
black volcanic stones and loose sand. At the distance of
60 fathoms from this central mass, the depth increased
rapidly. There was also a second shoal at the distance
of 450 feet SW. of the great reef, with 15 feet water over
it, also composed of rock, surrounded by deep sea. We can
scarcely doubt that the rock in the middle of the larger reef
is solid lava, which rose up in the principal crater, and that
the second shoal marks the site of the submarine eruption
observed in August, 1831, to the SW. of the island.
From the whole of the facts above detailed, it appears
that a hill 800 feet or more in height was formed by a
submarine volcanic vent, of which the upper part (only about
200 feet high) emerged above the waters, so as to form
an island. This cone must have been equal in size to
one of the largest of the lateral volcanos on the flanks of
Ktna, and about half the height of the mountain Jorullo in
Mexico, which was formed in the course of nine months, in
1759. In the centre of the new voleano a large cavity was
kept open by gaseous discharges, which threw out scorie ;
and fluid lava probably rose up in this cavity. It is not
uncommon for. small subsidiary craters to open near the
summit of a cone, and one of these may have been formed in
the case of Graham Island ; a vent perhaps, connected with
the main channel of discharge which gave passage in that
direction to elastic fluids, scoriz, and melted lava. It does
not appear that, either from this duct, or from the principal
vent, there was any overflowing of lava; but melted rock
may have flowed from the flanks or base of the cone (a common
occurrence on land), and may have spread in a broad sheet
over the bottom of the sea,
The dotted lines in the annexed figure are an imaginary
D4)
ea.
OF the lave
d crater, and th
tailed, it appeas
was formal by:
p part (only aboct
5 go a8 to form
equal in sue ©
Cu. XXVII.] GRAHAM ISLAND. 63
restoration of the upper part of the cone, now removed by
the waves: the strong lines represent the part of the volcano
which is still under water: in the centre is a great column,
or dike, of solid lava, 200 feet in diameter, supposed
to fill the space by which the gaseous fluids rose; and on
each side of the dike is a stratified mass of scoriz and frag-
mentary lava. The solid nucleus of the reef, where the
black rock is now found, withstands the movements of the
sea; while the surrounding loose tuffs are cut away to a
somewhat lower level. In this manner the lava, which was
the lowest part of the island, or, to speak more correctly,
which scarcely ever rose above the level of the sea when the
island existed, has now become the highest point in the reef.
No appearances observed, either during the eruption or
since the island disappeared, give the least support to the
Rod a ih
Mes 1\)\ x
A x . PALS SS
Ze ee CLAY NWN?
z hh SZ Ss eS ‘
Gs (hf ' SY}! || BO 5°)
‘2D thik LN) WA :
‘o Ls, se Cfo, SSI! gee ass Xo
LPS SDA SW
4% GLY SOL fof | nS
~ CLLL g WAS a
N NSS SONS SS ES
Supposed section of Graham Island. (C. Maclaren.*)
opinion promulgated by some writers, that part of the
ancient bed of the sea had been lifted up bodily.
The solid products, says Dr. John Davy, whether they
consisted of sand, light cinders, or vesicular lava, differed
more in form than in composition. The lava contained
augite; and the specific gravity was 2°07 and 2°70. When
the light spongy cinder, which floated on the sea, was reduced
to fine powder by trituration, and the greater part of the
entangled air got rid of, it was found to be of the specific
gravity 2°64; and that of some of the sand which fell in the
eruption was 2°75;+ so that the materials equalled ordinary
granites in weight and solidity. The only gas evolved in any
considerable quantity was carbonic acid.
Submarine eruptions in mid-Atlantic.—In the Nautical
* Geol. of Fife and the Lothians, + Phil. Trans. 1832, p. 243.
p. 41. Edin, 1839.
”
t Ibid. p. 249.
64 ERUPTION IN THE CANARY ISLANDS. [Cu. XXVqq,
Magazine for 1835, p. 642, and for 1838, p. 361, and in the
Comptes Rendus, April, 1838, accounts are given of a series
of volcanic phenomena, earthquakes, troubled water, floating
scoriz and columns of smoke, which have been observed at
intervals since the middle of the last century, in a space of
open sea between longitudes 20° and 22° west, about half a
degree south of the equator. These facts, says Mr. Darwin,
seem to show, that an island or an archipelago is in process
of formation in the middle of the Atlantic: a line joining
St. Helena and Ascension would, if prolonged, intersect this
slowly nascent focus of volcanic action.* Should land be
eventually formed here, it will not be the first that has been
produced by igneous action in this ocean since it was
inhabited by the existing species of testacea. At Porto Praya
in St. Jago, one of the Azores, a horizontal, calcareous
stratum occurs, containing shells of recent marine species, -
covered by a great sheet of basalt 80 feet thick.t It
would be difficult to estimate too highly the commercial and
political importance which a group of islands might acquire,
if in the next two or three thousand years they should rise in
mid-ocean between St. Helena and Ascension.
Bruption in Lancerote, 1730 to 1736.—An eruption hap-
pened in Lancerote, one of the Canary Islands, between the
years 1730 and 1736, of which a detailed description was
published by Von Buch, who visited that island in 1815, and
compared the accounts transmitted to us of the event, with
the present state and geological appearances of the country.
During this outbreak, which lasted for five successive years,
the flourishing town of St. Catalina and several other places
were buried under lava and scoriz 400 feet in thickness.
Thirty cones were thrown up arranged in one line running
nearly east and west and extending for a length of two
geographical miles. The most elevated of these hills reached
a height of about 600 feet above its base. The subterranean
cleft from which elastic fluids escaped seems to have opened
or widened at a succession of new points when the first
apertures had become obstructed by solid lava or ejected
* Darwin's Volcanic Islands, p. 92. + Tbrd?p=6-
€
ANyy,
In the
l Sigg
ating
ved at
Pace of
half a
darwin,
PrOcegy
Joining
Ct this
and be
as been
it was
» Praya
species,
k.t It
ial and
ener < a SR Tene)
|
|
\
;
Cu. XXVII.] SANTORIN, 65
matter. From one of the fissures which was still open in
1815 Von Buch found hot vapours issuing which raised the
thermometer to 145° Fahr., and was probably at the boiling
point lower down. The exhalations seemed to consist of
aqueous vapour; yet they could not be pure steam, for the
crevices were encrusted on either side by silicious sinter (an
opal-like hydrate of silica of a white colour), which extended
almost to the middle. This important fact attests the length
of time during which chemical processes continue after
eruptions, and shows how open fissures may be filled up by
mineral matter, sublimed from volcanic exhalations.
The quantity of dead fish which were strewed over the banks
and shores of the island or floated on the waters on more than
one occasion during this series of eruptions, some of them
of species which had never before been observed, is said to
have been indescribably great, especially where streams of
lava entered the sea. This fact is one of geological interest,
since many of the fossil fishes of ancient date, those of Monte
Bolea for example, are preserved in voleanic tuff or in marls
associated with contemporaneous igneous rocks. In August
1824 another eruption happened in Lanzerote near the port
of Rescif, forming a cone and crater from which Mr. Hartung
found hot vapours escaping during his visit in 1850.*
SANTORIN.
The Gulf of Santorin, in the Grecian Archipelago, has
been for 2,000 years a scene of active volcanic operations.
The largest of the three outer islands of the groups (to which
the general name of Santorin is given) is called Thera (or
sometimes Santorin), and forms more than two-thirds of the
circuit of the gulf. (See Map, fig. 95, p. 66.) The length
of the exterior coast-line of this and the other two islands
named Therasia and Aspronisi, taken together, amounts to
about 30 miles, and that of the inner coast-line of the
Same islands to about 18 miles. In the middle of the
gulf are three other islands, called the Little, the New, and
the Old ‘ Kaimenis,’ or ‘Burnt Islands.’ The accompanying
* G. Hartung, Lanzerote und Fuertaventura. 1856.
VOU, 1. F
to
AE
Map of Santorin in the Grecian Are eg from a Survey in 1848, by
Captain Graves, R.
The soundings are given in es
A. Shoal formed by submarine volcanic C. Mansell’s Rock.
QQ7 io}
pel taeda in 1650. By: Mount St. Elias, 1,887 feet high.
Be ‘thern entrance
Fig. 96.
; Aspronisi The three Kaimenis
Sew d ln
— ~ — —— -
os oS Oo BO
esate = aN ee Se Mo ; Ss
7 R Sey ‘ = swaie - ied . , e
Section of Sartorin, in a NE. and SW. direction, from Thera through th
Kaimenis to Asproni
he
. f fanene
. Old Kaimeni. d, d'. Great covering of white tw i
j t
. New Kaimeni. agelomerate or . ejecte ue matter con
Little Kaimeni. fragments of brown trachy
Lat, 36090N
Gr v
* Xyy
1948, by
t bigh-
Cu. XXVII.] sSANTORIN;: 67
map has been reduced from an Admiralty survey executed in
1848 by the late Captain Graves, R. N
Pliny informs us that the year 186, B.c., gave birth to the
Old Kaimeni, also called Hiera, or the ‘ Sacred Isle ;’ and in
the year 19 of our era ‘ Thia’ (the Divine) made its appearance
above water, and was soon joined by subsequent eruptions to
the older island, from which it was only 250 paces distant.
The Old Kaimeni also increased successively in size in 726
and in 1427. A century and a half later, in 1573, another
eruption produced the cone and crater called Micra-Kaimeni,
or ‘the Small Burnt Island.’ The next great event which
we find recorded occurred in 1650, when a submarine out-
break violently agitated the sea, at a point 34 miles to the
NE. of Thera, and which gave rise to a shoal (see A in
the Map) carefully examined during the survey of 1848 by
Captain Graves, and found to have 10 fathoms water over it,
the sea deepening around it in all directions. This eruption
lasted three months, covering the sea with floating pumice.
At the same time an earthquake destroyed many houses in
Thera, while the sea broke upon the coast, overthrew two
churches, and exposed to view two villages, one on each side
of the mountain of St. Stephen, both of which must have
been overwhelmed by showers of volcanic matter during some
previous eruptions of unknown date.* The accompanying
evolution of sulphur and hydrogen issuing from the sea killed
more than 50 persons, and above 1,000 domestic animals.
A wave, also, 50 feet high, broke upon the rocks of the Isle
of Nia, about 4 leagues distant, and advanced 450 yards
into the interior of the Island of Sikino. Lastly, in 1707 and
1709, Nea-Kaimeni, or the New Burnt Island, was formed
between the two others, Palaia and Micra, the Old and Little
Isles. This isle was composed originally of two distinct
parts; the first which rose was called the White Island,
composed of a mass of pumice, extremely porous. Goree, the
Jesuit, who was then in Santorin, says that the rock ‘ cut
like bread,’ and that, when the inhabitants landed on it, they
found a multitude of full-grown fresh oysters adhering’
* Virlet, Bull. de la Soc. Géol. de France, tom. iii. p. 100.
F 2
to it, which they ate.* This mass was afterwards covered,
in great part, by the matter ejected from the crater of
a twin-island formed simultaneously, and called Black
Island, consisting of brown trachyte. The trachytic lava
which rose on this spot appears to have been a long time in
an intumescent state, for the New Kaimeni was sometimes
lowered on one side while it gained height on the other, and
rocks rose up in the sea at different distances from the shore .
and then disappeared again. The eruption was renewed at
intervals during the years 1711 and 1712, and at length a
cone was piled up to the height of about 330 feet above the
level of the sea, its exterior slope forming an angle of 33°
with the horizon, and the crater on its summit being 80
yards in diameter. In addition to the two points of subaérial
eruption on the New and Little Kaimenis, two other cones,
indicating the sites of submarine outbursts of unknown date,
were discovered. under water near the Kaimenis during the
late survey.
In regard to the ‘ White Island,’ which was described and
visited by Goree in 1707, we are indebted to Mr. Edward
Forbes for having, in 1842, carefully investigated the layer
of pumiceous ash of which it is constituted. He obtained
from it many shells of marine genera, Pectunculus, Arca,
Cardita, Trochus, and others, both univalve and bivalve, all
of recent Mediterranean species. They were in a fine state
of preservation, the bivalves with the epidermis remaining,
and valves closed, showing that they had been suddenly
destroyed. Mr. Forbes, from his study of the habits of the
mollusca living at different depths in the Mediterranean, was
able to decide that such an assemblage of species could. not
have lived at a less depth than .220 feet, so that a bodily
upheaval of the mass to that amount must have taken place
in order to bring up this bed of ashes and shells to the level
of the sea, and they now rise 5 or 6 feet above that level.t
We may compare this partial elevation of solid matter to
the rise of a hardened crust of scorie, such as is usually
* Phil. Trans. No. 332.
+ E. Forbes, Brit. Association, Report for 1848, p. 177.
|| are
uring the
ribed and
. Edward
the layer
obtained
us, Arca,
ivalve, all
Cu. XXVII.] GULF OF SANTORIN. 69
formed on the surface of lava currents, even while they are
in motion, and which, although stony and capable of sup-
porting heavy weights, may be upraised without bursting by
the intumescence of the melted matter below. The reader
may also be reminded of the upheaval of a solid crust of lava
witnessed by Abich within the crater of Vesuvius in the
year 1834, already mentioned by me. (Vol. I. p. 629.) That
the upheaval was merely local is proved by the fact that
the neighbouring Kaimenis did not participate in the move-
ment, still less the three more distant or outer islands.
Bird's-eye view of the Gulf of Santorin during the volcanic eruption
of February, 1
a. Therasia. e. Aspronisi.
b. The ‘ northern entrance,’ 1,068 feet deep.
c. Thera. g. New Kaimeni.
d. Mount St. Elias, rising 1,887 feet above h. Old Kaimeni.
the sea, composed of granular limestone and @ Aphroessa.
i k. George
clay-slate, the only non-voleanic rocks in
Santorin.
Eruption of 1866.—Another eruption broke out in Nea
Kaimeni in February 1866. At the end of January the sea
had been observed in a state of ebullition off the south-west
coast, and part of the channel between New and Old Kaimeni
marked 70 fathoms in the Admiralty chart had become, on
February 11, only 12 fathoms deep. According to M. Julius
Schmidt, a gradual rising of the bottom went on until
70
SANTORIN. [Cu. XXVIT
a small island made its appearance called afterwards
Aphroessa.* (See 7, fig. 97.) It seems to have consisted of
lava pressed upwards and outwards almost imperceptibly
by steam, which was escaping at every pore through the
hissing scoriaceous crust. ‘It could be seen,’ says Com-
mander Lindsay Brine, R.N., ‘through the fissures in the cone
that the rocks within were red-hot, but it was not till later
that an eruption began.’t On February 11, the village of
Vulcano on the south-east coast, where there had been a
partial sinking of the ground, was in great part overwhelmed
by the materials cast out from a new vent which opened in
that neighbourhood, and to which the name of George was
given (see k, fig. 97), which finally, according to Schmidt,
became about 200 feet high. Commander Brine having
ascended on February 28, 1866, to the top of the crater of
Nea Kaimeni about 350 feet high, looked down upon the
new vent then in full activity. The whole of the cone was
swaying with an undulating motion to the right and left, and
appeared sometimes to swell to nearly double its size and
height, to throw out ridges like mountain spurs, till at last
a broad chasm appeared across the top of the cone, accom-
panied by a tremendous roar of steam, and the shooting up
from the new crater to the height of from 50 to 100
feet of tons of rock and ash mixed with smoke and steam.
Some of these which fell on Micra-Kaimeni at a distance of
600 yards from the crater, measured 30 cubic feet. This
effort over, the ridges slowly subsided, the cone lowered and
closed in, and then, after a few minutes of comparative
silence, the struggle would begin again with precisely similar
sounds, action, and result. Threads of vapour escaping from
the old crater of Nea Kaimeni proved that there was a sub-
terranean connection between the old and new vents.’ t
Aphroessa, of which the cone was at length raised to a
height of more than 60 feet, was united in August with the
main island. This was due in part at least to the upheaval
of the bottom of the sea, which is now only 7 fathoms
* Schmidt, cited by Von Hauer. Geographical Proc. Nov. 10th, 1866,
+ Brine, Visit to Santorin. Royal Svoli x. pesly. t Ibid.
- -«
R, Yy
yy
aoa) SANTORIN, ey
2ry: —
i ands : M4 . e . :
—s deep in the channel dividing the New and Old Kaimenis,
0 : : .
ceptihy whereas in the Admiralty chart (see fig. 95) the soundings
Ugh a gave 100 fathoms.
g
SQ P It will be seen by the map and section (figs. 95 and 96),
the ; that the Kaimenis are arranged in a linear direction, running
; : C
0 : “7 .
ne NE. and SW., in a manner different from that represented
in the older charts. In their longest diameter they form at
their base a ridge nearly bisecting the gulf or crater.
ot Notwithstanding this linear arrangement we may compare
a the three Kaimenis in the centre of the gulf to the modern
ened in cone of Vesuvius, and consider the outer islands Thera,
TYE was Aspronisi, and Therasia as the remains of an older and
Schmidt, ruined cone like Somma. Thera, which constitutes alone
having more than two-thirds of the outer circuit, presents everywhere
crater of towards the gulf high and steep precipices composed of
ipon the voleanic rocks. In all places near the base of its cliffs, a
sone was depth of from 800 to 1,000 feet of water was found, and
left, and Lieut. Leycester informs us that if the eulf, which is 6
size and miles in diameter, could be drained, a bowl-shaped cavity
1 at last would appear with walls 2,449 feet high in some places, and
, accoml- even on the south-west side, where it is lowest, nowhere less
oting up than 1,200 feet high; while the Kaimenis would be seen to
oe] . . . ° .
to 100 form in the centre a huge mountain 5} miles in circum-
ference at its base, with three principal summits (the
sesh Old, the New, and the Little Burnt Islands) rising severally
' This to the heights of 1,251, 1,629, and 1,158 feet above the
: d bottom of the abyss. The rim of the great cauldron thus
red 8 exposed would be observed to be in all parts perfect and
para unbroken, except at one point where there is a deep and long
y similar chasm or channel, known by mariners as the ‘northern
ing ea entrance’ (B, fig. 95, and b, fig. 97) between Thera and
is a su Therasia, and called by Lieut. Leycester ‘the door into the
7t | crater.’ Itis no less than 1,170 feet deep, and constitutes, as
ed to ® will appear by the soundings (see Map, fig. 95), a remarkable
vith the feature in the bed of the sea. There is no corresponding
ipheavt channel passing out from the gulf into the Mediterranean
fathom at any other point in the circuit between the outer islands,
the greatest depth there ranging from 7 to 66 feet. .
1966; We may conceive, therefore, if at some former time the
id
anti _ = te
72 SANTORIN» a
[Cu. XXVIT.
whole mass of Santorin stood at a higher level by 1,200 feet,
that this single ravine or narrow valley now forming ‘ the
northern entrance,’ was the passage by which the sea entered
a circular bay.
But at a still earlier period when the ancient voleanic
cone, of which the outer islands are the remains, was stil]
more elevated above the level of the sea, there may have
been a deep valley of subaérial erosion cut by the principal
river which then drained Santorin, which may have con-
sisted of one lofty voleanic cone afterwards truncated by a
paroxsymal explosion such as we have already spoken of in
the case of Galongoon, p. 57, and when treating of the sup-
posed origin of the Val del Bove on Etna. It would then be
necessary to imagine the subsidence and partial submergence
of this original island in order to explain the present gulf and
the deep channel (B, fig. 95) coinciding with the ancient
gorge of fluviatile erosion.
All the outer islands Thera, Therasia, and Aspronisi are
covered with one great uniform mass of volcanic matter,
expressed by d, d’, in the section fig. 96, p. 66. This ereat
overlying deposit has been called pumiceous by many ob-
servers, but M. Virlet says it isa white tufaceous agelomerate
through which are dispersed fragments of a brown trachyte.
Such a mass may well be imagined to be the product of that
paroxysmal eruption by which so large a part of the oreat
cone was destroyed, and the gulf formed, in the middle of
which the Kaimenis have since been thrown up.
Thera, Therasia, and Aspronisi are exclusively composed
of volcanic matter, except the southern part of Thera, where
Mount St. Elias (d d, fig. 97) reaches an elevation of 1,887
feet above the sea, or three times the height now attained by
the loftiest of the igneous rocks.* This mountain is formed
of granular limestone and argillaceous schist, and is much
more ancient than any part of the volcanic cone, one side of
the base of which now abuts against it. The inclination,
strike, and fractures of the caleareous and argillaceous strata
of St. Elias have no relation to the great cone, but, according
* Virlet, Bull. de la Soe. Géol. de France, tome iii. p. 103,
NRT ee eas 1 rE
Og X
XY]
I.
209 Ga XKVIL) SANTORIN. 73
2200
Ling “the to M. Bory St. Vincent, have the same direction as those of
a *Xtereg the other isles of the Grecian Archipelago, namely, from
NNW. to SSE. Each of the three islands, Thera, Therasia,
Volean; and Aspronisi, are composed of beds of trachytic lava and
1¢ )
tuff, having a gentle inclination of only 3° or 4°. Hach bed is
yery narrow and discontinuous, the successive layers being
moulded or dove-tailed, as M. Virlet expresses it, into the in-
) Wag stil]
may have
neg
mere equalities of the previously existing surface, on which showers
ated by 4 of cinders or streams of melted matter had been poured.
ken of , An important fact is adduced by M. Virlet, to show that
Pia ; the gentle dip of the lava streams in the three outer islands
the sup. towards all points of the compass, away from the centre of
dl then be the gulf, has not been due to the upheaval of horizontal beds,
mergence as conjectured by Von Buch, who had never visited Santorin.*
t gulf and The French geologist found that the vesicles or pores of the
e ancient — trachytic masses were lengthened out in the several directions
in which they would have flowed if they had descended from
ronisi are the axis of a cone occupying the centre of the crater. For
ce matter, it is well known that the bubbles of confined gas in a fluid in
This great motion assume an oval form, and the direction of their longer
many ob- axis coincides always with that of the stream.
vlomerate The absence of dikes in the cliffs surrounding the gulf is
trachyte. in favour of the theory that we here behold a section of
t of that the basal remains of an old voleanic cone. We have already
great spoken of the want of such dikes in those parts of the old
Vesuvius (see Vol. I. p. 635) or Somma, as well as of Mount
Etna, which are far from the original centres of eruption.
(Vol. II. p. 17.) We may confidently infer from analogy
compos that the missing part of the old cone of Santorin which rose
to a great height where the Kaimenis now stand, consisted
of steeply inclined lavas traversed by numerous vertical dikes.
tained by If we adopt the hypothesis above suggested, we are re-
middle of
is formel | quired to assume a subsidence of more than 1,000 feet in
js much order to explain the north-east channel (B, fig. 95, and 5, fig.
ne side es 97) as being a submerged valley or ravine of subaérial erosion.
ejinati™ ) In reference to this point we may mention that a large part
pus st? : of Thera actually sank down during a great earthquake in
ecore’”
* Poggendorf's Annalen 1836, p. 183.
74 BARREN ISLAND. (Cu. XXVIq.
1650, the subsidence being proved not only by tradition, but
by the fact that a road which formerly led between two
places on the east coast of Thera is now 12 fathoms under
water. A long succession, no doubt, of such events would be
demanded to bring about so great a submergence, and future
geologists will have to decide whether this or some other
theory will best account for this submarine chasm.
On a review, therefore, of all the facts now brought to light
respecting Santorin, I attribute the moderate slope of the
beds in Thera and the other external islands to their having
originally descended the inclined flanks of a large volcanic
cone, the principal orifice or vents of eruption having been
always situated where they are now, in or near the centre of
the space occupied by the gulf or crater, in other words where
the outburst of the Kaimenis has been witnessed in historical]
times. The single long and deep opening into the crater is
a feature common to all those remnants of ancient volcanos,
the central portions of which have been removed, and is pro-
bably connected with aqueous denudation. Ag to the age of
the more ancient volcanic formations of Santorin, I am in-
formed by M. Fouqué that they belong to the Newer Pliocene
period, as shown by marine shells which he collected in 1866.*
Barren Island.—There is a great analogy between the
structure of Barren Island in the Bay of Bengal, lat. 12° 15’,
and that of Santorin last described. When seen from the
ocean, this island presents, on almost all sides, a surface of
bare rocks, rising, with a moderate acclivity, towards the in-
terior ; but at one point there is a cleft by which we can pene-
trate into the centre, and there discover that it is occupied by a
great circular basin more than 8,000 feet in diameter bordered
all around by steep rocks, in the midst of which rises a volcanic
cone, very frequently in eruption. The height of the circular
border which encloses the basin has been variously estimated.
According to Von Liebig, who visited the island in 1857, it
was about 1,000 feet high, corresponding in elevation to the
modern cone, so that the latter can only be seen from the sea
Since the above was in print, have been published by Messrs. Fritsch,
splendid photographs and descriptions Reiss, and Stiibel. Triibner, London,
f the eruption of the Kaimenis in 1866 1867
(«
to light
Of the
having
rOleanic
ng been
entre of
8 where
istorical
Tater is
leanos,
rom the
rface of
the in-
n pene-
jed by #
ordered
-oleanie
ejrceulat
mated.
1 to the
the s&
pritsehs
oD,
.
oe
Gy, XXVIL] MUD VOLCANOS. m5
by looking through the ravine. The sides of this cone slope
at angles of from 35° to 40°. In some of the older accounts
the sea is described as entering the inner basin, but Von
Liebig says it was excluded at the time of his visit, and thata
streamof black lava 10 feet highwas traceable from the interior
Fig. 98.
——_——————___——. —— = —
Cone and erater of Barren Island, in the Bay of Bengal. Height of the central
cone (according to Capt. Miller, in 1834), 500 feet.*
to the outlet; there was also on the sides of the passage or
inlet a raised beach 20 feet high, composed of volcanic tuff
and rolled pebbles, indicative of a modern upheaval of the
island to that extent. It is most probable that the exterior
enclosure of Barren Island (c, d, fig. 99) is nothing more than
Big. 99,
pee
_ZB a
New aE gsSS Seu
te
Supposed section of Barren Island, in the Bay of Bengal.
the remains of a truncated cone, ¢, a, 6, d, a great portion of
which has been removed by explosion, which may have pre-
ceded the formation of the new interior cone f, é, g-T
MUD VOLCANOS.
Of Iceland.—Professor R. Bunsen, in his account of the
pseudo-voleanic phenomena of Tceland, describes many
valleys where sulphurous and aqueous vapours burst forth
with a hissing sound, from the hot soil formed of volcanic
tuff. In such spots a pool of boiling water is seen, in which
The annexed view is given by Von + Von Liebig Zeitschrift
Captain Horsburgh saw smoke — logischen Gesellschaft, vol. x
in 1803. 1858.
der Geo-
uch. Cap oi
; ee eo
proceeding from the crater in
6 MUD VOLCANOS. (Cu. XVI.
a bluish-black argillaceous paste rises in huge bubbles,
These bubbles on bursting throw the boiling mud to a height
of 15 feet and upwards, so that it accumulates in ledges
round the crater or basin of the spring.
Of Baku on the Caspian.—The formation of a new mud
voleano was witnessed on November 27, 1827, at Tokmali, on
the peninsula of Abscheron, east of Baku. Flames blazed up
to an extraordinary height, for a space of 3 hours, and con-
tinued for 20 hours more to rise about 3 feet above a crater,
from which mud was ejected. At another point in the same
district where flames issued, fragments of rock of large size
were hurled up into the air, and scattered around.*
Of Sicily.—At a place called Macaluba, near Girgenti in
Sicily, are several conical mounds from 10 to 30 feet in
height, with small craters at their summits, from which cold
water, mixed with mud and bitumen, is cast out. Bubbles
of carbonic acid and carburetted hydrogen gas are also dis-
engaged from these springs, and at certain periods with such
violence, as to throw the mud to the height of 200 feet.
These ‘air volcanos,’ as they are sometimes termed, are
known to have been in the same state of activity for the last
15 centuries; and Dr. Daubeny imagines that the gases
which escape may be generated by the slow combustion of
beds of sulphur, which is actually in progress in the blue
clay, out of which the springs rise.t But as the gases are
similar to those disengaged in volcanic eruptions, and as they
have continued to stream out for so long a period, they may
perhaps be derived from a more deep-seated source.
Of Beila in India.—In the district of Luss or Lus, south of
Beila, about 120 miles NW. of Cutch and the mouths of the
Indus (see Map, fig. 105, p. 98), numerous mud voleanos
are scattered over an area of probably not less than 1,000
square miles. Some of these have been well described by
Captain Hart, and subsequently by Captain Robertson, who
has paid a visit to that region, and made sketches of them,
which he has kindly placed at my disposal. From one of
these the annexed view has been selected. These conical
* Humboldt’s Cosmos. + Daubeny, Volcanos, p. 267.
‘
CR Heres «
R, Qyy,
bubble,
* height
le;w mud
“mali, on
lazeg Up
and cop.
a Crater,
the same
aTge size
‘genti in
) feet in
uich cold
Bubbles
also dis-
ith such
00 feet.
ned, are
the last
ne gases
istion of
the blue
ses are
| as they
hey may
Cu, XXVIL] NATURE OF SUBTERRANEAN IGNEOUS ROCKS. 77
hills occur to the westward of the Hara Mountains and the
river Hubb. (See Map, p. 98.) One of the cones is 400
feet high, composed of light-coloured earth, and having at
‘ts summit a crater 30 yards in diameter. The liquid mud
which fills the crater is continually disturbed by air-bubbles,
and here and there is cast up in small jets.*
Fig. 100.
Mud cones and craters of Hinglaj near Beila, district of Lus, 120 miles north-west
of mouth of Indus. From original drawing by Capt. Robertson. (See Map. p. 98.)
Frequency of eruptions, and nature of subterranean igneous
rocks.—When we speak of the igneous rocks of our own
times, we mean that small portion which, in violent erup-
tions, is forced up by elastic fluids to the surface of the
earth,—the sand, scorie, and lava, which cool in the open
air. But we cannot obtain access to that which is congealed
far beneath the surface under great pressure, equal to that
of many hundred, or many thousand atmospheres.
* See Buist, Volcanos of India, Trans. Captain Robertson, Journ. of Roy.
Bombay Geol. Soe. vol. x. Pp ,and Asiat. Soc. 1850.
lard
78 NATURE OF SUBTERRANEAN IGNEOUS ROCKS. [Cu. xxyqqz
.. During the last century, about 50 eruptions are recorded
of the five European volcanic districts, of Vesuvius, Etna,
Voleano, Santorin, and Iceland; but many beneath the gea
in the Grecian Archipelago and near Iceland may doubtless
have passed unnoticed. If some of them produced no lava,
others, on the contrary, like that of the Skaptar Jokul, 7
1783, poured out melted matter for 5 or 6 years consecutively ;
which cases, being reckoned as single eruptions, will com-
pensate for those of inferior strength. Now, if we consider
the active voleanos of Europe to constitute about a fortieth
part of those already known on the globe, and calculate that,
one with another, they are about equal in activity to the
burning mountains in other districts, we may then compute
that there happen on the earth about 2,000 eruptions in the
course of a century, or about 20 every year.
However inconsiderable, therefore, may be the superficial
rocks which the operations of fire produce on the surface, we
must suppose the subterranean changes now constantly in
progress to be on the grandest scale. The loftiest volcanic
cones and the lavas which have flowed from their craters
must be insignificant when contrasted with the products of
fire in the nether regions. In regard to these last or those
igneous rocks which have been formed in our own times in
the bowels of the earth, whether in rents and caverns, or by
the cooling of lakes of melted lava, we may safely infer that
they are heavier and less porous than ordinary lavas, and
more crystalline, although composed of the same mineral
ingredients. As the hardest crystals produced artificially
in the laboratory require the longest time for their formation,
so we must suppose that where the cooling down of melted
matter takes place by insensible degrees, in the course of
ages, a variety of minerals will be produced far harder than
any formed by natural processes within the short period of
human observation.
These subterranean voleanic rocks, moreover, cannot be
stratified in the same manner as sedimentary deposits from
water, although it is evident that when great masses con-
solidate from a state of fusion, they may separate into
natural divisions; for this is seen to be the case in many
qo Se
Ee
C —
Cu. XXVIT.] NATURE OF SUBTERRANEAN IGNEOUS ROCKS. 79
Teoy
Us, Bi lava currents. We may also expect that the rocks in
L the . question will often be rent by earthquakes, since these are
doubties common in voleanic’regions; and the fissures will be often
lo lava, injected with similar matter, 80 that dikes of crystalline
Jokul, ‘s J rock will traverse masses of similar composition It 1s also
CUtive)y clear, that no organic remains can be included in such
Will com masses, as also that these deep-seated 1gneous formations
conside, considered in mass must underlie all the strata containing
organic remains, because the heat proceeds from below up-
wards, and the intensity required to reduce the mineral in-
eredients to a fluid state must destroy all organic bodies in
4 fortieth
late that,
7 me rocks included in the midst of them.
rompute If by a continued series of elevatory movements, such
ns n the masses shall hereafter be brought up to the surface, in the
same manner as sedimentary marine strata have, in the
uperficial course of ages, been upheaved to the summit of the loftiest
riace, we mountains, it is not difficult to foresee what perplexing pro-
tantly in blems may be presented to the geologist. He may then,
- volcanic perhaps, study in some mountain-chain the very rocks pro-
r craters duced at the depth of several miles beneath the Andes, Ice-
oducts of land, or Java, in the time of Leibnitz, and draw from them
or those the same conclusion which that philosopher derived from
times in certain igneous products of high antiquity; for he conceived
ns, or by our globe to have been, for an indefinite period, in the state of
afer that a comet, without an ocean, and uninhabitable alike by aquatic
yas, and or terrestrial animals.
mineral
+ificially
ymation, }
f melte
ourse
jer tha”
eriod « |
nnot
its fom
5e8 cone
te jp t?
nan)
CHAPTER XXVIII.
EARTHQUAKES AND THEIR EFFECTS.
EARTHQUAKES AND THEIR EFFECTS—DEFICIENCY OF ANCIENT ACCOUNTS—
ORDINARY ATMOSPHERIC PHENOMENA— CHANGES PRODUCED BY EARTHQUAKES
IN MODERN TIMES CONSIDERED IN CHRONOLOGICAL ORDER—-EARTHQUAKE IN
CHILI IN 1887 AND 1885—ISLE OF SANTA MARIA RAISED TEN FEET— CHILI,
822—EXTENT OF COUNTRY ELEVATED—EARTHQUAKE OF CUTCH IN 1819—
SUBSIDENCE IN THE DELTA OF THE INDUS—ISLAND OF SUMBAWA IN 1815—
EARTHQUAKE OF CARACCAS IN 1812—SHOCKS AT NEW MADRID IN 1811 1n
THE VALLEY OF THE MISSISSIPPI.
In the sketch given in Chapter XXIII. of the geographical
boundaries of volcanic regions, I stated, that although the
points of eruption are but thinly scattered, constituting mere
spots on the surface of those vast districts, yet the sub-
terranean movements extend simultaneously over immense
areas. We may now proceed to consider the changes which
these movements produce on the surface, and in the internal
structure of the earth’s crust.
Deficiency of ancient accounts.—It is only within the last two
centuries, since Hooke first promulgated, in 1688, his views
respecting the connection between geological phenomena
and earthquakes, that the permanent changes effected by
these convulsions have excited attention. Before that time,
the narrative of the historian was almost exclusively confined
to the number of human beings who perished, the number of
cities laid in ruins, the value of property destroyed, or certain
atmospheric appearances which dazzled or terrified the ob-
servers. The creation of a new lake, the engulphing of @
city, or the raising of a new island, are sometimes, it is true,
adverted to, as being too obvious, or of too much geographical
or political interest to be passed over in silence. But n0
oe oe
|
|
{
|
———
yraphical
yugh the
ing mere
the sub-
immense
es which
internal
» last two
Cu. XXVUL] PHENOMENA ATTENDING EARTHQUAKES. 81
researches were made expressly with a view of ascertaining
the amount of depression or elevation of the ground, or any
particular alterations in the relative position of sea and land ;
and very little distinction was made between the raising of
soil by volcanic ejections, and the upheaving of it by forces
acting from below. The same remark applies to a very large
proportion of modern accounts: and how much reason we
have to regret this deficiency of information appears from
this, that in every instance where a spirit of scientific enquiry
has animated the eye-witnesses of these events, facts calcu-
lated to throw light on former modifications of the earth’s
structure are recorded.
Phenomena attending earthquakes.—As I shall confine myself
almost entirely, in the following notice of earthquakes, to the
changes brought about by them in the configuration of the
earth’s crust, I may mention, generally, some accompani-
ments of these terrible events which are almost uniformly
commemorated in history, so that it may be unnecessary to
advert to them again. Irregularities in the seasons preceding
or following the shocks; sudden gusts of wind, interrupted
by dead calms; violent rains at unusual seasons, or in-
countries where such phenomena are almost unknown; a
reddening of the sun’s disk, and haziness in the air, often
continued for months; an evolution of electric matter, or of
inflammable gas from the soil, with sulphurous and mephitic
vapours ; noises underground, like the running of carriages,
or the discharge of artillery, or distant thunder; animals
uttering cries of distress, and evincing extraordinary alarm,
being more sensitive than men of the slightest movement; a
Sensation like sea-sickness, and a dizziness in the head, ex-
perienced by men :—these, and other phenomena, less con-
nected with our present subject as geologists, have recurred
again and again at distant ages, and in all parts of the
globe.
I shall now begin the enumeration of earthquakes with
the latest authentic narratiyes, and so carry back the survey
retrospectively, that I may bring before the reader, in the
first place, the minute and circumstantial details of modern
times, and thus enable him, by observing the extraordinary
VOL. II, G
82 EARTHQUAKES OF THE NINETEENTH CENTURY. [Cu, XX VI.
amount of change within the last 170 years, to perceive how
great must be the deficiency in the meagre annals of earlier
eras.
EARTHQUAKES OF THE NINETEENTH CENTURY.*
New Zealand, 1855.—Permanent upheaval and subsidence of
land.—In no country perhaps, where the English language
is spoken, have earthquakes, or, to speak more correctly, the
subterranean causes to which such movements are due, been
so active in producing changes of geological interest ag in
New Zealand. The convulsions which have agitated this
archipelago since it was first known to whalers or settlers,
have visited different districts in succession.
e Rev. R. Taylor, many years a missionary in New
Zealand, states that the shocks of 1826, 1841, and 1843
expended each of them their chief violence in distinct areas,
In the year 1823, there was a small cove called the Jail,
about 80 miles north of Dusky Bay, much visited by sealers,
for it afforded suitable anchorage for their vessels, being
sheltered by lofty cliffs, and having deep water so close to
the shore that they could step out of their boats on ‘to the
rocks.
After a succession of earthquakes in 1826 and 1827, so
complete was the transformation of this coast that its former
features could no longer be recognised; the cove had become
dry land, and trees were seen under water near the coast,
havine’ probably been carried
g Pp y
* Since the publication of the first
edition of this work, numerous accounts
of recent earthquakes have been pub-
lished ; but as they do not illustrate any
hew principle, I cannot insert them, as
they would enlarge too much the size of
at every month is signalised by one
or many convulsions in some part of the
globe. See also Mallet’s Dynamies of
Earthquakes, Trans. Roy. Irish Acad.
1846; also Art. ‘ Earthquakes,’ <Ad-
down by landslips into what
miralty Manual, 1849; also Mr. Mallet’s
reports on earthquakes to Brit. Assoc.
1850, 1852, and 1858, containing a
complete catalogue of known earth-
of earthquakes and voleanic eruptions
by the last-mentioned author, drawn up
with great care, since 1842, has been
published by the Royal Academy of
Belgium, with the discussion of their
causes and effect. See also Hopkins’
Report, Brit. Assoc, 1847-8.
SS = — ——
R, Xv,
Rive re Cu. XXVIII. ] THOSE OF NEW ZEALAND. 83
of ean was previously deep water, for large masses are said to have
slid down from the hills into the sea. The same writer
¥ informs us, that in 1847, the hull of a vessel was discovered
on the western coast of the South Island. It was lying 200
tence of yards inland, and was supposed to be the ‘ Active,’ which was
langnace lost in 1814. A small tree was growing through its bottom,
ectly, the and Mr. Taylor suggests thatthe coast had risen, so as to
due, been, cause the ocean to retire to a distance of 200 yards from the
CSt ag in old shore line, where the vessel had been stranded ; but a
ated this more precise investigation of the locality will be required
r settlers before we can feel sure that the vessel was not carried in by
a wave raised during the earthquake, for such waves have,
in modern times, left much larger ships high and dry in
7 in N }
and me | the interior of Peru and some other countries.* (See p. 157.)
not. are | The natives are said to have told our first settlers that they
the Pa might expect a great earthquake every seven years; and
]
although such exact periodicity has by no means been veri-
fied, the average number of violent shocks in a quarter of a
century seems not to have fallen short of the estimate here
Ny sealers,
ls, being
) close to referred to.
on. ‘to the In the course of the year 1856, I had an opportunity of
conversing in London with three gentlemen, all well qualified
| 1827, 80 as scientific observers, who were eye-witnesses of the tremen-
its former dous earthquake experienced in January of the preceding
d become year in New Zealand. These were, Mr. Edward Roberts, of
the coast, the Royal Engineers department; Mr. Walter Mantell, son
nto what of the celebrated geologist; and Mr. Frederick A. Weld, a
utp, Mallets landed proprietor in the South Island.t The earthquake
Brit. Asso occurred in the night of January 23, 1855, and was most
ontaining ®@ =| violent in the narrowest part of Cook Strait, a few miles to
ree i the SE. of Port Nicholson (see Map, fig. 101); but the
quakes of shocks were felt by ships at sea 150 miles from the coast,
plished at | and the whole area shaken of land and water is esti-
: ene mated at 360,000 square miles, an area three times as large
ai ; as the British Isles. In the vicinity of Wellington, in the
or; ar i North Island, a tract of land comprising 4,600 square miles
9 ha
Boal * Rev. R. Taylor, ‘New a and in the Bulletin Ae la Soc. Géol. de
sins its Inhabitants, London, 18 France, 1856, p.
30 Hop tT This account was cbt’ by me
3 G 2
Fig. 101.
84. EARTHQUAKES OF THE NINETEENTH CENTURY. [Cu. xxyrqq
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NEW ZEALAND
A\ ee TNE PLACS
| WAIPAPA PY
Ca, XXVIII] EARTHQUAKES IN NEW ZEALAND. 85
(not much inferior to Yorkshire in dimensions), is supposed
by Mr. Roberts to have been permanently upraised from 1 to
9 feet. There was no perceptible elevation on the coast 16
miles N. of Wellington, but from that point to Pencarrow
Head, on the east side, at the entrance of Port Nicholson,
(see Map, fig. 101), the amount of upheaval went on increasing
somewhat gradually, till it reached a vertical height of 9 feet
along the eastern flank of the Remutaka Mountains. This
range terminates in Cook Strait, between Port Nicholson
and Palliser Bay, in a lofty coast rising rapidly to heights
about 4,000 feet above the sea. Here the vertical movement
ceased abruptly along the base of these hills, not affecting
the low country to the eastward, 6b, fig. 102, called the Plain
of Wairarapa. The points of minimum and maximum eleva-
tion, from NW. to SE., in the district above alluded to,
are about 23 miles Bait, which therefore expresses the
breadth of the upraised area. Mr. Roberts was employed
professionally, before and after January 23, in executing
several government works in the harbour of Port Nicholson
and on the coast, and had occasion to observe minutely the
changes in the level of the land, which took place at various
points, and especially in
the sea-cliff, called Muka- «4
eastern flank of the Remu- erent z
taka range, before de- —
Beribed, terminates south- Junction of aailit and tertiary strata at
wards in Cook Strait. Here ka-Muka cliff.*
a distinct line of fault, c,d, A- Avzillite oh an
B. re ‘strata. pies and faul
fig. 102, was observed, the
rocks on one side A, being raised vertically 9 feet, while
the strata B, on the other side of the fissure c, d, experienced
no movement. The uplifted mass A consists, according
to Mr. Walter Mantell, of argillite, having the ordinary
composition of clay state, but. not laminated. It presents
a cliff, several hundred feet high towards the straits, whereas
ae this section from the de- therefore be ae ae regarded as an ex-
scription of my informants, and it must planatory diagran
86 EARTHQUAKES OF THE NINETEENTH CENTURY. (Cu. XXVIIT
the horizontally stratified tertiary strata exposed to the
eastward form a comparatively low cliff, not exceeding 89
feet in height. These tertiary strata, which are of marine
origin, did not, as already stated, participate in the upward
movement. Mr. Roberts was able to measure accurately the
amount of permanent upheaval in the older formation, by
observing the altered position of a white band of nullipores,
with which the surface of the rock below the level of low tide
had been coated. This white zone, a few hours after the
earthquake, was found to be 9 feet above its former level,
Previously to the shock, there had been no room to pass
between the sea and the base of the perpendicular cliff
called Muka-Muka, except for a short time at low water, and
as the herdsmen were obliged to wait for low tide in order
to drive their cattle past the cliff, Mr. Roberts was engaged
in constructing a road there. But immediately after the
upheaval, a gently sloping raised beach, more than 100 feet
wide, was laid dry, affording ample space at all states of the
tide for the passage of man and beast. ;
The junction of the older and newer rocks along the line
of fault above described is marked in the interior of the
country by a continuous escarpment running north and south
along the base of the Remutaka Mountains, where they
present a steep slope towards the east, or towards the great
plain of the Wairarapa formed of the modern tertiary deposit
before mentioned. The course of the fault along the base of
the escarpment was rendered visible by a nearly perpendicular
cliff of fresh aspect 9 feet in height and traceable in an
inland direction to the extraordinary distance of about 90
miles, according to information given by Mr. Borlase, a
settler who lived in the Wairarapa valley about 60 miles
north of Cook Strait. I¢ was marked, moreover, In many
places by an open fissure into which cattle fell and could not
in some cases be recovered, or by fissures from 6 to 9 feet
broad filled here and there with soft mud and loose earth.
At the same time that this vertical movement took place on
January 23, the harbour of Port Nicholson, about 12 miles to
the westward of Muka-Muka cliff, together with the valley of
the Hutt, was raised from 4 to 5 feet, the greater elevation
ee
es of the
- the line
r of the
nd south
ere they
Cu, XXVIII] EARTHQUAKE IN NEW ZEALAND. 87
being on the eastern, and the lesser on the western side of
the harbour. A rock called the Balley Rock, a short distance
from Evans Bay, was formerly 2 feet under water at the
lowest tides, and a vessel having touched upon it, a buoy had
been placed over it, to mark its position. This rock projected
after the shock nearly 8 feet above the surface of the water
at low tide. The rise of the tide in the Hutt River was
sensibly diminished by the earthquake. At the time of the
convulsion great waves of the sea rolled in upon the coast,
and for several weeks the tides were very irregular. Dead
fish were left by a wave on the racecourse at Wellington, and
Mr. Mantell states that others were also met with by several
vessels in Cook Strait floating on the sea in surprising
numbers, some of them of species never seen before by the
fishermen.
Mr. Weld, who resided south of the straits in the South
Island, informed me that, besides experiencing there the shock
of the 23rd, he felt another next morning of equal violence,
and waves of the sea rolled in along the coast for a distance
of 50 miles. At a place called the Flags between Cape
Campbell and Waipapa (see Map), some men were loading a
vessel with wood, when they saw distinctly an earthquake
approaching them from a point called ‘the White Rocks,’
3 miles to the northward. Its approach was rendered visible
by the rolling of stones from the top of the cliffs, also by
landslips and clouds of dust, and by the accompanying sea
wave. Upon the whole it appears that the area convulsed in
the South Island was not so extensive as that upheaved
around Wellington, also that to the south of the Straits the
direction of the movement was reversed, being for the most
part a downward one. The valley of the Wairau, with parts
of the adjoining coast, subsided about 5 feet, so that the tide
flowed several miles farther up into the Wairau River than it
formerly did, and ships taking in fresh water were obliged to
go three miles farther up the river to obtain a supply than
they did before the earthquake.
There was no volcanic eruption, whether in the Northern
or Southern Island at the time of these events; but the
natives allege that the temperature of the Taupo hot springs
88 EARTHQUAKES OF THE NINETEENTH CENTURY. [Cu. XXVIIT
(see small Map, fig. 101) was sensibly elevated, just before the
catastrophe.
I will now conclude this sketch of the changes produced
in 1855 by observing that a question arose as to whether
in the region about Port Nicholson the land, after it wag
upheaved several feet in January, sank again to some slight
extent or a few inches in the course of 7 or 8 months, or
before September 1855. When Mr. Roberts left New Zealand
thiree months after the earthquake, there had been no sinking
of the upraised land, and he felt persuaded that he could not
have failed to notice even a slight change of level had any
occurred. He ascertained ten weeks after the shock that there
had certainly been no subsidence whatever on the coast at
Pencarrow Head, and the tides were so irregular long after the
earthquake, in the harbour of Port Nicholson and elsewhere,
that the supposed partial sinking of the coast which some
believed to have taken place might perhaps be deceptive. It is
surprising how soon the signs of a recent change of level ona
coast are effaced to all eyes but those of the scientific observer,
especially where there is a rise and fall of the tides. Rocks
newly exposed soon begin to weather and vegetation spreads
over the emerged land, and a new beach, with all the charac-
ters of the old one, is formed in a few months along the
sea-margin. .
The geologist has rarely enjoyed so good an opportunity
as that afforded him by this convulsion in New Zealand,
of observing one of the steps by which those great dis-
placements of the rocks called ‘ faults’ may in the course of
ages be brought about. The manner also in which the
upward movement increased from north-west to south-east
explains the manner in which beds may be made to dip more
and more.in a given direction by each successive shock.
An independent witness of the earthquake of January 1855,
a civil engineer, says in a letter to Mr. Robert Mallet that ‘the
first and greatest shock of January 23 lasted about a minute.
and a half. All the brick buildings in Wellington were
overthrown, as well as the bridge over the Hutt. The hillsides
opposite Wellington, those of the Remutaka range, were much
shaken, as evidenced by the many bare patches with which
tw Xy
vn Cu. XXVIIL.] EARTHQUAKES IN SYRIA AND CHILI IN 1837. 89
*
fore the they were chequered, fully to the extent of one-third of their
rod surface, whence trees had been shaken off.” The ground in
wh Ueed this range, he says, was more violently shaken than in
. — Wellington, and the direction of the shock was NE. and SW.,
Kee Was agreeing with that of the chain of hills. After the shock the
. Slight tide did not come at high water within 3 or 4 feet of its
uths, op former height.*
Zealand, . Mr. Weld was in the South Island during the previous
) Sinking earthquake of 1848, and he informed me that a great rent was
Ould not then caused in a chain of mountains varying in height from
had any 1,000 to 4,000 feet, which run southwards from the White
hat there Bluff in Cloudy Bay and may be considered a prolongation of
Coast at the Remutaka or Tararua chain above alluded to. (See Map.)
after the This fissure of 1848 was not more than 18 inches in average
sewhere, width, but was remarkable for its length, for it was partly
ich some traced by Mr. Weld and partly by observers on whom he
ve. Itis could rely, for 60 miles, striking north-north-east and south-
bel dais south-west in a line parallel to the axis of the chain.
observer, * Syria, January, 1837.—It has been remarked that earth-
Rocks quakes affect elongated areas. The violent shock which
esas devastated Syria in 1837 was felt on a line 500 miles in
oe length by 90 in breadth:+ more than 6,000 persons perished ;
y Chae deep rents were caused in solid rocks, and new hot springs
long the burst out at Tabereah.
Chili—Valdivia, 1837.—One of the earthquakes by which
yortunity in the present century the position of land is known to have
Zealant, been permanently altered is that which occurred in Chili, on
eat dis- November 7, 1837. On that day Valdivia was destroyed,
ourse of and a whaler, commanded by Captain Coste, was violently
nich the shaken at sea, and lost her masts, in lat. 43° 38’ S. in sight
ath-east of the land. The captain went on December 11 following to
lip more a spot near the island of Lemus, one of the Chonos archi-
ok. pelago, where he had anchored two years before, and found
ry 1859 that the bottom of the sea had been raised more than 8 feet.
hat ‘tb? | Some rocks formerly covered at all times by the sea were
minut. | now constantly exposed, and an enormous quantity of shells
si were and fish in a decaying state, which had been thrown there
pillside® | * Reports of Brit. Assoc. 1858, p. 105.
re uch {~ Darwin, Geol. Proceedings, vol. il. p. 658.
90 EARTHQUAKES OF THE NINETEENTH CENTURY. [Cu. XXVII.
by the waves, or suddenly laid dry during the earthquake,
attested the recent date of the occurrence. The whole coast
was strewed with uprooted trees.*
Chili—Conception, 1835.—Fortunately we have a still
more detailed account of the geographical changes produced
in the same country on February 20, 1835. An earthquake
was then felt at all places between Copiapo and Chiloe,
nearly 1,000 miles from north to south, and from Mendoza to
Juan Fernandez, about 500 miles from east to west. ‘ Vessels,’
says Mr. Caldcleugh, ‘navigating the Pacific, within 100
miles of the coast, experienced the shock with considerable
force.’ Conception, Taleahuano, Chillan, and other towns,
were thrown down. From the account of Captain Fitz Roy,
R.N., who was then employed in surveying the coast, we
learn that after the shock the sea retired in the Bay of
Conception, and the vessels grounded, even those which had
been lying in seven fathoms water : all the shoals were visible,
and soon afterwards a wave rushed in and then retreated, and
was followed by two other waves. The vertical height
of these waves does not appear to have been much greater
than 16 or 20 feet, although they rose to much greater
heights when they broke upon a sloping beach.
According to Mr. Caldcleugh and Mr. Darwin, the whole
volcanic chain of the Chilian Andes, a range 150 miles in
length, was in a state of unusual activity, both during the
shocks and for some time preceding and after the convulsion,
and lava was seen to flow from the crater of Osorno. (See
Map, fig. 103.) The island of Juan Fernandez, distant 365
geographical miles from Chili, was violently shaken at the
same time, and devastated by a great wave. A submarine
volcano broke out there near Bacalao Head, about a mile
from the shore, in 69 fathoms water, and illumined’ the
whole island during the night.
‘At Conception,’ says Captain Fitz Roy, ‘the earth opened
and closed rapidly in numerous places. The direction of the
cracks was not uniform, though generally from south-east to
* Dumoulin, Comptes Rendus de + Phil. Trans. 1836, p. 21.
Acad. des Sci. Oct. 1838, p. 706. t Ibid. 1826,
My
h Cu. XXVIII] EARTHQUAKES IN CHILI. 91
ites: | 10 Fig. 103.
Coast ——_—_—— ,
stil]
Odueeg fee
thquake
Chiloe, Z,
- mato
ess els,
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iderable ica
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itz Roy, a
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B visible, {1 of S. Mana
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ned the | |
\)
ened
i’ the oe = a
east north-west. The earth was not quiet for three days after the
great shock, and more than 300 shocks were counted between
February 20 and March 4. The loose earth of the valley of
92 EARTHQUAKES OF THE NINETEENTH CENTURY. [Cu. XXVIT
the Biobio was everywhere parted from the solid rocks which
bound the plain, there being an opening between them from
an inch to a foot in width.
‘For some days after February 20, the sea at Talcahuano,’
says Captain Fitz Roy, ‘did not rise to the usual marks by
A or 5 feet vertically. When walking on the shore, even
at high water, beds of dead mussels, numerous chitons, and
limpets, and withered sea-weed, still adhering, though life.
less, to the rocks on which they had lived, everywhere met
the eye.’ But this difference in the relative level of the land
Fig. 104.
PACIFIC
OCEAN
Part of Chili altered by Earthquake of February, 1835.
and sea gradually diminished, till in the middle of April the
water rose again to within 2 feet of the former highwater
mark. It might be supposed that these changes of level
merely indicated a temporary disturbance in the set of the
currents or in the height of the tides at Taleahuano; but, on
considering what occurred in the neighbouring island of Santa
Maria, Captain Fitz Roy concluded the land had been raised
4 or 5 feet in February, and that it had returned in April
to within 2 or 3 feet of its former level.
TT a ST YA SS
t Xyy,.
: ‘a Cu. XXVIII. ] EARTHQUAKES IN CHILI AND ISCHIA. 93
LS .
ri — Santa Maria, the island just alluded to, is about 7
: miles long and 2 broad, and about 25 miles south-west of
huang» Conception. (See Map, fig. ae The et observed
larks ‘ there are most important. It appeared, Says: Captain
re, se Fitz Roy, who visited Santa Maria twice, the first time
Ons ies at the end of March, and afterwards in the beginning
ek: sa of April, ‘that the southern extremity of the island had
oa it. been raised 8 feet, the middle 9, and the northern end
met upwards of 10 feet. On steep rocks, where vertical measures
the lang could be correctly taken, beds of dead mussels were found 10
Fits } feet above high-water mark.
‘An extensive rocky flat lies around the northern parts of
Santa Maria. Before the earthquake this flat was covered
— by the sea, some projecting rocks only showing themselves.
Now, the whole flat is exposed, and square acres of it are
wg covered with dead shell-fish, the stench arising from which
is abominable. By this elevation of the land the southern
) port of Santa Maria has been almost destroyed ; little shelter
. remaining there, and very bad landing.’ The surrounding
sea is also stated to have become shallower in exactly the
~ same proportion as the land had risen; the soundings having
diminished a fathom and a half everywhere around the island.
F At Tubal, also, to the south-east of Santa Maria, the land
was raised 6 feet, at Mocha 2 feet, but no elevation could
be ascertained at Valdivia.
Among other effects of the catastrophe, it is stated that
cattle standing on a steep slope, near the shore, were rolled
down into the sea, and many others were washed off by the
= great wave from low land and drowned.*
In November of the same year (1835), Conception was
+1 the shaken by a severe earthquake, and on the same day Osorno,
pt at the distance of 400 miles, renewed its activity. These
ph wait | facts prove not only the connection of earthquakes with
of leve volcanic eruptions in this region, but also the vast extent of
of the the subterranean areas over which the disturbing cause acts
put, 9? simultaneously.
if aie Ischia, 1828.—On February 2, the whole island of Ischia
) rals®’
1 Apt * Darwin’s Journ. of Travels in South America, Voyage of ‘ Beagle,’ p. 372.
94 EARTHQUAKES OF THE NINETEENTH CENTURY. [Cu, XXVIII
was shaken by an earthquake, and in the October following
T found all the houses in Casamicciol still without their roofs,
On the sides of a ravine between that town and Forio, I saw
masses of greenish tuff which had been thrown down. The
hot-spring of Rita, which was nearest the centre of the moye-
ment, was ascertained by M. Covelli to have increased in
temperature, showing, as he observes, that the explosion took
place below the reservoirs which heat the thermal waters.*
Bogota, 1827.—On November 16, 1627, the plain of Bogota,
in New Granada, or Colombia, was convulsed by an earth-
quake, and a great number of towns were thrown down.
Torrents of rain swelled the Magdalena, sweeping along vast
quantities of mud and other substances, which emitted a
sulphurous vapour and destroyed the fish. Popayan, which
is distant 200 geographical miles SSW. of Bogota, suffered
greatly. Wide crevices appeared in the road of Guanacas,
leaving no doubt that the whole of the Cordilleras sustained
a powerful shock. Other fissures opened near Costa, in the
plains of Bogota, into which the river Tunza immediately
began to flow.+ Extraordinary rains accompanied the shocks
before mentioned ; and two volcanos are said to have been in
eruption in the mountain-chain nearest to Bogota.
Chili, 1822.—On November 19, 1822, the coast of Chili
was visited by a most destructive earthquake. The shock
was felt simultaneously throughout a space of 1,200 miles
from north to south. St. Jago, Valparaiso, and some other
places, were greatly injured. When the district round
Valparaiso was examined on the morning after the shock, it
was found that the coast for a considerable distance was
raised above its former level.{ At Valparaiso, the elevation
was 3 feet, and at Quintero about 4 feet. Part of the bed
of the sea, says Mrs. Graham, remained bare and dry at
high water, ‘with beds of oysters, mussels, and other shells
adhering to the rocks on which they grew, the fish being all
dead, and exhaling most offensive effluvia.§
An old wreck of a ship, which before could not be ap-
* Biblioth. Univ. Oct. 1828, p. 175. Journ. of Sci. 1824, vol. xvii. p. 40.
f¢ Phil. Mag. July, 1828, p. 37. § Geol. Trans. vol. i. 2nd ser. P-
{ Geol. Trans. vol. i. 2nd ser., and 4165.
Cu, XXVIIL.] EARTHQUAKES IN CHILI IN 1822. 95
proached, became accessible from the land, although its
distance from the original sea-shore had not altered. It wag
observed that the watercourse of a mill, at the distance of
about a mile from the sea, gained a fall of 14 inches in little
more than 100 yards; and from this fact it is inferred that
the rise in some parts of the inland country was far more
considerable than on the borders of the ocean.* Part of the
coast thus elevated consisted of granite, in which parallel
fissures were caused, some of which were traced for a mile
and a half inland. Cones of earth about 4 feet high were
thrown up in several districts, by the forcing up of water
mixed with sand through funnel-shaped hollows,—a pheno-
menon very common in Calabria, and the explanation of
which will hereafter be considered. Those houses in Chili of
which the foundations were on rock were less damaged than
such as were built on alluvial soil.
Mr. Cruickshanks, an English botanist, who resided in the
country during the earthquake, has informed me that some
rocks of greenstone at Quintero, a few hundred yards from
the beach, which had always been under water till the shock
of 1822, have since been uncovered when the tide is at half-
ebb; and he states that, after the earthquake, it was the
general belief of the fishermen and inhabitants of the Chilian
coast, not that the land had risen, but that the ocean had
permanently retreated.
r. Meyen, a Prussian traveller, who visited Valparaiso in
1831, says that on examining the rocks both north and south
of the town, nine years after the event, he found, in corrobo-
ration of Mrs. Graham’s account, that remains of animals,
and sea-weed, the Lessonia of Bory de St. Vincent, which
has a firm ligneous stem, still adhered to those rocks which
in 1822 had been elevated above high-water mark.+ Ac-
cording to the same author, the whole coast of Central Chili
was raised about 4 feet, and banks of marine shells were laid
dry on many parts of the coast. He observed similar banks,
elevated at unknown periods, in several places, especially at
Copiapo, where the species all agree with those now living in
ed Ourn. of Sci. vol. xvii. p. 42. Meyen’s letter cited Foreign Quart. Rev.
t Reise um die Erde; and see Dr, No. 33. p. 13. 1836
96 EARTHQUAKES OF THE NINETEENTH CENTURY. [Cx. XXVIII
the ocean. Mr. Freyer also, who resided some years in
South America, has confirmed these statements;* and Mr.
Darwin obtained evidence that the remains of an ancient
wall, formerly washed by the sea, and now 114 feet above
high-water mark, acquired several feet of this elevation
during the earthquake of 1822.+
The shocks continued up to the end of September 1823;
even then, 48 hours seldom passed without one, and some-
times two or three were felt during 24 hours. Mrs. Graham
observed, after the earthquake of 1822, that besides a beach
newly raised above high-water mark, there were several older
elevated lines of beach, one above the other, consisting of
shingle mixed with shells extending in a parallel direction to
the shore, to the height of 50 feet above the sea.t
Hetent of country elevated.—By some observers it has been
supposed that the whole country from the foot of the Andes
to a great distance under the sea was upraised in 1822, the
ereatest rise being at the distance of about 2 miles from the
shore. ‘The rise upon the coast was from 2 to 4 feet:—at
the distance of a mile inland it must have been from 5 to 6
or 7 feet.’ § It has also been conjectured by the same eye-
witnesses to the convulsion, that the area over which this
permanent alteration of level extended may have been equal
to 100,000 square miles. Although the increased fall of
certain watercourses may have afforded some ground for
this conjecture, it must be considered as very hypothetical,
and the estimate may have exceeded or greatly fallen short
of the truth. It may nevertheless be useful to reflect on the
enormous amount of change which this single convulsion
occasioned, if the extent of country moved upward really
amounted to 100,000 square miles,—an extent just equal to
ialf the area of France, or about five-sixths of the area of
Great Britain and Ireland. If we suppose the elevation to
have been only 3 feet on an average, it will be seen that the
mass of rock added to the continent of America by the move-
ment, or, in other words, the mass previously below the leve
* Geol. Soc. Proceedings, No. xl: t Geol. Trans. vol. i. 2nd ser. p. 415.
p- 179, Feb. 1835. § Journal of Science, vol. xvil. pp.
+ Proceed. Geol. Soe. vol. ii. p. 447. 40, 46
NEDSS OTe a
| yy \
‘ ~ Ou. XXVUL] COAST OF CHILI ELEVATED. 97
ary ;
nd ‘. of the sea, and after the shocks permanently above it, must
®eient have contained 57 cubic miles in bulk ; which would be
t above sufficient to form a conical mountain 2 miles high (or about
evation as high as Htna), with a circumference at the base of nearly
33 miles. We may take the mean specific gravity of the
1899, rock at 2°655,—a fair average, and a convenient one in such
some. computations, because at such a rate a cubic se weighs 2
Trahan tons. Then, oe the a poe of Egypt,.if eet
a beach to weigh, in i ao with an estimate ks given,
al olde 6,000,000 tons, we may state the rock added to the continent
ee by the Chilian earthquake to have more than equalled
—_ - 100,000 pyramids.
ction to But it must always be borne in mind that the weight of
rock here alluded to constituted but an insignificant part. of
as been the whole amount which the voleanic forces had to overcome.
> Andes The thickness of rock between the surface of Chili and the
322, the subterranean foci of volcanic action may be many miles or
om the leagues deep. Say that the thickness was only 2 miles, even
et :—at then the mass which changed place and rose 3 feet, being
5 to 6 200,000 cubic miles in volume, must have exceeded in weight
ne eye- 363,000,000 pyramids.
ch this It may be instructive to consider these results in connection
n equal with others already obtained from a different source, and to
fall of compare the working of two antagonist forces—the levelling
md for | power of running water, and the expansive energy of sub-
hetical, terranean heat. How long, it may be asked, would the Ganges
» short require, according to data before explained (Vol. I. p. 481),
on the to transport to the sea a quantity of solid matter equal to
lsion that which may have been added to the land by the Chilian
"peal earthquake ? The discharge of mud in one year by the Ganges
1 to was estimated at 20,000,000,000 cubic feet. According to
baa of that estimate it would require about 4 centuries (or 418
oti a . years) before the river could bear down from the continent
{00 6 Into the sea a mass equal to that gained by the Chilian
at f earthquake. In about half that time, perhaps, the united
move waters of the Ganges and Burrampooter might accomplish
e Jevé the operation.
b. Cutch, 1819.—A violent earthquake occurred at Cutch, in
J the delta of the Indus, on June 16,1819. (See Map, fig. 105.)
VOL. I. -
98 FARTHQUAKES IN THE NINETEENTH CENFURY. (Cx. XXVIIt
The principal town, Bhooj, was converted into a heap of
ruins, and its stone buildings were thrown down. The move-
ment was felt over an area having a radius of 1,000 miles
from Bhooj, and extending to Khatmandoo, Calcutta, ang
Pondicherry.* The vibrations were felt in North-west
India, at a distance of 800 miles, after an interval of about
15 minutes after the earthquake at Bhooj. At Ahmedabad
the creat mosque, erected by Sultan Ahmed nearly 450 years
Fig. 108. d
Ge ge one ce Oe | | a) aos!
‘Beilta \ ‘| ae
: cf! ao of
~~ eee er
(N5 drabad | |
‘ | oA
fees
|
|
I!
|
————— er PEt
|
}
Ll ae oct
a Fe ob: CRIS
%,
Cal
> 2 Shoo} fee
= © ° ¥ Ahmed: abad |,
“ Cc
Scale of niiles.
#%% Mud vo'canos.
Areas RS rged during
earthquake
| Lhe Runn, alternately land
2a and w ater.
| Sneichen ee econ! Saeco
before, fell to the ground, attestine how long a period had
elapsed since a shock of similar violence had visited. that
point. At Anjar, the fort, with its tower and guns, were
hurled to the ground in one common mass of ruin. The
shocks continued until the 20th; when, 30 miles north-west
from Bhooj, the voleano called Denodur is said by some Me
have sent forth flames, but Captain Grant, when in Cutch m
1838, was unable to authenticate this statement.
* See Asiatic Journal, vol. i
es
7 XXy
heap of
medabaq
450) Years
TRIES |
OF THR |
Ss
come x
crutch ™
ee eR
Cu. XXVIII.] SUBSIDENCE IN THE DELTA OF THE INDUS. 99
Subsidence in the delta of the Indus.—Although the ruin of
towns was great, the face of nature in the inland country,
says Captain Macmurdo, was not visibly altered. In the
hills some large masses only of rock and soil were detached
from the precipices; but the eastern and almost deserted
channel of the Indus, which bounds the province of Cutch,
was greatly changed. This estuary, or inlet of the sea, was,
before the earthquake, fordable at Luckput, being only about
1 foot deep when the tide was at ebb, and at flood tide never
more than 6 feet; but it was deepened at the fort of Luckput,
after the shock, to more than 18 feet at low water.* On
sounding other parts of the channel, it was found, that where
previously the depth of the water at flood never exceeded 1
or 2 feet, it had.become from 4 to 10 feet deep. By these
and other remarkable changes of level, a part of the inland
navigation of that country, which had been closed for
centuries, became again practicable.
Fort and village submerged.—The fort and village of
Sindree, on the eastern arm of the Indus, above Luckput,
are stated by the same writer to have been overflowed; and,
after the shock, the tops of the houses and wall were alone to
be seen above the water, for the houses, although submerged,
were not cast down. Had they been situated, therefore, in
the interior, where so many forts were levelled to the ground,
their site would, perhaps, have been regarded as having
remained comparatively unmoved. Hence we may suspect
that great permanent upheavings and depressions of soil may
be the result of earthquakes, without the inhabitants being
in the least degree conscious of any change of level.
A more recent survey of Cutch, by Sir A. Burnes, who was
not in communication with Captain Macmurdo, confirms the
facts above enumerated, and adds many important details.+
That officer examined the delta of the Indus in 1826 and
1828, and from his account it appears that, when Sindree
subsided in June 1819, the sea flowed in by the eastern
mouth of the Indus, and in a few hours converted a tract of
* Macmurdo, Ed. Phil. Journ. iy. 106. brary of the Royal Asiatic Society of
~ This memoir is now in the Li- London.
H 2
100 EARTHQUAKES IN THE NINETEENTH CENTURY. [Cu. XXVIIq.
land, 2,000 square miles in area, into an inland sea, or lagoon,
Neither the rush of the sea into this new depression, nor the
movement of the earthquake, threw down entirely the small
fort of Sindree, one of the four towers, the north-western,
still continuing to stand; and, the day after the earthquake,
Fig. 106.
Fort of Sindree, on the eastern ee of the ae before it was ae. by
the earthquake of 1819, from a sketch of Capt. Grindlay, made in 1808.*
the inhabitants, who had ascended to the top of this tower,
saved themselves in boats.t
Elevation of the Ullah Bund.—Immediately after the shock,
the inhabitants of Sindree saw, at the distance of 5} miles
from their village, a long elevated mound, where previously
there had been a low and perfectly level plain. (See Map,
fig.105.) To this uplifted tract they gave the name of ‘Ullah
Bund,’ or the ‘Mound of God,’ to distinguish it from several
artificial dams previously thrown across the eastern arm of
the Indus.
Extent of country raised.—It has been ascertained that this
new-raised country is wpwards of fifty miles in length from
east to west, running parallel to that line of subsidence
* JT was indebted to my friend the late + Several particulars not given in
Sir Alexander Burnes for the accom- the earlier edition were afterwards ob-
Penns sketch (fig. 106) of the fort of | tained by me from persone a
indree, as it appeared eleven years munication with Sir A, Bur 1
Ee. the earthquake. London.
R, XV
x lagoon,
LL ny Dy the
the Smal}
~We Stern,
Y 'thquake
>
Fe 106
submerged by
D 1808.*
his towel,
the shock,
r 5 a miles
revi
Gy. XXVIIL] ELEVATION OF THE ULLAH BUND. ' 101
pefore mentioned which caused the grounds around Sindree
to be flooded. The range of this elevation extends from
Puchum Island towards Gharee ; its breadth from north to
south is conjectured to be in some parts siateen miles, and its
greatest ascertained height above the original level of the
delta 18 vation which appears to the eye to
be very uniform Pe ouhont
For several years after the convulsion of 1819, the course
of the Indus was very unsettled, and at leng th, in 1826, the
river threw a vast body of water into its eastern arm, that
called the Phurraun, above Sindree; and forcing its way in
a more direct course to the sea, burst through all the artificial
dams which had been thrown across its channel, and at length
cut right through the ‘Ullah Bund,’ whereby a natur al section
was Shinined: In the perpendicular cliffs thus laid open Sir
A. Burnes found that the upraised lands consisted of clay
filled with shells. The new channel of the river where it
intersected the ‘bund’ was 18 feet deep, and 40 yards in
width; but in 1828 the channel was still farther enlarged.
The Indus, when it first opened this new passage, threw
such a body of water into the new mere, or salt lagoon, of
Sindree, that it became fresh for many months; but it had
recovered its saltness in 1828, when the supply of river-water
was legs copious, and finally it became more salt than the sea,
in consequence, as the natives suggested to Sir A. Burnes, of
the saline particles with which the ‘Runn of Cutch’ is im-
pregnated.
In 1828 Sir A. Burnes went in a boat to the ruins of
Sindree, where a single remaining tower was seen in the
midst of a wide expanse of sea. The tops of the ruined
walls still rose 2 or 3 feet above the level of the water; and
standing on one of these, he could behold nothing in the
horizon but water, except in one direction, where a blue
streak of land to the north indicated the Ullah Bund. This
scene presents to the imagination a lively picture of the re-
volutions now in progress on the earth—a waste of waters
where a few years before all was land, and the only land
visible consisting of ground uplifted by a recent earthquake.
Ten years after the visit of Sir A. Burnes above alluded to,
102 EARTHQUAKES IN THE NINETEENTH CENTURY, [Cu. XXVIII.
my friend, Captain Grant, F.G.8., of the Bombay Engineers,
had the kindness to send at my request a native surveyor to
make a plan of Sindree and Ullah Bund, in March, 1838.
From his description it appears that, at that season, the
driest of the whole year, he found the channel traversing the
Bund to be 100 yards wide, without water, and encrusted
with salt. He was told that it has now only 4 or 5 feet of
water in it after rains. The sides or banks were nearly
perpendicular, and 9 feet in height. The lagoon has
diminished both in area and depth, and part near the fort
Fig. 107.
View of the Fort of Sindree, from the west, in March, 1838.
was dry land. The annexed drawing, made by Captain
Grant from the surveyor’s plan, shows the appearance of the
fort in the midst of the lake, as seen in 1838 from the west
or from the same point as that from which Captain Grindlay’s
sketch (see fig. 106), was taken in 1808, before the earth-
quake.
The Runn of Cutch is a flat region of a very peculiar
character, and no less than 7,000 square miles in area: a
greater superficial extent than Yorkshire, or about one-
fourth the area of Ireland. It is not a desert of moving
sand, nor a marsh, but evidently the dried-up bed of an
inland sea, which for a great part of every year hasa hard and
dry bottom without vegetation or only supporting here and
there a few tamarisks. But during the monsoons, when the
sea runs high, the salt-water driven up from the Gulf of
Cutch and the creeks at Luckput overflows a large part of the
Runn, especially after rains, when the soaked eround permits
' XXypy
‘Zine
YeYor to
h, 183g
wes the
SIhg the
Lerusted
ers,
» feet of
© Dearly
900 has
the tort
wa]
Captain
ne of the
the west
rindlay’s
1e earth-
peculiat
area: #
put one-
moving
“d of ap
pard a?
Cu, XXVIII.] EFFECTS OF THE EARTHQUAKE OF CUTCH. 103
the sea-water to spread rapidly. The Runn is also liable to
be overflowed occasionally in some parts by river-water : and
+t is remarkable that the only portion which was ever highly
cultivated (that anciently called Sayra) is now permanently
submerged. The surface of the Runn is sometimes encrusted
with salt about an inch in depth, in consequence of the
evaporation of the sea-water. Islands rise up in some parts
of the waste, and the boundary lands form bays and promon-
tories. The natives have various traditions respecting the
former separation of Cutch and Sinde by a bay of the sea,
and the drying up of the district called the Runn. But these
tales, besides the usual uncertainty of oral tradition, are
farther obscured by mythological fictions. The conversion
of the Runn into land is chiefly ascribed to the miraculous
powers of a Hindoo saint, by name Damorath (or Dhoorun-
nath), who had previously done penance for twelve years on
the summit of Denodur hili. Captain Grant infers, on various
grounds, that this saint’ flourished about the 11th or 12th
century of our era. In proof of the drying up of the Runn,
some towns far inland are still pointed out as having once
been ancient ports. It has, moreover, been always said that
ships were wrecked and engulphed by the great catastrophe ;
and in the jets of black muddy water thrown out of fissures in
that region, in 1819, there were cast up numerous pieces of
wrought iron and ship nails.* Cones of sand 6 or 8 feet in
height were at the same time formed on these lands.t
We must not conclude without alluding to a moral phe-
nomenon connected with this tremendous catastrophe, which
we regard as highly deserving the attention of geologists. It
is stated by Sir A. Burnes, that ‘ these wonderful events
passed unheeded by the inhabitants of Cutch;’ for the region
convulsed, though once fertile, had for a long period been
reduced to sterility by want of irrigation, so that the natives
were indifferent as to its fate. Now it is to this profound
apathy which all but highly civilised nations feel, in regard
to physical events not having an immediate influence on
* Capt. Burnes’ Account.
t Capt. Macmurdo’s Memoir, Ed. Phil. Journ. vol. iv. p. 106.
104. EARTHQUAKES IN THE NINETEENTH CENTURY, (Cu. XXVqqq.
their worldly fortunes, that we must ascribe the extraordinary
dearth of historical information concerning changes of the
earth’s surface, which modern observations show to be by no
means of rare occurrence in the ordinary course of nature,
Since the above account was written, a description has
been published of more recent geographical changes in the
district of Cutch, near the mouth of the Koree, or eastern
branch of the Indus, which happened in June 1845, A large
area seems to have subsided, and the Sindree lake had become
a salt marsh. *
Island of Sumbawa, 1815.—In April, 1815, one of the most
frightful eruptions recorded in history occurred in the province —
of Tomboro, in the island of Sumbawa (see Map, fig. 59,
Vol. I. p. 587), about 200 miles from the eastern extremity
of Java. In April of the preceding year the volcano had
been observed in a state of considerable activity, ashes having
fallen upon the decks of vessels which sailed past the coast. +
The eruption of 1815 began on April 5th, but was most
violent on the 11th and 12th, and did not entirely cease till
July. The sound of the explosions was heard in Sumatra,
at the distance of 970 geographical miles in a direct line ;
and at Ternate, in an opposite direction, at the distance of
720 miles. Out of a population of 12,000, in the province of
Tomboro, only 26 individuals survived. Violent whirlwinds
carried up men, horses, cattle, and whatever else came within
their influence, into the air ; tore up the largest trees by the
roots, and covered the whole sea with floating timber.t
Great tracts of land were covered by lava, several streams of
which, issuing from the crater of the Tomboro Mountain,
reached the sea. So heavy was the fall of ashes, that they
broke into the Resident’s house at Bima, 40 miles east of
the volcano, and rendered it as well as many other dwellings
in the town uninhabitable. On the side of Java the ashes
were carried to the distance of 300 miles, and 217 towards
Celebes, in sufficient quantity to darken the air. The floating
cinders to the westward of Sumbawa formed, on April 12th,
* Quart. Geol. Journ. vol. ii. p. 108. + Raftles’s Java, vol. i, p. 28.
t MS. of J. Crawfurd, Esq.
Xv,
Tdinary, Gu, XXVIII] EARTHQUAKE IN THE ISLAND OF SUMBAWA. 105
S of th. a, mass 2 feet thick, and several miles in extent, through which
% by ho ships with difficulty forced their way.
ture, The darkness occasioned in the daytime by the ashes in
ion hag Java was 80 profound, that nothing equal to it was ever
5 1M the witnessed in the darkest night. Although this pees =
easter, when it fell was an impalpable powder, it sine ie
A large able weight when Sa ing a nei of it woe beac
become ounces and three quarters. Some of = finest particles, |
says Mr. Crawfurd, ‘were transported to the islands of
™ _ Amboyna and Banda, which last is about 800 miles east
ae from the site of the voleano, although the south-east mon-
a aCe soon was then atits height.’ They must have been projected,
fig. 59, therefore, into the upper regions of the atmosphere, where
ctremity a counter-current prevailed.
ano had Along the sea-coast of Sumbawa and the adjacent isles,
s having the sea rose suddenly to the height of from 2 to 12 feet,
Coast. great wave rushing up the estuaries, and then suddenly
‘as most subsiding. Although the wind at Bima was still during the
ease till whole time, the sea rolled in upon the shore, and filled the
‘amatra. lower parts of the houses with water a foot deep. Every
set — prow and boat was forced from the anchorage, and driven
a on shore.
vince of The town called Tomboro, on the west side of Sumbawa,
eer? was overflowed by the sea, which encroached upon the shore
irlwinds so that the water remained permanently 18 feet deep in
e within places where there was land before. Here we may observe,
s by the that the amount of subsidence of land was apparent, in spite
pimber-+ of the ashes, which would naturally have caused the limits
ams of of the coast to be extended.
yantalD, The tremulous noises and other volcanic effects of this
vat they eruption extended over an area 1,000 statute miles in
east 9 diameter, having Sumbawa as its centre. It included the
velling® | whole of the Molucca Islands, Java, a considerable portion of
e ashes Celebes, Sumatra, and Borneo. In the island of Amboyna,
powards in the same month and year, the ground opened, threw out
doa ting water, and then closed again.*
In conclusion, I may remind the reader, that but for the
* Raffles’s Hist. of Java, vol. i. p. 25. Ed. Phil. Journ. vol. iu. p. 389.
106 EARTHQUAKES IN THE NINETEENTH CENTURY. [Cu. XXVIII.
accidental presence of Sir Stamford Raffles, then governor of
Java, we should scarcely have heard in Europe of this
tremendous catastrophe. He required all the residents in
the various districts under his authority to send in a state-
ment of the circumstances which occurred within their own
knowledge ; but, valuable as were their communications, they
are often calculated to excite rather than to satisfy the
curiosity of the geologists. They mention, that similar
effects, though ina less degree, had, about seven years before,
accompanied an eruption of Carang Assam, a volcano in the
island of Bali, west of Sumbawa; but no particulars of that
oreat catastrophe are recorded.*
Caraccas, 1812.—-On March 26, 1812, several violent
shocks of an earthquake were felt in Caraccas. The surface
undulated like a boiling liquid, and terrific sounds were heard
underground. The whole city with its splendid churches
was in an instant a heap of ruins, under which 10,000 of the
inhabitants were buried. On April 5, enormous rocks were
detached from the mountains. It was believed that the
mountain Silla lost from 300 to 360 feet of its height by
subsidence; but this was an opinion not founded on any
measurement. On April 27, a volcano in St. Vincent’s threw
out ashes; and, on the 30th, lava flowed from its crater into
the sea, while its explosions were heard at a distance equal
to that between Vesuvius and Switzerland, the sound being
transmitted, as Humboldt supposes, through the ground.
During the earthquake which destroyed Caraccas, an immense
quantity of water was thrown out at Valecillo, near Valencia,
as also at Porto Caballo, through openings in the earth;
and in the Lake Maracaybo the water sank. Humboldt
observed that the Cordilleras, composed of gneiss and mica
slate, and the country immediately at their foot, were more
violently shaken than the plains.+
South Carolina and New Madrid, Missouri, 1811-12.—
Previous to the destruction of La Guayra and Caraccas, in
1812, earthquakes were felt in South Carolina ; and the
* Life and Services of Sir Stamford + Humboldt’s Pers. Nar. vol. iv. p. 12;
Raffles, p. 241, London, 1830. and Ed. Phil. Journ. vol. i. p. 272. 1819.
a
|
XX,
Moy of Cu. XXVIII] EARTHQUAKE IN CARACCAS IN 1812. 107
t this shocks continued till those cities were destroyed. The valley
‘Nts in also of the Mississippi, from the village of New Madrid
t State. to the mouth of the Ohio in one direction, and to the St.
‘ir Own Francis in another, was convulsed in such a degree as to
8, they ereate new lakes and islands. It has been remarked by
sfy the Humboldt in his Cosmos, that the earthquake of New Madrid
similay presents one of the few examples on record of the incessant
before. quaking of the ground for several successive months far from
in the any volcano. lint, the geographer, who visited the country
of that ey en years after the event, informs us, that a tract of many
miles in extent, near the Little Prairie, became covered with
> water 8 or 4 feet deep; and when the water disappeared
Violent a stratum of sand was left in its place. Large lakes of
Surface 20 miles in extent were formed in the course of an hour,
© heard and others were drained. The graveyard at New Madrid
hurches was precipitated into the bed of the Mississippi; and it is
) of the stated that the ground whereon the town is built, and the
ks were river bank for 15 miles above, sank 8 feet below their
hat the former level.* The neighbouring forest presented for some
ight by years afterwards ‘a singular scene of confusion; the trees
on any standing inclined in every direction, and many having their
s threw trunks and branches broken.’ t
ter into The inhabitants relate that the earth rose in great undu-
e equal lations ; and when these reached a certain fearful height, the
d being soil burst, and vast volumes of water, sand, and pit-coal were
ial discharged as high as the tops of . the trees. Flint saw
mens hundreds of these deep chasms remaining in an alluvial soil,
‘Jencith seven years after. As the shocks lasted throughout a period
pe th: of three months the country people had time to remark that
eal A there were certain prevailing directions in which the fissures
bold opened in their district. Being all of them familiar with the
d mace use of the axe, they felled the tallest trees and made them fall
pe mote | at right angles to the direction of the chasms which usually
ran from SW. to NE., and by stationing themselves on the
j-12-— trees they often escaped being swallowed up when the earth
ecas, opened beneath them. At one period during this earthquake,
nd the
aie resin p- 243. Pitts- + Long’s wees - the Rocky Moun-
12; burgh, 182 tains, vol. 11
108 EARTHQUAKES IN THE NINETEENTH CENTURY. [Cu. XXVIII.
the ground not far below New Madrid swelled up so as to
arrest the Mississippi in its course, and to cause a temporary
reflux of its waves. The motion of some of the shocks is
described as having been horizontal, and of others perpen-
dicular; and the vertical movement is said to have been
much less desolating than the horizontal.
The above account has been reprinted exactly ag it
appeared in former editions of this work, compiled from the
authorities which I have cited; but having more recently
(March, 1846) had an opportunity myself of visiting the
disturbed region of the Mississippi, and conversing with many
eye-witnesses of the catastrophe, I am -able to confirm the
truth of those statements, and to add some remarks on the
present face and features of the county. I skirted, as was
before related (Vol. I. p. 456), part of the territory immediately
west of New Madrid, called ‘the sunk country,’ which was
for the first time permanently submerged during the earth-
quake of 1811-12. It is said to extend along the course of
the White Water and its tributaries for a distance of between
70 and 80 miles north and south, and 30 miles east and west.
I saw on its border many full-grown trees still standing
leafless, the bottoms of their trunks several feet under water,
and a still greater number lying prostrate. An active vege-
tation of aquatic plants is already beginning to fill up some
of the shallows, and the sediment washed in by occasional
floods when the Mississippi rises to an extraordinary height
contributes to convert the borders of the sunk region into
marsh and forest land. Even on the dry ground along the
confines of the submerged area, I observed in some places
that all the trees of prior date to 1811 were dead and leafless,
though standing erect and entire. They are supposed to
have been killed by the loosening of their roots during the
repeated undulations which passed through the ground for
three months in succession.
Mr. Bringier, an experienced engineer of New Orleans, who
was on horseback near New Madrid when some of the
severest shocks were experienced, related to me (in 1846),
that ‘as the waves advanced the trees bent down, and the
instant afterwards, while recovering their position, they often
q |
. XX
SO ag to Cu. XXVIII.) THOSE OF NEW MADRID, MISSOURI, IN 1811-12, 109
MPorary met those of other trees similarly inclined, so that their
Ocks ig branches becoming interlocked, they were prevented from
Perpep. righting themselves again. The transit of the wave through
ve been the woods was marked by the crashing noise of countless
boughs, first heard on one side and then on the other. At
Y as it the same time powerful jets of water, mixed with sand, mud,
Tom the and fragments of coaly matter, were cast up, endangering the
recently lives of both horse and rider.”
‘ing the I was curious to ascertain whether any vestiges still
th many remained of these ig of mud and water, and carefully
firm the examined between New Madrid and the Little Prairie several
o ‘gink holes’ as they are termed. They consist of cavities
: op the from 10 to 30 yards in width, and 20 feet or more in depth,
4 a Was and are very conspicuous as they interrupt the level surface
ediately of a flat alluvial plain. Round their edges I saw abundance
hich was of sand, which some of the inhabitants with whom I con-
e earth- versed had seen spouting from these deep holes, also frag-
ourse of ments of decayed wood and black bituminous shale, probably
between drifted down at some former period in the main channel of
nd west. the Mississippi, from the coal-fields farther north. I also
standing found numerous rents in the soil left by the earthquake, some
YY water, of them still several feet wide, and a yard or two in depth,
ve vege- although the action of rains, frost, and occasional inunda-
up some tions, and especially the leaves of trees blown into them in
easional countless numbers every autumn, have done much to fill them
‘ height up. I measured the direction of some of the fissures, which
‘on into usually varied from 10° to 45° W. of N., and were often
fone the parallel to each other; I found, however, a considerable
one ‘ diversity in their direction. Many of them are traceable for
e pla = half a mile and upwards, but they might easily be mistaken
leafless, for artificial trenches if resident settlers were not there to
posed ar assure us that within their recollection they were ‘as deep
ring the as wells.’ Fragments of coaly shale were strewed along the
yund for edges of some of these open fissures, together with white
sand, in the same manner as round the ‘ sink holes.’ *
108; wh? Among other monuments of the changes wrought in
of the 1811-12, I explored the bed of a lake called Eulalie, near
p 1846)
and the * See Lyell’s Second Visit to the United States, vol. ii. ch. xxxiii.
wy ofteh
} F r
110 REFLECTIONS ON EARTHQUAKES OF 19rx CENTURY. [Cu. XXVIII.
New Madrid, 300 yards long by 100 yards in width, which
was suddenly drained during the earthquake. The parallel]
fissures by which the water escaped were not yet entirely
closed, and all the trees growing on its bottom were at the
time of my visit less than 34 years old. They consisted of
cotton-wood, willows, the honey-locust, and other Species,
differing from those clothing the surrounding higher grounds,
which are more elevated by 12 or 15 feet. On them the
hiccory, the black and white oak, the gum and other trees,
many of them of ancient date, were flourishing.
Reflections on the earthquakes of the wineteenth century.— We
are now about to pass on to the events of the eighteenth
century: but before we leave the consideration of those
already enumerated, let us pause for a moment, and reflect
how many remarkable facts of geological interest are afforded
by the earthquakes above described, though they constitute
but a small part of the convulsions even of half a century.
New rocks have risen from the waters; new hot springs
have burst out, and the temperature of others has been
altered. A large tract in New Zealand has been upraised
from 1 to 9 feet above its former level, and another con-
tiguous region depressed several feet, and in the same archi-
pelago a fault or displacement of the rocks nearly 100 miles
long and about 9 feet in vertical height has been produced.
The coast of Chili has been thrice permanently elevated; a
considerable tract in the delta of the Indus has sunk down,
and some of its shallow channels have become navigable; an
adjoining part of the same district, upwards of 50 miles in
length and 16 in breadth, has been raised about 10 feet above
its former level; part of the ereat plain of the Mississippi,
for a distance of 80 miles in length by 30 in breadth, has
sunk down several feet; the town of Tomboro has been sub-
merged, and 12,000 of the inhabitants of Sumbawa have been
destroyed. Yet, with a knowledge of these and other terrific
catastrophes, witnessed during so brief a period by the
present generation, will the ¢
2
y
veologist declare with perfect
composure that the earth has at length settled into a state
of repose? Will he continue to assert that the changes of
relative level of land and sea, so common in former ages of i+
Hy
“AX;
h Ww] ‘ Cr. XXVIII.] REFLECTIONS ON EARTHQUAKES OF 19TH CENTURY. iki
) Lich
Paral] the world, have now ceased? If, in the face of so many
“Ntirehy striking facts, he persists in maintaining this favourite
ie at the dogma, it is in vain to hope that, by accumulating the proofs
“Sted of of similar convulsions during a series of antecedent ages, we
SPecieg shall shake his tenacity of purpose :—
=
> Ounds, Si fractus illabatur orbis
he ge ;
em the Tmpayidum ferient ruinee.
er trees,
‘y.—We
zhteenth
Of those
d reflect
afforded
onstitute
century.
springs
vas been
upraised
her con-
ne archi-
(0 miles
roduced.
rated ; a
k down,
able; 22
S$ rm
mile
et above
CHAPTER XXIX.
EARTHQUAKES OF THE EIGHTEENTH CENTURY—QUITO, 1797—stcILy, 1790—
CALABRIA, FEBRUARY 5, 1783—SHOCKS CONTINUED TO THE END OF THR YEAR
1786—AUTHORITIES—AREA CONVULSED—GEOLOGICAL STRUCTURE OF THE DIS-
TRICT—-MOVEMENT IN THE STONES OF TWO OBELISKS—BOUNDING OF DETACHED
MASSES INTO THE AIR—DIFFICULTY OF ASCERTAINING CHANGES OF LEVEL—
SUBSIDENCE OF THE QUAY AT MESSINA—SHIFT OR FAULT IN THE ROUND TOWER
OF TERRANUOVA—OPENING AND CLOSING OF FISSURES—LARGE EDIFICES EN-
GULPHED—DIMENSIONS OF NEW CAVERNS AND FISSURES—GRADUAL CLOSING
IN OF RENTS—DERANGEMENT OF RIVER COURSES —LANDSLIPS—BUILDINGS
TRANSPORTED ENTIRE TO GREAT DISTANCES—NEW LAKES—FUNNEL-SHAPED
HOLLOWS IN ALLUVIAL PLAINS—CURRENTS OF MUD~—FALL OF CLIFFS, AND
SHORE NEAR SCILLA INUNDATED —STATE OF STROMBOLI AND ETNA DURING THE
SHOCKS—-ORIGIN AND MODE OF PROPAGATION OF EARTHQUAKE WAVES—DEPTH
OF THE SUBTERRANEAN SOURCE OF THE MOVEMENT—NUMBER OF PERSONS
WHO PERISHED DURING THE EARTHQUAKE OF 1783— CONCLUDING REMARKS,
THE earthquakes of the 18th century which we have next
to consider are so numerous that a few of them only can
be mentioned. I shall select therefore such as are pe-
culiarly illustrative of geological changes, treating of the
more modern events first, and then of the others in retro-
spective order, according to the plan observed in the last
chapter for reasons there explained.
Quito, 1797.—The convulsion of this year in Quito was
remarkable for the extent of country shaken, and for the
alterations caused in river courses, and still more for the
floods of ‘moya’ or fetid mud which issued from the crater
of the volcano of Tunguragua.*
Caraccas, 1790.—During an earthquake in Caraccas in
1790 the granitic soil on which the forest of Aripao grew, is
said to ‘ees sunk, giving rise to a lake 800 yards in diameter,
and from 80 to 100 feet in depth. The trees remained
green for several months under water.
* Cavanilles, Journ. de Phys., tome xlix. p. 230. Gilbert’s Annalen, bd. vi
Humboldt’ s ae ». 317,
EMARKS.
have next
only can
s are pe-
1g of the
in retro-
n the last
Quito was
id for the
ve for the
he crater
yaccas .
8
o grew
aleD,
Cu. XXIX.] EARTHQUAKES IN SICILY, JAVA, CALABRIA. 1138
Sicily, 1790.—Ferrara informs us that in Sicily in the same
year (1790) at Santa Maria di Niscemi, some miles from
Terranuova, near the south coast, the ground sank down
during 7 shocks for a circumference of about 3 miles, and to
the depth in one place of 30 feet. The subsidence continued.
for a month, and several fissures sent forth sulphur, petro-
leum, steam and hot water, and a stream of mud flowed out
of one of them. ‘The strata where this happened consisted
of blue clay, and the site is far distant from the region both
of ancient and modern volcanos in Sicily.*
Java, -1786.—During an earthquake in 1786 at Batur in
Java which was followed by a volcanic eruption, the river
Dotog entered one of several newly-formed rents, and con-
tinued after the shocks to pursue a subterranean course.
This fact, noticed by contemporary writers, was afterwards
verified by Dr. Horsfield.
EARTHQUAKE OF CALABRIA, 1783.
Of all the subterranean convulsions of the last century, that
of Calabria in 1783 is almost the only one which has been so
circumstantially described as materially to aid the geologist
in appreciating the changes in the earth’s crust which a long
repetition of similar events must produce in the lapse of ages.
The shocks began in February of that year, and lasted for
nearly 4 years, to the end of 1786. Neither in duration, nor
in violence, nor in the extent of territory moved, was this
convulsion remarkable, when contrasted with many expe-
rienced in other countries, both during the last and present
century ; nor were the alterations which it occasioned in the
relative level of hill and valley, land and sea, so great as those
effected by some subterranean movements in South America,
in later times. The importance of the earthquake in question
arises from the circumstance, that Calabria affords the first
example of a region visited, both during and after the convul-
sions, by men possessing sufficient leisure, zeal, and. scientific
information to enable them to collect and describe with accu-
tacy such physical facts as throw light on geological questions.
* Ferrara, Campi. Fleg. p. 51.
VWAOM Whe I
4
*
114 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cu. XXIXx.
Authorities—Among the numerous authorities, Vivenzio,
physician to the King of Naples, transmitted to the court a
regular statement of his observations during the continuance
of the shocks; and his narrative is drawn up with care and
clearness. Francesco Antonio Grimaldi, then secretary of
war, visited the different provinces at the king’s command,
and published a most detailed description of the permanent
changes in the surface.t He measured the length, breadth,
and depth of the different fissures and gulphs which opened,
16 7
ite Rady A CITI
es Maye
Fig. 108.
3¢
mh)
That
ae
or
Pn
|
Pit S]
ee :
<SS== =~. Spartivento
16 1Z
Map of part of Calabria shaken by the earthquake of 1783.
and ascertained their number in many provinces. His com-
ments, moreover, on the reports of the inhabitants, and his
explanations of their relations, are judicious and instructive.
Pignataro, a physician residing at Monteleone, a town placed
in the very centre of the convulsions, kept a register of the
* Tstoria de’ Tremuoti della Calabria + Descriz. de’ Tremuoti 7s nelle
del 1788. Calabria nel 1783. Napoli, 1784.
pe noid
th, } breadth,
uch Opened,
‘been lost.
Cu. XXIX.]
EARTHQUAKE OF CALABRIA, 1788. 115
shocks, distinguishing them into four classes, according to
their degree of violence. From his work, it appears that, in
the year 1783, the number was 949, of which 501 were
shocks of the first degree of force; and in the following year
there were 151, of which 98 were of the first magnitude.
Count Mecliti, also, and many others, wrote descriptions
of the earthquake; and the age scuoaa| of Naples, not
satisfied with these and other observations, sent a deputation
from their own body into Calabria, before the shocks had
ceased, who were accompanied by artists instructed to illus-
trate by drawings the physical changes of the district, and
the state of ruined towns and edifices. Unfortunately these
artists were not very successful in their representations of
the condition of the country, particularly when they attempted
to express, on a large scale, the extraordinary revolutions
which many of the great and minor river-courses underwent.
But some of the plates published by the Academy are valu-
able; and as they are little known, I shall frequently avail
myself of them to illustrate the facts about to be described.*
In addition to these Neapolitan sources of information,
our countryman, Sir William Hamilton, surveyed the district,
not without some personal risk, before the shocks had
ceased; and his sketch, published in the Philosophical
Transactions, supplies many facts that would otherwise have
He has explained, in a rational manner, many
events which, as related in the language of some eye-wit-
nesses, appeared marvellous and incredible. Dolomieu also
examined Calabria during the catastrophe, and wrote an
account of the earthquake, correcting a mistake into which
Hamilton had fallen, who supposed that a part of the tract
shaken had consisted of volcanic tuff. It is, indeed, a cir-
cumstance which enhances the geological interest of the
commotions which so often modify the surface of Calabria,
that they are confined to a country where there are neither
ancient nor modern rocks of volcanic or trappean origin ;
so that at some future time, when the era of disturbance
shall have passed by, the cause of former revolutions will be
* Istoria de’ Fenomeni del Tremoto, Real. Accad. &c. di Nap. Napoli,
&e. nell’ An. 1783, posta in luce dalla 1788, fol.
iM Pe
116 EARTHQUAKES IN THE EIGHTEENTH CENTURY, [Cu. XXIX.
as latent as in parts of Great Britain now occupied exclusively
by ancient marine formations.
Extent of the area convulsed.—The convulsion of the earth,
sea, and air extended over the whole of Calabria Ultra, the
south-east part of Calabria Citra, and across the sea to
Messina and its environs; a district lying between the 38th
and 39th degrees of latitude. The concussion was percep-
tible over a great part of Sicily, and as far north as Naples ;
but the surface over which the shocks acted so forcibly as to
excite intense alarm did not generally exceed 500 square
miles in area. That part of Calabria is composed chiefly,
like the southern part of Sicily, of argillaceous strata of great
thickness, containing marine shells, sometimes associated
with beds of sand and limestone. For the most part these
formations resemble in appearance and consistency the Sub-
apennine marls, with their accompanying sands and sand-
stones ; and the whole group bears considerable resemblance,
in the yielding nature of its materials, to most of our tertiary
deposits in France and England. Chronologically considered,
however, the Calabrian formations are comparatively of
modern date, often abounding in fossil shells referable to
species now living in the Mediterranean. °
We learn from Vivenzio, that on the 20th and 26th of
March, 1783, earthquakes occurred in the islands of Zante,
Cephalonia, and St. Maura; and in the last-mentioned island
several public edifices and private houses were overthrown,
and many people destroyed.
If the city of Oppido, in Calabria Ultra, be taken as a
centre, and round that centre a circle be described, with a
radius of 22 miles, this space will comprehend the surface
of the country which suffered the greatest alteration, and
where all the towns and villages were destroyed. The first
shock, of February 5, 1783, threw down, in two minutes, the
ereater part of the houses in all the cities, towns, and villages,
from the western flanks of the Apennines in Calabria Ultra
to Messina in Sicily, and convulsed the whole surface of the
country. Another occurred on March 28, with almost equal
violence. The granitic chain which passes through Calabria
from north to south, and attains the height of many thousand
.
Be Aa tea
(Cx. XXqy
= percep.
A'S Naples,
cibly as to
yin Square
ed chiefly.
ita of oreat
associated
part these
sy the Sub-
and sand-
»semblance,
our tertiary
considered,
ratively of
-eferable to
nd 26th af
ds of Zante,
T med island
overthrow?
takeD as @
hed, with ;
the surface
ypatiod a
The firs
Cu, XXIX.) EFFECTS OF CALABRIAN EARTHQUAKE. Hiv
feet, was shaken but slightly by the first shock, but more
rudely by some which followed.
Some writers have asserted that the wave-like movements
which were propagated through the recent strata, from west
to east, became very violent when they reached the point of
junction with the granite, as if a reaction was produced
where the undulatory movement of the soft strata was
suddenly arrested by the more solid rocks. But the state-
ment of Dolomieu on this subject is most interesting, and
perhaps, in a geological point of view, the most important
of all the observations which are recorded.* The Apennines,
he says, which consist in great part of hard and solid granite,
with some micaceous and argillaceous schists, form bare
mountains with steep sides, and exhibit marks of great
degradation. At their base newer strata are seen of sand
and clay, mingled with shells; a marine deposit containing
such ingredients as would result from the decomposition of
granite. The surface of this newer (tertiary) formation con-
stitutes what is called the plain of Calabria—a platform
which is flat and level, except where intersected by narrow
valleys or ravines, which rivers and torrents have excavated
sometimes to the depth of 600 feet. The sides of these
ravines are almost perpendicular; for the superior stratum,
being bound together by the roots of trees, prevents the
formation of a sloping bank. The usual effect of the earth-
quake, he continues, was to disconnect all those masses
which either had not sufficient bases for their bulk, or which
were supported only by lateral adherence. Hence it follows
that throughout the whole length of the chain, the soil
which adhered to the granite at the base of the mountains
Caulone, Esope, Sagra, and Aspramonte, slid over the solid
and steeply inclined nucleus, and descended somewhat
lower, leaving almost uninterruptedly from St. George to
beyond St. Christina, a distance of from 9 to 10 miles, a
chasm between the solid granitic nucleus and the sandy
soil. Many lands slipping thus were carried to a considerabie
distance from their former position, so as entirely to cover
Dissertation on the Calabrian Aarthquake, &c., translated in Pinkerton’s
ACA Ag
Voyages and Trayels, vol. v.
118 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cu. XXIX.
others; and disputes arose as to whom the property which
had thus shifted its place should belong.
From this account of Dolomieu we might anticipate, as
the result of a continuance of such earthquakes, first, a
longitudinal valley following the line of junction of the older
and newer rocks; secondly, greater disturbance in the newer
strata near the point of contact than at a greater distance
from the mountains; phenomena very common in other
parts of Italy at the junction of the Apennine and Sub-
apennine formations.
Mr. Mallet, in his valuable essay on the Dynamics of
HKarthquakes,* offers the following explanation of the fact to
which Dolomieu has called attention. When a wave of
elastic compression, of which he considers the earth-wave to
consist, passes abruptly from a body having an extremely
low elasticity, such as clay and gravel, into another like
granite, whose elasticity is remarkably high, it changes not
only its velocity but in part also its course, a portion being
reflected and a portion refracted. The wave being thus sent
back again produces a shock in the opposite direction, doing
great damage to buildings on the surface by thus returning
upon itself. At the same time, the shocks are at once eased
when they get into the more elastic materials of the granitic
mountains.
The surface of the. country during the Calabrian earth-
quakes often heaved like the billows of a swelling sea, which
produced a swimming in the head, like sea-sickness. It is
particularly stated, in almost all the accounts, that just
before each shock the clouds appeared motionless; and,
although no explanation is offered of this phenomenon, it
seems obviously the same as that observed in a ship at sea
when it pitches violently. The clouds seem arrested in their
career as often as the vessel rises in a direction contrary to
their course ; so that the Calabrians must have experienced
precisely the same motion on the land.
Trees, supported by their trunks, sometimes bent’ during
the shocks to the earth, and touched it with their tops. This
* Proceed. Roy. Irish Acad. 1846, p. 26.
(Cy. XX7y
rt y Which
Other
and Syb.
hamics of
he fact to
Wave of
h wave to
extremely
other like
anges not
‘ion being
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ion, doing
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e granitic
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ess. ;
that just
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it
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nt , during
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Cu. XXIX.]) EFFECTS OF CALABRIAN EARTHQUAKE. 119
is mentioned as a well-known fact by Dolomieu; and he
assures us that he was always on his guard against the spirit
of exaggeration in which the vulgar are ever ready to indulge
when relating these wonderful occurrences.
The reader must not suppose that these waves, although
described as passing along the solid surface of the earth in a
given direction like a billow on the sea, have any strict
analogy with the undulations of a fluid. They must be
regarded as the effects of vibrations, radiating from some
deep-seated point, each vibration on reaching the surface
lifting up the ground, and then allowing it again to subside.
The manner in which the vibratory jar reaches different
points of the surface in succession according to the outline
of the country, will be explained in the sequel, see p. 136.
Fig. 109.
Shifts in the stones of two obelisks in the Convent of S. Bruno.
The Academicians relate that in sonie of the cities of
Calabria effects were produced seeming to indicate a whirling
or yorticose movement. Thus, for example, two obelisks
(fig. 109) placed at the extremities of a magnificent facade in
the convent of 8. Bruno, in a small town called Stefano del
Bosco, were observed to have undergone a movement of a
singular kind. The shock which agitated the building is de-
scribed as having been horizontal and vorticose. The pedestal
of each obelisk remained in its original place; but the sepa-
rate stones above were turned partially round, and removed
sometimes nine inches from their position without falling.
120. EARTHQUAKES IN THE EIGHTEENTH CENTURY.
[Cu. XXIX,
It has been suggested by Mr. Darwin, that this kind of
displacement may be due to a vibratory rather than a whirling
motion ;* and more lately Mr. Mallet, in the paper already
cited, has offered a very ingenious solution of the problem.
He refers the twisting simply to an elastic wave, which has
moved the pedestal forwards and back again, by an alternate
horizontal motion within narrow limits ; and he has succeeded
in showing that a rectilinear movement in the ground may
have sufficed to cause an incumbent body to turn partially
round upon its bed, provided a certain relation exist between
the position of the centre of gravity of the body and its centre
of adherence.t
The violence of the movement of the ground upwards was
singularly illustrated by what the Academicians call the
‘sbalzo,’or bounding into the air, to the height of sever
of masses slightly adhering to the surface. In some towns
a great part of the pavement stones were thrown up, and found
lying with their lower sides uppermost. In these cases, we
must suppose that they were propelled upwards by the mo-
mentum which they had acquired; and that the adhesion of
one end of the mass being greater than that of the other, a
rotatory motion had been communicated to them. When the
stone was projected to a sufficient height to perform somewhat
more than a quarter of a revolution in the air, it pitched
down on its edge, and fell with its lower side uppermost.
New fissures and changes of level.—I shall now consider, in
the first place, those changes which are connected with the
rending and fissuring of rocks or with alterations in the
relative level of the different parts of the land ; and afterwards
describe those which are more immediately connected with
the derangement of the regular drainage of the country, and
where the force of running water cooperated with that of
the earthquake.
In regard to alterations of relative level, none of the
accounts establish that they were on a considerable scale ;
but it must always be remembered that, in proportion to the
area moved is the difficulty of proving that the general level
and ii. ib, 808
* Journal of a Naturalist, p- 376, t Proceedings Roy. Irish Acad. 1846,
3. pp. 14-16.
alyards,
Mate
~ SUCCEEdag
TY und m
a Partially
Ist betwan,
ay
tween
id its Centre
Pwards Was
NS call the
veral yards, .
some towns
», and found
se Cases, We
by the mo-
adhesion of
the other, a
When the
m somewhat
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ermost.
Cl ynsider, 2
ith tha
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e scale;
e
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ye
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Cu. XXIX.] EFFECTS OF CALABRIAN EARTHQUAKE. 197
has undergone any change, unless the sea-coast happens to
have participated in the principal movement. Even then it
is often impossible to determine whether an elevation or de-
pression even of several feet has occurred, because there is
nothing to attract notice in a band of shingle and sand of un-
equal breadth above the level of the sea running parallel to
a coast; such bands generally marking the point reached by
the waves during spring tides, or the most violent tempests.
The scientific investigator has not sufficient topographical
knowledge to discover whether the extent of beach has di-
minished or increased; and he who has the necessary local
information scarcely ever feels any interest in ascertaining
the amount of the rise or fall of the ground. Add to this the
ereat difficulty of making correct observations, in consequence
of the enormous waves which roll in upon a coast during an
earthquake, and efface every landmark near the shore.
It is evidently in seaports alone that we can look for very
accurate indications of slight changes of level ; and when we
find them, we may presume that they would not be rare at
other points, if equal facilities of comparing relative altitudes
were afforded. Grimaldi states (and his account is confirmed
by Hamilton and others), that at Messina, in Sicily, the shore
was rent; and the soil along the port, which before the shock
was perfectly level, was found afterwards to be inclined to-
wards the sea,—the sea itself near the ‘ Branchia’ becoming
deeper, and its bottom in several places disordered. The
quay also sunk down about 14 inches below the level of the
sea, and the houses in its vicinity were much fissured.*
Unfortunately we are without data for determining whether
these changes were superficial only, and due to the sliding
down or settling of the soil, or whether they were connected °
with deep-seated movements altering the relative level of sea
and land.
Among various proofs of partial elevation and depression
in the interior, the Academicians mention, in their Survey,
that the ground was sometimes on the same level on both
sides of new ravines and fissures, but sometimes there had
* Phil. Trans. 1788.
122 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cu. XXIX,
been a considerable upheaving of one side, or subsidence of
the other. Thus, on the sides of long rents in the territory
of Soriano, the stratified masses had altered their relative
position to the extent of from 8 to 14 palms (6 to 104 feet).
Similar shifts in the strata are alluded to in the territory
of Polistena, where there appeared innumerable fissures in
the earth. One of these was of great length and depth; and
in parts the level of the corresponding sides was greatly
changed. (See fig. 110.)
In the town of Terranuova some houses were seen uplifted
above the common level, and others adjoining sunk down
into the earth. In several streets the soil appeared thrust
Deep fissure, near Polistena, caused by the earthquake of 1783.
up, and abutted against the walls of houses: a large circular
tower of solid masonry, part of which had withstood the
general destruction, was divided by a vertical rent, and one
‘side was upraised, and the foundations heaved out of the
ground. It was compared by the Academicians to a great
tooth half extracted from the alveolus, with the upper part
of the fangs exposed. (See fig. 111.)
Along the line of this shift, or ‘fault,’ as it would be termed
technically by miners, the walls were found to adhere firmly
to each other, and to fit so well, that the only signs of their
having been disunited was the want of correspondence in the
courses of stone on either side of the rent.
—
LVR, Noy
Stdenog of
erriton,
ir rel; are
epth ; and
48 greatly
"0 uplifted
unk down
red thrust
ig. 110,
nore eirculat
jstood the
nd one
Cu. XXIX.]
EFFECTS OF CALABRIAN EARTHQUAKE. 123
Dolomieu saw a stone well in the convent of the Augustins
at Terranuova, which had the appearance of having been
driven out of the earth. It resembled a small tower 8 or 9
feet in height, and a little inclined. This effect, he says,
was produced by the consolidation and consequent sinking of
the sandy soil in which the well was dug.
In some walls which had been thrown down, or violently
shaken, in Monteleone, the separate stones were parted from
the mortar, so as to leave an exact mould where they had
rested ; whereas in other cases the mortar was ground to
dust between the stones.
Ni
eeutt'
G
| : 8 hie \
\ Healt ; Ke i
Sy » Be C ae / )
Shift or ‘fault’ in the Round Tower of Terranuova in Calabria, occasioned by the
earthquake of 1783.
It appears that the wave-like motions often produced
effects of the most capricious kind. Thus, in some streets of
Monteleone, every house was thrown down but one; in
others, all but two; and the buildings which were spared
were often scarcely in the least degree injured. In many
cities of Calabria, all the most solid buildings were thrown
down, while those which were slightly built escaped; but at
Rosarno, as also at Messina in Sicily, it was precisely the
reverse, the massive edifices being the only ones that stood.
As the earthquake-wave passed along the surface of the
ground, rents and chasms opened and closed alternately, so
124 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cu. XXIX.
that houses, trees, cattle and men were first engulphed in an
instant, and then the sides of the fissures coming together
again no vestige of them was to be seen on the surface. We
may conceive the same effect to be produced on a small scale,
if, by some mechanical force, a pavement composed of large
flags of stone should be raised up, and then allowed to fall
suddenly, so as to resume its original position. If any small
pebbles happened to be lying on the line of contact of two
flags, they would fall into the opening when the pavement
rose, and be swallowed up, so that no trace of them would
appear after the subsidence of the stones. In many instances,
individuals are said to have been swallowed up by one shock,
Fig. 112.
pee,
Fissures near Jerocarne, in Calabria, caused by the earthquake of 1783.
and then thrown out again alive, together with large jets of
water, by the shock which immediately succeeded.
At Jerocarne, a country which, according to the Academi-
cians, was lacerated in a most extraordinary manner, the
fissures ran in every direction ‘like cracks on a broken pane
of glass.’ (See fig. 112.)
As we learn from Dolomieu that the direction of the new
chasms and fissures throughout Calabria was usually parallel
to the course of ravines and gorges pre-existing in their
neighbourhood, we may conclude that not a few of them
were due to a comparatively superficial movement of the
ground in a sideway direction.
(Cy. Xyy
Upheg i
tite
5 too
YS
Na
two
© pavemen;
them Would
AY Instances
V one shock.
large jets
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he jcadem
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of the ™
sally para ;
nt
ie
Cu. XXIX.] EFFECTS OF CALABRIAN EARTHQUAKE. 135
In the vicinity of Oppido, the central point where the
shocks of the earthquake were most violent, many houses
were swallowed up by the yawning earth, which closed
immediately over them. In the adjacent district, also, of
Cannamaria four farm-houses, several oil-stores, and some
spacious dwelling-houses were so completely engulphed in
one chasm, that not a vestige of them was afterwards dis-
cernible. The same phenomenon occurred at Terranuova,
S. Christina, and Sinopoi. The Academicians state parti-
cularly, that when deep abysses had opened in the argillaceous
strata of Terranuova, and houses had sunk into them, the
sides of the chasms closed with such violence, that, on
excavating afterwards to recover articles of value, the work-
men found the contents and detached parts of the buildings
jammed together so as to become one compact mass,
Sir W. Hamilton was shown several deep fissures in the
vicinity of Mileto, which, although not one of them was
above a foot in breadth, had opened so wide during the
earthquake as to swallow an ox and nearly one hundred
goats. The Academicians also found, on their return through
districts which they had passed at the commencement of
their tour, that many rents had, in that short interval,
eradually closed in, so that their width had diminished
several feet, and the opposite walls had sometimes nearly
met. Itis natural that this should happen in argillaceous
strata, while, in more solid rocks, we may expect that fissures
will remain open for ages. Should this be ascertained to be
a general fact in countries convulsed by earthquakes, it may
afford a satisfactory explanation of a common phenomenon in
mineral veins. Such veins often retain their full size so long
as the rocks consist of limestone, granite, or other indurated
materials ; but they contract their dimensions, become mere
threads, or are even entirely cut off, where masses of an
argillaceous nature are interposed. If we suppose the
filling up of fissures with metallic and other ingredients to
be a process requiring ages for its completion, it is obvious
that the opposite walls of rents, where strata consist of
yielding materials, must collapse or approach very near to
each other before sufficient time is allowed for the accretion
of a large quantity of veinstone.
i26 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cu. XXIX,
Some of the chasms which opened seem to imply the
sinking down of the earth into subterranean cavities. One
of these was abserved by the Academicians on the sloping
—— Big ss
= Sx
Chasm formed by the earthquake or 1783 near Oppido, in Calabria.
side of a hill near Oppido, into which part of a vineyard and
a considerable number of olive trees with a large quantity of
soil were precipitated. Yet a great gulf remained after the
Fig. 114.
= = —<—<————
Chasm in the hill of St. Angelo, near Soriano, in Calabria, cansed by the earth-
quake of 17838.
shock, in the form of an amphitheatre, 500 feet long and 200
feet deep. (See fig. 113.)
According to Grimaldi, many fissures and chasms, formed
Cu. XXIX.] . EFFECTS OF CALABRIAN EARTHQUAKE. 127
by the first shock of February 5th, were greatly widened,
lengthened, and deepened by the violent convulsions of
March 28th. Some of these were nearly a mile in length,
and from 150 to more than 200 feet in depth, usually
straight but some of them in the form of a crescent. The
annexed cut (fig. 114) represents one by no means remarkable
for its dimensions, which remained open by the side of a
small pass over the hill of St. Angelo, near Soriana. The
small river Mesima is seen in the foreground.
Formation of circular hollows and new lakes.—In the report
of the Academy, we find that some plains were covered with
Circular hollows inthe plain of Rosarno, formed by the earthquake of 1783.
circular hollows, for the most part about the size of carriage-
wheels, but often somewhat larger or smaller. When filled
with water to within a foot or two of the surface, they
appeared like wells; but, in general, they were filled with
dry sand, sometimes with a concave surface, and at other
times convex. (See fig. 115.) On digging down, they found
them to be funnel-shaped, and the moist loose sand in the
centre marked the tube up which the water spouted. The
annexed cut (fig. 116) represents a section of one of these
inverted cones when the water had disappeared, and nothing
but dry micaceous sand remained.
128 EARTHQUAKES IN THE EIGHTEENTH CENTURY, [Cu. XXIX,
A small circular pond of similar character was formed not
far from Polistena (see fig. 117); and in the vicinity of
Seminara, a lake was suddenly caused by the opening of a
ereat chasm, from the bottom of which water issued. This
Biot 1G;
lake was called Lago del Tolfilo. It extended 1,785 feet in
length, by 957 in breadth, and 52 indepth. The inhabitants,
dreading the miasma of this stagnant pool, endeavoured, at
ron llafe
Che
Bs be 5 =
SWANSEA yh beg i
Circular pond near Polistena in Calabria, caused by the earthquake in 1783.
’
ereat cost, to drain it by canals, but without success, as it
was fed by springs issuing from the bottom of the deep
chasm. |
Cones of sand thrown wp.—Many of the appearances ex-
hibited in the alluvial plains, such as springs spouting up
their water like fountains at the moment of the shock, have
been supposed to indicate the alternate rising and sinking of
.
.
(Cx XH
Pas Ary
f Ox. XXIX.] DERANGEMENT OF RIVER-COURSES. 129
“Tmed ;
. ho ‘
Vicinity ‘ the ground. The first effect of the more violent shocks was
_ 0 e . .
Ning of _ # usually to dry up the rivers, but they immediately afterwards
med Th overflowed their banks. In marshy places, an immense
' number of cones of sand were thrown up. These appearances
7 Hamilton explains, by supposing that the first movement
raised the fissured plain from below upwards, so that the
rivers and stagnant waters in bogs sank down, or at least
were not upraised with the soil. But when the ground
returned with violence to its former position, the water was
thrown up in jets through fissures.
The phenomenon, according to Mr. Mallet, may be simply
an accident contingent on the principal cause of disturbance,
the rapid transit of the earth-wave. ‘The sources,’ he Says,
‘of copious springs usually lie in flat plates or fissures filled
with water, whether issuing from solid rock, or from loose
785 foot ; materials; now, if a vein, or thin flat cavity filled with
ie 3 vi s water, be in such a position that the plane of the plate of
or ary water or fissure be transverse to the line of transit of the
-avoured, a
earth-wave, the effect of the arrival of the earth-wave at the
watery fissure will be, at the instant, to compress its walls
more or less together, and so squeeze out the water, which
will, for a moment, gush up atthe springhead like a fountain,
and again remain in repose after the transit of the wave.’
Derangement of river-cowrses.—Vivenzio states, that near
4 Sitizzano a valley was nearly filled up to a level with the
high grounds on each side, by the enormous masses detached
from the boundary hills, and cast down into the course of two
; _ Streams. By this barrier a lake was formed of great depth,
3 about 2 miles long and 1 mile broad. The same author
i mentions that, upon the whole, there were 50 lakes occasioned
during the convulsions: and he assigns localities to all of
these. The government Surveyors enumerated 215 lakes;
but they included in this number many small ponds.
Such lakes and ponds could only be permanent where rivers
and brooks were diverted into an entirely new course, whether
P into some adjoining ravine or into a different part of the
same alluvial plain. In cases where the new barrier obstructs
\— 7
& 2
=. &
oO wm
wm
sq OF ; ;
aranc’” ap the whole of the drainage, the water flowing over the dam
tins VOL. II. K
T+ wee |
ghot*’
f{
ing °
4 sit
130 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cu. XXIX.
will gradually deepen a new channel in it, and the lake will
exist no longer.*
From each side of the deep valley or ravine of 'l'erranuova,
enormous masses of the adjoining flat country were detached,
and cast down into the course of the river, so as to give rise
to lakes. Oaks, olive-trees, vineyards, and corn, were often
seen growing at the bottom of the ravine, as little injured as
their former companions, which still continued to flourish in
the plain above, at least 500 feet higher, and at the distance
of about 2 of a mile. In one part of this ravine was a mass,
200 feet high and about 400 feet at its base, which had been
detached by some former earthquake. It is well attested,
that this mass travelled down the ravine nearly 4 miles,
having been put in motion by the earthquake of February 5.
Hamilton, after examining the spot, declared that this phe-
nomenon might be accounted for by the declivity of the
valley, the great abundance of rain which fell, and the great
weight of the alluvial matter which pressed behind it.
Dolomieu also alludes to the fresh impulse derived from
other masses falling, and pressing upon the rear of those
first set in motion.
The first account sent to Naples of the two great slides or
landslips above alluded to, which caused a great lake near
Terranuova, was couched in these words :—‘ Two mountains
on the opposite sides of a valley walked from their original
position until they met in the middle of the plain, and there
joining together, they intercepted the course of a river,’ &ec.
The expressions here used resemble singularly those applied
to phenomena, probably very analogous, which are said to
have oceurred at Fez, during the great Lisbon earthquake,
as also in Jamaica and Java at other periods.
Not far from Soriano, the houses of which were levelled to
the ground by the great shock of February, a small valley,
containing a beautiful olive-grove, called Fra Ramondo,
underwent a most extraordinary revolution. TInnumerable
fissures first traversed the river-plain in all directions, and
absorbed the water until the argillaceous substratum became
* See Robert Mallet, Neapolitan Earthquake of 1867, vol. ii. p. 372.
Y. (Cy, Noy
the lake vi
Ler, TraNo;, |
“re Tetachey
S to gj )
l, Were of ‘
tle Injured a
to flourish ; in
, the distance
2 Was a mass
ich had bls
Well attested
arly 4 miles
f February 5,
that this phe-
clivity of the
and the great
“1 behind it.
derived from
rear of those
creat slides ot
reat lake neal
wo mountalls
mn art
att
y). ii B
Cu. XXTX.] LANDSLIPS NEAR SORIANO. 131
soaked, so that a great part of it was reduced to a state of
fluid paste. Strange alterations in the outline of the ground
were the consequence, as the soil to a great depth was easily
moulded into any form. In addition to this change, the
ruins of the neighbouring hills were precipitated into the
hollow; and while many olives were uprooted, others re-
mained growing on the fallen masses, and inclined at various
angles. (See fig. 118.) The small river Caridi was entirely
concealed for many days; and when at length it reappeared,
it had shaped for itself a new channel.
Near Seminara an extensive olive-ground and orchard were
Changes of the surface at Fra Ramondo, near Soriano, in Calabria.
. Portion of a hill covered with olives = New bed of the river Caridi.
Ties down . Town of Soriano.
hurled to a distance of 200 feet, into a valley 60 feet in depth.
At the same time a deep chasm was riven in another part of
the high platform from which the orchard had been detached,
and the river immediately entered the fissure, leaving its
former bed completely dry. A small inhabited house, stand-
ing on the mass of earth carried down into the valley, went
along with it entire, and without injury to the inhabitants.
The olive-trees, also, continued to erow on the land which
had slid into the valley, and bore the same year an abundant
crop of fruit.
182 EARTHQUAKES IN THE EIGHTEENTH CENTURY. Cn. XXIX.
Two tracts of land on which a great part of the town of
Polistena stood, consisting of some hundreds of houses, were
detached into a contiguous ravine, and nearly across it, about
half a mile from their original site; and what is most extra-
ordinary, several of the inhabitants were dug out from the
ruins alive and unhurt.
Two tenements, near Mileto, called the Macini and Vati-
cano, occupying an extent of ground about 1 mile long and 4
a mile broad, were carried for 1 mile down a valley. A
thatched cottage, together with large olive and mulberry
trees, most of which remained erect, were carried uninjured
to this extraordinary distance. According to Hamilton, the
surface removed had been long undermined by rivulets, which
Fig. 119.
Landslips near Cinquefrondi, caused by the earthquake of 1783.
were afterwards in full view on the bare spot deserted by the
tenements. The earthquake seems to have opened a passage
in the adjoining argillaceous hills, which admitted water
charged with loose soil into the subterranean channels of
the rivulets immediately under the tenements, so that the
foundations of the ground set in motion by the earthquake
were loosened. Another example of subsidence, where the
edifices were not destroyed, is mentioned by Grimaldi, as
having taken place in the city of Catanzaro, the capital of
the province of that name. The houses in the quarter called
San Giuseppe subsided with the ground to various depths
4 Cx. ny
the to
he Seg, of
> Wer
ut from the
ni and Vati.
0 long and
t Valley, A
1d my cn
ed uninjura
lamilton. the
vulets, which
Cu. XXIX.] LANDSLIPS NEAR 8. LUCIDO. 133
from 2 to 4 feet, but the buildings remained uninjured.
Among other territories, that of Cinquefrondi was greatly
convulsed, various portions of soil being raised or sunk, and
innumerable fissures traversing the country in all directions
(see fig. 119). Along the flanks of a small valley in this
district there appears to have been an almost uninterrupted
line of landslips.
Near S. Lucido, among other places, the soil is described
as having been ‘ dissolved,’ so that large torrents of mud
inundated all the low grounds, like lava. Just emerging
from this mud, the tops only of trees and of the ruins of
farm-houses were seen. Two miles from Laureana, the
swampy soil in two ravines became filled with calcareous
matter, which oozed out from the ground immediately before
the first great shock. This mud, rapidly accumulating, began,
ere long, to roll onward, like a flood of lava, into the valley,
where the two streams uniting, moved forward with increased
impetus from east to west. It now presented a breadth of
225 feet by 15 in depth, and, before it ceased to move,
covered a surface equal in length to an Italian mile. In its
progress it overwhelmed a flock of 380 goats, and tore up by
the roots many olive and mulberry trees, which floated like
ships upon its surface. When this calcareous lava had
ceased to move, it gradually became dry and hard, during
which process the mass was lowered 7} feet. It contained
fragments of earth of a ferruginous colour, and emitting a
sulphureous smell.
If our space permitted, we might fill a volume with local.
details of landslips, which the different authors above alluded
to, supply, showing to how great an extent the power of rivers
to widen valleys is increased where earthquakes are of
periodical occurrence. <A geologist can never fully under-
stand the manner in which valleys have been formed until
he duly appreciates the part which subterranean movements
repeated at long intervals play in combination with rivers,
during that lapse of ages which must always be required for
the elevation of a country to the height of many hundreds
of feet above the level of the sea.
Time must be allowed in the intervals between distinc-
184 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cu. XXIx,
convulsions, for running water to clear away the ruins
caused by landslips, otherwise the fallen masses will serve
as buttresses, and prevent the succeeding earthquake from
exerting its full power. The sides of the valley must be
again cut away by the stream, and made to form precipices
and overhanging cliffs, before the next shock can take effect
in the same manner.
Fall of the sea-cliffs—Along the sea-coast of the Straits of
Messina, near the celebrated rock of Scilla, the fall of huge
masses detached from the bold and lofty cliffs overwhelmed
many villas and gardens. At Gian Greco, a continuous line
of cliff, for a mile in length, was thrown down. Great
agitation was frequently observed in the bed of the sea
during the shocks, and, on those parts of the coast where the
movement was most violent, all kinds of fish were taken in
abundance, and with unusual facility. Some rare species, as
that called Cicirelli, which usually lie buried in the sand,
were taken on the surface of the waters in great quantity.
The sea is said to have boiled up near Messina and to have
been agitated as if by a copious discharge of vapours from
its bottom.
Shore near Scilla inundated.—The prince of Scilla had
persuaded a great part of his vassals to betake themselves to
their fishing-boats for safety, and he himself had gone on
board. On the night of February 5, when some of the people
were sleeping in the boats, and others on a level plain slightly
elevated above the sea, the earth rocked, and suddenly a
great mass was torn from the contiguous Mount Jaci, and
thrown down with a dreadful crash upon the plain. tm-
mediately afterwards, the sea, rising more than 20 feet
above the level of this low tract, rolled foaming over it, and
swept away the multitude. It then retreated, but soon
rushed back again with greater violence, bringing with it
some of the people and animals it had carried away. At the
same time every boat was sunk or dashed against the beach,
and some of them were swept far inland. The aged prince,
with 1,430 of his people, was destroyed.
State of Stromboli and Etna during the shocks.—The in-
habitants of Pizzo remarked that, on February 5, 1783,
n Precip
n take
Cffegy
he Straits of
fall of hnge
wverwhelmei
1tinuoUs line
WH. Great
Of the seq
st where the
ere taken in
re species, as
in the sand,
at quantity.
and to have
rapours from
* Scilla had
hemselves t
had gone 2
of the people
lain slightly
gnddenly #
ray:
‘ +b peach
. ce
ag e
Cu, XXIX.] ORIGIN OF EARTHQUAKE-WAVES. 135
when the first great shock afflicted Calabria, the volcano of
Stromboli, which is in full view of that town, and at the
distance of about 50 miles, smoked less, and threw up-a less
quantity of inflamed matter, than it had done for some years
previously. On the other hand, the great crater of Htna is
said to have given out a considerable quantity of vapour
towards the beginning, and Stromboli towards the close, of
the commotions. But as no eruption happened from either
of these great vents during the whole earthquake, the sources
of the Calabrian convulsions, and of the volcanic fires of Etna
and Stromboli, appear to be very independent of each other ;
unless, indeed, they have the same mutual relation as Vesuvius
and the voleanos of the Phlegreean Fields and Ischia, a violent
disturbance in one district serving as a safety-valve to the
other, and both never being in full activity at once.
Origin and mode of propagation of earthquake-waves.— We
have already hinted in Chapter XXIII. that there are good
reasons for suspecting that the subterranean causes of the
earthquake and volcano are the same. In what manner
portions of the solid crust of the earth may be melted from
time to time so as to form reservoirs of fused matter at
various depths, will be considered in Chapter XXXII.
Assuming for the present the existence of such reservoirs of
liquid lava in the interior, it is not difficult to understand
how steam may be generated whenever rain-water or the
waters of the sea, percolating through rocks, gain access to
such lava, and how when steam is generated, the incumbent
crust of the earth may be rent and dislocated.
During such movements fissures may be formed and
injected with gaseous or fluid matter, which may sometimes
fail to reach the surface, while at other times it may be
expelled through volcanic vents, stufas and hot springs.
When the strain on the rocks has caused them to split, or
the roofs of pre-existing fissures or caverns have been made
to fall in, vibratory jars will be produced and propagated in
all directions, like waves of sound through the crust of the
earth with varying velocity, according to the violence of the
original shock, and the density or elasticity of the substances
through which they pass. They will travel, for example,
1386 EARTHQUAKES IN THE EIGHTEENTH CENTURY.
[Cu. XXIX,
faster through granite than through limestone, and more
rapidly through the latter than through wet clay, but the
rate will be uniform through the same homogeneous medium.
To the inhabitants of a shaken district the wave or vibration
appears to radiate horizontally, outwards from the spot on
the surface where it is first felt; but the force does not
really operate in a horizontal direction like a wave caused by
a pebble on the surface of a pond, for at every point except
that immediately above the focus of the shock it comes up
obliquely from below, causing the ground to move forwards
Fig. 120,
C
Diagram showing the mode in which an earthquake-wave is transmitted from
a subterranean focus of disturbance such as A.
- f earthquake. c, ¢, d, ad’. Section of spherical shells show-
B. Seismic vertical, or point wl the shock ing the manner in which th chquake-way
first reaches the surface. is propagated in all directions from the centre
y A
upposed focus of greater depth. Here of disturbance
the line C, 1, representing the angle of emerg- :
ence, is steeper than the line A, 1. ee +p
139.)
| Taos Ee Coseismi points, or points on the
surface reached simultaneously by the earth-
quake-wave. So also 2, 2’. 3, 3’.
and then backwards in a more or less horizontal direction,
so that all objects which do not participate fully in the
movements, such as the walls of a building, appear to move
in a direction contrary to that of the ground, and fall by
their own weight or inertia. The mode in which the wave
is transmitted will be best understood by the accompanying
diagram, fig. 120. Suppose the subterranean centre of dis-
turbance to be several miles below the surface or at A, the
crust of the earth being homogeneous, the shock will
s Ly
ve Mens,
nsmitted from
cal shells § show-
yerica as aye
tre
4] directio™
eae ae
—
MOTION OF THE EARTHQUAKE-WAVES, 137
Cu. XXIX.]
proceed in all directions as a wave of compression displacing
the particles of the vibrating medium for a certain space,
and then allowing them to recover their original position
usually without fracture of the rock. The wave moves in
the form of a series of spherical shells, sections of which are
represented in the diagram at ¢ c, dd’, &c. When the
movement extends to the circle d d’ the earthquake will be
first felt at the surface at a point immediately above A.
This point B, where the shock will be felt most violently by
the inhabitants as being nearest to the original impulse, is
called the seismic vertical. The vibrations will reach the
points 1 and 1’ some seconds later according to the distance
of such points from the focus A. The wave will successively
reach the points 2 and 2’, and 3 and 3’, and its emergence
at the surface of the country will take place in a series of
concentric rings receding farther and farther from B where
the shock was first felt, as in fig. 121. The wave therefore,
or vibratory jar, although having the appearance of being
propagated horizontally in all directions from B, is in reality
transmitted direct from A. The circles 1 1’ and 2 2’ in figs.
120 and 121 are called coseismal
circles, because all points in their
circumference are simultaneously
shaken. The reader will observe
that all these spherical shells c and
c’, d and d/, and the points of |
emergence, 1, 2, 3, &c., relate to
the continuous transmission through
the earth of a single shock, and
not to a series of separate waves , 9,
following each other. Mr. Robert
Mallet and the late Mr. Hopkins have endeavoured to devise
instruments and methods of observation, by which the rate of
transit of the earthquake-wave, and the depth of the focus of
disturbance, might be measured.
Mr. Mallet * has the merit of having been the first to make
a practical application of the rules deduced from mechanical
Fig. 121.
. Seismic vertica
ees points ath te
3’, respectively.
* Great Neapolitan Earthquake of 1857; in two vols. London, 1862.
138 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cu. XXIx,
principles bearing on this subject. With this object he
visited part of the Neapolitan territory, shortly after the
great earthquake of December, 1857. The region most
violently shaken at that period was about 40 miles east of
Salerno, in latitude 40° 30’ N., wholly to the north of the
district convulsed in 1783. Although many towns were then
laid in ruins, and there was much loss of life, the destruction
was by no means so great as that of 1783, and the changes
wrought in the river-courses were not on so grand a scale,
To obtain the seismic vertical Mr. Mallet observed the
direction in which chimneys, urns, and statues had been
thrown down from the tops of high buildings. Such bodies
in consequence of their inertia usually fall backwards in the
direction from which the shock comes, but sometimes they
are thrown forwards. In either case they indicate the
direction of the shocks, and two or more such lines of
direction prolonged to their point of intersection give the
seismic vertical. That point being found, the next step is to
ascertain the angle at which the wave emerged at different
points at the surface.
Suppose a rectangular building d, e, f, g (fig. 122), to stand
with its principal walls in the direction of the shock, and the
Fig. 122. earthquake-wave to emerge in
C the direction A,C. The shock
q will tend to produce fissures
hh’, iv, at right angles to its
1 = if . own path. The inclination of
B - ay , | — A, C, to the horizon, or the
ve angle of emergence, being thus
/ known by reference to these
ve fissures, we obtain the position
of the focus A, by imagining
fp the line c, h’, to be prolonged
till it meets the vertical line
= By referring to the former
diagram, fig. 120, the reader will at once see that the angle
of emergence of the wave at any given distance from the
seismic vertical, B, will depend upon the depth of the focus;
7 (Oy ee
7 Object h
y afte, ,
CZion
mM
niles eens
Orth of the
8 Were then
destrye
tion
t he c
hanges
id a Scale.
served the
S had beep
Such bodies
wards in the
1etimes they
indicate the
ich lines of
ion give the
ext step is to
at different
92). to stand
i ck, and the
to emerge
The shoe
duce fissu
angles to™
‘nclinatio? 0
ee
Cu, XXIX.] THEORY OF THE EARTHQUA KE-WAVE. 139
in other words, it will be always steeper as the depth
increases, as the line C, 1, for example, is more steeply
inclined than A, 1.
By aid of a dynamical formula which we need not cite
here, Mr. Mallet came to the conclusion that the depth of
the original shock in 1857 did not exceed 7 or 8 miles, and
although this can only be a rough approximation to the
truth it is of considerable interest, and the repetition of
such investigations may hereafter lead to more reliable
results, especially when observations in regard to the time,
direction, and intensity of the shocks shall have been made
with scientific care at the moment of the convulsion. Such
observations require the aid of delicate instruments, and
the problem is exceedingly complicated, far more so than
the reader may have inferred from the simple illustration
above given. For in the first place the shock which
produces the vibration or earthquake-wave does not give rise
to a single movement, as above supposed, but to two move-
ments, one longitudinal and the other transverse ; the second
of which at the outset follows the principal one almost instan-
taneously, and is at right angles to it; but, as this latter
vibration travels somewhat slower than the former, it reaches
the surface, if the distance be considerable, after a distinct
interval of time and often does more mischief to buildings than
the first. It will also be seen by the elaborate report of Mr.
Hopkins * that the earthquake-wave when it passes through
rocks differing in density and elasticity, changes in some degree
not only its velocity but its direction, being both refracted and
reflected in a manner analogous to that of light when it passes
from one medium to another of a different density. When the
shock traverses the earth’s crust through a thickness of several
miles, it will encounter a great variety of rocks as well as
rents and faults by which the course of the vibratory move-
ments will be more or less interfered with. The fracture
also of buildings is considerably modified by the nature of
their component materials, and of the coherence of the
mortar by which stones or bricks are cemented together.
* Geological Theories of Elevation and Earthquakes, Brit. Assoc. 1847, p. 33.
140 EARTHQUAKES IN THE EIGHTEENTH CENTURY.
[Cu. XXIX,
We must make due allowance therefore for the uncertainty
of the data at Mr. R. Mallet’s disposal when he attempted to
compute the depth beneath the surface at which the shock of
1857 originated, and it is still more difficult for us to form a
probable conjecture as to the distance frum the surface from
which the subterranean movements of 1783 may have pro-
ceeded. It isa matter, however, of general interest that Mr.
Mallet deduces from all the facts at present known to him
respecting the movements of earthquakes, that the subterra-
nean points where the shocks originate are never very deep,
perhaps never exceeding thirty geographical miles; a very
important conclusion should it hereafter be confirmed by
observation and theory.
Number of persons who perished during the earthquake of
1783.—The number of persons who perished during the
earthquake in the two Calabrias and Sicily, is estimated by
Hamilton at about 40,000; and about 20,000 more died by
epidemics, which were caused by insufficient nourishment,
exposure to the atmosphere, and malaria, arising from the
new stagnant lakes and pools.
By far the greater number were buried under the ruins of
their houses ; but many were burnt to death in the confla-
grations which almost invariably followed the shocks. These
fires raged the more violently in some cities, such as Oppido,
from the immense magazines of oil which were consumed.
Many persons were engulfed in deep fissures, especially the
peasants when flying across the open country, and their
skeletons may perhaps be buried at various depths in the
earth to this day.
When Dolomieu visited Messina after the shock of Febru-
ary 5, he describes the city as still presenting, at least at a
distance, an imperfect image of its ancient splendour. Every
house was injured, but the walls were standing: the whole
population had taken refuge in wooden huts in the neigh-
bourhood, and all was solitude and silence in the streets: it
seemed as if the city had been desolated by the plague, and
the impression made upon his feelings was that of melancholy
and sadness. ‘ But when I passed over to Calabria, and first
beheld Polistena, the scene of horror almost deprived me of
Confirmed }y
earthquake oj
d during the
estimated by
more died by
nourishment,
sing from the
r the ruins df
in the conf
hocks. These
ch as Opp
. consume
| especially the
and thet
TY; a the
depths
INCIDENTS AT TERRANUOVA. 141
Cu, XXIX.]
my faculties; my mind was filled with mingled compassion
and terror; nothing had escaped ; all was levelled with the
dust; not a single house or piece of wall remained; on all
sides were heaps of stone so destitute of form, that they gave
no conception of there ever having been a town on the spot.
The stench of the dead bodies still rose from the ruins. I
conversed with many persons who had been buried for three,
four, or even for five days; I questioned them respecting
their sensations in so dreadful a situation, and they agreed
that, of all the physical evils they endured, thirst was the
most intolerable; and that their mental agony was increased
by the idea that they were abandoned by their friends, who
might have rendered them assistance.’ *
It is supposed that about a fourth part of the inhabitants
of Polistena, and of some other towns, were buried alive, and
might have been saved had there been no want of hands ;
but in so general a calamity, where each was occupied with
his own misfortunes or those of his family, aid could rarely be
obtained. Neither tears, nor supplications, nor promises of
high rewards were listened to. Many acts of self-devotion,
prompted by parental and conjugal tenderness, or by friend-
ship, or the gratitude of faithful servants, are recorded; but
individual exertions were, for the most part, ineffectual. It
frequently happened, that persons in search of those most
dear to them could hear their moans—could recognise their
voices—were certain of the exact spot where they lay buried
beneath their feet, yet could afford them no succour. The
piled mass resisted all their strength, and rendered their
efforts of no avail.
At Terranuova, four Augustin monks, who had taken refuge
in a vaulted sacristy, the arch of which continued to support
an immense pile of ruins, made their cries heard for the space
of four days. One only of the brethren of the whole convent
was saved, and ‘of what avail was his strength to remove the
enormous weight of rubbish which had overwhelmed his
companions » He heard their voices die away gradually ;
and when afterwards their four corpses were disinterred, they
* Pinkerton’s Voyages and Travels, vol. v. as cited above, p. 117, note.
142 EARTHQUAKES IN THE EIGHTEENTH CENTURY. (Cu. RIK
were found clasped in each other’s arms. Affecting narratives
are preserved of mothers saved after the fifth, sixth, and even
séventh day of their interment, when their infants or children
had perished with hunger.
It might have been imagined that the sight of sufferings
such as these would have been sufficient to awaken sgentj-
ments of humanity and pity in the most savage breasts; but
while some acts of heroism are related, nothing could exceed
the general atrocity of conduct displayed by the Calabrian
peasants: they abandoned the farms, and flocked in ereat
numbers into the towns—not to rescue their countrymen
from a lingering death, but to plunder. They dashed through
the streets, fearless of danger, amid tottering walls and
clouds of dust, trampling beneath their feet the bodies of the
wounded and half-buried, and often stripping them, while
yet living, of their clothes.*
But to enter more fully into these details would be foreign
to the purpose of the present work, and several volumes would
be required to give the reader a just idea of the sufferings
which the inhabitants of many populous districts have under-
gone during the earthquakes of the last 150 years. A bare
mention of the loss of life—as that 50,000 or 100,000 souls
perished in one catastrophe—conveys to the reader no idea
of the extent of misery inflicted: we must learn, from the
narratives of eye-witnesses, the various forms in which death
was encountered, the numbers who escaped with loss of limbs
or serious bodily injuries, and the multitude who were sud-
denly reduced to penury and want. It has been often re-
marked, that the dread of earthquakes is strongest in the
minds of those who have experienced them most frequently ;
whereas, in the case of almost every other danger, familiarity
with peril renders men intrepid. The reason is obvious—
scarcely any part of the mischief apprehended in this instance
is imaginary ; the first shock is often the most destructive ;
and, as it may occur in the dead of the night, or if by day,
without giving the least warning of its approach, no fore-
thought can guard against it; and when the convulsion has
* Dolomieu, Pinkerton’s Voyages and Trayels, vol. y.
y
2 ha
tives
th. and ae
Sor chilidse
Q
if Suffe
rake
bre:
Tings
N Senti.
asts ; > but
could Xceed
Ce yuntry Then
shed through
Z walls and
bodies of the
them, while
ld be foreign
‘lumes would
ne sufferings
have under-
ars. A bare
00.000 souls
vder no idea
mn, from the
which death
loss of limbs
10 were sud-
—
Cu. XXIX.] SITE OF ANCIENT CALABRIAN TOWNS. 148
begun, no skill, or courag>, or presence of mind, can point
out the path of safety. During the intervals, of uncertain
duration, (lasting perhaps for centuries) between the more
fatal shocks, slight tremors of the soil are not unfrequent ;
and as these sometimes precede more violent convulsions,
they become a source of anxiety and alarm, The terror
arising from this cause alone is of itself no inconsiderable
evil.
Although pe incuic of pure religion are frequently
awakened by these awful visitations, yet we more commonly
find that an habitual state of fear, a sense of helplessness,
and a belief in the futility of all human exertions, prepare
the minds of the vulgar for the influence of a demoralising
superstition.
Where earthquakes are frequent, there can never be perfect
security of property under the best government; industry
cannot be assured of reaping the fruits of its labour; and the
most daring acts of outrage may occasionally be perpetrated
with impunity, when the arm of the law is paralysed by the
general consternation. It is hardly necessary to add, that
the progress of civilisation and national wealth must be re-
tarded by convulsions which level cities to the ground, destroy
harbours, throw down bridges, render roads impassable, and
cause the most cultivated valley-plains to be covered with
lakes, or the ruins of adjoining hills.
In regions exposed to the frequent recurrence of severe
shocks, experience and scientific knowledge might, no doubt,
alleviate the evil.
The Calabrian towns of medieval date were most of them
perched, for the purposes of defence and security, on the tops
of isolated hills, where they are said to be rocked by every
shock like sailors on the top of a mast.* The same sites have
usually precipices on several sides, over the edges of which
the tottering buildings may readily be precipitated together
with some of the ground on which their foundations repose.
When towns are placed in the more open country, and con-
structed on such a plan, and of such materials as are best
* Mallet, Neapolitan Earthquake of 1857, vol. i. p. 30.
144 EARTHQUAKES IN THE EIGHTEENTH CENTURY. [Cu. XXIX.
suited to lessen the danger, the loss of life must be sensibly
diminished. That architects do not despair of successfully
contending with the danger, is shown by their frequently
advertising their houses in Sicily as earthquake-proof.
T shall endeavour to point out in the sequel, that the
general tendency of subterranean movements, when their
effects are considered for a sufficient lapse of ages, is emi-
nently beneficial, and that they constitute an essential part
of that mechanism by which the integrity of the habitable
surface is preserved, and the very existence and perpetuation
of dry land secured. Why the working of this same machi-
nery should be attended with so much evil, is a mystery far
beyond the reach of our philosophy, and must probably remain
so until we are permitted to investigate, not our planet alone
and its inhabitants, but other parts of the moral and material
universe with which they may be connected. Could our
survey embrace other worlds, and the events, not of a few
centuries only, but of periods as indefinite as those with
which geology renders us familiar, some apparent contradic-
tions might be reconciled, and some difficulties would doubt-
less be cleared up. But even then, as our capacities are
finite, while the scheme of the universe may be infinite, both
in time and space, it is presumptuous to suppose that all
sources of doubt and perplexity would ever be removed. On
the contrary, they might, perhaps, go on augmenting in
number, although our confidence in the wisdom of the plan
of Nature should increase at the same time; for it has been
justly said, that the greater the circle of light, the greater the
boundary of darkness by which it is surrounded.”
* Sir H. Davy, Consolations in Travel, p. 246.
(Cn, Ny
} ya
| Sensib},
SUCK Ag
° fhe, shh
Ment},
Proof,
el, that th
when the; :
ann er
8,18 enj.
=
table
Perpetuation
Same machi.
mystery far
bably remain
* planet alone
and material
Could ow
not of a few
s those with
nt contradic-
would doubt-
apacities are
infinite, both
pose that a
moved. On
omenting in
of the plan
. jt has been
e greater ihe
*
ON
Cu, XXX.] EARTHQUAKE OF JAVA. 145
CHAPTER XXX.
EARTHQUAKES—continued.
EARTHQUAKE OF JAVA, 1772—TRUNCATION OF A LOFTY CONE—ST. DOMINGO,
1770—11sBon, 1775—GREAT AREA OVER WHICH THE SHOCKS EXTENDED—
RETREAT OF THE SEA—PR oes autaocael EXPLANATIONS—CONCEPTION BAY, Pega
—PORTION OF PORT
CHANGE IN THE LAST 170 YEARS—ELEVATION AND SUBSIDENCE OF LAND IN BAY
OF BALA—EVIDENCE OF THE SAME AFFORDED BY THE TEMPLE OF SERAPIS.
In this chapter, I shall conclude my remarks on the earth-
quakes of the 18th century, and then pass on to those of
earlier date respecting which we have information which may
be of interest to the geologist.
Java, 1772.—Truncation of a lofty cone.—In the year 1772,
Papandayang, formerly one of the loftiest volcanos in the
island of Java, was in eruption. Before all the inhabitants
on the declivities of the mountain could save themselves by
flight, the ground is said to have given way, and a great part
of the volcano to have fallen in and disappeared. It was
estimated that an extent of ground of the mountain itself
and its immediate environs, 15 miles long and full 6 broad,
was by this commotion swallowed up in the bowels of the
earth. Forty villages were destroyed, some being engulphed
and some covered by the substances thrown out on this
occasion, and 2,957 of the inhabitants perished. A pro-
portionate number of cattle were also killed, and most of the
plantations of cotton, indigo, and coffee in the adjacent
districts were buried under the volcanic matter. This cata-
strophe appears to have resembled, although on a grander
scale, that of the ancient Vesuvius in the year 79.
was reduced in height from 9,000 to about
VOL. Il. y
The cone
5,000 feet; and,
146 EARTHQUAKE OF HINDOSTAN. [Cu. XXX
as vapours still escape from the crater on its summit, a new
cone may one day rise out of the ruins of the ancient moun-
tain, as the modern Vesuvius has risen from the remains of
Somma.*
Junghuhn, who examined the mountain in 1842, was
unable to obtain positive proof that there had been a sinking
in of the ground, and concluded that, if any, it must hae
been near the summit of the cone, or where a new crater wag
formed. He found that the town and villages destroyed
were far distant from the summit, and buried under a mass
of ejected materials; so that they seem to have suffered the
fate of Herculaneum and Pompeii, and the lowering of the
mountain was probably due for the most part to explosion,
rather than to engulfment.
St. Domingo, 1770.—During a tremendous earthquake
which destroyed a great part of St. Domingo, innumerable
fissures were caused throughout the island, from which
mephitic vapours emanated and produced an epidemic. Hot
springs burst forth in many places where there had been no
water before; but after a time they ceased to flow.t
In a previous earthquake, in November 1751, a violent
shock destroyed the capital, Port au Prince, and part of the
coast, twenty leagues in length, sank down, and has ever
since formed a bay of the sea.
Hindostan, 1762.—The town of Chittagong, in Bengal, was
violently shaken by an earthquake, on April 2, 1762, the
earth opening in many places, and throwing up water and
mud of a sulphureous smell. Ata place called Bardavan, a
large river was dried up ; and at Bar Charra, near the sea, a
tract of ground sank down, and 200 people, with all their
cattle, were lost. It is said, that 60 square miles of the
Chittagong coast suddenly and permanently subsided during
this earthquake, and that Ces-lung-Toom, one of the Mug
mountains, entirely disappeared, and another sank so low,
that its summit only remained visible. Four hills are also
* Dr. Horsfield, Batay. Trans. vol. + Essai sur Hist. Nat. de l'Isle de
viii. p. 26. Raffles’s account (History St. Domingue. Paris, 1776.
of Java, vol. i.) is derived from Hors- i
field. .
t Hist. de VAcad. des Sciences.
1752. -Parig,
ny, 7
ney Crater,
lages destroy
ed under a ne
have Suffere] th
l Wering of i,
art to explosio,
dous earthqual:
ngo, innumenth
ind, from whid
n epidemic, Hi
here had been u
to flow.t
r 1751, a violet
. and part of the
en, and has et
i, in Bengal, "8
9 1762, the
il 2, 1/04
g Up water ‘
alled Baris
q, near the -
e, with all —'
ire miles oa
enbsided d us
one of the a
er § nk 80 Js
r pills are
t. de isi
ist 1778 aio
Cu. XXX.] EARTHQUAKE OF LISBON. 147
described as having been variously rent asunder, leaving open
chasms from 30 to 60 feet in width. Towns which subsided
several cubits, were overflowed with water; among others,
Deep Gong, which was submerged to the depth of 7 cubits.
Two volcanos are said to have opened in the Secta Cunda
hills.) The shock was also felt at Calcutta.* While the
Chittagong coast was sinking, a corresponding rise of the
ground took place at the island of Ramree, and at Cheduba.
(See Map, fig. 59, Vol. I. p. 587.) ¢
Earthquake of Lisbon, 1755.—Kztent of the shock.—In no
part of the volcanic region of southern Europe, has so
tremendous an earthquake occurred in modern times as that
which began on November 1, 1755, at Lisbon. he in-
habitants had had no warning of the coming danger, when a
sound like that of thunder was heard underground, and
immediately afterwards a violent shock threw down the
greater part of their city. In the course of about six minutes,
60,000 persons perished. The sea first retired and laid the
bar dry; it then rolled in, rising 50 feet or more above its
-ordinary level. The mountains of Arrabida, Estrella, Julio,
Marvan, and Cintra, being some of the largest in Portugal,
were impetuously shaken, as it were, from their very foun-
dations; and some of them opened at their summits, which
were split and rent in a wonderful manner, huge masses
of them being thrown down into the subjacent valleys.t
Flames are related to have issued from these mountains,
which are supposed to have been electric; they are also said
to have smoked; but vast clouds of dust may have given rise
to this appearance.
Subsidence of the quay.—Among other extraordinary events
related to have occurred at Lisbon during the catastrophe,
was the subsidence of a new quay, built entirely of marble
at an immense expense. A great concourse of people had
collected there for safety, as a spot where they might be
* MClelland’s Report on Min. Re- + Journ. Asiat. Soe. Bengal, vol. x.
sources of India, 1838. Calcutta. For ° pp. 351, 438.
vol. { Hist. and Philos. of Earthquakes,
p. 317.
other particulars, see Phil. Trans.
liii.
148 EARTHQUAKE OF LISBON. (Cu, XXX,
beyond the reach of falling ruins; but suddenly the quay
sank down with all the people on it, and not one of the dead
bodies ever floated to the surface. A great number of boats
and small vessels anchored near it, all full of people, were
swallowed up, as in a whirlpool.* No fragments of these
wrecks ever rose again to the surface, and the water in the
place where the quay had stood is stated, in many accounts,
to be unfathomable; but Whitehurst says he ascertained it
to be 100 fathoms.t
Circumstantial as are the contemporary narratives, I was
informed by Mr. F. Freeman, in 1841, that no part of the
Tagus was then more than 30 feet deep at high tide, and an
examination of the position of the new quay, and the
memorials preserved of the time and manner in which it was
built, render the statement of so great a subsidence in 1755
quite unintelligible. Perhaps a deep narrow chasm, such as
was before described in Calabria (p. 125), opened and closed
again in the bed of the Tagus, after swallowing up some
incumbent buildings and vessels. We have already seen
that such openings may collapse after the shock suddenly, or
in places where the strata are of soft and yielding materials,
very gradually. According to the observations made at
Lisbon, in 1837, by Mr. Sharpe, the destroying effects of this
earthquake were confined to the tertiary strata, and were
most violent on the blue clay, on which the lower part of the
city is constructed. Nota building, he says, on the secondary
limestone or the basalt was injured.t
The area over which this convulsion extended is very
remarkable. It has been computed, says Humboldt§, that
on November 1, 1755, a portion of the earth’s surface four
times greater than the extent of Europe was simultaneously
shaken. The shock was felt in the Alps, and on the coast of
Sweden, in small inland lakes on the shores of the Baltic, in
Thuringia, in the flat country of northern Germany, and in
+ On the Formation of the Earth,
DD:
* Rev. C. Davy’s Letters, vol. ii.
Letter ii. p. 12, who was at Lisbon at
ro
the time, and ascertained that the boats t Geol. Soc. Proceedings, No. 69,
and vessels said to have been swallowed op. 36. 1888.
were missing § Cosmos, vol. i.
' Aeconns,
*Tlained i
Ves,
I wag
ATT of the 3
de, and ay
> And the
ch it Was
ce in 1735
m, such as
and closed
r up some
ready seen
iddenly, or
materials,
made at
cts of this
and welt
: art of the
secondaly
d is vey
ats, that
rface fot
taneots!
ne coast?
Baltic, i I
Iv; and
h,
f the Bos
Ou, XXX.] SHOCKS AT SEA. 149
Great Britain. The thermal springs of Téplitz dried up, and
again returned, inundating everything with water discoloured
by ochre. In the islands of Antigua, Barbadoes, and Mar-
tinique in the West Indies, where the tide usually rises little
more than 2 feet, it suddenly rose above 20 feet, the water
being discoloured and of an inky blackness. The movement
was also sensible in the great lakes of Canada. At Algiers
and Fez, in the north of Africa, the agitation of the earth
was as violent as in Spain and Portugal; and at the distance
of 8 leagues from Morocco, a village with the inhabitants, to
the number of about 8,000 or 10,000 persons, is said to have
been swallowed up; the earth soon afterwards closing over
them.
Shocks felt at sea.—The shock was felt at sea, on the deck
of a ship to the west of Lisbon, and produced very much the
same sensation as on dry land. Off St. Lucar, the captain
of the ship Nancy felt his vessel so violently shaken, that he
thought she had struck the ground; but, on heaving the
lead, found a great depth of water. Captain Clark, from
Denia, in latitude 36° 24’ N., between 9 and 10 in the
morning, had his ship shaken and strained as if she had
struck upon a rock, so that the seams of the deck opened,
and the compass was overturned in the binnacle. Another
ship, 40 leagues west of St. Vincent, experienced so violent
a concussion, that the men were thrown a foot and a half
perpendicularly up from the deck.
Rate at which the movement travelled.—The agitation of
lakes, rivers, and springs, in Great Britain, was remarkable.
At Loch Lomond, in Scotland, for example, the water, with-
out the least apparent cause, rose against its banks, and then
subsided below its usual level. This is explained by sup-
posing that the water does not partake of the sudden shove
given to the land, so that it dashes over that side of the
basin from which the shock is given. The greatest perpen-
dicular height of the rise in Loch Lomond was 2 feet 4
inches. It is said that the undulatory movement of this
earthquake travelled at the rate of 20 miles a minute, its
velocity being calculated by the intervals between the time
150 EARTHQUAKE OF LISBON.
[Cu. XXX,
when the first shock was felt at Lisbon, and its time of
occurrence at several distant places.*
Great wave and retreat of the sea.—A great wave swept
over the coast of Spain, and is said to have been 60 feet high
at Cadiz. At Tangier, in Africa, it rose and fell 18 times on
the coast. At Funchal, in Madeira, it rose full 15 feet per-
pendicular above high-water mark, although the tide, which
ebbs and flows there 7 feet, was then at half ebb. Besides
entering the city, and committing great havoc, it over-
flowed other seaports in the island. At Kinsale, in Ireland,
a body of water rushed into the harbour, whirled round
several vessels, and poured into the market-place.
It was before stated that the sea first retired at Lisbon;
and this retreat of the ocean from the shore, at the com-
mencement of an earthquake, and its subsequent return in a
violent wave, is a common occurrence. In order to account
for the phenomenon, Michell imagined a subsidence at the
bottom of the sea, from the giving way of the roof of some
cavity in consequence of a vacuum produced by the conden-
sation of steam. Such condensation, he observes, might be
the first effect of the introduction of a large body of water
into fissures and cavities already filled with steam, before
there has been sufficient time for the heat of the incandescent
lava to turn so large a supply of water into steam, which
being soon accomplished causes a greater explosion.
Another proposed explanation is, the sudden rise of the
land, which would cause the sea to abandon immediately the
ancient line of coast; and if the shore, after being thus
heaved up, should fall again to its original level, the ocean
would return. This theory, however, will not account for
the facts observed during the Lisbon earthquake ; for the
retreat preceded the wave, not only on the coast of Portugal,
but also at the island of Madeira, and several other places.
If the upheaving of the coast of Portugal had caused the
retreat, the motion of the waters, when propagated to
Madeira, would have produced a wave previous to the retreat.
The shock transmitted through the earth from Lisbon,
* Geol. Soc. Proceedings, No. 60, p. 86. 1838.
OO
— mgt Ua eee
|
|
|
\
“nt return in
ler to account
adence at th
roof of som
y the conda-
ves, might le
body of wate
steam, befor
, incandesce!!
steam, whit
EARTHQUAKE-WAVES IN THE SEA, 151
Cu. XXX.]
reached Madeira in 25 minutes, and the sea-wave took 24
hours to travel the same distance, which agrees well with the
time which it required to reach other places according to
their distance. We cannot, therefore, explain the great
motion of the waters at Madeira, by a momentary upward
movement of the solid crust of the earth, for in that case the
rise of the beach would have occurred at the first period or
25 minutes after the Lisbon shock ; besides, it will be seen in
the sequel, page 153, that where the sea is deep near the shore,
and the beach very steep, as in Madeira, the land-wave can-
not cause a retreat of the sea.
The following is another solution of the problem, which
has been offered :—Suppose a portion of the bed of the sea
to be suddenly upheaved ; the first effect will be to raise over
the elevated part a body of water, the momentum of which
will carry it much above the level it will afterwards assume,
causing a draught or receding of the water from the neigh-
bouring coasts, followed immediately by the return of the
displaced water, which will also be impelled by its momentum
much farther and higher on the coast than its former level.*
Mr. Darwin, when alluding to similar waves on the coast
of Chili, states his opinion, that ‘the whole phenomenon is
due to a common undulation in the water, proceeding froma
line or point of disturbance some little way distant. If the
waves,’ he says, ‘ sent off from the paddles of a steam-vessel
be watched breaking on the sloping shore of a still river, the —
water will be seen first to retire two or three feet, and then
to return in little breakers, precisely analogous to those con-
sequent on an earthquake.’ He also adds, that ‘the earth-
quake-wave occurs some time after the shock, the water at
first retiring both from the shores of the mainland and of
outlying islands, and then returning in mountainous breakers.
Their size is modified by the form of the neighbouring coast ;
for it is ascertained in South America, that places situated at
the head of shoaling bays have suffered most, whereas towns
like Valparaiso, seated close on the border of a profound
* Quarterly Review, No. lxxxvi. p, 459.
152 EARTHQUAKE OF LISBON, [Cu XXX
ocean, have never been inundated, though severely shaken
by earthquakes.’*
More recently (February, 1846), Mr. Mallet, in his memoir
above cited (p. 137), has endeavoured to bring to bear on this
difficult subject the more advanced knowledge obtained of
late years respecting the true theory of waves. He conceives
that when the origin of the shock 1s beneath the deep ocean,
one wave is propagated through the land, and another
moving with inferior velocity is formed on the surface of the
ocean. This last rolls in upon the land long after the earth-
wave has arrived and spent itself. However irreconcilable
it may be to our common notions of solid bodies, to imagine
them capable of transmitting, with such extreme velocity,
motions analogous to tidal waves, it seems nevertheless cer-
tain that such undulations are produced, and it is supposed
that when the shock passes a given point, each particle of
the solid earth describes an ellipse in space. The facility
with which all the particles of a solid mass can be made to
vibrate may be illustrated, says Gay-Lussac, by many familiar
examples. IPf we apply the ear to one end of a long wooden
beam, and listen attentively when the other end is struck by
a pin’s head, we hear the shock distinctly ; which shows that
every fibre throughout the whole length has been made to
vibrate. The rattling of carriages on the pavement shakes
the largest edifices; and in the quarries underneath some
quarters in Paris, it is found that the movement is communi-
cated through a considerable thickness of rock.+
The great sea-wave originating directly over the centre of
disturbance is propagated, as Michell correctly stated, in
every direction, like the circle upon a pond when a pebble is
dropped into it, the different rates at which it moves depend-
ing (as he also suggested) on variations in the depth of the
water. ‘This wave of the sea, says Mr. Mallet, is raised by
the impulse of the shock immediately below it, which in
great earthquakes lifts up the ground 2 or 3 feet perpendicu-
larly. The velocity of the shock, or earth-wave, is greater
* Darwin’s Travels in South Ame- + Ann. de. Ch. et de Ph. tom, xxii.
rica, &c. 18382 to 1886. Voyage of 428,
H.M.S, Beagle, vol. iii. p, 377,
ig a sor
—-e_
SS
a
——_ ————
|
|
|
"eR NCilable
to}
: Imaging
eV elocity,
the less Cer.
iS su
»
Upposed
particle of
The
e Ti
facility
iade to
ny familiar
ng
wooden
3 struck by
shows that
1 made t0
nt
shakes
eath some
commull-
, centre a
Cu. XXX. ] GREAT WAVE OF THE SEA. 153
because it ‘depends upon a function of the elasticity of the
crust of the earth, whereas the velocity of the sea-wave
depends upon a function of the depth of the sea.’
‘ Although the shock in its passage under the deep ocean
gives no trace of its progress, it no sooner gets into soundings
or shallow water, than it gives rise to another and smaller
wave of the sea. It carries, as it were, upon its back, this
lesser aqueous undulation; a long narrow ridge of water,
which corresponds in form and velocity to itself, being pushed
up by the partial elevation of the bottom. It is this small
wave, called technically the ‘ forced sea-wave,’ which com-
municates the earthquake-shock to ships at sea, as if they
had struck upon a rock. It breaks upon a coast at the same
moment that the shock reaches it, and sometimes it may
cause an apparent slight recession from the shore, followed
by its flowing up somewhat higher than the usual tide mark :
this will happen where the beach is very sloping, as is usual
where the sea is shallow, for then the velocity of the low flat
earth-wave is such, that it slips, as it were, from under the
undulation in the fluid above. It does this at the moment
of reaching the beach, which it elevates by a vertical height
equal to its own, and as instantly lets drop again to its
former level.’
‘While the shock propagated through the solid earth has
thus travelled with extra rapidity to the land, the great sea-
wave has been following at a slower pace, though advancing
at the rate of several miles in a minute. It consists, in the
deep ocean, of a long low swell of enormous volume, having an
equal slope before and behind, and that so gentle that it
might pass under a ship without being noticed. But when
it reaches the edge of soundings, its front slope, like that of
a tidal wave under similar circumstances, becomes short and
steep, while its rear slope is long and gentle. If there be
water of some depth close into shore, this great wave may
roll in long after the shock, and do little damage: but if
the shore be shelving, there will be first a retreat of the
water, and then the wave will break upon the beach and roll
in far upon the land.’ *
* Mallet, Proceed. Roy. Irish Acad. 1846.
154 EARTHQUAKE IN CHILI. [Cu XXX,
The various opinions which have been offered by Michell
and later writers, respecting the remote causes of earthquake
shocks in the interior of the earth, will more properly be
discussed in Chapter XX XIII.
Chili, 1751.—On May 24, 1751, the ancient town of Con-
ception, otherwise called Penco, was totally destroyed by an
earthquake, and the sea rolled over it. (See plan of the
bay, fig. 104, p.92.) The ancient port was rendered entirely
useless, and the inhabitants built another town about 10
miles from the sea-coast, in order to be beyond the reach of
similar inundations. At the same time, a colony recently
settled on the sea-shore of Juan Fernandez was almost entirely
overwhelmed by a wave which broke upon the shore.
It has been already stated, that in 1835, or 84 years after
the destruction of Penco, the same coast was overwhelmed
by a similar flood from the sea during an earthquake; and
it is also known that 21 years before (or in 1780), a like
wave rolled over these fated shores, in which many of the
inhabitants perished. A series of similar catastrophes hag
also been tracked back as far as the year 1590,* beyond
which we have no memorials save those of oral tradition.
Molina, who has recorded the customs and legends of the
aborigines, tells us, that the Araucanian Indians, a tribe
inhabiting the country between the Andes and the Pacific,
including the part now called Chili, ‘had among them a
tradition of a great deluge, in which only a few persons were
saved, who took refuge upon a high mountain called Thegtheg,
“the thundering,” which had three points.’ Whenever a
violent earthquake occurs, these people fly for safety to the
mountains, assigning as a reason, that they are fearful,
after the shock, that the sea will again return and deluge
the world.+
Notwithstanding the tendency of writers in his day to
refer all traditionary inundations to one remote period,
Molina remarks that this flood of the Araucanians ‘was
probably very different from that of Noah.’ We have,
indeed, no means of conjecturing how long this same tribe
* See Father Acosta’s work ; and Sir ings, vol. ii. p. 215.
Woodbine Parish, Geol. Soc. Proceed- f Molina, Hist. of Chili, vol. i1.
ee =
ee
ee
OW OCCU
project a
rery shal
img to t]
werly 4 «
mur hyd
famnot be
if the n
Y Mi
ea rth wl
"openly | be
v n of Con.
st entirely
re,
years after
TWwhelmed
uake; and
0), a like
ny of the
ophes has
* beyond |
tradition.
ds of the
Ss, a tribe
e Pacific,
y them 4
° yng wert
Thegtheg,
senevel 4
ty to the
, fearftl
1 deluge
| ae
was
"pave
ne se to
ol. it
day” |
Cu. XXX. ] ELEVATION IN CONCEPTION BAY. 155
had flourished in Chili, but we can scarcely doubt, that if its
experience reached back even for three or four centuries,
several inroads of the ocean must have occurred within that
period. But the memory of a succession of physical events,
similar in kind, though distinct in time, can never be pre-
served by a people destitute of written annals. Before two
or three generations have passed away all dates are forgotten,
and even the events themselves, unless they have given
origin to some customs, or religious rites and ceremonies.
Oftentimes the incidents of many different earthquakes and
floods become blended together in the same narrative ; and
in such cases the single catastrophe is described in terms so
exaggerated, or is so disguised by mythological fictions, as
to be utterly valueless to the man of science.
Proofs of elevation of the coast.—During a late survey of
Conception Bay, Captains Beechey and Sir EH. Belcher dis-
covered that the ancient harbour, which formerly admitted
all large merchant vessels which went round the Cape, is
now occupied by a reef of sandstone, certain points of which
project above the sea at low water, the greater part being
very shallow. A tract of 13 mile in length, where, accord-
ing to the report of the inhabitants, the water was for-
merly 4 or 5 fathoms deep, is now a shoal; consisting, as
our hydrographers found, of hard sandstone, so that it
cannot be supposed to have been formed by recent deposits
of the river Biobio, an arm of which earries down loose
micaceous sand into the same bay.
It is impossible at this distance of time to affirm that the
bed of the sea was uplifted at once to the height of 24 feet,
during the single earthquake of 1751, because other move-
ments may have occurred subsequently ; but it is said, that
ever since the shock of 1751, no vessels have been able to
approach within 14 mile of the ancient port of Penco.
(See Map, p. 92.) In proof of the former elevation of the
coast near Penco, our surveyors found above high-water
mark an enormous bed of shells of the same species as those
now living in the bay, filled with micaceous sand like that
which fa Biobio now conveys to the bay. These shells, as
well as others, which cover the adjoining hills of mica-schist
156 EARTHQUAKE IN PERU. (Cu. XXX,
to the height of several hundred feet, have been examined
by experienced conchologists in London, and identified with
those taken at the same time in a living state from the bay
and its neighbourhood.*
Ulloa, therefore, was perfectly correct in his statement
that, at various heights above the sea between Talcahuano
and Conception, ‘mines were found of various sorts of shells
used for lime of the very same kinds as those found in the
adjoining sea.” Among them he mentions the great mussel
called Choros, and two others which he describes. Some of
these, he says, are entire, and others broken; they occur at
the bottom of the sea, in 4, 6, 10, or 12 fathom water,
where they adhere to a sea-plant called Cochayuyo. They
are taken in dredges, and have no resemblance to those
found on the shore or in shallow water; yet beds of them
occur at various heights on the hills. ‘I was the more
pleased with the sight,’ he adds, ‘as it appeared to me
a convincing proof of the universality of the deluge, although
Tam not ignorant that some have attributed their position
to other causes.’+ It has, however, been ascertained that
the foundation of the Castle of Penco was so low in 1835,
or at so inconsiderable an elevation above the highest spring
tides, as to discountenance the idea of any permanent up-
heaval in modern times, on the site of that ancient port;
but no exact measurements or levellings appear as yet to
have been made to determine this point, which is the more
worthy of investigation, because it may throw some light
on an opinion often promulgated of late years, that there is
a tendency in the Chilian coast, after each upheaval, to sink
gradually and return towards its former position.
Peru, 1746.—Peru was visited, on October 28, 1746, by
a tremendous earthquake. In the first 24 hours, 200 shocks
were experienced. The ocean twice retired and returned
impetuously upon the land: Lima was destroyed, and part
of the coast near Callao was converted into a bay: 4 other
harbours, among which were Cavalla and Guanape, shared
* Captain Belcher showed me these + Ulloa’s be to ae. America,
shells, and the collection was examined a ii. book vill, ch
by Mr. Broderip.
a es —____...
SE as —<egurrr ene c— rr
|
|
(Ce, yy.
<n Cu, XXX.] EARTHQUAKE IN PERU. 157
fea the same fate. There were 23 ships and vessels, great and
L aie small, in the harbour of Callao, of which 19 were sunk ; ae
7 the other 4, among which was a frigate called St. Fermin,
statem, were carried by the force of the waves to a great sicbags up
leah, ut the country, and left on dry ground at a considerable height
BF te, above the sea. The number of inhabitants in this city
hee. amounted to 4,000. 200 only escaped, 22 of whom bi pa
et the saved on a small fragment of the fort of Vera Cruz, which
A Mosse] remained as the only memorial of the town after this dreadful
Some of inundation. Other portions of its site were completely
YCCur at - covered with heaps of sand and gravel.
T Water, A voleano in Lucanas burst forth the same night, and
0. They such quantities of water descended from the cone that the
to those whole country was overflowed; and in the mountain near
Of then | Pataz, called Conversiones de Caxamarquilla, three other
the mor volcanos burst out, and frightful torrents of water swept
d t m down their sides.*
althoush | There are several records of prior convulsions in Peru,
- position . accompanied by similar inroads in the sea, oue of which
ned that happened 59 years before (in 1687), when the ocean, ac-
. aan cording to Ulloa, first retired and then returned in a moun-
"i ei tainous wave, overwhelming Callao and its environs, with
ob Spr the miserable inhabitants.+ This same wave, according to
nent Up- Lionel Wafer, carried ships a league into the country, and
nt port; drowned man and beast for 50 leagues along the shore. t
is yet to Tnundations of" still earlier dates are carefully recorded by
he more Ulloa, Wafer, Acosta, and various writers, who describe
me light them as having expended their chief fury some on one part
there 8 of the coast, some on another.
| to sik But all authentic accounts cease when we ascend to the
era of the conquest of Peru by the Spaniards. The ancient
746, by Peruvians, although far removed from barbarism, were with-
y shocks out written annals, and therefore unable to preserve a distinct
turned recollection of a long series of natural events. They had, «
of part OVONer, according to Antonio de Herrera, who, in the
“g oth! beginning of the 17th century, investigated their antiquities,
shat?
it Ulloa’s Voyage to South America, { Wafer, cited by Sir W. Parish,
sper vol. ii. book vii. chap. vii. Geol. Soc. Proceedings, vol. ii. p. 215.
re t Ibid. vol. ii. p. 82.
158 EARTHQUAKE IN JAVA, 1699. (Cu, XXX,
a tradition, ‘that many years before the reign of the Incas,
at a time when the country was very populous, there hoe
pened a ereat flood; the sea breaking out beyond its bounds,
so that the land was covered with water and all the people
perished. To this the Guacas, inhabiting the vale of Xausea,
and the natives of Chiquito, in the province of Callao, add
that some persons remained in the hollows and caves of the
highest mountains, who again peopled the land. Others of —
the mountain people affirm that all perished in the deluge,
only 6 persons being saved on a float, from whom descended
all the inhabitants of that country.’ *
On the mainland near Lima, and on the neighbouring
island of San Lorenzo, Mr. Darwin found proofs that the
ancient bed of the sea had been raised to the height of more
than 80 feet above water within the human epoch, strata
having been discovered at that altitude, containing pieces
of cotton thread and plaited rush, together with sea-weed
and marine shells.+ The same author learnt from Mr. Gill,
a civil engineer, that he discovered in the interior near Lima,
between Casma and Huaraz, the dried-up channel of a large
river, sometimes worn through solid rock, which, instead of
continually ascending towards its source, has, in one place,
a steep downward slope in that direction, for a ridge or line
of hills has been uplifted directly across the bed of the stream,
which is now arched. By these changes the water has been
turned into some other course; and a district, once fertile,
and still covered with ruins, and bearing the marks of
ancient cultivation, has been converted into a desert.
Java, 1699.—On January 5, 1699, a terrible earthquake
visited Java, and no less than 208 considerable shocks were
reckoned. Many houses in Batavia were overturned, and
the flame and noise of a volcanic eruption were seen and
heard in that city, which were afterwards found to proceed
from Mount Salek,$ a voleano 6 days’ journey distant.
Next morning the Batavian river, which has its rise from
that mountain, became very high and muddy, and brought
* Hist. of America, decad. iii. book Tel biGey
dhe Cie ae § eee pee in Hocke’s Ac-
~ Darwin’s Journal, p. 451. count
—— er oo ——_—__—.
— ee
vV_—_—_—
1 a et
in t he delay
descend
Neighbor
ri rots that thy
eight of or
Epoch, strat
aining pigs
rith sea-yesj
rom M. Gill
wr near Lim,
nel of a lane
h, instead
in one place |
ridge or line
f the stra,
d, on f
QUITO, 1698.—SICILY, 1693. 159
Cx. XXX]
down abundance of bushes and trees, half burnt. The
channel of the river being stopped up, the water overflowed
the country round the gardens about the town, and some of
the streets, so that fishes lay dead in them. All the fish in
the river, except the carps, were killed by the mud and
turbid water. A great number of drowned buffaloes, tigers,
rhinoceroses, deer, apes, and other wild beasts, were brought
down by the current; and, ‘ notwithstanding,’ observes one
of the writers, ‘that a crocodile is amphibious, several of
them were found dead among the rest.’ *
It is stated that seven hills bounding the river sank down;
by which must be meant, as by similar expressions in the
description of the Calabrian earthquakes, seven great land-
slips. ‘These hills, descending some from one side of the
valley and some from the other, filled the channel, and the
waters then finding their way under the mass, flowed out
thick and muddy. The Tangaran river was also dammed up
by nine hills, and in its channel were large quantities of drift
trees. Seven of its tributaries also are said to have been
‘covered up with earth.’ <A high tract of forest land, between
the two great rivers before mentioned, is described as having
been changed into an open country, destitute of trees, the
surface being spread over with a fine red clay. This part of
the account may, perhaps, merely refer to the sliding down
of woody tracts into the valleys, as happened to so many ex-
tensive vineyards and olive-grounds, in Calabria, in 1783.
The close packing of large trees in the Batavian river is
represented as very remarkable, and it attests in a striking
manner the destruction of soil bordering the valleys which
had been caused by floods and landslips.t
Quito, 1698.—In Quito, on the 19th of J uly, 1698, during
an earthquake, a great part of the crater and summit of the
voleano Carguairazo fell in, and a stream of water and mud
issued from the broken sides of the hill. t
Steily, 1693.—Shocks of earthquakes spread over all Sicily
in 1693, and on the 11th of January the city of Catania
and 49 other places were levelled to the ground, and about
* Hooke’s Posthumous Works, p. 487.
1705,
+ Phil. Trans. 1700.
+ Humboldt, Atl. Pit. p. 106.
160 MOLUCCAS, 1693.—JAMAICA, 1699. [Gm Xai
100,000 people killed. The bottom of the sea, says Vicentino
Bonajutus, sank down considerably, both in ports, incloged
bays, and open parts of the coast, and water bubbled up along
the shores. Numerous long fissures of various breadths were
caused, which threw out sulphurous water; and one of them,
in the plain of Catania (the delta of the Simeto), at the
distance of 4 miles from the sea, sent forth water as salt as
the sea. The stone buildings of a street in the city of Noto,
for the length of half a mile, sank into the ground, and
remained hanging on one side. In another street, an opening
large enough to swallow a man and horse appeared.*
Moluccas, 1693.—The small Isle of Sorea, which consists
of one great volcano, was in eruption in the year 1693. Dif-
ferent parts of the cone fell, one after the other, into a deep
crater, until almost half the space of the island was converted
into a fiery lake. Most of the inhabitants fled to Banda; but
great pieces of the mountain continued to fall down, so that
the lake of lava became wider ; and finally the whole popula-
tion was compelled to emigrate. It is stated that, in pro-
portion as the burning lake increased in size, the earthquakes
were less vehement.t+
Jamaica, 1692.—Subsidence in the harbowr.—In the year
1692, the island of Jamaica was visited by a violent earth-
quake; the ground swelled and heaved like a rolling sea,
and was traversed by numerous cracks, 200 or 300 of
which were often seen at a time, opening and then closing
rapidly again. Many people were swallowed up in these
rents ; some the earth caught by the middle, and squeezed to
death ; the heads of others only appeared above ground; and
some were first engulfed, and then cast up again with great
quantities of water. Such was the devastation, that.even in
Port Royal, then the capital, where more houses are said
to have been left standing than in the whole island beside,
three-quarters of the buildings, together with the ground they
stood on, sank down with their inhabitants entirely under
water.
The large store-houses on the harbour side subsided, so as
* Phil. Trans. 1693-4. + De la Béche, Manual of Geol., p. 133, 2nd edition.
OT Ores — ~ee
————
h COnsists
93, Dit
ito a deep
converted
anda; but
n, 80 that
le popul-
t, in prv-
rthquakes
the year
nt earth-
ling sea,
sitio”
pad ©
Cu. XXX.] CHANGES CAUSED BY EARTHQUAKES. 161
to be 24, 36, and 48 feet under water; yet many of them
appear to have remained standing, for it is stated that, after
the earthquake, the mast-heads of several ships wrecked in
the harbour, together with the chimney-tops of houses, were
just seen projecting above the waves. A tract of land round
the town, about 1,000 acres in extent, sank down in less than
one minute, during the first shock, and the sea immediately
rolled in. The Swan frigate, which was repairing in the
wharf, was driven over the tops of many buildings, and then
thrown upon one of the roofs, through which it broke. The
breadth of one of the streets is said to have been doubled by
the earthquake.
According to Sir H. de la Béche, the part of Port Royal
described as having sunk was built upon new-formed land,
consisting of sand, in which piles had been driven ; and the
settlement of this loose sand, charged with the weight of heavy
houses, may, he suggests, have given rise to the subsidences
alluded to.*
There have undoubtedly been instances in Calabria and
elsewhere of slides of land on which the houses have stil]
remained standing; and it is possible that such may have
been the case at Port Royal. The fact at least of submerg-
ence is unquestionable, for I was informed by the late Admiral
Sir Charles Hamilton that he frequently saw the submerged
houses of Port Royal in the year 1780, in that part of the
harbour which lies between the town and the usual anchor-
age of men-of-war. Bryan Edwards also Says, in_ hig
history of the West Indies, that in 1793 the ruins were
visible in clear weather from the boats which sailed over
them.+ Lastly, Lieutenant B. Jeffery, R.N., told me that,
being engaged in a survey between the years 1824 and 1835,
he repeatedly visited the site in question, where the depth of
the water is from 4 to 6 fathoms, and whenever there was
but little wind perceived distinct traces of houses. He saw
these more clearly when he used the instrument called the
‘diver’s eye,’ which is let down below the ripple of the
wave.t
he i Béche, Manual of Geol., p. tT Vol. i. p. 285, 8vo ed. 8 vols. 1801.
133, second edition.
VOL. Il. M
{ Letter to the Author, May 1838.
162 MOUNTAINS SHATTERED, [Cu. XXX,
At several thousand places in Jamaica the earth is related
to have opened. On the north of the island, severa] plan-
tations, with their inhabitants, were swallowed up, and a
lake appeared in their place, covering above 1,000 acres,
which afterwards dried up, leaving nothing but sand and
gravel, without the least sien that there had ever been a
house or a tree there. Several tenements at Yallows were
buried under land-slips; and one plantation was removed
half a mile from its place, the crops continuing to grow
upon it uninjured. Between Spanish Town and Sixteen-mile
Walk, the high and perpendicular cliffs bounding the river
fell in, stopped the passage of the river and flooded the latter
place for 9 days, so that the people ‘concluded it had been
gunk as Port Royal was.’ But the flood at length subsided,
for the river had found some new passage at a great distance.
Mountains shattered.—The Blue and other of the highest
mountains are declared to have been strangely torn and rent.
They appeared shattered and half-naked, no longer affording
a fine green prospect, as before, but stripped of their woods
and natural verdure. The rivers on these mountains first
ceased to flow for about 24 hours, and then brought down
into the sea, at Port Royal and other places, several hundred
thousand tons of timber, which looked like floating islands
on the ocean. The trees were in general barked, most of
their branches having been torn off in the descent. It is
particularly remarked in this, as in the narratives of so many
earthquakes, that fish were taken in great numbers on the
coast during the shocks. The correspondents of Sir Hans
Sloane, who collected with care the accounts of eye-witnesses
of the catastrophe, refer constantly to swbsidences, and some
supposed the whole of Jamaica to have sunk down.*
Reflections on the amount of change since the close of the
seventeenth centwry.—I have now only enumerated some few of
the earthquakes of the last and present centuries, respecting
which facts illustrative of geological enquiries are on record.
Even if my limits permitted, it would be an unprofitable task
to examine all the obscure and ambiguous narratives of
* Phil. Trans. 1694.
:
:
|
bal
&
CD
on
B
1 and rent,
r affording )
heir wood -
ntains fint
ight dom
a] hundred
ng islands
1, most
nt. Tt
of so wal)
ers on te
Cu. XXX.] REFLECTIONS ON CHANGES BY EARTHQUAKES. 1638
similar events of earlier epochs ; although, if the places were
now examined by geologists well practised in the art of inter-
preting the monuments of physical changes, many events
which have happened within the historical era might doubt-
less be still determined with precision. It must not be
imagined that, in the above sketch of the occurrences of a
short period, I have given an account of all, or even the
greater part, of the mutations which the earth has under-
gone by the agency of subterranean movements. Thus, for
example, the earthquake of Aleppo, in the present century,
and of Syria, in the middle of the 18th, would doubtless have
afforded numerous phenomena, of great geological importance,
had those catastrophes been described by scientific observers,
The shocks in Syria in 1759 were protracted for three mouths,
throughout a space of 10,000 square leagues: an area com-
pared to which that of the Calabrian earthquake in 1783 was
insignificant. Accon, Saphat, Balbeck, Damascus, Sidon,
Tripoli, and many other places, were almost entirely levelled
to the ground. Many thousands of the inhabitants perished
in each ; and, in the valley of Balbeck alone, 20,000 men are
said to have been victims to the convulsion. In the absence
of scientific accounts, it would be as irrelevant to our present
purpose to enter into the details of such calamities, as
to follow the track of an invading army, to enumerate the
cities burnt or razed to the ground, and reckon the number
of individuals who perished by famine or sword.
If such, then, be the amount of ascertained changes in less
than two centuries, notwithstanding the extreme deficiency
of our records during that brief period, how important must
we presume the physical revolutions to have been in the
course of 30 or 40 centuries, during which some countries
habitually convulsed by earthquakes have been peopled by
civilised nations! Towns engulfed during one earthquake
may, by repeated shocks, have sunk to great depths beneath
the surface, while the ruins remain as imperishable as the
hardest rocks in which they are enclosed. Buildings and
cities, submerged, for a time, beneath seas or lakes, and
covered with sedimentary deposits, must, in some places,
have been re-elevated to considerable heights above the level
M 2
164 DEFICIENCY OF HISTORICAL RECORDS. [Cu. XXX,
of the ocean. The signs of these events have, probably, been
rendered visible by subsequent mutations, as by the en-
croachments of the sea upon the coast, by deep excavations
made by torrents and rivers, by the opening of new ravines,
and chasms, and other effects of natural agents, so active in
districts agitated by subterranean movements.
If it be asked why, if such wonderful monuments exist, go
few have hitherto been brought to light, we reply—because
they have not been searched for. In order to rescue from
oblivion the memorials of former occurrences, the enquirer
must know what he may reasonably expect to discover, and
under what peculiar local circumstances. He must be ac-
quainted with the action and effect of physical causes, in
order to recognise, explain, and describe correctly the phe-
nomena when they present themselves.
The best known of the great volcanic regions, of which the
boundaries were sketched in Chapter XXII., is that which
includes Southern Europe, Northern Africa, and Central Asia;
yet nearly the whole, even of this region, must be laid down,
in a geological map, as ‘Terra Incognita,’ for we are only
beginning to know something of one small portion of it, viz.
the district round Naples; and even here it is to recent
antiquarian and geological research, not to history, that we
are principally indebted for the information. I shall now
proceed to lay before the reader some of the results of modern
investigations in the Bay of Baie and the adjoining coast.
PROOFS OF ELEVATION AND SUBSIDENCE IN THE BAY OF BAIA.
Temple of Jupiter Serapis.—This celebrated monument of
antiquity, a representation of which is given in the frontis-
piece * of this work (Vol. L.), affords in itself alone unequi-
vocal evidence that the relative level of land and sea has
changed twice at Puzzuoli since the Christian era; and each
* The view of the temple given in trate a paper by Mr. Babbage on the
the frontispiece has been reduced from temple of Serapis, read March, 1834,
art of a beautiful coloured drawing and published in the Quart. ‘Journ.
taken in 1836, with the aid of the ca- of the Geol. Soc. of London, vol. ill.
mera lucida, by Mr. I’Anson, to illus- 1847.
————_ —_
Cu, XXX.] BAY OF BALE—ELEVATION AND SUBSIDENCE. 165
movement, both of elevation, and subsidence, has exceeded
20 feet. Before examining these proofs, | may observe, that
a geological examination of the coast of the Bay of Baize, both
on the north and south of Puzzuoli, establishes in the most
Fig. 123,
Monte
Barbaro,
—>
Monte
Nusvo.
gail ly
a
GZ,
SS
i
iN
IWS
“yy,
LL}.
LG
Yo
Temple of -Zir,
Sera Pls. 25 A
Pd ea
> ff
Pu ceuoli po
"Mole.
Ground plan of the coast of the Bay of Baiz, in the environs of Puzzuoli.
satisfactory manner an elevation, at no remote period, of
more than 20 feet, and, at one point, of more than 30 feet;
and the evidence of this change would have been complete,
even if the temple had, to this day, remained undiscovered.
Coast south of Puzzuoli.i—lIf we coast along the shore from
Naples to Puzzuoli, we find, on approaching the latter place,
that the lofty and precipitous cliffs of indurated tuff, re-
sembling that of which Naples is built, retire slightly from
the sea; and that a low level tract of fertile land, of a very
different aspect, intervenes between the present sea-beach
and what was evidently the ancient line of coast.
The inland cliff may be seen opposite the small island of
Nisida, about 24 miles south-east of Puzzuoli (see Map, fig.
60, Vol. I. p. 599), where, at the height of 32 feet above the
level of the sea, Mr. Babbage observed an ancient mark,
such as might have been worn by the waves; and, upon
further examination, discovered that, along that line, the
face of the perpendicular rock, consisting of very hard tuff,
was covered with barnacles (Balanus sulcatus, Lamk.),
166 CHANGES OF LEVEL, PUZZUOLI. (Cu. XXX
and drilled by boring testacea. Some of the hollows of the
lithodomi contained the shells; while others were filled with
the valves of a species of Arca.*
¢ Nearer to Puzzuoli, the inland cliff
Fig. 124. cdl is 80 feet high, and as_perpen-
I. WS wee
C dicular as if it were still under-
mined by the waves. At its base,
a new deposit, constituting the
fertile tract above alluded to, at-
tains a height of about 20 feet
above the sea; and since it is
a. Antiquities on hill §.B. of Puzzuoli 5
(see ground plan, fig. 123). composed of regular sedimentary
= : ai
bd. Ancient cliff, now inland. = Sa ae
c. Terrace composed of recent sub- deposits, containing marine shells,
marine deposit. its Pp O siti on proves tha t, sabes
quently to its formation, there has been a change of more
than 20 feet in the relative level of land and sea.
The sea encroaches on these new incoherent strata; and
as the soil is valuable, a wall has been built for its protec-
tion; but when I first visited the spot in 1828, the waves
had swept away part of this rampart, and exposed to view
a regular series of strata of tuff, more or less argillaceous,
alternating with beds of pumice and lapilli, and containing
great abundance of marine shells, of species now common
on this coast, and amongst them Cardiuwm rusticwm, Ostrea
edulis, Donax trunculus, Lamk., and others. The strata vary
from about a foot to a foot and a half in thickness, and one
of them contains abundantly remains of works of art, tiles,
squares of mosaic pavement of different colours, and small
sculptured ornaments, perfectly uninjured. Intermixed with
these I collected some teeth of the pig and ox. These frag-
ments of building occur below as well as above strata con-
taining marine shells. Puzzuoli itself stands chiefly on a
promontory of the older tufaceous formation, which cuts off
the new deposit, although I detected a small patch of the
latter in a garden under the town.
From the town the ruins of a mole, called Caligula’s
%- Nir eBabhace as
thisspot in rous specimens of the shells collected
company with Sir Edmund Head in there, and in the Temple of Serapis.
June 1828, and has shown me nume-
——_—
er
xX. ] COAST NORTH OF PUZZUOLI. 167
Cu.
Bridge, run out into the sea. (See Plate VII.)* This mole,
which is believed to be eighteen centuries old, consists of a
number of piers and arches, thirteen of which are now
standing, and two others appear to have been overthrown.
Mr. Babbage found, on the sixth pier, perforations of litho-
domi four feet above the level of the sea; and, near the
termination of the mole on the last pier but one, marks of
the same, ten feet above the level of the sea, together with
ereat numbers of balani and flustra. The depth of the sea,
at avery small distance from most of the piers, is from 30
to 50 feet.
Coast north of Puzzuoli.—If we then pass to the north of
Puzzuoli, and examine the coast between that town and
Monte Nuovo, we find a re-
er
petition of analogous phe- yyy 195,
nomena. Thesloping sides of
Monte Barbaro slant down
within ashort distance of the
coast, and terminate in an | x.,
inland cliff of moderate ele- <=.
vation, to which the eeolo- to gst of Cicero’s villa, N. side of Puz-
gist perceives at once that 2. Ancient cliff, now inlan
C. Terr race — La Lae composed of recent
the sea must, at some for- aw
mer period, have extended.
Between this cliff and the sea is the low plain or terrace,
before alluded to, called La Starza (c, fig. 125), corresponding
to that before described on the south-east of the town; and
as the sea encroaches rapidly, fresh sections of the strata may
readily be obtained, of which the annexed is an example.
Section on the shore north of the town of Puzzuoli:—
d. Temple of Serapis.
Ft. In.
1. Vegetable soil 1 0
2. | beds of. peas ae scorise, with ad fragments of
unrolled bricks, bones of animals, and marine shells . 6
3. Beds of lapilli, containing abundance of marine shells, arnesplls
Cardium rusticum, Donax trunculus, Lam., Ostrea edulis, Triton
cutacewm, Lam., and Buccinum serratum, Brocchi, the beds varying
in thickness en. one to eighteen inches 0
4, oo tuff, eames bricks and feaomapnts of faites net
unded by attri : ; : : . . * 6
This view is taken from Sir W. + This spot here indicated on he
a. Campi Phlegrei, plate 26. summit of the cliff is that from eee
168 TEMPLE OF JUPITER SERAPIS.
[Cu. XXx,
The thickness of many of these beds varies greatly as we
trace them along the shore, and sometimes the whole srou
rises to a greater height than at the point above described,
The surface of the tract which they compose appears to slope
gently upwards towards the base of the old cliffs.
Now, if such appearances presented themselves on the coast
of England, a geologist might endeavour to seek an explana-
tion in some local change in the set of the tides and currentg:
but there are scarcely any tides in the Mediterranean ; and,
to suppose the sea to have sunk generally from twenty to
twenty-five feet since the shores of Campania were covered
with sumptuous buildings, is an hypothesis obviously un-
tenable. The observations, indeed, made during modern
surveys on the moles and cothons (docks) constructed by the
ancients in various ports of the Mediterranean, have proved
that there has been no sensible variation of level in that sea,
during the last two thousand years.*
Thus we arrive, without the aid of the celebrated temple, at
the conclusion, that the recent marine deposit at Puzzuoli
was upraised in modern times above the level of the sea, and
that not only this change of position, but the accumulation
of the modern strata, was posterior to the destruction of
many edifices, of which they contain the embedded relics.
If we next examine the evidence afforded by the temple
itself, it appears, from the most authentic accounts, that the
three pillars now standing erect continued, down to the
middle of the last century, almost buried in the new marine
strata (c, fig. 125). The upper part of each, protruding
several feet above the surface was concealed by bushes, and
had not attracted, until the year 1749, the notice of anti-
quaries; but, when the soil was removed in 1750, they were
seen to form part of the remains of a splendid edifice, the
pavement of which was still preserved, and upon it lay a
number of columns of African breccia and of granite. The
original plan of the building could be traced distinctly:
it was of a quadrangular form, 70 feet in diameter, and
Hamilton’s view, plate 26, Campi Phle-
grei (reduced in Plate VII.), is taken,
and on which, he says, Cicero’s Villa,
ealled the Academia, anciently stood.
* On the authority of the late Ad-
miral Smyth, R.N.
=
a
Cu, XXX.] TEMPLE OF JUPITER SERAPIS. 169
the roof had been supported by 46 noble columns, 24.
of granite, and the rest of marble. The large court was
surrounded by apartments, supposed to have been used
as bathing-rooms; for a thermal spring, still used for
medicinal purposes, issues just behind the building, and the
water of this spring appears to have been originally conveyed
by a marble duct, still extant, into the chambers, and then
across the pavement by a groove an inch or two deep, to a
conduit made of Roman brickwork, by which it gained the sea.
Many antiquaries have entered into elaborate discussions
as to the deity to which this edifice was consecrated. It is
admitted that, among other images found in excavating the
ruins, there was one of the god Serapis; and at Puzzuoli a
marble column was dug up, on which was carved an ancient
inscription, of the date of the building of Rome 648 (or B.c.
105), entitled ‘Lex parieti faciundo.’ This inscription, written
in very obscure Latin, sets forth a contract, between the
municipality of the town, and a company of builders who
undertook to keep in repair certain public edifices, the
Temple of Serapis being mentioned amongst the rest, and
described as being near or towards the sea, ‘ad mare vorsum.’
Sir Edmund Head, after studying, in 1828, the topography
and antiquities of this district, and the Greek, Roman, and
Italian writers on the subject, informed me, that at Alex-
andria, on the Nile, the chief seat of the worship of Serapis,
there was a Serapeum of the same form as this temple at
Puzzuoli, and surrounded in like manner by chambers, in
which the devotees were accustomed to pass the night, in
the hope of receiving during sleep a revelation from the god,
as to the nature and cure of their diseases. Hence it was
very natural that the priests of Serapis, a pantheistic divinity,
who, among other usurpations, had appropriated to himself
the attributes of Esculapius, should regard the hot spring as
@ suitable appendage to the temple, although the original
Serapeum of Alexandria could boast no such medicinal waters.
Signor Carelli* and others, in objecting to these views, have
insisted on the fact, that the worship of Serapis, which we
* Dissertazione sulla Sagra Archittetura degli Antichi.
170 TEMPLE OF JUPITER SERAPIS. [Cu. XXX,
know prevailed at Rome in the days of Catullus (in the first
century before Christ), was prohibited by the Roman Senate,
during the reign of the Emperor Tiberius. But there is little
doubt that, during the reigns of that Emperor’s successors,
the shrines of the Egyptian god were again thronged by
zealous votaries; and in no place more so than at Puteoli
(now Puzzuoli), one of the principal marts for the produce of
Alexandria.
Without entering farther into an enquiry which is not
strictly geological, I shall designate this valuable relic of
antiquity by its generally received name, and proceed to
consider the memorials of physical changes inscribed on the -
three standing columns in most legible characters by the
hand of Nature. (See Frontispiece, Vol. I.) These pillars,
which have been carved each out of a single block of marble,
are 40 feet 84 inches in height. An horizontal fissure nearly
intersects one of the columns; the other two are entire.
They are all slightly out of the perpendicular, inclining
somewhat to the south-west, that is, towards the sea.* Their
surface is smooth and uninjured to the height of about twelve
feet above their pedestals. Above this is a zone, about nine
feet in height, where the marble has been pierced by a species
of marine perforating bivalve—Lithodomus, Cuv.t The holes
of these animals are pear-shaped, the external opening being
minute, and gradually increasing downwards. At the bottom
of the cavities, many shells are still found, notwithstanding
the great numbers that have been taken out by visitors; in
many the valves of a species of arca, an animal which con-
ceals itself in small hollows, occur. The perforations are so
considerable in depth and size, that they manifest a long-
continued abode of the lithodomi in the columns; for, as the
inhabitant grows older and increases in size, it bores a larger
cavity, to correspond with the increased magnitude of its
shell. We must, consequently, infer a long-continued im-
* This appears fromthe measurement formed out of a single stone was first
of Captain Basil Hall, BN Proceed- pointed out to me by Mr. James Hall,
ings of Geol. Soc., No. 38, p. 114; see and is pes as ete to oe
also Patchwork, as the same author, why Saas we shaken
vol. ili. p. 158. The fact of the three + Modiola pre 6 ee "Mytilus
standing columns having been each lithophagus, Linn.
ae ee
Cu. XXX.] TEMPLE OF JUPITER SERAPIS. Iv
mersion of the pillars in sea-water, at a time when the lower
part was covered up and protected by marine, fresh-water,
and volcanic strata, afterwards to be described, and by the
rubbish of buildings; the highest part, at the same time, pro-
jecting above the waters, and being consequently weathered,
but not materially injured. (See fig. 126, p. 172.)
On the pavement of the temple lie some columns of marble,
which are also perforated in certain parts; one, for example,
to the length of 8 feet, while, for the length of 4 feet, it is
uninjured. Several of these broken columns are eaten into,
not only on the exterior, but on the cross fracture, and, on
some of them, other marine animals (serpule, &c.) have fixed
themselves.* All the granite pillars are untouched by litho-
domi. The platform of the temple, which is not perfectly
even, was, when I visited it in 1828, about one foot below
high-water mark (for there are small tides in the Bay of
Naples); and the sea, which was only 100 feet distant,
soaked through the intervening soil. The upper part of the
perforations, therefore, was at least 23 feet above high-
water mark; and it is clear that the columns must have
continued for a long time in an erect position, immersed in
salt water, and then the submerged portion must have been
upraised to the height of about 23 feet above the level of
the sea.
By excavations carried on in 1828, below the marble pave-
ment on which the columns stand, another costly pavement
of mosaic was found, at the depth of about 5 feet below the
upper one (a, b, fig. 126). The existence of these two pave-
ments, at different levels, clearly implies some subsidence
previously: to the building of the more modern temple which
had rendered it necessary to construct the new floor at a
higher level.
We have already seen (p. 169) that a temple of Serapis
existed long before the Christian era. The change of level
just mentioned must have taken place some time before the
end of the second century, for inscriptions have been found
in the temple, from which we learn that Septimius Severus
* Serpula contortuplicata, Linn.,and as well as the Lithodomus, are now in-
Vermilia triquetra, Lam. These species, habitants of the neighbouring sea.
172 TEMPLE OF JUPITER SERAPIS.
[Cu. XXX.
adorned its walls with precious marbles, between the years
194 and 211 of our era, and the emperor Alexander Severus
displayed the like munificence between the years 222 and
235.* From that era there is an entire dearth of historical
information for a period of more than twelve centuries,
except the significant fact that Alaric and his Goths sacked
Puzzuoli in 410, and that Genseric did the like in 445, ap.
Yet we have fortunately a series of natural archives self-
registered during the dark ages, by which many events which
occurred in and about the temple are revealed to us. These
natural records consist partly of deposits, which envelop the
pillars below the zone of lithodomous perforations, and
partly of those which surround the outer walls of the temple.
Mr. Babbage, after a minute examination of these, has shown
(see p. 164, note) that incrustations on the walls of the
A
Temple of Serapis at its period of greatest depression.
ab. Ancient mosaic pavement. ee. Freshwater calc deposit.
cc. Dark marine i station. Jf. Second filling up.
d d. First filling up, shower of ashes. A. Stadium.
exterior chambers and on the floor of the building demon-
strate that the pavement did not sink down suddenly, but
was depressed by a gradual movement. The sea first entered
the court or atrium, and mingled its waters partially with
those of the hot spring. From this brackish medium a dark
calcareous precipitate (c c, fig. 126) was thrown down, which
became, in the course of time, more than two feet thick,
including some serpulz in it. The presence of these annelids
teaches us that the water was salt or brackish. After this
period the temple was filled up with an irregular mass of
volcanic tuff (d d, fig. 126), probably derived from an erup-
tion of the neighbouring crater of the Solfatara, to the
_* Brieslak, Voy. dans la Campanie, tom. ii. p. 167.
SS
Cu. XXX.] TEMPLE OF JUPITER SERAPIS. 173
height of from 5 to 9 feet above the pavement. Over this
again a purely freshwater deposit of carbonate of lime (e e,
fig. 126) accumulated with an wneven bottom, since it neces-
sarily accommodated itself to the irregular outline of the
upper surface of the volcanic shower before thrown down.
The top of the same deposit (a freshwater limestone) was
perfectly even and flat, bespeaking an ancient water level.
It is suggested by Mr. Babbage that this freshwater lake
may have been caused by the fall of ashes which choked up
the channel previously communicating with the sea, so that
the hot spring threw down calcareous matter in the atrium
without any marine intermixture. To the freshwater lime-
stone succeeded another irregular mass of volcanic ashes and
rubbish (f f, fig. 126), some of it perhaps washed in by the
waves of the sea during a storm, its surface rising to 10 or
11 feet above the pavement. And thus we arrive at the
period of greatest depression expressed in the accompanying
diagram, when the lower half of the pillars was enveloped
in the deposits above enumerated, and the uppermost 20 feet
were exposed in the atmosphere, the remaining or middle
portion, about 9 feet long, being for years immersed in salt
water and drilled by perforating bivalves. After this period
other strata, consisting of showers of volcanic ashes and
materials washed in during storms, covered up the pillars to
the height in some places of 35 feet above the pavement.
The exact time when these enveloping masses were heaped
up, and how much of them were formed during submergence,
and how much after the re-elevation of the temple, cannot
be made out with certainty.
The period of deep submergence was certainly antecedent
to the close of the 15th century. Professor James Forbes*
has reminded us of a passage in an old Italian writer,
Loffredo, who says that in 1530, or 50 years before he wrote,
which was in 1580, the sea washed the base of the hills
which rise from the flat land called La Starza, as represented
in fig. 126; go that, to quote his words, ‘a person might
then have fished from the site of those ruins which are now
called the stadium ’ (A, fig. 126)
* Ed. Journ. of Science, new series, No. II. p. 281.
174 TEMPLE OF JUPITER SERAPIS. [Cu. XXX,
But we know from other evidence that the upward move-
ment had begun before 1530, for the Canonico Andrea di Jorio
cites two authentic documents in illustration of this point.
The first, dated Oct. 1503, is a deed written in Italian, by
which Ferdinand and Isabella grant to the University of
Puzzuoli a portion of land, ‘where the sea is drying up’
(che va seccando el mare) ; the second, a document in Latin,
dated May 23, 1511, or nearly 8 years after, by which
Ferdinand grants to the city a certain territory around
Puzzuoli, where the ground is dried up (desiccatum).*
The principal elevation, however, of the low tract un-
questionably took place at the time of the great eruption of
Monte Nuovo in 1538. That event and the earthquakes
which preceded it have been already described (Vol. I.
p- 609) ; and we have seen that two of the eye-witnesses of
the convulsion, Falconi and Giacomo di Toledo, agree in
declaring that the sea abandoned a considerable tract of the
shore, so that fish were taken by the inhabitants; and,
among other things, F'alconi mentions that he saw two springs
im the newly discovered ruins.
The flat land, when first upraised, must have been more
extensive than now, for the sea encroaches somewhat rapidly,
both to the north and south-east of Puzzuoli. The coast
had, when I examined it in 1828, given way more than a
foot in a twelvemonth ; and I was assured, by fishermen in
the bay, that it has lost ground near Puzzuoli, to the extent
of 30 feet, within their memory.
It is, moreover, very probable that the land rose to a
greater height at first, before it ceased to move upwards, than
the level at which it was observed to stand when the temple
was re-discovered in 1749, for we learn from a memoir of
Niccolini, published in 1838, that since the beginning of the
19th century, the temple of Serapis has subsided more than
2 feet. That learned architect visited the ruins frequently,
for the sake of making drawings, in the beginning of the
year 1807, and was in the habit of remaining there through-
out the day, yet never saw the pavement overflowed by the
* Sul Tempio di Serap. ch. viii.
eee eld
- Cu, XXX.] TEMPLE OF JUPITER SERAPIS. 175
-
sea, except occasionally when the south wind blew violently.
On his return, 16 years after, to superintend some exca-
vations ordered by the King of Naples, he found the
pavement covered by sea-water twice every day at high tide,
so that he was obliged to place there a line of stones to stand
upon. This induced him to make a series of observations
from Oct. 1822 to July 1838, by which means he ascertained
that the ground had been and was sinking, at the average
rate of about 7 millimetres a year, or about | inch in 4 years ;
so that, in 1838, fish were caught every day on that part of
the pavement where, in 1807, there was never a drop of
water in calm weather.*
Mr. Smith, of Jordan Hill, examined the temple in 1847,
and came to the conclusion from a comparison of various data
that the rate of subsidence at that period was one inch
annually.t Signor Scacchi, in 1852, after an examination
undertaken by him at my request, inferred that the down-
ward movement had ceased for several years, or had at least
become almost inappreciable. I made several observations
in 1857 and 1858, and came to the conclusion that there was
a depth of about 2 feet of water on the pavement near the
bronze ring on calm days at high tide when the Bay of Baiz
was not raised above its ordinary level by the wind. Although
it would require a long series of measurements to obtain the
exact average height of the tide in the bay, I cannot doubt
that the relative level of the pavement and the sea has
altered very sensibly since Niccolini first frequented the
place.
From what was said before (p. 167), we saw that the
marine shells in the strata forming the plain called La
Starza, considered separately, establish the fact of an up-
heaval of the ground to the height of 23 feet and upwards.
The temple proves much more, because it could not have
been built originally under water, and must therefore first
have sunk down 20 feet at least below the waves, to be
afterwards restored to its original position. Yet if such was
the order of events, we ought to meet with other independent
eee ars Chrono!ogica, &c. + Quart. Journ. Geol. Soc. vol. ii.
Napoli, 18 p. 237.
176 ROMAN ROADS UNDER WATER. [Cu. XXX, *
signs of a like subsidence round the margin of a bay once so
studded with buildings as the Bay of Baie. Accordingly,
memorials of such submergence are not wanting. About a
mile NW. of the temple of Serapis, and about 500 feet
from the shore, are the ruins of a temple of Neptune and
others of a temple of the Nymphs, now under water. The
columns of the former edifice stand erect in five feet water,
their upper portions just rising to the surface of the sea.
The pedestals are doubtless buried in the sand or mud; so
that, if this part of the bottom of the bay should hereafter
be elevated, the exhumation of these temples micht take
place after the manner of that of Serapis. Both these
buildings probably .participated in the movement which
raised the Starza; but either they were deeper under water
than the temple of Serapis, or they were not raised up again
to so great a height. There are also two Roman roads under
water in the bay, one reaching from Puzzuoli to the Lucrine
Lake, which may still be seen, and the other near the castle of
Baie (No. 8, Plate VII. page 167). The ancient mole, too, of
Puzzuoli (No. 4, ibid.), before alluded to, has the water up to
a considerable height of the arches ; whereas Brieslak justly
observes, it is next to certain that the piers must formerly
have reached the surface before the springing of the arches;*
so that, although the phenomena before described prove that
this mole has been uplifted 10 feet above the level at which
it once stood, it is still evident that it has not yet been
restored to its original position.
A modern writer also reminds us, that these effects are not
so local as some would have us to believe ; for on the opposite
side of the Bay of Naples, on the Sorrentine coast, which,
as well as Puzzuoli, is subject to earthquakes, a road, with
fragments of Roman buildings, is covered to some depth by
the sea. In the island of Capri, also, which is situated some
way out at sea, in the opening of the Bay of Naples, one of
the palaces of Tiberius is now covered with water.t
* Voy. dans la Campanie, tome ii. 1829. When I visited Puzzuoli, and
p. 162. arrived at the al lusions, I knew
f Mr. Forbes, Physical Notices ofthe nothing of Mr. Forbes’s observations,
Bay of Naples. Ed. Journ. of Sci., | which I first saw on my return to Eng-
No, I., new series, p. 280. October land the year following.
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Cu. XXX.] HEAT THE CAUSE OF CHANGE OF LEVEL. 177
That buildings should have been submerged, and afterwards
upheaved, without being entirely reduced to a heap of ruins,
will appear no anomaly, when we recollect that, in the year
1819, when the delta of the Indus sank down, the houses
. within the fort of Sindree subsided beneath the waves
| without being overthrown. In like manner, in the year 1692,
the buildings around the harbour of Port Royal, in J amaica,
descended suddenly to the depth of between 30 and 50 feet
under the sea without falling. Even on small portions of
land transported to a distance of a mile down a declivity,
tenements, like those near Mileto, in Calabria, were carried
entire. At Valparaiso buildings were left standing in 1822,
when their foundations, together with a long tract of the
Chilian coast, were permanently upraised to the height of
several feet. It is still more easy to conceive that an edifice
may escape falling during the upheaval or subsidence of land,
if the walls are supported on the exterior and interior with a
deposit like that which surrounded and filled to the height
of 10 or 11 feet the temple of Serapis all the time it wag
sinking, and which enveloped it to more than twice that
height when it was rising again to its original level.
We can scarcely avoid the conclusion, as Mr. Babbage has
hinted, ‘that the action of heat is in some way or other the
cause of the phenomena of the change of level of the temple.
Its own hot spring, its immediate contiguity to the Solfatara,
its nearness to the Monte Nuovo, the hot spring at the baths
of Nero (No. 6, Plate VII.), on the opposite side of the Bay
of Baie; the boiling springs and ancient volcanos of Ischia
on one side and Vesuvius on the other, are the most prominent
of a multitude of facts which point to that conclusion.’ * And
when we reflect on the dates of the principal oscillations of
level, and the volcanic history of the country before described
(Chapter XXTV.), we seem to discover a connection between
each era of upheaval and a local development of volcanic
heat, and again between each era of depression and the local
quiescence or dormant condition of the subterranea
causes. Thus, for example, before the Christian er
many vents were in frequent eruption in Ischia,
— ——————
n igneous
a, when so
and when
* Quart. Journ. Geol, Soc. 1847, vol. iii. p. 203,
N
VOL, II.
178 PERMANENCE OF THE OCEAN’S LEVEL. [CH. XXX,
Avernus and other points in the Phlegrean Fields were
celebrated for their volcanic aspect and character, the ground
on which the temple stood was several feet above water.
Vesuvius was then regarded as a spent voleano; but when,
after the Christian era, the fires of that mountain were
rekindled, scarcely a single outburst was ever witnessed in
Ischia, or around the Bay of Baie. Then the temple was
sinking. Vesuvius, at a subsequent period, became nearly
dormant for five centuries preceding the great outbreak of
1631 (see Vol. I. p. 618), and in that interval the Solfatara was
in eruption a.p. 1198, Ischia in 1302, and Monte Nuovo was
formed in 1538. Then the foundations on which the temple
stood were rising again. Lastly, Vesuvius once more became
a most active vent, and has been so ever since, and during
the same lapse of time the area of the temple, so far as we
know anything of its history, has been subsiding.
These phenomena would agree well with the hypothesis,
that when the subterranean heat is on the increase, and
when lava is forming without obtaining an easy vent, like
that afforded by a great habitual chimney, such as Vesuvius,
the incumbent surface is uplifted ; but when the heated rocks
below are cooling and contracting, and sheets of lava are
slowly consolidating and diminishing in volume, then the
incumbent land subsides.
Signor Niccolini, when he ascertained in 1838 that the
relative levels of the floor of the temple and of the sea were
slowly changing from year to year, embraced the opinion
that it was the sea which was rising. But Signor Capocei
successfully controverted this view, appealing to many ap-
pearances which attest the local character of the movements
of the adjoining country, besides the historical fact that in
1538, when the sea retired permanently 200 yards from
the ancient shore at Puzzuoli, there was no simultaneous
retreat of the waters from Naples, Castelamare, and Ischia.*
Permanence of the ocean’s level.—In concluding this subject,
I may observe, that the interminable controversies to which
the phenomena of the Bay of Baie gave rise, have sprung
from an extreme reluctance to admit that the land, rather
* Nuove Ricerche sul Temp, di Serap.
—
ds We Cu. XXX. ] PERMANENCE OF THE OCEAN’S LEVEL. 179
| Stung than the sea, is subject alternately to rise and fall. Had it
: Water been assumed, as most probable, that the level of the ocean
“ Whey, was invariable, on the ground that no fluctuations have as
In Wer, yet been clearly established, and that, on the other hand, the
“S8ed jp continents are inconstant in their level, as has been de-
ple Wag monstrated by the most unequivocal proofs again and again,
© Near) from the time of Strabo to our own times, the appearances
break i of the temple at Puzzuoli could never have been regarded
tara was as enigmatical. Even if contemporary accounts had not
10¥0 a distinctly attested the upraising of the coast, this explanation
should have been proposed in the first instance as the most
vemnple natural, instead of being now adopted unwillingly when all
became others have failed.
| during To the strong prejudices still existing in regard to the
ar as We mobility of the land, we may attribute the rarity of such
discoveries as have been recently brought to light in New
vothesis, Zealand, the Bay of Baig, and the Bay of Conception. A
ase, and false theory, it is well known, may render us blind to facts,
ont. like which are opposed to our prepossessions, or may conceal
estvits, from us their true import when we behold them. But it is
od rocks time that the geologist should, in some degree, overcome
— those first and natural impressions which induced the poets
hen the of old to select the rock as the emblem of firmness—the sea
as the image of inconstancy. Our modern poet, In a more
philosophical spirit, saw in the sea ‘the image of eternity,’
hat the and has finely contrasted the fleeting existence of the suc-
ea - cessive empires which have flourished and fallen on the
opine borders of the ocean with its own unchanged stability.
a noc
ae ' ——— Their decay
1) “ Has dried up realms to deserts :—not so thou,
een” | Unchangeable, save to thy wild waves’ play :
m | Time writes no wrinkle on thine azure brow:
that Such as creation’s dawn beheld, thou rollest sie
5 fro HILDE Harorp, Canto iy.
neo!
chia”
objec .
we
spre
rath?
180
CHAPTER XXXII.
ELEVATION AND SUBSIDENCE OF LAND WITHOUT EARTHQUAKES.
CHANGES IN THE RELATIVE LEVEL OF LAND AND SEA IN REGIONS NOT
VOLCANIC—OPINION OF CELSIUS THAT THE WATERS OF THE BALTIC SEA AND
NORTHERN OCEAN WERE SINKING—OBJECTIONS RAISED TO HIS OPINION—
PROOFS OF THE STABILITY OF THE SEA LEVEL IN THE BALTIC—PLAYFAIR’S
HYPOTHESIS THAT THE LAND WAS RISING IN SWEDEN—OPINION OF VON BUCH
—-MARKS CUT ON THE ROCKS—SURVEY OF THESE IN 1820—SIGNS OF OSCILLA-
OF SWEDEN—SUPPOSED MOVEMENT IN OPPOSITE DIRECTIONS IN PROCEEDING
FROM THE NORTH CAPE SOUTHWARDS TO SCANIA—CHANGE OF LEVEL ON THE
NORWAY IS NOW RISING—-MODERN SUBSIDENCE IN PART OF GREENLAND—
PROOFS AFFORDED BY THESE MOVEMENTS OF G REAT SUBTERRANEAN CHANGES.
We have now considered the phenomena of volcanos and
earthquakes according to the division of the subject before
proposed (Vol. I. p. 577), and have next to turn our attention to
those slow and insensible changes in the relative level of land
and sea which take place in countries remote from volcanos,
and where no violent earthquakes have occurred within the
period of human observation. Harly in the last century the
Swedish naturalist, Celsius, expressed his opinion that the
waters, both of the Baltic and Northern Ocean, were gradually
subsiding. From numerous observations, he inferred that the
rate of depression was about 40 Swedish inches in a century.*
In support of this position, he alleged that there were many
rocks both on the shores of the Baltic and the ocean known
to have been once sunken reefs, and dangerous to navigators,
* |
~
1e Swedish measure scarcely dif- into twelve inches, and being less than
fers from ours; the foot being divided ours by three-eighths of an inch only.
QUAKES,
| of land
—_— nin
Cu. XXXI.] RISE OF LAND IN SWEDEN. 181
but which were in his time above water—that the waters of
the Gulf of Bothnia had been gradually converted into land,
several ancient ports having been changed into inland cities,
small islands joined to the continent, and old fishing grounds
deserted as being too shallow, or entirely dried up. Celsius
also maintained, that the evidence of the change rested not
only on modern observations, but on the authority of the
ancient geographers, who had stated that Scandinavia was
formerly an island. This island, he argued, must in the
course of centuries, by the gradual retreat of the sea, have
become connected with the continent; an event which he
supposed to have happened after the time of Pliny, and
before the ninth century of our era.
To this argument it was objected that the ancients were
so ignorant of the geography of the most northern parts of
Europe, that their authority was entitled to no weight; and
that their representation of Scandinavia as an island, might
with more propriety be adduced to prove the scantiness of
their information, than to confirm so bold an hypothesis. It
was also remarked, that if the land which connected Scandi-
navia with the main continent was laid dry between the time
of Pliny and the 9th century, to the extent to which it is
known to have risen above the sea at the latter period, the
rate of depression could not have been uniform, as was pre-
tended; for it ought to have fallen much more rapidly between
the 9th and 18th centuries.
Many of the proofs relied on by Celsius and his followers
were immediately controverted by several philosophers, who
saw clearly that a fall of the sea in any one region could not
take place without a general sinking of the waters over the
whole globe; they denied that this was the fact, or that the
depression was universal, even in the Baltic. In proof of the
stability of the level of that sea, they appealed to the position
of the island of Saltholm, not far from Copenhagen. This
island is so low, that in autumn and winter it is perma-
nently overflowed; and it is only dry in summer, when it
serves for pasturing cattle. It appears, from the documents
of the year 1280, that Saltholm was then also in the same
state, and exactly on a level with the mean height of the sea,
182 RISE OF LAND IN SWEDEN. (Cu. XXXI.
instead of having been about 20 feet under water, as it ought
to have been, according to the computation of Celsius. Se veral
towns, also, on the shores of the Baltic, as Lubeck, Wismar,
Rostock, Stralsund, and others, after 600 and even 800 years,
are as little elevated above the sea as at the era of their
foundation, being now close to the water’s edge. The lowest
part of Dantzic was no higher than the mean level of the
sea in the year 1000; and after 8 centuries its relative posi-
tion remains exactly the same.*
Several of the examples of the gain of land and shallowing
of the sea pointed out by Celsius, and afterwards by Linneeus,
who embraced the same opinions, were ascribed by others to
the deposition of sediment at points where rivers entered ;
and, undoubtedly, Celsius had not sufficiently distinguished
between changes due to these causes and such as would arise
if the waters of the ocean itself were diminishing. Man
large rivers descending from a mountainous country, at the
head of the Gulf of Bothnia, enter the sea charged with sand,
mud, and pebbles; and it was said that in these places the
low land had advanced rapidly, especially near Torneo. At
Piteo also, 4 a mile had been gained in 45 years; at Luleo,t+
no less than 1 mile in 28 years; facts which might all be
admitted consistently with the assumption that the level of
the Baltic has remained unchanged, like that of the Adriatic,
during a period when the plains of the Po and the Adige have
greatly extended their area.
It was also alleged that certain insular rocks, once entirely
covered with water, had at length protruded themselves above
the waves, and grown, in the course of a century and a half,
to be 8 feet high. The following attempt was made to ex-
plain away this phenomenon :—In the Baltic, large erratic
blocks, as well as sand and smaller stones which lie on shoals,
are liable every year to be frozen into the ice, where the sea
freezes to the depth of 5 or 6 feet. On the melting of the
snow in spring, when the sea rises about $ a fathom, numerous
* For a full account of the Celsian ~ Pitio and Luleo are spelt, in many
controversy, we may refer our readers English maps, Pitea and Lulea, but the
to Von Hoff, Geschichte, &c. vol. i. @ is not sounded in the Swedish diph-
p. 439. thong a,
Sy
it Oey Cu. XXXI.] RISE OF LAND IN SWEDEN. 183
Ser, ice-islands float away, bearing up these rocky fragments so
Vignes | as to convey them to a distance; and if they are driven by
D Years the waves upon shoals, they may convert them into islands
of the}, . by depositing the blocks ; if stranded upon low islands, they
: Lote may considerably augment their height.
Of th Browallius, also, and some other Swedish naturalists,
ve sie affirmed that some islands were lower than formerly ; and
a . that, by reference to this kind of evidence, there was equally
loving | good reason for contending that the level of the Baltic was
Nit, gradually rising. ‘They also added another curious proof of
TN, the permanency of the water level, at some points at least,
thers W for many centuries. On the Finland coast were some large
ntered pines and oaks, growing close to the water’s edge; these
guished were cut down, and, by counting the concentric rings of
Id arise annual growth, as seen in a transverse section of the trunk,
Many it was demonstrated that some of them had stood there
» at the | for nearly 400 years. Now, according to the Celsian hypo-
h sand | thesis, the sea had sunk about 15 feet during that period, in
ces the which case the germination and early growth of these trees
~, At must have been, for many seasons, below the level of the
Luleot water. In like manner, it was asserted that the lower walls
“all be of many ancient castles, such as those of Sonderburg and
level of Abo, reached then to the water’s edge, and must, therefore,
arate according to the theory of Celsius, have been originally con-
i structed below the level of the sea.
ze hare In reply to this last argument, Colonel Hallstrom, a
Swedish engineer, well acquainted with the Finland coast,
ntirely assured me, that the base of the walls of the castle of Abo is
sabore now ten feet above the water, so that there may have been a
a half, considerable rise of the land at that point since the building
to es was erected. But the argument founded on the position of
pyratiC the trees is, as Professors Lovén and Erdmann have lately
spoals remarked, unanswerable so far ag it relates to a part at least
he | of the Finnish coast.
of he Playfair, in his ‘Illustrations of the Huttonian Theory,’
eso in 1802, admitted the sufficiency of the proofs adduced by
Celsius, but attributed the change of level to the movement
‘a wg of the land, rather than to a diminution of the waters. He
We observed, ‘that in order to depress or elevate the absolute
184 RISE OF LAND IN SWEDEN. (Cu. XXXI,
Fig. 127.
.
,| Christiania |
fo
Ay
Yantzic =
2USSIA
level of the sea, by a given quantity, in any one place, we
must depress or elevate it by the same quantity over the
whole surface of the earth; whereas no such necessity exists
Cu. XXXI.] RISE OF LAND IN SWEDEN. 185
with respect to the elevation or depression of the land.’ *
The hypothesis of the rising of the land, he adds, ‘agrees
well with the Huttonian theory, which holds that our conti-
nents are subject to be acted upon by the expansive forces
of the mineral regions; that by these forces they have been
actually raised up, and are sustained by them in their pre-
sent situation.’ +
In the year 1807, Von Buch, after returning from a tour
in Scandinavia, announced his conviction, ‘that the whole
country, from Frederickshall in Norway to Abo in Finland,
and perhaps as far as St. Petersburg, was slowly and in-
sensibly rising.” He also suggested ‘that Sweden may
rise more than Norway, and the northern more than the
southern part.’ | He was led to these conclusions principally
by information obtained from the inhabitants and pilots
respecting marks which had been set on the rocks, and
partly by the occurrence of marine shells of recent species,
which he had found at several points on the coast of Norway
above the level of the sea. Von Buch, therefore, has the
merit of being the first geologist who, after a personal ex-
amination of the evidence, declared in favour of the rise of
land in Scandinavia.
The attention excited by this subject in the early part of
the last century, had induced many philosophers in Sweden
to endeavour to determine, by accurate observations, whether
the standard level of the Baltic was really subject to peri-
odical variations ; and under their direction, lines or grooves,
indicating the ordinary level of the water on a calm day,
together with the date of the year, were chiselled out upon
the rocks. In 1820-21, all the marks made before those
years were examined by the officers of the pilotage establish-
ment of Sweden; and in their report to the Royal Academy
of Stockholm they declared, that on comparing the level of
the sea at the time of their observations with that indicated
by the ancient marks, they found that the Baltic was lower
relatively to the land in certain places, but the amount of
change during equal periods of time had not been everywhere
* Sect. 393, tT Sect. 398. + Transl. of his Travels, p. 387.
186 RISE OF LAND IN SWEDEN. [Cu. XXXTI.
the same. During their survey, they cut new marks for
the guidance of future observers, several of which I had
an opportunity of examining fourteen years after (in the
summer of 1834), and in that interval the land appeared. to
me to have risen at certain places north of Stockholm, as
near Gefle, for example, about 4 inches, or at the rate of less
than 24 feet per century. But at Stockholm, I inferred from
the position of certain aged oak-trees only 8 feet above the
level of the Baltic, that the rise could not have been at a
greater rate than 10 inches in a century, and might be less.*
Professor Axel Erdmann in 1847 calculated that the rige could
hardly have exceeded six inches at Stockholm, and in the
same year he pointed out, in a paper read to the Royal
Society of Sweden, the necessity of determining the mean
level of the Baltic by a long series of observations in dif-
ferent seasons of the year. Mr. Wolfstedt, a Swedish en-
gineer, has shown that the northern part of the Bothnian
Gulf, where several great rivers enter, is 16 feet higher than
the southern part; but as this gulf is about 600 miles in
length, it will be seen that the rate of fall per mile accord-
ing to this measurement is exceedingly small, so that the
height of the water at corresponding seasons may vary but
slightly, except when it is influenced by the wind. When I
gave the results of my Swedish tour in the fourth edition
of this work. published in 1835, I expressed my belief that
there were signs of the upheaval of the land in different
places visited by me, both on the coast of the Bothnian
Gulf and on that of the ocean, i.e. the west coast of Sweden
near Gothenburg. But I then stated that ‘we have not only
to learn whether the motion proceeds always at the same rate,
but also whether it has been uniformly in one direction. The
level of the land may oscillate; and for centuries there
may be a depression, and afterwards a re-elevation, of the
same district. Some phenomena in the neighbourhood of
Stockholm appear to me only explicable on the supposi-
tion of the alternate rising and sinking of the ground
* See a paper on ‘Rise of Land in 1830, part i, p. 13—read in November
Sweden,’ by the author. Phil. Trans. 1834,
—————— ee
Cu. XXXI.] RISE OF LAND IN SWEDEN. 187
since the country was inhabited by man. In digging a
canal, in 1819, at Sddertelje, about sixteen miles to the
south of Stockholm, to unite Lake Maeler with the Baltic,
marine strata, containing fossil shells of Baltic species, were
passed through. At a depth of about 60 feet, they came
down upon what seems to have been a buried fishing-hut,
constructed of wood in a state of decomposition, which soon
crumbled away on exposure to the air. The lowest part,
however, which had stood on a level with the sea, was ina
more perfect state of preservation. On the floor of this hut
was a rude fireplace, consisting of a ring of stones, and
within these were cinders and charred wood. On the out-
side lay boughs of the fir, cut as with an axe, with the
leaves or needles still attached. It seems impossible to
explain the position of this buried hut, without imagining,
first, a subsidence to the depth of more than 60 feet, then a
re-elevation. During the period of submergence, the hut
must have become covered over with gravel and shelly marl,
under which not only the hat, but several vessels also were
found, of a very antique form, and having their timbers
fastened together by wooden pegs instead of nails.’ *
The investigations of MM. Lovén, Hrdmann, Norden-
skidld, and others, made since my visit to Sweden in 1834,
have on the whole tended to confirm the idea previously
entertained, that some changes are now going on in the
relative level of land and sea in certain parts of the Swedish
coast, but they incline to the opinion that they are local.
With a view of accurately determining the reality of the
movement, and its amount and direction, they have insti-
tuted a regular series of annual observations, which, how-
ever, have not yet been continued long enough to lead to
positive results.
ord Selkirk in 1866 re-examined many of the marks
which T had seen, both in the Gulf of Bothnia and on the
See my paper, before referred to, come filled up in time by sand drifted
art 1. pp. 8,9. At- bythe wind. The engineers who super-
tempts have been since made to explain intended the works in 1819, and with
away the position of this hut, by con- whom I conversed, had considered every
Jecturing that a more ancient trench had hypothesis of the kind, but could not so
been previously dug here, which had be- explain the facts.
188 RISE OF LAND IN SWEDEN, (Cu. XXXT,
Swedish coast near Gothenburg, in 1834. Among the former,
the principal one, that of Loferund, near Gefle, seemed to in-
dicate a fall of the water of about 9 inches in 32 years, which
would give a rise of the land of between 2 and 3 feet in a
century, as I had suggested; but other marks in the neighbour-
hood implied a smaller dlinsios of level. A line which I myself
cut on a rock in the island of Gulholmen, off Oregrund, on
the west coast, was found to be only 3 inches higher above
the sea-level than when I made it. On the whole, after a com-
parison of this and various other marks, Lord Selkirk came to
the conclusion, that, notwithstanding the absence of lunar
tides both in the Baltic and on the west coast of Sweden
near Gothenburg, there is so much fluctuation in the sea-~
level from day to day, owing to the action of the wind and
other causes, that the observations of a casual visitor are
of no real value in determining the average water-level.*
After a review of all that has been said and published on
this subject since the commencement of the present century,
I am inclined to believe, with the pilots, fishermen, and
engineers, that a slow alteration in the relative level of land
and sea is taking place along certain parts of the Swedish
coast. This notion is not merely entertained by the inha- —
bitants of those localities where rivers are carrying down
sediment into the sea, but prevails equally in districts where
the rocks for hundreds of miles plunge abruptly into deep
water. It should be borne in mind, that, except near the
Cattegat, there are no tides in the Gulf of Bothnia. It is
only when particular winds have prevailed for several days
in succession, or at certain seasons when there has been an
unusually abundant influx of river-water, or when these
causes have combined, that this sea is made to rise 2 or 3
feet above its standard level.
There are, moreover, peculiarities in the configuration of
the shore which facilitate, in a remarkable degree, the appre-
ciation of slight changes in the relative level of land and
water. It has often been said, that there are two coasts,
* Lord Selkirk ‘On some ae a-water Level Marks on the Coast of Sweden.’
Quart. Geol. Journ. 1867, p.
Cu. XXXI.] RISE OF LAND IN SWEDEN. 189
an inner and an outer one; the inner being the shore of the
mainland; the outer one, a fringe of countless rocky islands
of all dimensions, called the skir (shair). Boats and small
vessels make their coasting voyages within this skiar; for
here they may sail in smooth water, even when the sea
without is strongly agitated. But the navigation is very
intricate, and the pilot must possess a perfect acquaintance
with the breadth and depth of every narrow channel, and
the position of innumerable sunken rocks. If on such a
coast the land rises 1 or 2 feet in the course of half a
century, the minute topography of the skir is entirely altered.
To a stranger, indeed, who revisits it after an interval of
many years, its general aspect remains the same; but the
inhabitant finds that he can no longer penetrate with his
boat through channels where he formerly passed, and he can
tell of countless other changes in the height and breadth of
isolated rocks, now exposed, but once only seen through the
clear water.
The rocks of gneiss, mica~schist, and quartz are usually
very hard on this coast, slow to decompose, and, when pro-
tected from the breakers, remaining for ages unaltered in
their form. Hence it is easy to mark the stages of their
progressive emergence by the aid of natural and artificial
marks imprinted on them. Besides the summits of fixed
rocks, there are numerous erratic blocks of vast size strewed
over the shoals and islands in the skir, which have been
probably drifted by ice in the manner before suggested.* All
these are observed to have increased in height and dimensions
within the last half-century. Some, which were formerly
known as dangerous sunken rocks, are now only hidden
when the water is highest. On their first appearance, they
usually present a smooth, bare, rounded protuberance, a few
feet or yards in diameter; and a single sea-gull often appro-
priates to itself this resting-place, resorting there to devour
its prey. Similar points, in the meantime, have grown to
long reefs, and are constantly whitened by a multitude of
sea-fowl; while others have been changed from a reef,
* See p. 182 and Chap. XVI. Vol. I.
190 RISE OF LAND IN SWEDEN, [Cu. XXXI.
annually submerged, to a small islet, on which a few lichens,
a fir-seedling, and a few blades of grass, attest that the shoal
has at length been fairly changed into dry land. Thousands
of wooded islands around show the greater alterations which
time can work. In the course of centuries, also, the spaces
intervening between the existing islands may be laid dry, and
become grassy plains encircled by heights well clothed with
lofty firs. This last step of the process, by which long fiords
and narrow channels, once separating wooded islands, are
deserted by the sea, has been exemplified within the memory
of living witnesses on several parts of the coast.
It was admitted on all hands when I visited Sweden, in
1834, that the supposed change in the relative level of sea
and land was by no means going on at a uniform rate, or in
a uniform direction, at all points between the North Cape
and Scania, or the southermost part of Sweden, places
distant from each other more than 1,000 miles. The
rate of upheaval was said to be greatest at the North Cape,
but no accurate scientific proof of this fact has yet been
obtained. At Gefle, 90 miles north of Stockholm, the move-
ment may possibly, as before stated, amount to 2 or 8 feet in
a century, whereas at Stockholm it can hardly exceed 6
inches. 16 miles to the south-west of Stockholm, at
Sddertelje, the land seems to have been quite stationary
during the last century. Proceeding still farther south, the .
upward movement seems to give place to one in an opposite
direction. In proof of this fact, Professor Nilsson has
remarked, in the first place, that there are no elevated beds
of recent marine shells in Scania like those farther to the
north. Secondly, Linnzus, with a view of ascertaining
whether the waters of the Baltic were retiring from the
Scanian shore, measured, in 1749, the distance between the
sea and a large stone near Trelleborg. This same stone
was, in 1836, a hundred feet nearer the water’s edge than
in Linneus’s time, or 87 years before. Thirdly, there is
also a submerged peat moss, consisting of land and fresh-
water plants, beneath the sea at a point to which no peat
could have been drifted down by any river. Fourthly, and
what is still more conclusive, it is found that in seaport
Cu, XXXI.] RISE OF LAND IN SWEDEN, 191
towns, all along the coast of Scania, there are streets below
the high-water level of the Baltic, and in some cases below
the level of the lowest tide. Thus, when the wind is high at
Malmé, the water overflows one of the present streets, and
some years ago some excavations showed an ancient street
in the same place 8 feet lower, and it was then seen that
there had been an artificial raising of the ground, doubtless
in consequence of that subsidence. There is also a street at
Trelleborg, and another at Skanér, a few inches below high-
water mark, and a street at Ystad is exactly on a level with
the sea, at which it could not have been originally built.
When we cross from the Gulf of Bothnia to the coast
north of Gothenburg, we find that the opinion still prevails
there, as it did in the days of Celsius, among the fishing and
seafaring inhabitants, that there is a slow sinking of the sea
going on; so. that rocks, both on the shore of the main-
land and in the islands, are more and more exposed to view.
If this conclusion be confirmed by future observation, the
breadth of the tract from WNW. to ESE., which is rising,
must exceed 200 geographical miles, without including the
bed of the two seas adjacent to the coasts.
Hitherto we have confined our attention almost exclusively
to changes of level in historical times; but we may next
enquire what geological proofs exist of the sojourn of the
Sea on the land, at a very modern period, in those parts of
Sweden where there is ground for suspecting that a move-
ment of elevation is in progress.
In this case, the evidence is most satisfactory. Near
Uddevalla and the neighbouring coastland, we find upraised
deposits of shells belonging to species such as now live in
the ocean ; while on the opposite or eastern side of Sweden,
near peokholm, Gefle, and other places bordering the
Bothnian Gulf, there are analogous beds containing ahalle of
species characteristic of the Baltic.
Von Buch announced in 1807, that he had discovered in
Norway and at Uddevalla in Sweden, beds of shells of
existing species, at considerable heights above the sea.
Since that time, other naturalists have confirmed his ob-
servation; and, according to Torell, deposits occur at
192 RISE OF LAND IN SWEDEN. [Cu. XXXI.
elevations of 600 and even 700 feet above the sea in some
parts of Norway. M. Alex. Brongniart, when he visited
Uddevalla, ascertained that one of the principal masses of
shells, that of Capellbacken, is raised more than 200 feet
above the sea, resting on rocks of gneiss, all the species being
identical with those now inhabiting the contiguous ocean.
The same naturalist also stated, that on examining with care
the surface of the gneiss, immediately above the ancient
shelly deposit, he found barnacles (balani) adhering to the
rocks, showing that the sea had remained there for a long
time. I was fortunate enough to be able to verify this
observation by finding in the summer of 1834, at Kured,
about 2 miles north of Uddevalla, and at the height of more
than 100 feet above the sea, a surface of gneiss newly laid
open by the partial removal of a mass of shells used largely
in the district for making lime and repairing the roads. So
firmly did these barnacles adhere to the gneiss, that I was
able to break off portions of the rock with the shells attached.
The face of the gneiss was also encrusted with bryozoa; but
had these or the barnacles been exposed in the atmosphere
ever since the elevation of the rocks above the sea, they
would doubtless have decomposed and been obliterated.
The town of Uddevalla (see Map, p. 184) stands at the
head of a narrow creek overhung by steep and barren rocks
of gneiss, of which all the adjacent country is composed,
except in the low grounds and bottoms of valleys, where
strata of sand, clay, and marl frequently hide the funda-
mental rocks. To these newer and horizontal deposits, some-
times 40 feet thick, the fossil shells above mentioned belong,
and similar marine remains are found at about the same
height above the sea on the opposite island of Orust, as well
as in that of Tjérn, and at points near the coast still farther
south.
Mr. J. Gwyn Jeffreys visited Uddevalla in 1862, and collected
from the beds there 83 species of mollusca, characteristic of
the Glacial Period. He also obtained evidence that a littoral
and shallow-water deposit underlaid the shells proper to
deeper water; a fact clearly implying a depression of the bed
of the sea previous to that upheaval which has since carried
seieaeiniaiall
Cu, XXXI.J RISE OF LAND IN SWEDEN. 1938
up the land where the marine shells are found, to the height
of more than 200 feet.* As to the date of this last upheaval,
Mr. Torell has shown that it by no means reaches back to the
Glacial Period, to which the shells above alluded to belong.
Those shells, so characteristic of a cold climate, are specifi-
cally identical with mollusca now living in the seas of Spitz-
bergen, 10 degrees of latitude north of Uddevalla. But in
some recent deposits near Uddevalla, Mr. Torell detected,
at the height of 200 feet above the sea, the remains of
marine testacea, agreeing with species now proper to the
fauna of the adjacent and more temperate sea.t It appears,
therefore, that the series of movements in the district under
consideration consisted, first, of a depression converting the
shallow water into deep sea at a time when the cold was very
severe, and then of an elevation of more than 200 feet when
the waters of the sea had acquired their present milder
temperature.
To return now to the coast of the Baltic. I observed
near the shores of the Gulf of Bothnia, at Sddertelje, 16
miles SW. of Stockholm, strata of sand, clay, and marl,
more than 100 feet high, and containing shells of species now
inhabiting the gulf. These consist partly of marine- and
partly of freshwater species; but they are few in number,
the brackishness of the water appearing to be very unfavour-
able to the development of testacea. The most abundant
species are the common cockle and the common mussel and
periwinkle of our shores (Cardium edule, Mytilus edulis, and
Inttorina littorea), together with a small telling (T. Baltica,
L.; T. solidula, Pult.), and a few minute univalves allied to
Paludina ulva. These live in the same water as a, Lymneus,
a Neritina (N. fluviatilis), and some other freshwater shells.
But the marine mollusks of the Baltic above mentioned,
although very numerous in individuals, are dwarfish in size,
scarcely ever attaining a third of the average dimensions
which they acquire in the salter waters of the ocean. By
this character alone a geologist would generally be able to
* Gwyn Jeffrey's Report to Brit. to
Assoc. 1863, p. 73 j
Molluscous Fauna of Spitzbergen.
»p. 73. 59.
~ Torell, Beitrige, &e. Contributions
Ov
VOL. II. 0
194 RISE OF LAND IN SWEDEN. [Cu XXXI,
recognise at once an assemblage of Baltic fossils as distin-
guished from those derived from a deposit inthe ocean. The
absence also of oysters, barnacles, whelks, scallops, limpets
(ostrea, balanus, buccinum, pecten, patella),and many other forms
abounding alike in the sea near Uddevalla, and in the fos-
siliferous deposits of modern date on that coast, supplies an
additional negative character of the greatest value, distin-
guishing assemblages of Baltic from those of oceanic shells.
Now the strata containing Baltic shells are found in many
localities near Stockholm, Upsala, and Gefle, and will pro-
bably be discovered everywhere around the borders of the
Bothnian Gulf; for I have seen similar remains brought
from Finland, in marl resembling that found near Stockholm.
The utmost distance to which these deposits had been traced
inland in 1835 was on the southern shores of Lake Maeler,
at a place 70 miles from the sea, but they have since been
traced by Erdmann to Linde, at the head of a lake of that
name, to a distance of 130 miles west of Stockholm, and to a
height of about 230 feet above the sea. Hence it appears, from
the distinct assemblage of fossil shells found on the eastern
and western coasts of Sweden, that the Baltic has been for a
long period separated as now from the ocean, although the
intervening tract of land was once much narrower, even
after both seas had become inhabited by all the existing
species of testacea.
Whether any of the land in Norway is now rising, must
be determined by future investigations. Marine fossil shells, .
of recent species, have been collected from inland places
near Drontheim; but Mr. Everest, in his ‘Travels through
Norway,’ informs us that the small island of Munkholm,
which is an insulated rock in the harbour of Drontheim,
affords conclusive evidence of the land having in that region
remained stationary for the last 8 centuries. The area of
this isle does not exceed that of a small village; and by an
official survey, its highest point has been determined to be
93 feet above the mean high-water mark, that is, the mean
between neap and spring tides. Now, a monastery was
founded there by Canute the Great, A.D. 1028, and 33 years
before that time it was in use as a common place of execution.
Cu, XXXL] RISE OF LAND IN NORWAY. 195
According to the assumed average rate of rise in Sweden
(about 40 inches in a century), we should be obliged to
suppose that this island had been 8 feet 8 inches below high-
water mark when it was originally chosen as the site of the
monastery.
Professor Keilhau of Christiania, after collecting the ob-
servations of his predecessors respecting former changes of
level in Norway, and combining them with his own, has
made the fact of a general change of level at some unknown
but, geologically speaking, modern period (that is to say,
within the period of the actual testaceous fauna), very
evident. He infers that the whole country from Cape Lin-
desnees to Cape North, and beyond that as far as the fortress
of Vardhuus, has been gradually upraised, and on the south-
east coast the elevation has amounted to more than 600 feet.
The marks which denote the ancient coast-lines are so
nearly horizontal, that the deviation from horizontality,
although the measurements have been made ata ereat
number of points, is too small to be appreciated.
Morerecently (1844), however, it appears from the researches
of M. Bravais, member of the French scientific commission
have undergone
a greater amount of upheaval in proportion as we advance
inland.*
The different heights at which horizontal raised beaches
containing recent shells have been observed along the western
and northern coasts of Norway, have been Supposed to prove
the suddenness of the upheaval of the land at successive
periods ; but when truly interpreted, these appearances prove
rather that the elevatory force has been intermittent in its
action, and that there have been long pauses in the process
* Quarterly Journ. of Geol. Soe. No. 4,
M. Brayais’ observations were
verified in 1849 by Mr. R. Chambers in
his ‘ Tracings of N. of Europe,’ p. 208.
oO 2
196 SUBSIDENCE IN PART OF GREENLAND. [Cu. XXXI.
of upheaval. They mark eras at which the level of the sea
has remained stationary for ages, and during which new
strata were deposited near or on the shore in some places,
while in others the waves and currents had time to hollow
out rocks, undermine cliffs, and throw up long ranges of
shingle. They undoubtedly show that the movement has
not been always uniform or continuous, but they do not
establish the fact of any sudden alterations of level.
Subsidence in part of Greenland.—The rise of Scandinavia
has naturally been regarded as a very singular and scarcely
credible phenomenon, because no region on the globe has
been more free within the times of authentic history from
violent earthquakes. In common, indeed, with our own
island and with almost every spot on the globe, some move-
ments have been, at different periods, experienced, both in
Norway and Sweden. But some of these, as for example
during the Lisbon earthquake in 1755, may have been mere
vibrations or undulatory movements of the earth’s crust
prolonged from a great distance. Others, however, have
been sufficiently local to indicate a source of disturbance
immediately under the country itself. Notwithstanding
these shocks, Scandinavia has, upon the whole, been as
tranquil in modern times, and as free from subterranean
convulsions, as any region of equal extent on the globe.
The same may be said of another large area in Greenland,
which in modern times has been undergoing a slow and
insensible movement, but in an opposite direction. Two
Danish investigators, Dr. Pingel and Captain Graah, have
brought to light abundant evidence of the sinking down 0
part of the west coast of Greenland, for a space of more than
600 miles from north to south. The observations of Captain
Graah were made during a survey of Greenland in 1823-24;
and afterwards in 1828-29; those by Dr. Pingel were made
in 1830-32. It appears from various signs and traditions,
that the coast has been subsiding for the last 4 centuries
from the firth called Igaliko, in lat. 60° 43’ N., to Disco
Bay, extending to nearly the 69th degree of north latitude.
Ancient buildings on low rocky islands and on the shore of
the mainland have been gradually submerged, and experience
Cu, XXXI.] CHANGES OF LEVEL, HOW CAUSED. lve
has taught the aboriginal Greenlander never to build his hut
near the water’s edge. In one case the Moravian settlers
have been obliged more than once to move inland the poles
upon which their large boats were set, and the old poles
still remain beneath the water as silent witnesses of the
change.*
The fact of the gradual elevation and depression of land
throughout vast areas of Europe and Arctic America, which
we have considered in this chapter, partly in the historical
period and partly in geological times immediately antecedent
lead us naturally to speculate on the wonderful changes
which must be continually in progress in the subterranean
foundations of these same countries. Whether we ascribe
these changes to the expansion of solid matter exposed to
hydrothermal action, or to the melting of rock, or the solidi-
fication of mineral masses, in whatever conjectures we indulge,
we cannot doubt that at some unknown depths the structure
of the crust of our globe is a undergoing very im-
portant modifications.
* See Proceedings of Geol. Soe. No. Pingel on the subject at Copenhagen in
42, p. 208. I also conversed with Dr.
CHAPTER XXXII.
CAUSES OF EARTHQUAKES AND VOLCANOES.
INTIMATE CONNECTION BETWEEN THE CAUSES OF VOLCANOS AND EARTH-
QUAKES—SUPPOSED ORIGINAL STATE OF FUSION OF THE PLANET—ITS SIMUL-
DEPTH, BUT NOT UALLY — NO INTERNAL TID EF SUPPOSED CENTRAL
FLUID PERCEPTIBLE—-SUPPOS HANGE OF AXIS OF EARTH'S CRUST —PARTIAL
FLUIDITY THE EARTH'S CRUST MOST CONSISTENT WITH VOLCANIC PHE-
NOMENA OF THE PAST AND PRESENT—-ABANDONMENT OF THE DATA BY WHICH
THE EARLIER GEOLOGISTS SUPPORTED THEIR THEORY OF THE PRISTINE
FLUIDITY OF THE EARTH’S CRUST—DOCTRINE OF A CONTINUAL DIMINUTION
OF TERRESTRIAL AND SOLAR HEAT CONSIDERED.
Ir will hardly be questioned, after the description before
given of the phenomena of earthquakes and volcanos, that
both of these agents have, to a certain extent, a common
origin; and I may now, therefore, proceed to enquire into
their probable causes. But, first, it may be well to re-
capitulate some of those points of relation and analogy which
lead naturally to the conclusion that they spring from a
common source.
The regions convulsed by violent earthquakes include
within them the site of all the active voleanos. Harth-
quakes, sometimes local, sometimes extending over vast
areas, often precede volcanic eruptions. The subterranean
movement and the eruption return again and again, at ir-
regular intervals of time, and with unequal degrees of force,
to the same spots. The action of either may continue for a
few hours, or for several consecutive years. Paroxysmal
convulsions are usually followed, in both cases, by long
periods of tranquillity. Thermal and mineral springs are
abundant in countries of earthquakes and active volcanos.
Lastly, springs situated in districts considerably distant
Cu. XXXII.] SUPPOSED CENTRAL FLUIDITY OF THE EARTH. 199
from voleanic vents have been observed to have their tem-
perature suddenly raised or lowered, and the volume of their
water increased or lessened, by subterranean movements.
All these appearances are evidently more or less connected
with the passage of heat from the interior of the earth to
the surface; and where there are active volcanos, there
must exist, at some unknown depth below, enormous masses
of matter intensely heated, and, in many instances, in a
constant state of fusion. We have first, then, to enquire,
whence is this heat derived ?
Supposed central fiwidity of the earth.—It has long been
a favourite conjecture, that the whole of our planet was
originally in a state of igneous fusion, and that the central
parts still retain a great portion of their primitive heat.
Some have imagined, with the late Sir W. Herschel, that the
elementary matter of the earth may have been first in a
gaseous state, resembling those nebule which we behold in
the heavens, and which are of dimensions so vast, that some
of them would fill the orbits of the remotest planets of our
system. ‘The increased power of the telescope has of late
years resolved the greater number of these nebulous ap-
pearances into clusters of stars; but so long as they were
confidently supposed to consist of aériform matter, it was a
favourite conjecture that they might, if concentrated, form
solid spheres; and it was also imagined that the evolution
of heat, attendant on condensation, might retain the ma-
terials of the new globes in a state of igneous fusion.
Without dwelling on such speculations, which can only
have a distant bearing on geology, we may consider how far
the spheroidal form of the earth affords sufficient ground
for presuming that its primitive condition was one of universal
fluidity. The discussion of this question would be superfluous,
were the doctrine of original fluidity less popular; for it
may well be asked, why the globe should be supposed to
have had a pristine shape different from the present one ?—
why the terrestrial materials, when first called into existence,
or assembled together in one place, should not have been
subject to rotation, so as to assume at once that form
200 SPHEROIDAL FORM OF THE EARTH. (Cu. XXXIT,
which alone could retain their several parts in a state of
equilibrium ?
Let us, however, concede that the statical figure may be
a modification of some other pre-existing form, and suppose
the globe to have been at first a perfect and quiescent
sphere, covered with a uniform ocean—what would happen
when it was made to turn round on its axis with its present
velocity 2? This problem has been considered by Playfair
in his Illustrations; and he has decided, that if the surface
of the earth, as laid down in Hutton’s theory, has been
repeatedly changed by the transportation of the detritus of
the land to the bottom of the sea, the figure of the planet
must in that case, whatever it may have been originally,
be brought at length to coincide with the spheroid of equi-
librium.* Sir John Herschel also, in reference to the same
hypothesis, observes, ‘A centrifugal force would in that case
be generated, whose general tendency would be to urge the
water at every point of the surface to recede from the amis.
A rotation might indeed be conceived so swift as to flirt the
whole ocean from the surface, like water from a mop. But
this would require a far greater velocity than what we now
speak of. In the case supposed, the weight of the water
would still keep it on the earth; and the tendency to recede
from the axis could only be satisfied therefore by the water
leaving the poles, and flowing towards the equator; there
heaping itself up in a ridge, and being retained in opposition
to its weight or natural tendency towards the centre by the
pressure thus caused. This, however, could not take place
without laying dry the polar regions, so that protuberant
land would appear at the poles, and a zone of ocean be
disposed around the equator. This would be the first or
immediate effect. Let us now see what would afterwards
happen if things were allowed to take their natural course.
‘The sea is constantly beating on the land, grinding it
down, and scattering its worn-off particles and fragments,
in the state of sand and pebbles, over its bed. Geological
facts afford abundant proof that the existing continents have
* Tlust. of Hutt. Theory, § 485—443.
AIR
Cu. XXXII.] SPHEROIDAL FORM OF THE EARTH. 201
all of them undergone this process even more than once,
and been entirely torn in fragments, or reduced to powder,
and submerged and reconstructed. Land, in this view of
the subject, loses its attribute of fixity. As a mass, it might
hold together in opposition to forces which the water freely
obeys ; but in its state of successive or simultaneous degra-
dation, when disseminated through the water, in the state
of sand or mud, it is subject to all the impulses of that fluid.
In the lapse of time, then, the protuberant land would be
destroyed, and spread over the bottom of the ocean, filling
up the lower parts, and tending continually to remodel the
surface of the solid nucleus, in correspondence with the
form of equilibrium. Thus, after a sufficient lapse of time, in
the case of an earth in rotation, the polar protuberances
would gradually be cut down and disappear, being trans-
ferred to the equator (as being then the deepest sea), till the
earth would assume by degrees the form we observe it to
have—that of a flattened or oblate ellipsoid.
‘We are far from meaning here to trace the process by
which the earth really assumed its actual form; all we intend
is to show that this is the form to which, under a condition
of a rotation on its axis, it must tend, and which it would
attain even if originally and (so to speak) perversely consti-
tuted otherwise.’ *
Although in the above passage no mention is made of
rivers, yet it must be understood that they would play a
leading part in the degradation of the polar land under the
condition above assumed. Sir J. Herschel has also confined
his observations to the effects of aqueous causes only ; neither
he nor Playfair seem to have followed out the same enquiry
with reference to another part of Hutton’s system ; namely,
that which assumes the successive fusion by heat of different
parts of the solid earth. Yet the progress of geology has
continually strengthened the evidence in favour of the doctrine
that local variations of temperature have melted one part after
another of the earth’s crust, and this influence has perhaps
extended downwards to the very centre. — If, therefore, before
* Herschel’s Astronomy, chap. iii.
202 DENSITY OF THE EARTH. [Cu. XXXII.
the globe had assumed its present form, it was made to revolve
on its axis, all matter to which freedom of motion was given
by fusion, must before consolidating have been impelled
towards the equatorial regions in obedience to the centrifugal
force. Thus, lava flowing out in superficial streams would
have its motion retarded when its direction was towards the
pole, accelerated when towards the equator, or if lakes and
seas of lava existed beneath the earth’s crust in equatorial
regions, as probably now beneath the Peruvian Andes, the
imprisoned fluid would force outwards and permanently
upheave the overlying rocks. The statical figure, therefore,
of the terrestrial spheroid (of which the longest diameter
exceeds the shortest by about twenty-five miles), may have
been the result of gradual and even of existing causes, and
not of a primitive, universal, and simultaneous fluidity.*
Experiments made with the pendulum, and observations
on the manner in which the earth attracts the moon, have
shown that our planet is not an empty sphere, but, on the
contrary, that its interior, whether solid or fluid, has a higher
specific gravity than the exterior. It has also been inferred
from certain inequalities in the moon’s motion, that there is
a regular increase in density from the surface towards the
centre, and that the equatorial protuberance is continued
inwards; that is to say, that layers of equal density are
arranged elliptically, and symmetrically, from the exterior to
the centre.
The mean density of the earth has been computed by
Laplace to be about 54, or more than 5 times that of water.
Now the specific gravity of many of our rocks is from 24 to
3, and the greater part of the metals range between that
density and 21. Hence some have imagined that the terres-
trial nucleus may be metallic—that it may correspond, for
example, with the specific gravity of iron, which is about 7.
But here a curious question arises in regard to the form
which materials, whether fluid or solid, might assume, if
subjected to the enormous pressure which must obtain at the
earth’s centre. Water, if it continued to decrease in volume
See Hennessy, On Changes in Dublin, 1849; and Proc. Roy. Irish
Earth’s Figure, &c. Journ. Geol. Soc. Acad. vol. iv. p. 337.
Cu. XXXIT.] THICKNESS OF EARTH’S CRUST. 208
according to the rate of compressibility deduced from experi-
ment, would have its density doubled at the depth of 93 miles,
and be as heavy as mercury at the depth of 362 miles. Dr.
Young computed that, at the earth’s centre, steel would be
compressed into one-fourth, and stone into one-eighth of its
bulk.* It is more than probable, however, that after a
certain degree of condensation, the compressibility of bodies
may be governed by laws altogether different from those
which we can put to the test of experiment; but the limit is
still undetermined, and the subject is involved in such ob-
scurity, that we cannot wonder at the variety of notions
which have been entertained respecting the nature and con-
ditions of the central nucleus. Some have conceived it to be
fluid, others solid; some have imagined it to have a cavernous
structure, and have even endeavoured to confirm this opinion
by appealing to observed irregularities in the vibrations of
the pendulum in certain countries.
An attempt has been made by Mr. Hopkins to determine
the least thickness which can be assigned to the solid crust
of the globe, if we assume the whole to have been once
perfectly fluid, and a certain portion of the exterior to have
acquired solidity by gradual refrigeration. This result he
has endeavoured to obtain by a new solution of the delicate
problem of the precessional motion of the pole of the earth,
caused, as before mentioned, p. 274, Vol. I., by the attraction
of the sun and moon, and principally the moon, on the
protuberant parts at the earth’s equator; for if these parts
were solid to a great depth, the motion thus produced would
differ considerably from that which would exist if they were
perfectly fluid, and incrusted over with a thin shell only a
few miles thick. In other words, the disturbing action of
the moon will not be the same upon a globe all solid and
upon one nearly all fluid, or it will not be the same upon a
globe in which the solid shell forms one-half of the mass,
and another in which it forms only one-tenth.
Mr. Hopkins has, therefore, calculated the amount of
precessional motion which would result if we assume the
* 5 eee ? ole : ; :
aie! s Lectures, and Mrs. Somerville’s Connection of the Physical Sciences,
204 RATE OF HEAT INCREASING WITH DEPTH. [Cu. XXXII.
earth to be constituted as above stated; 7.¢. fluid internally,
and enveloped by a solid shell; and he finds that the amount
will not agree with the observed motion, unless the crust of
the earth be of a certain thickness. In calculating the exact
amount, some ambiguity arises in consequence of our ignorance
of the effect. of pressure in promoting the solidification of
matter at high temperatures. ‘The hypothesis least favourable
for a great thickness is found to be that which assumes the
pressure to produce no effect on the process of solidification.
Even on this extreme assumption, the thickness of the solid
crust must be nearly four hundred miles, and this would lead
to the remarkable result that the proportion of the solid to
the fluid part would be as 49 to 51, or, to speak in round
numbers, there would be nearly as much solid as fluid matter
in the globe. The conclusion, however, which Mr. Hopkins
announces as that to which his researches have finally con-
ducted him, is thus expressed: ‘Upon the whole, then, we
may venture to assert that the minimum thickness of the
crust of the globe, which can be deemed consistent with the
observed amount of precession, cannot be less than one-fourth
or one-fifth of the earth’s radius ;’ that is, from 800 to 1,000
miles.*
It will be remarked, that this is a minimum, and any still
greater amount would be quite consistent with the actual
phenomena; the calculations not being opposed to the sup-
position of the general solidity of the entire globe. Nor do
they preclude us from imagining that great lakes and seas of
melted matter may be distributed through a shell 400 or 800
miles thick, provided they be so inclosed as to move with it,
whatever motion of rotation may be communicated by the
disturbing forces of the sun and moon.
Rate of heat increasing with depth.—The hypothesis of
internal fluidity calls for the more attentive consideration,
as it has been found that the heat in mines augments in pro-
portion as we descend. Observations have been made, not
only on the temperature of the air in mines, but on that of
* Phil. Trans. 1839, and Researches Phenomena and Theory of Volcanos,
in Physic: il Geology, Ist, 2nd, and 8rd__— Report Brit, Assoc. 1847.
series, London, 18839—1842; also on
eeeeeeeeeeeseeer tae a
Cu. XXXII.] THEORY OF CENTRAL HEAT. 205
the rocks, and on the water issuing from them. The mean
rate of increase, calculated from the most careful experiments
yet made in 2 shafts, one near Durham, and another near
Manchester, each of them 2,000 feet deep, is 1° Fahrenheit
for every increase of depth of from 65 to 70 feet, a rate of
increase considerably less than that previously deduced from
coal-mines in the same districts.* This rate, however, agrees
very nearly with previous observations made in several of
the principal lead and silver mines in Saxony, which gave
1° Fahr. for every 65 feet. In this case, the bulb of the
thermometer was introduced into cavities purposely cut in
the solid rock at depths varying from 200 to about 900
feet. But in other mines of the same country, it was
necessary to descend thrice as far for each degree of tem-
perature.t
A thermometer was fixed in the rock of the Dolcoath
mine, in Cornwall, by Mr. Fox, at the great depth of 1,380
feet, and frequently observed during 18 months; the mean
temperature was 68° Fahr., that of the surface being 50°,
which gives 1° for every 75 feet.
Kupffer, after an extensive comparison of the results in
different countries, makes the increase 1° Fahr. for about
every 37 English feet.t M. Cordier announces, as the result
of his experiments and observations on the temperature of
the interior of the earth, that the heat increases rapidly with
the depth; but the increase does not follow the same law
over the whole earth, being twice or three times as much in
one country as in another, and these differences are not in
constant relation either with the latitudes or longitudes of
places. He is of opinion, however, that the increase would
not be overstated at 1° Cent. for every 25 métres, or about
1° Fahr. for every 45 feet.§ The experimental well bored at
Grenelle, near Paris, gave, as before stated (Vol. I. p- 390), an
increase of about 1° Fahr. for every 60 Hinglish feet to the
depth of 1,800 feet.
* These oe were made by i alle of the Interior of the
Professor Phi ilips. Earth, June, 1827. Mém. de Il’'Instit.
tT Cordier, Mém. de I’Instit. tom. vil. tom. vil., and Edin. New Phil. Journal,
Pog. Ann. tom. xv. p. 159. No, viii. p. 27
§ See M. Cordier’s Memoir on the
206 THEORY OF CENTRAL HEAT. (Cu. XXXII,
At Naples, according to Mr. Mallet, the water in the Artesian
well at the Royal Palace, at the depth of 1,460 feet, hag a
temperature of only 68° Fahr., which, deducting for the
mean temperature of the surface soil, 61° Fahr., gives an
increment of only 1° Fahr. for every 208 feet in depth.
Another well in the same city, only a mile distant from the
former and 909 feet deep, gives 1° Fahr. for 88 feet in depth.
It is conjectured that the low temperature of the well first
mentioned may be due to the cooling influence both of fresh
and sea water which may be filtered through porous beds of
tufa.
Some writers have endeavoured to refer these phenomena
(which, however discordant as to the ratio of increasing heat,
appear all to point one way) to the condensation of air con-
stantly descending from the surface into the mines. For the
air under pressure would give out latent heat, on the same
principle as it becomes colder when rarefied in the higher
regions of the atmosphere. But, besides that the quantity
of heat is greater than could be supposed to flow from this
source, the argument has been answered in a satisfactory
manner by Mr. Fox, who has shown, that in the mines of
Cornwall the ascending have generally a higher temperature
than the descending aérial currents. The difference between
them was found to vary from 9° to 17° Fahr.: a proof that,
instead of imparting heat, these currents actually carry off a
large quantity from the mines.*
If we adopt the mean increase of 1° Fahr. for every 65 feet
of depth, and assume, with the advocates of central fluidity,
that the increasing temperature is continued downwards for
an indefinite distance, we should reach the ordinary boiling
point of water at rather more than 2 miles below the surface,
and at the depth of about 34 miles should arrive at the
melting point of iron, or 2,786° Fahr. according to Daniell’s
pyrometer, a heat sufficient to fuse almost every known sub-
stance. In the diagram, fig. 128, p. 212, the outer circular
line represents a thickness of 25 miles, and the space between
the 2 circles, together with the lines themselves, represents a
crust of 200 miles in depth. If, therefore, the heat went on
* Phil. Mag. and Ann. Feb. 1830.
Ne ——————
ne
Cu. XXXIT.] THEORY OF CENTRAL HEAT. 207
increasing at the rate above alluded to, we should encounter
not far below the outer line a temperature many times
ereater than that sufficient to melt the most refractory sub-
stances known to us. At much greater depths, and long
before approaching the central nucleus, the heat would be so
intense (160 times that of melted iron), that we cannot con-
ceive the external crust to resist fusion.*
It may be said that we may stand upon the hardened sur-
face of a lava current while it is still in motion—nay, may
descend into the crater of Vesuvius after an eruption, and
stand on the scoriz while every crevice shows that the rock
is red-hot 2 or 3 feet below us; and at a somewhat greater
depth, all is, perhaps, in a state of fusion. May not, then,
a much more intense heat be expected at the depth of several
hundred yards or miles? The answer is,—that, until a
great quantity of heat has been given off, either by the
emission of lava, or in a latent form by the evolution of
steam and gas, the melted matter continues to boil in the
crater of a volcano. But ebullition ceases when there is no
longer a sufficient supply of heat from below, and then a
crust of lava may form on the top, and showers of scoriz
may then descend upon the surface, and remain unmelted.
If the internal heat be raised again, ebullition will recom-
mence, and soon fuse the superficial crust. So in the cage
of the moving current, we may safely assume that no part of
the liquid beneath the hardened surface is much above the
temperature sufficient to retain it in a state of fluidity.
M. Poisson, in his Mathematical Theory of Heat, published
in 1835, controverted the doctrine of the high temperature of
a central nucleus, and declared his opinion that if the globe
had ever passed from a liquid to a solid state in consequence
of the loss of heat by radiation, the cooling and consolidation
of the nucleus would have begun at the earth’s centre.
The expansion of platinum was the
. other test yet invented for measuring
test employed by Mr. Daniell, in his
Pyrometer, which was found to yield
. But Dr. Perey
informs me that neither this nor any
intense heat, can be fully depended upon.
Malleable iron, he remarks i
iron, in which the metal is mixed with a
small percentage of carbon.
908 SUPPOSED CHANGE OF AXIS OF EARTH’S CRUST. [Cu. Xxxqt.
No internal tides.—Many of the advocates of central fluidity
have admitted that there must be tides in the internal ocean;
but their effect, says Cordier, has become feeble, although
originally, when the fluidity of the globe was perfect, ‘the
rise and fall of these ancient land tides could not have been
less than from 13 to 16 feet.’ Now, granting for a moment
that these tides have become so feeble as to be incapable of
causing the fissured shell of the earth to be first uplifted and
then depressed every 6 hours, still may we not ask whether,
in every voleano during an eruption, the lava, which is sup-
posed to communicate with a great central ocean, would not
rise and fall sensibly, or whether, in a crater like Stromboli,
where there is always melted matter in a state of ebullition,
the ebbing and flowing of the liquid would not be constant?
Supposed change of awis of earth’s crust.—I alluded in
Chapter XIII. to an ingenious paper,* replete with specula-
tions of no ordinary interest, by Mr. Evans, in which he
suggested that former changes of climate on the surface
might be connected with the shding of a solid shell over an
internal fluid nucleus. Granting for the moment the fluidity,
the equilibrium of the external shell might, no doubt, be
disturbed by the transfer of the sediment from one part of
the surface to another, or by the upheaval of new continents
and islands; and Mr. Evans shows that, whenever matter is
abstracted from one part and added to another, the centri-
fugal force of the augmented extraneous matter would tend
to draw over the shell towards the equator, or an opposite
effect would be produced if the surface was relieved of part
of its weight, in which case the lighter part would move
towards the pole.
Newton, and afterwards Laplace, had argued against the
probability of a shifting of the earth’s axis of rotation, and
more recently Mr. Airy had among other arguments pointed
out that the elevation of mountain chains at certain geolo-
gical periods, which had been proposed as causing an altera-
tion in the earth’s centre of gravity, was an insignificant
cause, since the size of such mountain masses was very
minute when compared to the equatorial protuberance,
* T. Evans, Royal Society Proceedings, 1866.
Cu. XXXII.] PARTIAL FLUIDITY OF EARTH'S CRUST. 209
which he says is a mass of matter 25,000 miles’ long,
6,000 miles broad, and 13 miles deep. But Mr. Evans
suggests that the axis of rotation of the nucleus might
remain unchanged, while a solid shell not more, perhaps,
than 25 miles in thickness might have its axis of rotation
altered. To this hypothesis there are several objections :—
First, in all geological times, the transfer of sediment hag
been taking place not only from higher to lower latitudes,
but also from lower to higher. There is the like tendency in
the various elevations and depressions of land simultane-
ously in progress to balance each other. It is only the
excess of alteration in one direction that can be available as
a disturbing cause, and we can hardly imagine this excess
to be important enough to cause a sensible change in the
axis of rotation even of the external shell, such as might
explain the altered climate of the same country in successive
geological periods.
Secondly, a greater difficulty arises out of the fact that
the earth is a spheroid and not a perfect sphere, since it
becomes necessary to imagine the fluidity of the nucleus to
be so perfect as to allow the shell to slide freely over it. If
the lower or inner surface of the envelope be irregular in
shape, or if it be even viscous in part, great resistance
would be offered to any change in its position. Its freedom
of motion would be checked by its not fitting the nucleus,
let its change of position be ever so slight, and this change
could only be effected by the most violent friction, attended
by the bending and rending of the incumbent mass.
Partial flwidity of the earth’s crust most consistent with
volcanic phenomena.—It must not be forgotten that the
geological speculations still in vogue respecting the original
fluidity of the planet, and the gradual consolidation of
its external shell, belong to a period when theoretical ideas
were entertained ag to the relative age of the crystalline
foundations of that shell wholly at variance with the present
state of our knowledge. It was formerly imagined that all
granite was of very high antiquity, and that rocks such as
snelss, mica-schist, and clay slate, were also anterior in date
to the existence of organic beings on a habitable surface. It
VOL. It. Pp
210 ‘THE EARTH'S CENTRAL FLUIDITY QUESTIONED. [Cu. XXXII-
was, moreover, supposed that these primitive formations, as
they were called, implied a continual thickening of the crust
at the expense of the original fluid nucleus. These notions
have been universally abandoned. It is now ascertained
that the granites of different regions are by no means all of
the same antiquity, and that it is hardly possible to prove any
one of them to be as old as the oldest known fossil organic
remains. It is likewise now admitted, that gneiss and other
stratified crystalline strata are sedimentary deposits which
have undergone metamorphic action, and they can almost
all be demonstrated to be newer than the lately discovered
fossil called Eozoon Canadense. It follows from such views,
which are of comparatively modern date, that instead of
these crystalline rocks, which are often of enormous volume,
implying a constant thickening of the earth’s crust from
the remotest periods, they most of them bear testimony to
aqueous denudation on a vast scale, or, in other words, they
bespeak the removal of just as much solid matter from one part
of the earth’s circumference as has been contemporaneously
accumulated in the shape of new strata in some other part.
It was, moreover, taken for granted by the earlier theorists,
without any sufficient geological proof, that the energy of
the voleanic force was far more intense in the remoter
periods of the earth’s history than in the later. No adequate
conception had been formed of the great lapse of time occu-
pied in the elaboration of each of the principal groups of
the primary, secondary, and tertiary fossiliferous rocks, and
of the gradual manner in which contemporaneous volcanic
products were locally developed during each of those periods.
The limited areas to which the volcanic outbursts were
confined at any one epoch, the Cretaceous for example, 1s
proved by the general absence in strata of the same age of
associated igneous formations. It can be demonstrated that
the volcanic power was by no means dormant. but it was
locally developed. There are wide tracts in North America
and Russia where very ancient strata, such as the Silurian and
Carboniferous, are horizontal and undisturbed, and wholly de-
void of contemporaneous igneous products, showing that such
areas were not only free from volcanic action in paleozoic
ee
Cu. XXXII.] THE EARTH’S CENTRAL FLUIDITY QUESTIONED. rE
times, but that they have never been the theatres of such
action at any subsequent epoch. On the other hand, we
often find that regions where showers of voleanic ashes and
the intrusion of igneous matter into fissures were once most
frequent, are now entirely free from volcanic disturbance.
The continual transfer, therefore, of the points of chief
development of the earthquake and volcano from one part
of the earth’s crust to another, is established as a general
law by the clearest geological evidence. We have also seen
(Chapter XXIII.) that voleanic operations are now in progress
on the grandest scale, and also that single currents of lava of
modern date are as voluminous as any which can be shown
to have ever poured out in the earliest eras to which our
geological retrospect can be carried.
The doctrine, therefore, of the pristine fluidity of the interior
of the earth, and the gradual solidification of its crust con-
sequent on the loss of internal heat by radiation into space,
is one of many scientific hypotheses, which has been adhered
to after the props by which it was at first supported have given
way one afterthe other. Theastronomer may find good reasons
for ascribing the earth’s form to the original fluidity of the
mass intimes long antecedent tothe first introduction of living
beings into the planet ; but the geologist must be content to
regard the earliest monuments which it is his task to inter-
pret as belonging to a period when the crust had already
acquired great solidity and thickness, probably as great as
it now possesses, and when volcanic rocks not essentially dif-
fering from those now produced were formed from time to
time, the intensity of volcanic heat being neither greater
nor less than it is nowe This heat has, no doubt, eiven rise
at successive periods to many of the leading changes in the
form and structure of the earth’s crust; but their macnitude
is by no means such as to warrant our invoking the igneous
fusion of the whole planet to account for them. If the
reader will refer to the diagram, fig. 128, p. 212, he may
convince himself that a machinery more utterly disproportion-
ate to the effects which it is required to explain was never
appealed to. The outer circular line of the diagram repre-
sents a portion of the earth’s diameter equal to 25 miles
PQ
3 so
212 THE EARTH’S CENTRAL FLUIDITY QUESTIONED. [Cu. XXXII.
that if the loftiest mountain chains, even such as the
Himalaya, 5 miles in their greatest height, could be ex-
pressed by white marks within this line, they would form a
feature in it which would be scarcely appreciable.
The space between the two circles, including the thickness
of the lines themselves, has a breadth or diameter of 200
miles. Let us, then, suppose very thin lines 2 inches long,
and equal in width to only 4 of the outer line, to be drawn
Fig. 128,
/]
X\ : a
Se
Fas meet
cee oe
Section of the earth in which the breadth of the outer boundary line represents a
thickness of 25 miles ; the space between the circles, including the breadth of
the lines, 200 miles
here and there within this crust of 200 miles in thickness.
These lines, faint and unimportant as they would appear,
might nevertheless represent sections of seas or oceans of
melted lava 5 miles deep and 5,000 miles long. It can-
not be denied that the expansion, melting, solidification
and shrinking of such subterranean seas of lava at various
depths, aye suffice to cause great movements or earth-
quakes at the surface, and even great rents in the earth’s
crust several thousand miles long, such as may be implied
a ee
Cu. XXXII.] SUPPOSED SECULAR LOSS OF HEAT IN SUN. 213
by the linearly arranged cones of the Andes or mountain
chains like the Alps.
Supposed secular loss of heat in the solar system.—lt is a
favourite dogma of some: physicists, that not only the earth
but the sun itself is continually losing a portion of its heat,
and that as there is no known source by which it can be
restored, we can foresee the time when all life will cease to
exist upon this planet, and on the other hand we can look
back to the period when the heat was so intense as to be in-
compatible with the existence of any organic beings such as
are known to us in the living or fossil world.
When we consider the discoveries recently made of the
convertibility of one kind of force into another, and how
light, heat, magnetism, electricity and chemical affinity are
intimately connected, we may well hesitate before we
accept this theory of the constant diminution from age to
age of a great source of dynamical and vital power. I shall
consider in the next chapter the connection of solar and
terrestrial magnetism, and the extent to which electricity
may be conceived to be a source of volcanic heat. A geo-
logist, in search of some renovating power, by which the
amount of heat may be made to continue unimpaired for
millions of years, past and future, in the solid parts of the
earth, although perpetually shifting the chief points of its
development, has been compared by an eminent physicist
to one who dreams he can discover a source of perpetual
motion, and invent a clock with a self-winding apparatus.
But why should we despair of detecting proofs of such a
regenerating and self-sustaining power in the works of a
Divine Artificer? What is the origin of the force which
governs the motions of the heavenly bodies? It has been
likened to the intellectual power of the human will, which
initiates and directs all our muscular actions. To define. its
nature, has hitherto baffled the efforts of the metaphysician
and natural philosopher, but assuredly we are not yet so far
advanced in our knowledge of the system of the universe as
to entitle us to declare that a great dynamical force like that
of heat is on the wane.
CHAPTER XXXIII.
CAUSES OF EARTHQUAKES AND VOLCANOS—continued.
AGENCY OF STEAM IN VOLCANIC ERUPTIONS—GEYSERS OF ICELAND—-EXPANSIVE
VOLCANIC HEAT—CHEMICAL ACTION—CAUSES OF PERMANENT ELEVATION AND
SUBSIDENCE OF LAND—BALANCE OF DRY LAND, HOW PRESERVED—RECAPITU-
LATION OF CHAPTERS XXII. AND XXIII
AGENCY OF STEAM IN VOI.CANIC ERUPTIONS.—We have
seen that almost all the active voleanos are on sea-coasts or
in islands. ‘ Out of 225 volcanos,’ says Sir John Herschel,
‘which are known to have been in eruption within the
last 150 years, there is only a single instance of one more
thah 320 miles from the sea, and even that one, Mount
Demawend in Persia, is on the edge of the Caspian, the
largest of all the inland seas.’ Jorullo in Mexico, which was
in eruption in 1759, is no less than 120 miles from the nearest
ocean; but, as Dr. Daubeny observes, it forms part of a train
of voleanos one extremity of which is near the sea. (See
Vol. I. p. 584, and Chap. XXVII. Vol. II. p. 53.) The
voleano said to have been in activity in the 7th century
in Central Tartary is 260 geographical miles from the ocean,
but near a large lake. (Vol. I. p. 591.)
Mr. Dana, in his valuable and original observations on the
volcanos of the Sandwich Islands, reminds us of the prodigious
volume of atmospheric water which must be absorbed into
the interior of such large and lofty domes, composed as they
are entirely of porous lava. To this source alone he refers
the production of the steam by which the melted matter is
et
Cu. XXXII.) GEYSERS OF ICELAND. 210
propelled upwards, even to the summit of cones 3 miles in
height.*
Geysers of Iceland.—The extent to which porous rocks are
percolated by rain-water to great depths in almost every
region, however far from the sea, has been alluded to in our
chapter on springs (Vol. I. p. 387) and as there is no doubt
that ordinary steam plays a prominent part in volcanic
eruptions generally, it may be well before going farther to
consider attentively a case in which we know it to be exclusively
the moving power, namely, that of the Geysers of Iceland.
These intermittent hot springs occur in a district situated in
the south-western division of Iceland, where nearly 100 of
them are said to break out within a circle of 2 miles, That
the water is of atmospheric origin, derived from rain and
melted snow, is proved, says Professor Bunsen, by the nitrogen
which rises from them either pure or mixed with other gases.
The springs rise through a thick current of lava, which may
perhaps have flowed from Mount Hecla, the summit of that
volcano being seen from the spot at the distance of more
than 30 miles. In this district the rushing of water is
sometimes heard in chasms beneath the surface; for here, as
on Etna, rivers flow in subterranean channels through the
porous and cavernous lavas. It has more than once happened,
after earthquakes, that some of the boiling fountains have
increased or diminished in violence and volume, or entirely
ceased, or that new ones have made their appearance—changes
which may be explained by the opening of new rents and the
closing of pre-existing fissures.
Few of the Geysers play longer than 5 or 6 minutes at
a time, although sometimes half an hour. The intervals
between their eruptions are for the most part very irregular.
The Great Geyser rises out of a spacious basin at the summit
of a circular mound composed of siliceous inerustations de-
posited from the spray of its waters. The diameter of this
basin, in one direction, is 56 feet, and 46 in another. (See
fiz. 129.) ;
In the centre is a pipe 78 feet in perpendicular depth,
* Geology of American Exploring Expedition, p. 369.
216 GEYSERS OF ICELAND. (Cu. XXXII,
and from 8 to 10 feet in diameter, but gradually widening
as it rises into the basin. The inside of the basin is whitish,
consisting of a siliceous crust, and perfectly smooth, as are
likewise two small channels on the sides of the mound,
down which the water escapes when the bowl is filled to the
margin. The circular basin is sometimes empty, as repre-
sented in the following sketch; but is usually filled with
beautifully transparent water in a state of ebullition. Durine
the rise of the boiling water in the pipe, especially when the
a)
View of the crater of the Great Geyser in Icelan:
ebullition is most violent, and when the water is thrown up
in jets, subterranean noises are heard, like the distant firing
of cannon, and the earth is slightly shaken. The sound then
increases, and the motion becomes more violent, till at length
a column of water is thrown up, with loud explosions, to the
height of 100 or 200 feet. After playing for a time lke an
artificial fountain, and giving off great clouds of vapour,
the pipe or tube is emptied; and a column of steam, rushing
up with amazing force and a thundering noise, terminates
the eruption.
If stones are thrown into the c rater, they are instantly
ejected ; and such is the explosive force, that very hard rocks
are sometimes shivered by it into small pieces. Henderson
found that by throwing a great quantity of large stones into
_
<a
ie ra
=
a.
Cu. XXXIII.] AGENCY OF STEAM IN VOLCANOS. 217
the pipe of Strockr, one of the Geysers, he could bring on an
eruption in a few minutes.* The fragments of stone, as well
as the boiling water, were thrown in that case to a much
greater height than usual. After the water had been ejected,
a column of steam continued to rush up with a deafening
roar for nearly an hour; but the Geyser, as if exhausted by
this effort, did not send up a fresh eruption when its usual
Fig. 130.
omelet
Eruption of the New Geyser in 1810. (Mackenzie.)
interval of rest had elapsed. The account given by Sir George
Mackenzie of a Geyser which he saw in eruption in 1810
(see fig. 130), agrees perfectly with the above description
by Henderson. The steam and water rose for half an hour
to the height of 70 feet, and the white column remained
perpendicular notwithstanding a brisk gale of wind which
was blowing against it. Stones thrown into the pipe were
* Journal of a Residence in Iceland, p. 74.
218 GEYSERS OF ICELAND. [Cu. XXXIII.
projected to a greater height than the water. To leeward of
the vapour, a heavy shower of rain was seen to fall.*
Among the’ different theories proposed to account for these
phenomena, I shall first mention one suggested by Sir J.
Herschel. An imitation of these jets, he says, may be pro-
duced on a small scale, by heating red-hot the stem of a
tobacco pipe, filling the bowl with water, and so inclining
the pipe as to let the water run through the stem. Its
escape, instead of taking place in a continued stream, is then
performed by a succession of violent explosions, at first of
steam alone, then of water mixed with steam; and, as the
pipe cools, almost wholly of water. At every such paroxysmal
escape of the water, a portion is driven back, accompanied
with steam, into the bowl. The intervals between the ex-
plosions depend on the heat, length, and inclination of the
pipe; their continuance, on its thickness and conducting
power.t The application of this experiment to the Geysers
merely requires that a subterranean stream, flowing through
the pores and crevices of lava, should suddenly reach a fissure,
around which the rock is red-hot or nearly so. Steam would
immediately be formed, which, rushing up the fissure, might
force up water along with it to the surface, while, at the
same time, part of the steam might drive back the water of
the supply for a certain distance towards its source. And
when, after the space of some minutes, the steam was all
condensed, the water would return, and a repetition of the
phenomena take place.
There is, however, another mode of explaining the action
of the Geyser, perhaps more probable than that above de-
scribed. Suppose water percolating from the surface of the
earth to penetrate into the subterranean cavity A D (fig. 131)
by the fissures FF, while, at the same time, steam at an
extremely high temperature, such as ‘is commonly given out
from the rents of lava currents during congelation, emanates
from the fissures C. A portion of the steam is at first con-
densed into water, while the temperature of the water is
raised by the latent heat thus evolved, till, at last, the lower
* Mackenzie’s Iceland,
~ MS. read to Geol. Soc. of London. Feb. 29, 1832.
ieee
Cx. XXXIJI.] AGENCY OF STEAM IN VOLCANOS. 219
part of the cavity is filled with boiling water and the upper
with steam under high pressure. The expansive force of the
steam becomes, at length, so great, that the water is forced
up the fissure or pipe E B, and runs over the rim of the basin.
When the pressure is thus diminished, the steam in the upper
part of the cavity A expands, until all the water D is driven
into the pipe; and when this happens, the steam, being the
lighter of the two fluids, rushes up through the water with
great velocity. Ifthe pipe be choked up artificially, even for
Fig. 131.
ip
a few minutes, a great increase of heat must take place; for
it is prevented from escaping in a latent form in steam; so_
that the water is made to boil more violently, and this brings
on an eruption.
Professor Bunsen, before cited, adopts this theory to account
for the play of the ¢ Little Geyser,’ but says it will not explain
the phenomena of the Great one. He considers this, like the
others, to be a thermal spring, having a narrow funnel-shaped
tube in the upper part of its course, where the walls of the
channel have become coated over with siliceous incrustations.
* From Sir George Mackenzie’s Iceland.
220 GEYSERS OF ICELAND. (Cu. XX XIII.
At the mouth of this tube the water has a temperature,
corresponding to the pressure of the atmosphere, of about
212° Fahr., but at a certain depth below it is much hotter. This
the Professor succeeded in proving by experiment; a thermo-
meter suspended by a string in the pipe rising to 266° Fahr,,
or no less than 48° above the boiling point. After the
column of water has been expelled, what remains in the basin
and pipe is found to be much cooled.
Previously to these experiments of Bunsen and Descloizeaux,
made in Iceland in 1846, it would scarcely have been supposed
possible that the lower part of a free and open column of
water could be raised so much in temperature without causing
a circulation of ascending and descending currents, followed
by an almost immediate equalisation of heat. Such circula-
tion is no doubt impeded greatly by the sides of the well not
being vertical, and by numerous contractions of its diameter,
but the phenomenon may be chiefly due to another cause.
According to experiments on the cohesion of liquids by
Mr. Donny of Ghent, it appears that when water is freed
from all admixture of air, its temperature can be raised, even
under ordinary atmospheric pressure, to 275° Fahr., so much
does the cohesion of its molecules increase * when they
are not separated by particles of air. As water long boiled
becomes more and more deprived of air, it is probably very
free from such intermixture at the bottom of the G eysers.
Among other results of the experiments of Bunsen and his
companion, they convinced themselves that the column of
fluid filling the tube is constantly receiving accessions of hot
water from below, while it becomes cooler above by evapora-
tion on the broad surface of the basin. They also came to a
conclusion of no small interest, as bearing on the probable
mechanism of ordinary volcanic eruptions, namely, that the
tube itself is the main seat or focus of mechanical force.
This was proved by letting down stones suspended by strings
to various depths. Those which were sunk to considerable
distances from the surface were not cast up again when the
next eruption of the Geyser took place, whereas those nearer
* See Mr. Horner's Anniversary Address, Quart. Journ, Geol. Soe. 1847, li.
Cu. XXXITT.] AGENCY OF STEAM IN VOLCANOS. 221
the mouth of the tube were ejected to a height of 100 feet.
Other experiments also were made, tending to demonstrate the
singular fact, that there is often scarcely any motion below,
when a violent rush of steam and water is taking place above.
It seems that when a lofty column of water possesses a
temperature increasing with the depth, any slight ebullition
or disturbance of equilibrium in the upper portion may first
force up water into the basin, and then cause it to flow over
the edge. A lower portion, thus suddenly relieved of part of
its pressure, expands and is converted into vapour more
rapidly than the first, owing to its greater heat. This allows
the next subjacent stratum, which is much hotter, to rise and
flash into a gaseous form; and this process goes on till the
ebullition has descended from the middle to near the bottom
of the funnel.*
In speculating, therefore, on the mechanism of an ordinary
volcanic eruption, we may suppose that large subterranean
cavities exist at the depth of some miles below the surface of
the earth, in which melted lava accumulates; and when
water containing the usual mixture of air penetrates into
these, the steam thus generated may press upon the lava and
force it up the duct of a volcano, in the same manner as a
column of water is driven up the pipe of a Geyser. In other
cases we may suppose a continuous column of liquid lava
mixed with red-hot or white-hot water (for water may exist in
that state, as Professor Bunsen reminds us, under pressure),
and this column may have a temperature regularly increasing
downwards. A disturbance of equilibrium may first bring on
an eruption near the surface, by the expansion and conversion
into gas of entangled water and other constituents of what
we call lava, so as to occasion a diminution of pressure. More
steam would then be liberated, carrying up with it jets of
melted rock, which being hurled up into the air may fall in
showers of ashes on the surrounding country, and at length,
by the arrival of lava and water more and more heated at the
orifice of the duct or the crater of the volcano, expansive
* Liebig’s Annalen der Chimie und Memoirs’ of Cavendish Soe.
London,
Pharmacie, translated in ‘Reports and 1848, p. 851,
222 EXPANSIVE POWER OF LIQUID GASES. [Cu. XXxIIq.
power may be acquired sufficient to expel a massive current
of lava. After the eruption has ceased, a period of tranquil-
lity succeeds, during which fresh accessions of heat are com-
municated from below, and additional masses of rock fused
by degrees, while at the same time atmospheric or sea water
is descending from the surface. At length the conditions
required for a new outburst are obtained, and another cycle
of similar changes is renewed.
Expansive power of liquid gases.—Although aqueous vapour
or steam forms a principal part of the aériform fluids which
rush out for days, months, or even years continuously from
voleanic vents, there are other gases, such as the carbonie,
sulphurous, and hydrochlorous acids, which are also present,
and sometimes in great volume. The experiments of Faraday
and others have shown that all these gases may be condensed
into liquids by pressure. At temperatures of from 30° to 50°
Fahr. the pressure required for this purpose varies from 15
to 50 atmospheres; and this amount of pressure we may
regard as very insignificant in the operations of nature. A
column of Vesuvian lava that would reach from the lip of
the crater to the level of the sea, must be equal to about
300 atmospheres; so that, at depths which may be termed
moderate in the interior of the crust of the earth, the gases
may be condensed into liquids, even at very high tempera-
tures. The method employed to reduce some of these gases
to a liquid state is, to confine the materials, from the mutual
action of which they are evolved, in tubes hermetically sealed,
so that the accumulated pressure of the vapour, as it rises
and expands, may force some part of it to assume the liquid
state. A similar process may, and indeed must, frequently
take place in subterranean caverns and fissures, or even in
the pores and cells of many rocks; by which means, a much
greater store of expansive power may be packed into a small
space than could happen if these vapours had not the pro-
perty of becoming liquid. For, although the gas occupies
much less room in a liquid state, yet it exerts exactly the
same pressure upon the sides of the containing cavity as if it
remained in the form of vapour.
If a tube, whether of glass or other materials, filled with
very sligh
no outbur
subterrans
of spring;
ties alten
Whether
Occur ag
Tatlon an
PaSSa on
BY
‘ment,
heioh of
rt
Cx. XXXIII.] EXPANSIVE POWER OF LIQUID GASES. 228
condensed gas, have its temperature slightly raised, it will
often burst; for a slight increment of heat causes the
elasticity of the gas to increase in a very high ratio. If a
minute hole be bored in the tube, the liquid gas will become
instantly aériform, or, in the language of some writers, it
flashes into vapour, and in rushing out often bursts the
vessel. We have only to suppose certain rocks, permeated by
these liquid gases (as porous strata are sometimes filled with
water), to have their temperature raised some hundred
degrees, and we obtain a power capable of lifting superin-
cumbent masses of almost any conceivable thickness ; while,
if the depth at which the gas is confined be great, there is
no reason to suppose that any other appearances would be
witnessed by the inhabitants at the surface than vibratory
movements and rents, since the gases, in making their way
through fissured rocks or soft yielding strata, may be cooled
and absorbed by water. For water has a strong affinity to
several of the gases, and will absorb large quantities, with a
very slight increase of volume. In such cases there may be
no outburst at the surface, nor any obvious indication of
subterranean change. ° The temperature, perhaps, or volume
of springs may be augmented, and their mineral proper-
ties altered, but no volcanic explosion may be witnessed.
Whether a permanent change of level may be expected to
occur aS a consequence or accompaniment of such gene-
ration and heating of gases in the interior of the earth’s
crust, will be considered in the sequel.
The volcano of Cotopaxi has been known to throw out, to
the distance of 8 or 9 miles, a mass of rock about 100 cubic
yards in volume, and there is no difficulty in understanding
how the most solid substances which oppose the upward
passage of the exploding gases may be reduced to small
fragments, or even to dust, such as we see hurled to the
height of many miles into the air by the volcano.
Access of salt water to the volcanic Joci.—Although the
theory which assumes that water plays a principal part in
volcanic operations does’ not necessarily imply the proximity
of volcanic vents to the ocean, it seems still to follow naturally
that the superficial outbursts of steam and lava will be most
224 ACCESS OF SALT WATER TO VOLCANIC FOCI. [Cu. Xxxqtq.
prevalent where there is an incumbent body of salt water, or
in any regions rather than in the interior of a continent, where
the quantity of rain-water is reduced to a minimum. The
experiments and observations of the most eminent chemists
have gradually removed, one after another, the objections
which were first offered to the doctrine that the salt water
of the sea plays a leading part in most volcanic eruptions.
Sir H. Davy observed that the fumes which escaped from the
Vesuvian lava deposited common salt.*
Gay-Lussac, although he avowed his opinion that the
decomposition of water contributed largely to volcanic action,
called attention, nevertheless, to the supposed fact, that
hydrogen had not been detected in a separate form among
the gaseous products of volcanos; nor could it, he said, be
present; for, in that case, it would be seen inflamed in the
air by the red-hot stones thrown out during an eruption.+
But M. Abich remarked, on the other hand, ‘ that although
it be true that vapour illuminated by incandescent lava
has often been mistaken for flame,’ yet he had clearly
detected the flame of hydrogen in the eruption of Vesuvius
in 1834.t
In the memoir just alluded to, M. Gay-Lussac expressed
doubt as to the presence of sulphurous acid; but the abun-
dant disengagement of this gas during eruptions has been
since ascertained: and thus all difficulty in regard to the
general absence of hydrogen in an inflammable state is
removed ; for, as Dr. Daubeny suggests, the hydrogen of
decomposed water may unite with sulphur to form sulphu-
retted hydrogen gas, and this gas will then be mingled with
the sulphurous acid as it rises to the crater. It is shown
by experiment, that these gases mutually decompose each
other when mixed where steam is present; the hydrogen of
the one immediately uniting with the oxygen of the other
to form water, while the excess of sulphurous acid alone
escapes into the atmosphere. Sulphur is at the same time
precipitated.
* Davy, Phil. Trans. 1828, p. 244.
“+ Ann. de Chim. et de Phys. tom. xxi.
} Phénom. Géol. &e. p. 3
a
Ae
+
ot
aE SET
a el
Low
Cu. XXXIII.] ESCAPE OF HYDROGEN DURING ERUPTIONS, 295
This explanation is sufficient; but it may also be observed
that the flame of hydrogen would rarely be visible during an
eruption ; as that gas, when inflamed in a pure state, burng
with a very faint blue flame, which even in the night could
hardly be perceptible by the side of red-hot and incandes-
cent cinders. Its immediate conversion into water when
inflamed in the atmosphere, might also account for its not
appearing in a separate form.
The observations of Bunsen in Iceland in 1844, of St.
Claire Deville on Vesuvius in 1855 and 1861, and of Fouqué
on Santorin in 1866, have proved that there is an abundant
escape of hydrogen, both in a free state and in combination
with other substances, during eruptions; and the two last-
mentioned chemists have succeeded in demonstrating the
perfect accordance of the chemical composition of the pro-
ducts of volcanic eruptions, both gaseous and solid, with the
doctrine that salt water has been largely present in the vol-
eanic foci. It had been asked why then are there no salts of
magnesia in volcanic fumeroles? They reply that these salts
are readily decomposable by hot steam, and that when water
and heat are present they produce hydrochloric acid and
magnesia. That acid is found in the vapours which are
disengaged from red-hot lava, and the magnesia which ig
not volatile is left behind in the lava itself, constituting one
of its most important elements.* In like manner, the last-
mentioned French chemists have shown that common salt
can be resolved into its elements by hot steam alone, which
Gay-Lussac had thought impossible.
M. Fouqué affirms that in the recent eruption of Etna
(in 1865) which he witnessed, the gaseous emanations agreed
in kind with those which we might have looked for if large
bodies of sea-water had gained access to reservoirs of sub-
terranean lava, and if they had been decomposed and ex-
pelled with the lava; and more than this, he calculated that
the quantity of aqueous vapour was relatively to other gases
in due proportion—that there was a daily emission from
* Fouqué, Rapport sur les Phénoménes Chimigques, Eruption of Etna in 1865,
. d7.
VOL. II. Q
226 EARTH'S CRUST A BODY COOLING FROM FUSION. (Cu. XXXIII.
the several vents which were open on Etna, of no less than
22,000 cubic metres of aqueous vapour.
Access of atmospheric air and fresh water to the volcanic
foci.—The presence of nitrogen among the gases evolved
from craters in eruption, and in the waters of thermal
springs, has been another subject of enquiry and discussion.
Sir H. Davy, in his memoir on the ‘ Phenomena of Vol-
canos,’ remarks, that there was every reason to suppose in
Vesuvius the existence of a descending current of air; and
he imagined that subterranean cavities which threw out
large volumes of steam during the eruption, might after-
wards, in the quiet state of the volcano, become filled with
atmospheric air.* The presence of ammoniacal salts in
voleanic emanations, and of ammonia (which is in part com-
posed of nitrogen) in lava, favours greatly the notion of
air as well as water being deoxidated in the interior of
the earth.t
Dr. Daubeny suggests that water containing atmospheric
air may descend from the surface of the earth to the
volcanic foci, and that the same process of combustion by
which water is decomposed may deprive such subterranean
air of its oxygen. In this manner great quantities of nitro-
gen may be evolved.
The presence of vast numbers of siliceous cases of infu-
soria in the tuff covering Pompeii, and composed of matter
ejected from Vesuvius and other volcanos, has already been
alluded to. (Vol. I. p. 644.) They prove that water and
mud have penetrated downwards from the surface into rents
and caverns in the interior, and have then been thrown out
again during volcanic eruptions.
The earth’s crust a body cooling from a state of fusion.—W hat
we have now said of the manner in which aqueous and other
gases may be expected to operate mechanically and chemi-
cally on the crust of the earth, whenever water and various
acids, stored up in caverns and fissures at great depths, have
their temperatures raised, must satisfy the reader that it is
only necessary, in order to explain the action of volcanos,
* Phil. Trans. 1828.
{~ See Daubeny, Encye. Metrop. Part 40.
f
\
:
}
a
—————— ote ne ee
voleano
of lava
what we
phenom
been inf
depths
have ad
equalled
hold a Ve
The com
C * DS. a“ | J
LL. JIS . 95
to disc
over ich:
er some cause which is capable of bringi
ringing about
leap:
“Unie such a concentration of |
{V0 . : reat as LAV F
: a other, certain portions of the Ses melt, one after the
rua] Nt cath of subterrancan ; Cr ee so as to form seas,
ISS} a cet ava. is being o
Pi the greater part of the crust at any giv oC rene granted,
ot Vol. | at various depths sheets of se given time will contain
088 jy somo Somi-finid. others is slowly parting with
3 and others beginning to consolidate or er ee less viscous, and
‘Wout state, therefore, of the exterior of ae ‘ ganeere The general
afte. a, mass once heated, and which 1 planet would be that of
d Wj but in certai 1as been gradually cooling;
with ain spots, namely the regions of acti y cooling ;
alts i: regions very limited and excep tional s of active volcanos,
t com surface, the heat will be on the ieee “ se bebe the whole
sae ally manifest its intensity in the op eo and will occasion-
rior of 7 Nee earthquake. perations of the volcano
at beneath the And
es and other or
bse tae there are reservoirs, at i. ee areas of active
an of lava in a constant state of fusion, ¢ epth of some miles,
ion b what we have already stated (pp. 9 he aang
siti phenomena fi ; pp. 90 and 202). All the ob
mat mena from which the exist ora
ranedl been inferred ; : xistence of central fluidi
en See secbneilable withthe uidity has
epths of such masses of occurrence at certain
have admi of lava in the earth’
ah admitted to be probable, and whi 8 crust as we
z aie the Atlantic and Pacific O i ae, even if they
matiel ee a very subordinate place in the ae in volume, may
i e connection of earthquakes with a ai shell of the planet.
pant Se reservoirs of melted rock is quit ie crust overlying
pet Flewibility of the earth’s crust poe Sopembee
poll | a who are mostly fishermen, are said t eu sinomeetd
| olcano as a weather-glass, the : o make use of that
wt | f tle when. th > eruptions being co :
Wit ne he sky is serene, but increasi g comparatively
oth?! . i ing tempestuous weather, so that i asing in turbulence
pew 7 oe to shake from its found ei ee
iio . calling attention to these ar 7 Ones Be Ee Serope,
pat? rst started the idea nd other analogous fact
re | diminished (as long ago as the year 1825 .
5 storm pressure of the atmospher : r 1825) that the
go ae weather, may modify the int ©, the concomitant of
- He suggests that where li sat of the volcanic
quid lava communicates
228 FLEXIBILITY OF THE EARTH'S CRUST. [Ca. XXXII,
or fall in the vent on the same principle as mercury in a
barometer; because the ebullition or expansive power of the
steam contained in the lava would be checked by every
increase, and augmented by every diminution of weight.
In like manner, if a bed of liquid lava be confined at an
immense depth below the surface, its expansive force may be
counteracted partly by the weight of the incumbent rocks,
and also in part by atmospheric pressure acting contem-
poraneously on a vast superficial area. In that case, if the
upheaving force increase gradually in energy, it will at
length be restrained by only the slightest degree of supe-
riority in the antagonist or repressive power, and then the
equilibrium may be suddenly .destroyed by any cause, such
as an ascending draught of air, which is capable of depressing
the barometer. In this manner we may account for the
remarkable coincidence so frequently observed between the
state of the weather and subterranean commotions, although
it must be admitted that earthquakes and volcanic eruptions
react in their turn upon the atmosphere, so that disturbances
of the latter are generally the consequences rather than the
forerunners of volcanic disturbances.*
From an elaborate catalogue of the earthquakes experienced
in Europe and Syria during the last fifteen centuries, M.
Alexis Perrey concludes that the number which happen in
the winter season preponderates over those which occur in
any one of the other seasons of the year, there being, how-
ever, some exceptions to this rule, as in the Pyrenees.
Curious and valuable as are these data, M. d’Archiac justly
remarks, in commenting upon them, that they are not as yet
sufficiently extensive or accordant in different regions, to
entitle us to deduce any general conclusions from them
respecting the laws of subterranean movements throughout
the globe.t
M. Perrey has also, in a later report of earthquakes (1863),
inferred, as the result of 10,000 observations on the earth-
quakes of the first half of the present century, that they
occur more frequently and with more violence when the
* Scrope on Voleanos, pp. 58-
t+ Archiac, Hist. des cies Gl la Géol. 1847, vol. i. pp. 605-610.
|
|
|
|
|
|
|
|
|
|
|
its solid
the sea.
down, y
brings a
In its we
Side risi
out thro
takes pl
Very par
ae on t
steat de
tertiary
Oceania
“dually ;
Sedimen,
lands “
, Upog
th e ) ‘Ns
b
‘lem
ao
Cu. XXXIII.] FLEXIBILITY OF THE EARTH’S CRUST. VAP
moon is in perigee, or nearest the earth, than at other periods,
when that satellite being less near is exerting a minor degree
of force, or less strain upon the solid crust of our planet. In
like manner he thinks he has detected a relation between the
frequency of earthquakes and our winter and summer solstices,
the greatest number of shocks occurring in perihelion when
the sun is nearest, and the least number in aphelion when
it is farthest from the earth.* On this subject Sir John
Herschel remarks, ‘ The action of the sun and moon, though
it cannot produce a tide in the solid crust of the earth, tends
to do so, and were it fluid would produce it. It does there-
fore, in point of fact, bring the solid portions of the earth’s
surface into a state alternately of strain and compression.’ +
Sir John Herschel, when endeavouring to suggest a cause
for the frequent proximity of chains of active volcanos, like
the Andes, to the sea, assumes that the solid bottom of the
latter and the neighbouring land may be regarded as float-
ing on a subterranean fluid mass. The land, he observes, is
always undergoing waste by aqueous action, and portions of
its solid matter are carried down in the form of sediment into
the sea. By this means the bed of the ocean is pressed
down, while the continent is relieved of pressure, and this
brings about a state of strain in the crust which will crack
in its weakest part, the heavy side going down, and the light
side rising. The subterranean fiery matter will then burst
out through the rent, as water oozes up when a crack
takes place in the ice.{ This hypothesis appears to me of
very partial application, for active volcanos, even such as
are on the borders of continents, are rarely situated where
great deltas have been forming, whether in pliocene or post-
tertiary times. The number, also, of active volcanos in
oceanic islands is very great, not only in the Pacific, but
equally in the Atlantic, where no load of coral matter or ¢ any
sedimentary deposits derived from the waste of neighbouring
lands can cause a partial weighting and pressing down of
& supposed flexible crust.
* Alexis Perrey, Propositions sur les Pocuite Subjects, ee p. 45.
Tremblements de Terre 1863. { Herschel, ibid. p. 1
t Herschel, Parnilion Lectures on
230 ELECTRICITY AND MAGNETISM CONSIDERED [Cx. XXXII.
Electricity and magnetism considered as sources of voleanie
heat.—The popular notion of a central fiuid nucleus, on which
a thin outer shell is floating, has diverted the speculations
of the physicist and natural philosopher from attempting
to invent some theory which might explain the continual
shifting of the points of the chief development of heat from
one part of the shell to another, leaving large portions
previously in a state of fusion to cool and consolidate,
Soon after the first great discoveries of Oersted in electro-
magnetism, Ampére suggested that all the phenomena of the
magnetic needle might be explained by supposing currents
of electricity to circulate constantly in the shell of the globe
in directions parallel to the magnetic equator. This
theory has acquired additional consistency the farther we
have advanced in science; and according to the experiments of
Mr. Fox, on the electro-magnetic properties of metalliferous
veins, some trace of electric currents seems to have been
detected in the interior of the earth.*
Some philosophers ascribe these currents to the chemical
action going on in the superficial parts of the globe to which
air and water have the readiest access; while others refer
them, in part at least, to thermo-electricity excited by the
solar rays on the surface of the earth during its rotation;
successive parts of the atmosphere, land, and sea being ex-
posed to the infiuence of the sun, and then cooled again in
the night. That this idea is not a mere speculation, is
proved by the correspondence of the diurnal variations of the
magnet with the apparent motion of the sun; and by the
greater amount of variation in summer than in winter, and
during the day than in the night.
Allusion was made in the first volume (p. 308) to the recent
discovery of a connection between periodical changes in the
spots of the sun and variations in terrestrial magnetism,
suggesting the idea that solar magnetism has a powerful
influence on the earth’s crust. According to Sir John
Herschel, the cycle of change, including the periods when
the spots are most abundant and large, and those when they
are least apparent, occupies rather more than 11 years,
* Phil. Trans, 1830, p. 399.
ee < 9, emma, “cilia F
—— oo a ee 2 =
;
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ments, b
recorded
made a |
the very
the sola
had reac
“By di
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at Melbe
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Places th
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ra
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al]
ee
ee
Cu. XXXIJII.] AS SOURCES OF VOLCANIC HEAT. 231
so that there are 9 of these cycles in a century. So late
as September 1, 1859, when the spots were very large, ‘two
observers, far apart and unknown to each other, were viewing
them with powerful telescopes, when suddenly, at the same
moment of time, both saw a strikingly brilliant luminous
appearance, like a cloud of light, far brighter than the general
surface of the sun, break out in the immediate neighbourhood
of one of the spots, and sweep across and beside it. It occu-
pied about five minutes in its passage, and in that time
travelled over a space on the sun’s surface which could not
be estimated at less than 35,000 miles. A magnetic storm
was in progress at the time. From August 28 to September 4
many indications showed the earth to have been in a perfect
convulsion of electro-magnetism.’
At Kew, where there are self-registering magnetic instru-
ments, by which the positions of three magnetic needles are
recorded by photography, it was found that all three had
made a strongly marked jerk from their former positions at
the very moment when the bright light had been seen crossing
the solar spot. It would appear that the magnetic influence
had reached the earth at the same time with the light.
‘ By degrees, accounts began to pour in of great Auroras
seen on the nights of those days, not only in these latitudes,
but at Rome, in the West Indies, on the tropics within 18°
of the equator (where they hardly ever appear), nay, what is
still more striking, in South America and in Australia, where,
at Melbourne, on the night of the 2nd of September, the
greatest Aurora ever seen there made its appearance. These
Auroras were accompanied with unusually great electro-
magnetic disturbances in every part of the world. In many
places the telegraphic wires struck work. At Washington
and Philadelphia, in America, the telegraph signal-men
received severe electric shocks. Ata station in Norway the
telegraphic apparatus was set fire to; and at Boston, in
North America, a flame of fire followed the pen of Bain’s
electric teleoraph, which writes down the message upon
chemically prepared paper.’ *
* Herschel, Familiar Lectures on Scientific Subjects, 1866, p. 80.
232 ELECTRICITY A SOURCE OF VOLCANIC HEAT. [Cu. XXXIII.
The passage of this electro-magnetic force from the gun to
our globe may, perhaps, be one of the principal means by
which heat lost by conduction into space may be restored to
the planet; and we may easily imagine that at successive
geological periods, when new mountain chains have been
thrown up and old ones have been removed by subsidence or
denudation, when even oceans and continents have changed
places, the circulation of electro-magnetic currents and the
local concentration of heat due to them may affect new parts
of the exterior of the planet. It is scarcely possible to exag-
gerate the amount of action and reaction to which the cause
here alluded to may give rise. ‘ The silent and slow operation
of electricity as a chemical agent is more important,’ says
Davy, ‘in the economy of nature than its grand and impressive
operation in ightning and thunder. It may be considered,
not only as directly producing an infinite variety of changes,
but as influencing almost all which take place; it would
seem, indeed, that chemical attraction itself is only a peculiar
form of the exhibition of electrical attraction.’ *
Thermo-electricity may be generated by great inequalities
of temperature, arising from a partial distribution of volcanic
heat. Wherever, for example, masses of rock occur of great
horizontal extent, and of considerable depth, which are at
one point ina state of fusion (as beneath some active volcano);
at another, red-hot; and at a third, comparatively cold—
strong thermo-electric action may be excited, and subterra-
nean electric currents, if once excited, may melt rock or
possess the decomposing power of the voltaic pile.
Chemical action.—When Sir H. Davy first discovered the
metallic bases of the earths and alkalies, he threw out the
idea that stores of those metals might abound in an un-
oxidised state in the subterranean regions to which water
must occasionally penetrate. Whenever this happened,
gaseous matter would be set free, the metals would combine
with the oxygen of the water, and sufficient heat might be
evolved to melt the surrounding rocks. This hypothesis was
at first very favourably received both by the chemist and the
*®
Consolations in Trayel, p. 271.
* ce i ae ey
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therefore
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the lower
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lation og
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at t}
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ava
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Cu. XXXIIZ.] CHEMICAL ACTION. 983
geologist : for silica, alumina, lime, soda, and oxide of iron
—substances of which lavas are principally composed—
would all result from the contact of the inflammable metals
“alluded to with water. But when Davy failed to detect,
gaseous products evolved from the crater, he was disposed to
renounce or to attach but little importance to his theory.
We have seen (p. 225) that it is now ascertained that hydro-
gen is disengaged during eruptions in large quantities ; but,
according to M. Fouqué, there is always much more proto-
carbonate of hydrogen than free hydrogen, whereas the
reverse ought to be the case, if these combustible eases
resulted from the contact of alkaline metals with water.*
The same chemist remarks, that to explain the disengagement
of heat during the last eruption of Htna, we should require
a mass of sodium of at least 7,000,000 cubic métres, and
therefore the quantity of alkaline metals beneath all the
active volcanos, which has given rise in each to a long series
of eruptions, would be incredibly great.
M. Fouqué is satisfied with the hypothesis of a subterranean
sheet of fluid lava, to which water occasionally may gain
access, central heat being invoked as the power by which
the lower parts of the earth’s crust are retained in a melted
state, and no explanation being attempted by him of the
shifting of the voleanic force from one part of the earth’s
envelope to another.
In former editions, I have suggested that if the accumu-
lation of heat be granted as successively developed in
different parts of the earth’s shell, we may readily conceive
that the waters of lakes and seas might gain access to the
fluid lava during earthquakes, large bodies of water being
occasionally engulfed, and then, when the sides of the
fissures closed again with violence (see page 125), the steam
generated by contact of the water with the heated subterra-
nean fluid, would not escape by the same rents, but might
Tush out with lava from some distinct and perhaps habitual
during an eruption of Vesuvius, any hydrogen among the
* Fouqué, R
apport sur les Phénoménes Chimiques de l’Eruption de I’Etna
en 1865, p. 80
.
OF PERMANENT ELEVATION
CAUSES [Cu. XXXIII.
voleanic openings. That there should be so much heat and
chemical action and reaction, developed in certain parts of
the interior of the earth, is not so wonderful as the ordinary
repose and inertness of the internal mass. When we con-
sider the combustible nature of the elements of the earth, go
far as they are known to us—the facility with which their
compounds may be decomposed and made to enter into new
combinations—the quantity of heat which they evolve
during these processes; when we recollect the expansive
power of steam, and that water itself is composed of two
gases which, by their union, produce intense heat; when we
call to mind the number of explosive and detonating com-
pounds which have been already discovered, we may be
allowed to share the astonishment of Pliny, that a single day
should pass without a general conflagration :—‘ Hxcedit
profectd omnia Aaa ullum diem fuisse quo non cuncta
conflagrarent.’
But the difficulties we ‘encounter when we attempt to form
a chemical theory of volcanos, are almost insurmountable, in
consequence of our inability to test experimentally the mode
in which different substances, solid, fluid, or gaseous, would
behave under conditions of pressure and temperature wholly
different from those experienced at the surface. A simple
difference in the amount of heat may, observes Seemann,
cause all the chemical affinities of bodies to be essentially
modified. Mercury, he remarks, ‘does not combine with
oxygen at ordinary tempera tures, but combines with it at its
boiling point, and then gives it off again at an incipient red
heat. Here we have three different states of chemical affinity
within the limits of a few hundred degrees; and who would
dare assert, that at this last phase of separation, the chemical
action between these two elements ceases definitely and for
all higher temperatures? But what is true of mercury and
oxygen, is likewise true for all other elements.’+
Causes of permanent elevation and subsidence of land.—The
position of the fossiliferous and other rocks in the earth’s
* Hist. Mundi, lib. ii. ec. 107.
f Louis Semann, Notes on Daubrée on Meteorites, Geol. Mag. 1866, p. 362.
V—_— = -eoeoe OO i nn rc
|
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_i
chains are
of their P}
in a sing]
downward
varying po
course of |
points of
the voleat
results 0!
electricity
Experin
ascertain
commonly
of heat.*
annual yar
make a cc
joints shox
the Stone
— Te. cee
LR CTE. TRE ee, pn
Cu. XXXIII.] AND SUBSIDENCE OF LAND. 285
erust, has enabled the geologist to infer that some of these
rocks have been lifted up to the height of several miles above
the level at which they were originally formed in the bed of
the ocean, and also that there have been gradual subsidences
of rocks to a vast amount below the levels which they once
occupied. ‘These great movements have been caused by
subterranean or volcanic heat, which has affected different
parts of the earth in succession. The existing mountain
chains are of different ages, and few of them owe the whole
of their present conformation to the movements experienced
in a single epoch. The forces, whether in an upward or
downward direction, to which they are due, and by which the
varying position of continents and oceanic basins has in the
course of ages been determined, have evidently shifted their
points of chief development from one region to another, like
the voleano and the earthquake, and are in fact all the
results of the same internal operations, to which heat,
electricity, magnetism, and chemical affinity give rise.
Experiments were made in America, by Colonel Totten, to
ascertain the ratio according to which some of the stones
commonly used in architecture expand with given increments
of heat.* It was found impossible, in a country where the
annual variation of temperature was more than 90° Fahr., to
make a coping of stones, 5 feet in length, in which the
joints should fit so tightly as not to admit water between
the stone and the cement; the annual contraction and
expansion of the stones causing, at the junctions, small
crevices, the width of which varied with the nature of the
tock. It was ascertained that fine-grained granite expanded
with 1° Fahr. at the rate of 000004825; white crystalline
marble 000005668 ; and red sandstone "000009532, or about
twice as much as granite,
Now, according to this law of expansion, a mass of sand-
stone, a mile in thickness, which should have its temperature
raised 200° Fahr. would lift a superimposed layer of rock to
the height of 10 feet above its former level. But, suppose a
part of the earth’s crust, 50 miles in thickness and equally
* Silliman’s American Journ. vol. results to the theory of earthquakes was
XX1l. p. 1386. The application of these first suggested to me by Mr. Babbage.
236 ELEVATION AND SUBSIDENCE OF LAND. [Ca.Xxxqt.
expansible, to have its temperature raised 600° or 800°, this
might produce an elevation of between 1,000 and 1,500 feet,
The cooling of the same mass might afterwards cause the
overlying rocks to sink down again and resume their origina]
position. By such agency we might explain the gradual
rise of part of Scandinavia or the subsidence of Greenland.
It is also possible that as the clay in Wedgwood’s pyro-
meter contracts, by giving off its water, and then, by inci-
pient vitrification; so, large masses of argillaceous strata in
the earth’s interior may shrink, when subjected to heat and
chemical changes, and allow the incumbent rocks to subside
eradually.
Moreover, if we suppose that lava cooling slowly at great
depths may be converted into various granitic rocks, we
obtain another source of depression; for, according to the
experiments of Deville and the calculations of Bischoff, the
contraction of granite when passing from a melted or plastic
to a solid and crystalline state must be more than 10 per cent.*
Dr. Bischoff has also remarked, that when the silicates
which enter so largely into the composition of the oldest rocks
—gneiss, mica-schist, clay-slate, and others—are percolated
by carbonic acid gas, which is of almost universal occurrence
at great depths, they must be continually decomposed. When
that happens, the carbonates formed by the new combinations
thence arising must often augment the volume of the altered
rocks. This increase of bulk, he says, must sometimes give
rise to a mechanical force of expansion capable of uplifting
the incumbent crust of the earth, and the same force may act
laterally, so as to compress, dislocate, and tilt the strata on
each side of a mass in which the new chemical changes are
developed. The same eminent German chemist has attempted
to calculate the exact amount of distension to which the new
mineral products thus formed may give rise by adding to the
volume of the rocks.
If once some parts of the earth’s crust are shattered, as in
regions of earthquakes, and reservoirs of melted stone and
heated vapours have acquired force enough to uplift the
* Bulletin de la Soc. Géol. 2nd series, vol. iv. p. 1812.
slowly depre
the geogray
areas of ele
contiguous |
Balance 0
historical dé
movement, 1
or without
developed in
tions produe
a few yo
hardly doub
mation of };
ava Currents
tnd loyy land
ena =
forces. and
7
sone
—
Cu, XXXIII.] PRESERVATION OF BALANCE OF DRY LAND. 237
incumbent mass, we may easily conceive how the country
may remain permanently upheaved. For in some places the
fractured rocks below may have assumed an arched form, or
lava may have been driven into fissures, in which it may
consolidate, and afford an enduring support to the foun-
dations of the newly raised strata.
The sudden subsidence of limited areas of land may be
occasioned by subterranean caverns giving way, when gases
are condensed, or when they escape through newly-formed
erevices. ‘The subtraction, moreover, of matter from certain
parts of the interior, by the flowing of lava, and of mineral
springs, must, in the course of ages, cause vacuities below,
so that the undermined surface may at length fall in or be
slowly depressed. In this manner we may, perhaps, explain
the geographical connection which seems to exist between
areas of elevation and of subsidence, a deep sea being often
contiguous to elevated land.
Balance of dry land, how preserved.—It will appear, from the
historical details above given, that the force of subterranean
movement, whether intermittent or continuous, whether with
or without disturbance, does not operate at random, but is
developed in certain regions only; and although the altera-
tions produced during the time required for the occurrence
of a few volcanic eruptions may be inconsiderable, we can
hardly doubt that, during the ages necessary for the for-
mation of large volcanic cones, composed of thousands of
lava currents, shoals might be converted into lofty mountains,
and low lands into deep seas.
In a former chapter (Vol. I. p. 327), I have stated that
aqueous and igneous agents may be regarded as antagonist
forces; the aqueous labouring incessantly to reduce the in-
equalities of the earth’s surface to a level, while the igneous
are equally active in renewing the unevenness of the surface.
By some geologists it has been thought that the levelling
power of running water was opposed rather to the elevating
force of earthquakes than to their action generally. This
Opinion is, however, untenable ; for the sinking down of the
bed of the ocean is one of the means by which the gradual
submersion of land is prevented. The depth of the sea cannot
PRESERVATION OF BALANCE OF DRY LAND. [Cu. XXXIIT.
be increased at any one point without a universal fall of the
waters, nor can any partial deposition of sediment occur
without the displacement of a quantity of water of equal
volume, which will raise the sea, though in an imperceptible
degree, even to the antipodes. The preservation, therefore,
of the dry land may sometimes be effected by the subsidence
of part of the earth’s crust (that part, namely, which igs
covered by the ocean), and in like manner an upheaving
movement must often tend to destroy land; for if it render
the bed of the sea more shallow, it will displace a certain
quantity of water, and thus tend to submerge low tracts.
If the dimensions of the planet have remained uniform
during the period which we contemplate in geology, it would
be necessary to suppose that the amount of depression caused
by subterranean heat must exceed that of elevation, otherwise
there would not be a perpetual restoration of those inequa-
lities of the earth’s surface which the levelling power of
water tends to efface. It would be otherwise if the action of
voleanos and mineral springs were suspended; for then
the forcing outwards of the earth’s envelope ought to be no
more than equal to its sinking in.
To understand this proposition more clearly, it must be
borne in mind, that the deposits of rivers and currents
probably add as much to the height of lands which are
rising, as they take from those which have risen. Suppose
a large river to bring down sediment to a part of the ocean
2,000 feet deep, and that the depth of this part is gradually
reduced by the accumulation of sediment till only a shoal
remains, covered by water at high tides; if now an upheaving
force should uplift this shoal to the height of 2,000 feet, the
result would be a mountain 2,000 feet high. But had the
movement raised the same part of the bottom of the sea
before the sediment of the river had filled it up; then,
instead of changing a shoal into a mountain 2,000 feet high,
it would only have converted a deep sea into a shoal.
It appears, then, that the operation of the volcanic or
subterranean forces is often such as to cause the levelling
power of water to counteract itself; and, although the idea
may appear paradoxical, we may be sure, wherever we find
wean
ee — . ss,
and portion
external act
dimensions
of depressic
the elevati:
of the eart.
the surface
subsidence
of depressic
ciples, since
either to pre
diminution -
the subtract.
luinera] spr
Masgeg by g
Cu. XXXIU.] PRESERVATION OF BALANCE OF DRY LAND. 238
hills and mountains composed of stratified deposits, that
such inequalities of the surface would have had no existence
if water, at some former period, had not been labouring to
reduce the earth’s surface to one level.
But, besides the transfer of matter by running water from
the continents to the ocean, there is a constant transporta-
tion from below upwards, by mineral springs and volcanic
vents. As mountain masses are, in the course of ages,
created by the pouring forth of successive streams of lava, so
stratified rocks of great extent originate from the deposition
of carbonate of lime, and other mineral ingredients, with
which springs are impregnated. The surface of the land,
and portions of the bottom of the sea, being thus raised, the
external accessions due to these operations would cause the
dimensions of the planet to enlarge continually, if the amount
of depression of the earth’s crust were no more than equal to
the elevation. In order, therefore, that the mean diameter
of the earth should remain uniform, and the unevenness of
the surface be preserved, it is necessary that the amount of
subsidence should be in excess. And such a predominance
of depression is far from improbable, on mechanical prin-
ciples, since every upheaving movement must be expected
either to produce caverns in the mass below, or to cause some
diminution of its density. Vacuities must, also, arise from
the subtraction of the matter poured out from volcanos and
mineral springs, or from the contraction of argillaceous
masses by subterranean heat; and the foundations having
been thus weakened, the earth’s crust, shaken and rent by
reiterated convulsions, must, in the course of time, fall in.
If we embrace these views, important geological conse-
quences will follow; since, if there be, upon the whole, more
subsidence than elevation, the average depth to which former
surfaces have sunk beneath their original level must exceed
the height which ancient marine strata have attained above
the sea. If, for example, marine strata, about the age
of our chalk and greensand, have been lifted up in Europe
to an extreme height of more than 11,000 feet, and a mean
elevation of some hundreds, we may conclude that certain
parts of the surface, which existed when those strata were
240 RECAPITULATION OF CHAPS. XXXII. AND XXXIII. [Cu. Xxx.
deposited, have sunk to an extreme depth of more than 11,000
feet below their original level, and to a mean depth of more
than » few hundreds.
In regard to faults, also, we must infer, according to the
hypothesis now proposed, that a greater number have arisen
from the sinking down than from the elevation of rocks,
It seems, therefore, to be rendered probable, by the views
above explained, that the constant repair of the land, and the
subserviency of our planet to the support of terrestrial as
well as aquatic species, are secured by the elevating and
depressing power of causes acting in the interior of the
earth; which, although so often the source of death and
terror to the inhabitants of the globe—visiting in succession
every zone, and filling the earth with monuments of ruin and
disorder—are nevertheless the agents of a conservative prin-
ciple above all others essential to the stability of the system.
Recapitulation of Chapters XXXII. and XXXIII.—I will
now recapitulate the principal conclusions arrived at in this
and in the preceding chapter.
1. The primary causes of the volcano and the earthquake
are to a great extent the same, and connected with the deve-
lopment of heat and chemical action at various depths in the
interior of the globe.
2. Volcanic heat has been supposed by many to be the result
of the high temperature which belonged to the whole planet
when it was in a state of igneous fusion, a temperature which
they suppose to have been always diminishing and still to
continue to diminish by radiation into space.
3. The spheroidal figure of the earth does not of necessity
imply a universal and simultaneous fluidity, in the beginning;
for whatever may have been the original shape of our planet,
the statical figure must have been assumed, if sufficient time
be allowed, by the gradual operation of the centrifugal force,
acting on yielding materials brought successively within its
action by aqueous and igneous causes.
4. The late Mr. Hopkins inferred that the precessional
motion of the earth could not be such as it now is, unless
the solid crust was from 800 to 1,000 miles thick; but the
precessional movement is consistent with the supposition of
supposed 80)
nucleus in ce
to lower, 01
because the
direction we
of the earth
8, Assumi
for inferring
fluidity need
Cx. XXXIII.] RECAPITULATION OF CHAPS. XXXII. AND XXXIII. 241]
a much greater, and even the general solidity of the entire
globe, provided that lakes or oceans of melted matter, which
may be distributed through it, are so enclosed as to move
with the solid portion.
5. The heat in mines and Artesian wells increases as we
descend, but not in a uniform ratio, in different regions. If
the heat were continued downwards at the same rate, it would
imply such an elevation of temperature in the central nucleus
as must instantly fuse the crust.
6. The hypothesis of a central fluid and of a thin solid
shell resting or floating upon it, is inconsistent with the
absence of internal tides, such as would make the lava ebb
and flow in volcanic craters during eruptions.
7. The hypothesis of a change in the axis of rotation of a
supposed solid envelope, made to slide over an internal fluid
nucleus in consequence of the transfer of sediment from higher
to lower, or from lower to higher, latitudes, is untenable,
because the excess of matter displaced and carried in one
direction would be extremely slight, and the spheroidal fioure
of the earth would render such freedom of motion impossible.
8. Assuming that there were good astronomical grounds
for inferring the original fluidity of the planet, such pristine
fluidity need not affect the question of volcanic heat, for the
volcanic action of successive periods belongs to a state of the
globe long posterior to its origin, and implies the melting of
different parts of the solid crust one after the other.
9. The quantity of lava, fluid at any one time in the earth’s
crust, although it may be of importance in reference to super-
ficial changes, such as the formation of mountain chains, or
lines of volcanic vents, or regions of earthquakes, may still
be quite insignificant in relation to the size of an external
shell having a diameter of 50 miles.
10. The supposed greater energy of the volcanic forces in
the remoter periods is by no means borne out by geological
observations on the quantity of lava produced in those several
periods.
11. The old notion that the crystalline rocks, whether
stratified or unstratified, such as granite and gneiss, were
produced in the lower parts of the earth’s crust at the expense
VOL. II. R
942 RECAPITULATION OF CHAPS. XXXII. AND XXXIITI. [Cu. XXXII,
of a central nucleus slowly cooling from a state of fusion by
heat, has had to be given up, now that granite is found to be
of all ages, and now that we know the metamorphic rocks to
be altered sedimentary deposits implying the denudation of a
previously solidified crust.
12. (Chap. XXIII.) The powerful agency of steam or
aqueous vapour in volcanic eruptions leads us to compare its
power of propelling lava to the surface with that which it
exerts in driving up water in the pipe of an Icelandic Geyser.
Various gases, also rendered liquid by pressure at great
depths, may aid in causing volcanic outbursts, and in fissuring
and convulsing the rocks during earthquakes.
13. The number of active volcanos on sea-coasts and in
islands is probably connected with the agency of water in
voleanic operations. The latest chemical observations on
the products of recent eruptions, favour the doctrine that
large bodies of salt water gain access to the volcanic foci.
14. The flexibility of certain parts of the earth’s crust, as
deduced from observations on earthquakes, may imply the
continuous existence of vast reservoirs of melted matter
beneath the surface, but such nevertheless as might hold a
very subordinate place in the earth’s crust.
15. The existence of electrical currents in the earth’s crust,
and the changes in direction which they may undergo after
great geological revolutions in the position of mountain chains
and of land and sea, the connection also of solar and terres-
trial magnetism, and of this last with electricity and chemical
action, may help us to conceive such a cycle of change as may
restore to the planet the heat supposed to be lost by radiation
into space.
16. The permanent elevation and subsidence of land now
observed, and which has been going on throughout past
geological ages, may be commeutdd with the expansion and
contraction of parts of the solid srust, some of which have
been cooling from time to time, while others have been
gaining fresh accessions of heat.
17. In the preservation of the average proportion of land
and sea, the igneous agents exert a conservative power, Te-
storing the unevenness of the surface, which the levelling
are
to the well-
oxistence of
Cu, XXXIIL] RECAPITULATION OF CHAPS. XXXII. AND XXXII. 243
power of water in motion would tend to destroy. If thé
diameter of the planet remains always the same, the down-
ward movements of the crust must be somewhat in excess, to
counterbalance the effect of voleanos and mineral springs,
which are always bringing up materials from the interior of
the earth and pouring tubes out at the surface, so as to raise
its level. Subterranean movements, therefore, however de-
structive they may be during great earthquakes, are essential
to the well-being of the habitable surfa ce, and even the very
existence of terrestrial species.
BOOK III.
CHANGES OF THE ORGANIC WORLD NOW IN PROGRESS.
CHAPTER XXXIV.
LAMARCK ON THE TRANSMUTATION OF SPECIES.
IVISION OF THE SUBJECT—— EXAMINATION OF THE QUESTION, WHETHER
ECIES, AND HIS CONJECTURES RESPECTING THE ORIGIN
OF EXISTING ANIMALS AND PLANTS-——-HIS THEORY OF THE TRANSFORMATION
THE ORANG-OUTANG INTO THE HUMAN SPECIES
HirHerto we have been occupied, from Chap. XV. to Chap.
XXXIII., with the consideration of the changes brought
about on the earth’s surface, within the period of human ob-
servation, by inorganic agents; such, for example, as rivers,
marine currents, volcanos, and earthquakes. But there is
another class of phenomena relating to the organic world,
which have an equal claim on our attention, if we desire to
obtain possession of all the preparatory knowledge respecting
the existing course of nature, which may be available in the
interpretation of geological monuments. It appeared from
our preliminary sketch of the progress of the science, that
the most lively interest was excited among its earlier culti-
vators, by the discovery of the remains of animals and plants
in the interior of mountains frequently remote from the sea.
Much controversy arose respecting the nature of these
remains, the causes which may have brought them into so
singular a position, and the want of a specific agreement
between them and known animals and plants. To qualify
ourselves to form just views on these curious questions, we
must first study the present condition of the animate creation
on the globe.
ind plants be
Secondly, ¥
individuals of
or be preserve
framework of
ages a8 MONnUr
time when the
Before we
fndeavour to |
We attach to ¢
iM geology tha
they ‘who cont
Cy. XXXIV.] MEANING OF THE TERM ‘SPECIES: 245
This branch of our enquiry naturally divides itself into two
parts —
First, we may consider the various meanings which have
been attached to the term ‘species,’ and the question which
has been raised whether each species has remained from its
origin the same, only varying within certain fixed and de-
fined limits, or whether a species may be indefinitely modified
in the course of a long series of generations. This will lead
us to examine into the dependence of each species of animal
and plant on certain fluctuating and temporary conditions in
the animate and inanimate world, and the consequent ex-
tinction of species one after the other, and the manner in
which the places left vacant may be supplied by new animals
and plants better fitted for the new conditions.
Secondly, we may consider the processes by which some
individuals of certain species may occasionally become fossil,
or be preserved in such a manner as to form part of the solid
framework of the earth’s crust, so that they may serve in after
ages as monuments of the state of the living world at the
time when they became fossil.
Before we can advance a step in our enquiry, we must
endeavour to make up our minds as to the meaning which
we attach to the term ‘species.’ This is even more necessary
in geology than in the ordinary studies of the naturalist; for
they who contend for the indefinite modifiability of species,
admit, nevertheless, that a botanist or zoologist may reason
as if the specific character were constant, because they confine
their observations to a brief period of time. Just as the
astronomer, in constructing his maps of the heavens, may
proceed century after century as if the apparent places of the
fixed stars remained absolutely the same, and as if no altera-
tion were brought about by the proper motion of the sun;
80, it is said, in the organic world, the stability of a species
may be taken ag absolute, if we do not extend our views
bey ond the narrow period of human history; but let a suffi-
Cent number of centuries elapse, to allow of important
revolutions in climate, physical geography, and other cir-
cumstances, and the characters, say they, of the descendants
246 LAMARCK’S THEORY OF THE
[Cu. XXXTy,
of common parents may deviate indefinitely from their original
e.
Now, if these doctrines be tenable, we are at once presented
with a principle of incessant change in the organic world ;
and no degree of dissimilarity in the plants and animals
which may formerly have existed, and are found fossil, would
entitle us to conclude that they may not have been the proto-
types and progenitors of the species now living. Accordingly
MM. Lamarck and Geoffroy St. Hilaire declared their opinion
in the beginning of the present century that there had been
an uninterrupted succession in the animal kingdom, effected
by means of generation, from the earliest ages of the world
up to the present day, and that the ancient animals whose
remains have been preserved in the strata, however different,
may nevertheless have been the ancestors of those now in
being. In order to explain the facts and reasoning by which
this theory was originally supported, I cannot do better than
offer the reader a rapid sketch of the proofs which were
regarded by Lamarck as confirmatory of his views, shared
as they were to a great extent by his contemporary, Geoffroy
St. Hilaire.*
Lamarck’s arguments in favour of the transmutation of
species.—The name of ‘species,’ observes Lamarck, has been
usually applied to ‘every collection of similar individuals
produced by other individuals like themselves.’+ This defini-
tion, he admits, is correct; because every living individual
* I have reprinted in this chapter,
word for word, my abstract of Lamarck’s
doctrine of transmutation as drawn up
by me in 1832 in the first edition of the
‘Principles of Geology,’ vol. ii. chap. ib
Ihave thought it right to do this in jus-
tice to Lamarck, ie order to show how
ng
large body of naturalists respecting the
indefinite variability of species, and the
reader must
bear in mind that when I made this
analysis of the ‘Philosophie Zoolo-
gique,’ in 1832, I was altogether op-
posed to the doctrine that the animals
d plants now living were the lineal
descendants of distinct species only
known to us in a fossil state. There is,
therefore, no room for suspicion that my
account of the Lamarckian hypothesis,
itten by me thirty-five years ago, de-
riv a any ence ing from my own views
tending to bring it more into harmony
with the aces since promulgated by
Darwin. The law of natural selection,
by which the last-mentioned great
naturalist has thrown so much new light
on the origin of species, will be ex-
i he next and succeeding
+ Phil Zool. tom, i. p. 54. 1809.
ms
menting “
yese
Jong ao a
ton, 8°
woth an extent
to vary
inh si to
rord ‘species,
argument : =
diferent orga
globe, the “
what ought to
to limit and di
lections are ¢
and all our ii
ubitrary dete
upon the slig
form characte
Sometimes yr
lightly differ
Varieties,
a gre
ate)
me Cu. XXXIV.] TRANSMUTATION OF SPECIES. 247
mal pears a very near resemblance to those from which it springs.
But this is not all which is usually implied by the term
te | ‘species; ’ for the majority of naturalists agree with Linnzeus
a in supposing that all the individuals propagated from one
tal stock have certain distinguishing characters in common,
‘ald which will never vary, and which have remained the same
to. | since the creation of each species. Lamarck proposed,
igly therefore, to amplify the received definition in the following
Mon manner. ‘A species consists of a collection of individuals
een | resembling each other, and reproducing their like by genera-
‘ted tion, so long as the surrounding conditions do not alter to
orld | such an extent as to cause their habits, characters, and forms
103e | to vary.’
ent, In order to show the grounds for this limitation of the
rin word ‘species, Lamarck entered upon the following line of
Lich | argument :—The more we advance in the knowledge of the
han | different organised bodies which cover the surface of the
ere | globe, the more our embarrassment increases to determine
a what ought to be regarded as a species, and still more how
roy to limit and distinguish genera. In proportion as our col-
lections are enriched, we see almost every void filled up,
i . and all our lines of separation effaced! we are reduced to
> arbitrary determinations, and are sometimes fain to seize
upon the slight differences of mere varieties, in order to
- | form characters for what we choose to call a species; and
wi | sometimes we are induced to pronounce individuals but
ual ) slightly differing and which others regard as true species, to
asl be varieties.
peal The greater the abundance of natural objects assembled
together, the more do we discover proofs that everything
passes by insensible shades into something else; that even
the more remarkable differences are evanescent, and that
nature has, for the most part, left us nothing at our disposal
for establishing distinctions, save trifling, and, in some re-
ses 3S
SB = =
— ny
SSS ee = eer + eee
nf
W spects, puerile peculiarities.
s e find that many genera amongst animals and plants
if are of such an extent, in consequence of the number of
& species referred to them, that the study and determination
08 of these last has become almost impracticable. When the
248 LAMARCK’S THEORY OF THE
[Cu. XXXTYV.
species are arranged in a series, and placed near to each
other, with due regard to their natural affinities, they each
differ in so minute a degree from those next adjoining, that
they almost melt into each other, and are in a manner con-
founded together. If we see isolated species, we may presume
the absence of some more closely connected, and which have
not yet been discovered. Already are there genera, and
even entire orders—nay, whole classes—which present an
approximation to the state of things here indicated.
If, when species have been thus placed in a regular series,
we select one, and then, making a leap over several inter-
mediate ones, we take a second, at some distance from the
first, these two will, on comparison, be seen to be very dis-
similar; and it is in this manner that every naturalist begins
to study the objects which are at his own door. He then
finds it an easy task to establish generic and specific distinc-
tions; and it is only when his experience is enlarged, and
when he has made himself master of the intermediate links,
that his difficulties and ambiguities begin. But while we
are thus compelled to resort to trifling and minute characters
in our attempt to separate species, we find a striking disparity
between individuals which we know to have descended from
a common stock; and these newly acquired peculiarities are
regularly transmitted from one generation to another, consti-
tuting what are called races.
From a great number of facts, continues the author, we
learn that in proportion as the individuals of one of our
species change their situation, climate, and manner of living,
they change also, by little and little, the consistence and
proportions of their parts, their form, their faculties, and
even their organisation, in such a manner that everything in
them comes at last to participate in the mutations to which
they have been exposed. Even in the same climate, a great
difference of situation and exposure causes individuals to
vary ; but if these individuals continue to live and to be
reproduced under the same difference of circumstances,
distinctions are brought about in them which become in
some degree essential to their existence. In a word, at the
end of many successive generations, these individuals, which
give rise to @
more develop
quite peculiar
What natu
occasion sudd:
a species has |
vegetables ta
gardens, und:
tecognisable g
hairy become
"
|
|
|
:
|
|
|
Cu, XXXIV.] TRANSMUTATION OF SPECIES. 249
originally belonged to another species, are transformed into
a new and distinct species.*
Thus, for example, if the seeds of a grass, or any other
plant which grows naturally in a moist meadow, be acci-
dentally transported, first to the slope of some neighbouring
hill, where the soil, although at a greater elevation, is damp
enough to allow the plant to live; and if, after having lived
there, and having been several times regenerated, it reaches
by degrees the drier and almost arid soil of a mountain
declivity, it will then, if it succeeds in growing, and per-
petuates itself for a series of generations, be so changed that
botanists who meet with it will regard it as a particular
species.* The unfavourable climate in this case, deficiency
of nourishment, exposure to the winds, and other causes,
give rise to a stunted and dwarfish race, with some organ
more developed than others, and having proportions often
quite peculiar.
What nature brings about in a great lapse of time, we
occasion suddenly by changing the circumstances in which
a species has been accustomed to live. All are aware that
vegetables taken from their birthplace, and cultivated in
gardens, undergo changes which render them no longer
recognisable as the same plants. Many which were naturally
hairy become smooth, or nearly so; a great number of such
as were creepers and trailed along the ground, rear their
stalks and grow erect. Others lose their thorns or asperities ;
others, again, from the ligneous condition which characterised
their stem in the hot climates, where they were indigenous,
pass to the herbaceous ; and, among them, some which were
perennials become mere annuals. So well do botanists know
the effects of such changes of circumstances, that they are
averse to describe species from garden specimens, unless
they are sure that they have been cultivated for a very short
period.
‘Is not the cultivated wheat’ (Triticum sativum), asks
Lamarck, ‘a vegetable brought by man into the state in
which we now see it? Let anyone tell me in what country
@ similar plant grows wild, unless where it has escaped from
* Phil. Zool. tom. i. p. 63.
250 CHANGES IN ANIMALS AND PLANTS
(Cu. XXXIV.
cultivated fields? Where do we find in nature our cabbages,
lettuces, and other culinary vegetables, in the state in which
they appear in our gardens? Is it not the same in regard
to a great quantity of animals which domesticity has changed
or considerably modified?’* Our domestic fowls and
pigeons are unlike any wild birds. Our domestic ducks and
geese have lost the faculty of raising themselves into the
higher regions of the air, and crossing extensive countries in
their flight, like the wild ducks and wild geese from which
they were originally derived. A bird which we breed in a
cage cannot, when restored to liberty, fly like others of the
same species which have been always free. This small
alteration of circumstances, however, has only diminished
the power of flight, without modifying the form of any part
of the wings. But when individuals of the same race are
retained in captivity during a considerable length of time,
the form even of their parts is gradually made to differ,
especially if climate, nourishment, and other circumstances
be also altered.
The numerous races of dogs which we have produced by
domesticity are nowhere to be found in a wild state. In
nature we should seek in vain for mastiffs, harriers, spaniels,
ereyhounds, and other races, between which the differences
are sometimes so great that they would be readily admitted
as specific between wild animals; ‘yet all these have sprung
originally from a single race, at first approaching very near
to a wolf, if, indeed, the wolf be not the true type which at
some period or other was domesticated by man.’
Although important changes in the nature of the places
which they inhabit modify the organisation of animals as
well as vegetables; yet the former, says Lamarck, require
more time to complete a considerable degree of transmu-
tation; and, consequently, we are less sensible of such
occurrences. Next to a diversity of the medium in which
animals or plants may live, the circumstances which have
most influence in modifying their organs are differences in
exposure, climate, the nature of the soil, and other local
particulars. These circumstances are as varied as are the
* Phil. Zool. tom. i. p. 227.
ll
a
&
ame parts be
jprelopment foll
w, Other org
jininished in $1
shi in their pl
lixharge of nev
I must here i1
tt no positive
ume entirely n,
‘one other sup]
Dh
Necesgion of o
ss 7
Cu, XXXIV.] CAUSED BY DOMESTICATION. 251
characters of the species, and, like them, pass by insensible
shades into each other, there being every intermediate gre
dation between the opposite extremes. But each locality
remains for a very long time the same, and is altered me
slowly that we can only become conscious of the reality of
the change by consulting geological monuments, by which
we learn that the order of things which now reigns in each
place has not always prevailed, and by inference anticipate
that it will not always continue the same.*
Every considerable alteration in the local circumstances in
which each race of animals exists causes a change in their
wants, and these new wants excite them to new actions and
habits. These actions require the more frequent employment
of some parts before but slightly exercised, and then greater
development follows as a consequence of their more frequent
use. Other organs no longer in use are impoverished and
diminished in size, nay, are sometimes entirely annihilated,
while in their place new parts are insensibly produced for the
discharge of new functions.+
I must here interrupt the author’s argument, by observing,
that no positive fact is cited to exemplify the substitution of
some entirely new sense, faculty, or organ, in the room of
some other suppressed as useless. All the instances adduced
go only to prove that the dimensions and strength of mem-
bers and the perfection of certain attributes may, in a long
succession of generations, be lessened and enfeebled by dis-
use; or, on the contrary, be matured and augmented by
active exertion ; just as we know that the power of scent is
feeble in the greyhound, while its swiftness of pace and. its
acuteness of sight are remarkable—that the harrier and
stag-hound, on the contrary, are comparatively slow in their
movements, but excel in the sense of smelling.
It was necessary to point out to the reader this important
chasm in the chain of evidence, because he might otherwise
imagine that I had merely omitted the illustrations for the
sake of brevity ; but the plain truth is, that there were no
examples to be found; and when Lamarck talked ‘of the
* Phil. Zool. tom. i. p. 232.
T Ibid. p. 234.
252 LAMARCR’S THEORY OF THE [CH XOX ys
efforts of internal sentiment,’ ‘the influence of subtle fluids,’
and ‘acts of organisation,’ as causes whereby animals and
plants acquire new organs, he substituted names for things ;
and resorted to fictions almost as ideal as the ‘plastic
virtue’ of some geologists of the middle ages.
It is evident that, if some well-authenticated facts could
have been adduced to establish one complete step in the pro-
cess of transformation, such as the appearance, in indi-
viduals descending from a common stock, of a sense or organ
entirely new, and a complete disappearance of some other
enjoyed by their progenitors, time alone might then be sup-
posed sufficient to bring about any amount of metamor-
phosis. We must bear in mind, therefore, that a point so vital
to the theory of transmutation, was gratuitously assumed
by its advocate.
But to proceed with the system: it being taken for eranted,
as an undoubted fact, that a change of external circum-
stances may cause one organ to become entirely obsolete and
a new one to be developed, such as never before belonged to
the species, the following proposition is announced, which,
however startling it may seem, is logically deduced from the
assumed premises. It is not the organs, or, in other words,
the nature and form of the parts of the body of an animal,
which have given rise to its habits and its particular facul-
ties; but, on the contrary, its habits, its manner of living,
and those of its progenitors, have in the course of time
determined the form of its body, the number and condition
of its organs—in short, the faculties which it enjoys. Thus
otters, beavers, waterfowl, turtles, and frogs, were not made
web-footed in order that they might swim; but their wants
having attracted them to the water in search of prey, they
stretched out the toes of their feet to strike the water and
move rapidly along its surface. By the repeated stretching
of their toes, the skin which united them at the base ac-
quired a habit of extension, until, in the course of time, the
broad membranes which now connect their extremities were
formed.
In like manner, the antelope and the gazelle were not
endowed with light agile forms, in order that they might
unaltered
ought ne
such sexi
animals ;
tions are
Hybrids }
between {
alone, say
a
Cu. XXXIV.] TRANSMUTATION OF SPECIES. 258
escape by flight from carnivorous animals ; but, having been
exposed to the danger of being devoured by lions, tigers, and
other beasts of prey, they were compelled to exert themselves
in running with great celerity ; a habit which, in the course
of many generations, gave rise to the peculiar slenderness of
their legs, and the agility and elegance of their forms.
The giraffe was not gifted with a long flexible neck be-
cause it was destined to live in the interior of Africa, where
the soil was arid and devoid of herbage; but, being reduced
by the nature of that country to support itself on the foliage
of lofty trees, it contracted a habit of stretching itself up
to reach the high boughs, until its neck became so elongated
that it could raise its head to the height of 20 feet above the
ground.
Another line of argument was then entered upon, in
further corroboration of the instability of species. In order,
it was said, that individuals should perpetuate themselves
unaltered by generation, those belonging to one species
ought never to ally themselves to those of another; but
such sexual unions do take place, both among plants and
animals ; and though the offspring of such irregular connec-
tions are usually sterile, yet such is not always the case.
Hybrids have sometimes proved prolific, where the disparity
between the species was not too great; and by this means
alone, says Lamarck, varieties may gradually be created by
near alliances, which would become races, and in the course
of time would constitute what we term species.*
After explaining his reasons for believing in the soundness
of the arguments and inferences above set forth, Lamarck
next proceeded to enquire what were the original types of
form, organisation, and instinct, from which the diversities
of character, as now exhibited by animals and plants, were
derived? We know, said he, that individuals which are
mere varieties of the same species would, if their pedigree
could be traced back far enough, terminate in a single stock ;
80, according to the same train of reasoning, the species of
a genus, and even the genera of a great family, must have
* Phil. Zool. p. 64.
254 LAMARCK’S THEORY OF THE
[Cu. XXXIV,
had a common point of departure. What, then, was the
single stem from which so many varieties of form have
ramified? Were there many of these, or are we to refer the
origin of the whole animate creation, as the Hgyptian
priests did that of the universe, to a single egg ?
n the absence of any positive data for framing a theory
on so obscure a subject, the following considerations were
deemed by Lamarck of importance to guide conjecture.
In the first place, if we examine the whole series of known
animals, from one extremity to the other, when they are
arranged in the order of their natural relations, we find that
we may pass progressively, or, at least, with very few inter-
ruptions, from beings of more simple to those of a more com-
pound structure; and, in proportion as the complexity of
their organisation increases, the number and dignity of their
faculties increase also. Among plants, a similar approxima-
tion to a graduated scale of being is apparent. Secondly, it
appears, from geological observations, that plants and animals
of more simple organisation existed on the globe before the
appearance of those of more compound structure, and the
latter were successively formed at more modern periods; each
new race being more fully developed than the most perfect of
the preceding era.
Of the truth of the last-mentioned geological theory,
Lamarck seems to have been fully persuaded; and he also
shows that he was deeply impressed with a belief prevalent
amongst the older naturalists, that the primeval ocean in-
vested the whole planet long after it became the habitation
of living beings; and thus he was inclined to assert the
priority of the types of marine animals to those of the
terrestrial, so as to fancy, for example, that the testacea of
the ocean existed first, until some of them, by gradual evolu-
tion, were improved into those inhabiting the land.
These speculative views had already been, in a great degree,
anticipated by Demaillet in his Telliamed, and by several other
writers who preceded Lamarck ; so that the tables were com-
pletely turned on the philosophers of antiquity, with whom
it was a received maxim, that created things were always
most perfect when they came first from the hands of their
others we
views, in¢
with life ;
added to
Were afte
faculties -
to prog ress
the ration:
DG jf nee,
Cu. XXXIV.] TRANSMUTATION OF SPECIES. 255
Maker; and that there was a tendency to progressive dete-
rioration in sublunary things when left to themselves—
———— omnia fatis
In pejus ruere, ac retro sublapsa referri.
So deeply was the faith of the ancient schools of philo-
sophy imbued with this doctrine, that, to check this uni-
versal proneness to degeneracy, nothing less than the re-
intervention of the Deity was thought adequate; and
it was held, that thereby the order, excellence, and pristine
energy of the moral and physical world had been repeatedly
restored.
But when the possibility of the indefinite modification
of individuals descending from common parents was once
assumed, as also the geological inference respecting the
progressive development of organic life, it was natural that
the ancient dogma should be rejected, or rather reversed,
and that the most simple and imperfect forms and faculties
should be conceived to have been the originals whence all
others were developed. Accordingly, in conformity to these
views, inert matter was supposed to have been first endowed
with life; until, in the course of ages, sensation was super-
added to mere vitality: sight, hearing, and the other senses
were afterwards acquired; then instinct and the mental
faculties; until, finally, by virtue of the tendency of things
to progressive improvement, the irrational was developed into
the rational.
The reader, however, will immediately perceive that when
all the higher orders of plants and animals were thus sup-
posed to be comparatively modern, and to have been derived
in a long series of generations from those of more simple
conformation, some further hypothesis became indispensable,
in order to explain why, after an indefinite lapse of ages,
there were still so many beings of the simplest structure.
Why have the majority of existing creatures remained
stationary throughout this long succession of epochs, while
others have made such prodigious advances? Why are there
such multitudes of infusoria and polyps, or of conferve and
other cryptogamic plants ? Why, moreover, has the process
256 LAMARCK’S THEORY OF THE [CH. XXXIV.
of development acted with such unequal and irregular force
on those classes of beings which have been greatly perfected,
so that there are wide chasms in the series ; gaps so enorm-
ous, that Lamarck fairly admits we can never expect to
fill them up by future discoveries ?
The following hypothesis was provided to meet these ob-
jections. Nature, we are told, is not an intelligence, nor
the Deity ; but a delegated power—a mere instrument—a
piece of mechanism acting by necessity—an order of things
constituted by the Supreme Being, and subject to laws which
are the expressions of His will. This Nature is obliged to
proceed gradually in all her operations ; she cannot produce
animals and plants of all classes at once, but must always
begin by the formation of the most simple kinds, and out of
them elaborate the more compound, adding to them, succes-
sively, different systems of organs, and multiplying more and.
more their number and energy.
This Nature is daily engaged in the formation of the ele-
mentary rudiments of animal and vegetable existence, which
correspond to what the ancients termed spontaneous genera-
toon. She is always beginning anew, day by day, the
work of creation, by forming monads, or ‘rough draughts’
(6bauches), which are the only living things she gives birth
to directly.*
There are distinct primary rudiments of plants and animals,
and probably of each of the great divisions of the animal
and vegetable kingdoms.t These are gradually developed
into the higher and more perfect classes by the slow but
unceasing energy of two influential principles: first, the
tendency to progressive advancement in organisation, accom-
panied by greater dignity in instinct, intelligence, dc. ;
secondly, the force of external cirewmstances, or of variations
in the physical condition of the earth, or the mutual re-
lations of plants and animals. For, as species spread them-
selves gradually over the globe, they are exposed from time
to time to variations in climate, and to changes in the
* Phil. Zool. pp. 65 and 2
+ Animaux sans Vert. Pte i + As tpduiees p. 56 note.
Cu. XXXIV.] TRANSMUTATION OF SPECIES. 257
quantity and quality of their food; they yal sat
plants and animals which assist or retard their evel pment
by supplying them with nutriment, or destroying their foes.
The nature, also, of each locality is in itself fluctuating; go
that, even if the relation of other animals and plants were
invariable, the habits and organisation of species would be
modified by the influence of local revolutions.
Now, if the first of these principles, the tendency to pro-
gressive development, were left to exert itself with perfect
freedom, it would give rise, says Lamarck, in the course of
ages, to a graduated scale of being, where the most insensible
transition might be traced from the simplest to the most
compound structure, from the humblest to the most exalted
degree of intelligence. But, in consequence of the perpetual
interference of the external causes before mentioned, this
regular order is greatly interfered with, and an approxi-
mation only to such a state of things is exhibited by the
animate creation, the progress of some races being retarded
by unfavourable, and that of others accelerated by favourable,
combinations of circumstances. Hence, all kinds of anomalies
interrupt the continuity of the plan; and chasms, into which
whole genera or families might be inserted, are seen to sepa-
rate the nearest existing portions of the series.
Lamarck’s theory of the transformation of the orang-outang
into the human species.—Such is the machinery of the La-
marckian system; but the reader will hardly, perhaps, be
able to form a perfect conception of so complicated a piece
of mechanism, unless it is exhibited in action, so that we
may see in what manner it can work out, under the author’s
guidance, all the extraordinary effects which we behold in the
present state of the animate creation. Without attempting
to follow the author through the entire process by which,
after a countless succession of generations, a small gelatinous
body is transformed into an oak or an ape, I shall pass on at
once to the last grand step in the progressive scheme, by
which the orang-outang, having been evolved out of a monad,
is made slowly to attain the attributes and dignity of man.
One of the races of quadrumanous animals which had
reached the highest state of perfection, lost, by constraint of
S
VOL. II.
258 CONVERSION OF THE ORANG-OUTANG [Cx. XXXIV.
circumstances, the habit of climbing trees, and of hanging on
by grasping the boughs with their feet as with hands. The
individuals of this race being obliged, for a long series of
generations, to use their feet exclusively for walking, and
ceasing to employ their hands as feet, were transformed into
bimanous animals, and what before were thumbs became
mere toes, no separation being required when their feet were
used solely for walking. Having acquired a habit of holding
themselves upright, their legs and feet assumed, insensibly,
a conformation fitted to support them in an erect attitude,
till at last these animals could no longer go on all-fours
without much inconvenience.
The Angola orang (Sima troglodytes, Linn.) is the most
perfect of animals; much more so than the Indian orang
(Simia Satyrus), which has been called the orang-outang,
although both are very inferior to man in corporeal powers
and intelligence. These animals frequently hold themselves
upright; but their organisation has not yet been sufficiently
modified to sustain them habitually in this attitude, so that
the standing posture is very uneasy to them. When the
Indian orang is compelled to take flight from pressing
danger, he immediately falls down upon all-fours, showing
clearly that this was the original position of the animal.
Even in man, whose organisation, in the course of a long
series of generations, has advanced so much farther, the
upright posture is fatiguing, and can be supported only for
a limited time, and by aid of the contraction of many muscles.
If the vertebral column formed the axis of the human body,
and supported the head and all the other parts in equilibrium,
then might the upright position be a state of repose; but,
as the human head does not articulate in the centre of
eravity, as the chest, belly, and other parts press almost
entirely forward with their whole weight, and as the verte-
bral column reposes upon an oblique base, a watchful activity
is required to prevent the body from falling.* Children who
have large heads and prominent bellies can hardly walk at
the end even of two years; and their frequent tumbles indi-
* Phil. Zool. p. 353.
Cu, XXXIV.] INTO THE HUMAN SPECIES. 259
cate the natural tendency in man to resume the quadrupedal
state.*
Now, when so much progress had been made by the
quadrumanous animals before mentioned, that they could
hold themselves habitually in an erect attitude, and were
accustomed to a wide range of vision, and ceased to use
their jaws for fighting and tearing, or for clipping herbs for
food, their snout became gradually shorter, their incisor
teeth became vertical, and the facial angle grew more open.
Among other ideas which the natural tendency to perfection
engendered, the desire of ruling suggested itself, and this
‘race succeeded at length in getting the better of the other
animals, and made themselves masters of all those spots on
the surface of the globe which best suited them. They drove
out the animals which approached nearest them in organisa-
tion and intelligence, and which were in a condition to dis-
pute with them the good things of this world, forcing them
to take refuge in deserts, woods, and wildernesses, where
their multiplication was checked, and the progressive de-
velopment of their faculties retarded ; while, in the mean-
time, the dominant race spread itself in every direction, and
lived in large companies, where new wants were successively
created, exciting them to industry, and gradually perfecting
their means and faculties.
In the supremacy and increased intelligence acquired by
the ruling race, we see an illustration of the natural tendency
of the organic world to grow more perfect; and, in their
influence in repressing the advance of others, an example of
one of those disturbing causes before enumerated, that force
of external cirewmstances which causes such wide chasms in
the regular series of animated being.
When the individuals of the dominant race became very
numerous, their ideas greatly increased in number, and they
felt the necessity of communicating them to each other, and
of augmenting and varying the signs proper for the com-
munication of ideas. Meanwhile the inferior quadrumanous
animals, although most of them were gregarious, acquired
no new ideas, being persecuted and restless in the deserts,
* Phil. Zool. p. 354.
s 2
260 ORIGIN OF SPEECH. (Cu. XXXIV.
and obliged to fly and conceal themselves, so that they
conceived no new wants. Such ideas as they already had
remained unaltered, and they could dispense with the com-
munication of the greater part of these.. To make them-
selves, therefore, understood by their fellows, required merely
a few movements of the body or limbs—whistling, and the
uttering of certain cries varied by the inflexions of the voice.
On the contrary, the individuals of the ascendant race,
animated with a desire of interchanging their ideas, which
became more and more numerous, were prompted to multiply
the means of communication, and were no longer satisfied
with mere pantomimic signs, nor even with all the possible
inflexions of the voice, but made continual efforts to acquire
the power of uttering articulate sounds, employing a few at
first, but afterwards varying and perfecting them according
to the increase of their wants. The habitual exercise of
their throat, tongue, and lips, insensibly modified the con-
formation of these organs, until they became fitted for the
faculty of speech.*
In effecting this mighty change, ‘the exigencies of the
individuals were the sole agents; they gave rise to efforts,
and the organs proper for articulating sounds were developed
by their habitual employment.’ Hence, in this peculiar race,
the origin of the admirable faculty of speech; hence also the
diversity of languages, since the distance of places where the
individuals composing the race established themselves soon
favoured the corruption of conventional signs.t
In conclusion, it may be proper to observe that the above
sketch of the Lamarckian theory is no exaggerated picture,
and those passages which have probably excited the greatest
surprise in the mind of the reader are literal translations from
the original.
* Lamarck’s Phil. Zool. tom. i. p. 356. t Ibid. p. 357.
CHAPTER XXXYV.
uch
THEORIES AS TO THE NATURE OF SPECIES, AND DARWIN
ply
p * ON NATURAL SELECTION.
hed
ble OBJECTIONS URGED AGAINST THE THEORY OF TRANSMUTATION AND L AMARCK’S
Me REPLIES—MUMMIES OF ANIMALS AND SEEDS OF PLANTS FROM EGYPTIAN TOMBS
ure IDENTICAL IN CHARACTER WITH SPECIES NOW LIVING—LINN EUS’ OPINION
at THAT SPECIES HAVE BEEN CONSTANT SINCE THEIR CREATION—BROCCHIS
ine HYPOTHESIS OF THE GRADUAL DIMINUTION OF VITAL POWER IN A SPECIES
5 —WHETHER IF NEW SPECIES ARE CREATED FROM TIME TO TIME THEIR
a FIRST APPEARANCE MUST HAVE BEEN WITNESSED BY THE NATURALIST—
on- GEOFFROY ST. HILAIRE AND LAMARCK ON RUDIMENTARY ORGANS—THE
QUESTION OF SPECIES AS TREATED OF IN THE ‘VESTIGES OF CREAT TION ’—MR
the ALFRED WALLACE ON THE LAW WHICH HAS REGULATED THE INTRODUCTION
OF NEW SPECIES—MR. DARWIN ON NATURAL SELECTION AND MR. WALLACE
ON THE SAME—DARW. IN’ S ORIGIN OF SPECIES AND THE CHANGE OF OPINION
the WHICH IT EFFECTED—DR. HOOKER’S FLORA OF AUSTRALIA AND HIS VIEWS
rts, AS TO THE ORIGIN OF SPECIES BY VARIATION.
OBJECTIONS URGED AGAINST THE THEORY OF TRANSMU-
TATION AND. LAuMarcK’s Repitirts.—The theory of the
he transmutation of species, considered in the last chapter,
he was received with some degree of favour by many naturalists,
yo from their desire to dispense, as far as possible, with the
repeated intervention of a First Cause, as often as geological
yve monuments attest the successive appearance of new races
re, of animals and plants, and the extinction of those pre-
est existing. But, independently of a predisposition to account,
op if possible, for a series of changes in the organic world by
the regular action of secondary causes, we have seen that in
truth many perplexing difficulties present themselves to all
who attempt to establish the reality and constancy of the spe-
cific character. And if once there appears ground for
reasonable doubt, in regard to the constancy of species, the
amount of transformation which they are capable of under-
going might seem to resolve itself into a mere question of
262 THEORIES AS TO THE NATURE OF SPECIES. [Cu. XXXV.
the quantity of time assigned to the past and future duration
of animate existence.
The opponents of Lamarck objected to his arguments that
he could not adduce a single instance of the gradual conver-
sion of any one species of animal or plant into another ; and
that in his appeal to the results obtained by the breeder and
horticulturist, he had failed to show sucha change in the
structure and constitution of individuals descending from a
common stock as might fairly entitle the new race to rank as
a distinct species. It was conceded, for example, on all hands
that the modifications produced in the different races of dogs
exhibit the influence of man in the most striking point of view.
These animals had been transported into every climate, and
placed in every variety of circumstances : they had been made,
as M. Dureau de la Malle observed, the servant, the com-
panion, the guardian, and the intimate friend of man, and
the power of a superior genius had had a wonderful influence
not only on their forms, but on their manners and intellj-
gence.* Different races have undergone remarkable changes
in the quantity and colour of their clothing; the dogs of
Guinea are almost naked, while those of the arctic circle are
covered with a warm coat both of hair and wool, which enables
them to bear the most intense cold without inconvenience.
There are differences also of another kind no less remarkable,
as in size, the length of their muzzles, and the convexity of
their foreheads. ‘The difference in stature,’ said Cuvier,
‘in some canine races ag compared to others is as 1 to 5 in
linear dimensions,’ making a difference of a hundredfold in
volume.t
But, said the advocates of the immutability of species, if
we look for some essential changes, such as might serve as a
foundation for the theory of Lamarck, respecting the growth
of new organs and the gradual obliteration of others, we find
nothing of the kind. In all the varieties of the dog, as
Cuvier affirmed, the relation of the bones with each other
remains essentially the same; the form of the teeth never
* Dureau de la Malle, An. des Sei. Nat., tom. xxi. p. 53, Sept. 18380.
t Cuvier, Discours Prélimin., p. 128.
ee
most 8
the do
fertile
cated |
yarieti
offspri
mule.
parent
Wh
the an
cation,
sion, t:
accura
hande¢
might
4
—_ YE SP EZ 7)
et
oc Eh = |
Cu, XXXV.] EGYPTIAN MUMMIES. 263
changes in any perceptible degree, except that, in some
individuals, one additional false grinder occasionally appears,
sometimes on the one side, and sometimes on the other.*
The greatest departure from a common type and it con-
stitutes the maximum of variation as yet known in the animal
kingdom—is exemplified in those races of dogs which have <
supernumerary toe on the hind foot with the corresponding
tarsal bones; a variety analogous to one presented by six-
fingered families of the human race.t
It was moreover urged, and of all objections this was the
most serious, that however distinct were the various races of
the dog they could all breed freely together and produce
fertile offspring, as was also the case with various domesti-
cated birds, such as the common fowl, of which such marked
varieties had been obtained. In no instance had the mongrel
offspring been shown to be habitually sterile, like the common
mule or the offspring of the horse and ass, where the two
parents belong to two undoubtedly distinct species.
When the controversy had been brought to this point, and
the amount of possible variation of animals under domesti-
cation, and of plants under culture, was still under discus-
sion, the followers of Lamarck sometimes lamented that no
accurate descriptions, and figures of known species, had been
handed down from the earliest periods of history, such as
might have afforded data for comparing the condition of the
game species, at two periods considerably remote. To this,
however, the opponents of transmutation replied, that we are
in a great measure independent of such evidence, since, by a
singular accident, the priests of Egypt have bequeathed to
us, in their cemeteries, that information which the museums
and works of the Greek and Roman philosophers have failed
to transmit.
Tt had fortunately happened that the men of science who
accompanied the French armies during their four years’ occu-
pation of Egypt from 1797 to 1801, instead of employing
their whole time, as go many preceding investigators had
done, in exclusively collecting human mummies, had ex-
amined diligently, and sent home great numbers of embalmed
* Dise. Prél. p. 129, sixth edition. + Ibid.
264 THEORIES AS TO THE NATURE OF SPECIES. [Cu. XXXV.
bodies of consecrated animals, such as the bull, the dog, the
cat, the ape, the ichneumon, the crocodile, and the ibis.
They who have never raised their conceptions of the
import of Natural History beyond the admiration of beauti-
ful objects or the exertion of skill in detecting specific diffe-
rences, would wonder at the enthusiasm expressed in Paris
at the beginning of this century, amidst the din of arms and
the stirring excitement of political events, in regard to these
precious remains. In the official report, drawn up by the
Professors of the Museum at Paris, on the value of the objects
alluded to, the following passages might seem extravagant,
unless we reflect how fully the reporters (Cuvier, Lacépéde,
and Lamarck) appreciated the bearing of the facts thus
brought to light on the past history of the globe.
‘It seems,’ say they, ‘as if the superstition of the ancient
Egyptians had been inspired by Nature, with a view of trans-
mitting to after ages a monument of her history. That
extraordinary and eccentric people, by embalming with so
much care the brutes which were the objects of their stupid
adoration, have left us, in their sacred grottos, cabinets of
zoology almost complete. The climate has conspired with
the art of embalming to preserve the bodies from corruption,
and we can now assure ourselves by our own eyes what was
the state of a great number of species three thousand years
ago. We can scarcely restrain the transports of our imagi-
nation, on beholding thus preserved, with their minutest
bones, with the smallest portions of their skin, and in every
particular most perfectly recognisable, many an animal, which
at Thebes or Memphis, 2,000 or 3,000 years ago, had its own
priests and altars.’ *
Among the Egyptian mummies thus procured were not’
only those of numerous wild quadrupeds, birds, and reptiles ;
but, what was perhaps ot still higher importance in helping
to decide the great question under discussion, there were the
mummies of domestic animals, among which those above
mentioned, the bull, the dog, and the cat, were frequent.
Now, such was the conformity, says Cuvier, of the whole of
these species and races to those now living, that there was no
* Ann. du Muséum d’Hist. Nat. tom. i. p. 234. 1802,
Cu. XXXV.] EGYPTIAN MUMMIES. 265
more difference between them than between the human mum-
mies and the embalmed bodies of men of the present day. Yet
some of these animals have since that period been trans-
ported by man to almost every variety of climate, and forced
to’accommodate their habits to new circumstances as farsas
their nature would permit. The cat, for example, has been
carried over the whole earth, and, within the last three
centuries, has been naturalised in every part of the New
World—from the cold regions of Canada to the tropical
plains of Guiana; yet it has scarcely undergone any percep-
tible mutation, and is still the same animal which was held
sacred by the Egyptians. Of the ox, undoubtedly, there are
many very distinct races: but the bull Apis, which was led
in solemn processions by the Egyptian priests, did not differ
from some of those now living.
Nor was the evidence derived from the Egyptian monu-
ments confined to the animal kingdom; the fruits, seeds,
and other portions of twenty different plants, were faithfully
preserved in the same manner; and among these the com-
mon wheat was procured by Delille, from closed vessels in
the sepulchres of the kings, the grains of which retained not
only their form, but even their colour; so effectual had
proved the process of embalming with bitumen in a dry and
equable climate. No difference could be detected between
this wheat and that which now grows in the East and else-
where, and. similar identifications were made in regard to
many other plants.
In answer to the argument drawn from this class of facts
Lamarck observed, that ‘the animals and plants referred to
had not experienced any modification in their specific cha-
racters, because the climate, soil, and other conditions of
life had not varied in the interval. But if,’ he went on to
say, ‘the physical geography, temperature, and other natural
conditions of Egypt had altered as much as we know they
have done in many countries in the course of geological pe-
riods, the same animals and plants would have deviated from
their pristine types so widely as to rank as new and distinct
species.’ *
* Phil. Zool. pp. 70-71.
266 THEORIES AS TO THE NATURE OF SPECIES. [Cu. XXXV.
This reply, when we consider its date (about the year 1809),
may well lay claim to our admiration, as it evinced Lamarck’s
thorough conviction, that geological changes are brought
about so slowly that the lapse of thirty or forty centuries
is, utterly insignificant in the history of a species. Nearly
all the men of science of his day, even the great majority of
geologists, entertained extremely narrow views in regard to
the duration of those periods of the past of which they
were studying the archives. They were generally inclined
to attribute all great changes of the earth’s crust, and its
inhabitants, to brief and violent catastrophes, against which
Lamarck emphatically protested.* Yet neither he nor any
of his contemporaries could as yet form any conception of
the number and real magnitude of the revolutions in the ani-
mate world with which paleontology has since made us
familiar. In certain passages of his work he admitted that
possibly the Paleotherium, Anoplotherium, and some other
fossil genera of quadrupeds then recently described by Cuvier
as occurring in tertiary strata near Paris, may have disap-
peared, having, perhaps, been exterminated by the power of
man. But in regard to smaller animals, especially those of
the aquatic tribes, which could not have been the victims
of human intervention, he sometimes expressed a doubt
whether most of these may not still have their representatives
surviving in regions unexplored by the naturalist. Being
aware, however, that the specific and generic forms of ani-
mals and plants preserved in the rocks are more unlike
those now existing in proportion as they are more ancient,
Lamarck expressed his belief that in those cases where the
fossil animals could be identified with the living, the strata
containing them must be very modern, their descendants not
having had time to vary, except within extremely narrow
limits.t
It was by this constant reference to time as an essential
element even in the definition of a species, that the teaching
of Lamarck differed from that of Linnzeus, Blumenbach, and
Cuvier.
* Phil. Zool. p. 80.
t Ibid. chap. iii., De ?Espece, p. 79.
;
Poin
tnd ¢
¥
.' QO
SPecieg
‘G,
Nordio
N log.
Tp aR aE BEE ae Eee gE
Cu. XXXV.] LINNAXUS ON SPECIES. 267
Tinneus on species.—Linneus in one of his treatises had
said that classes and orders are the inventions of science,
but species are the work of nature.* In another place he
went so far as to declare that genera, like species, are
primordial creations.t
Expressions may doubtless be found in some of his specu-
lative essays, implying that he thought that some species at
least were the daughters of time, ‘ temporis filie, t and we
shall see in Chap. XX XVII. that when a great number of
closely allied species existed in the same region, he strongly
suspected that they might be derived from other species—pos-
sibly that they were hybrids, and had become so far perma-
nent as to require to be treated as distinct species. But his
deliberate opinion was contained in the following aphorism:
‘We reckon just so many species as there were different forms
created in the beginning.’ § Blumenbach declared that ‘no
general rule can be laid down for determining the distinctness
of species, as there is no particular class of characters which
can serve asa criterion. In each case we must be guided by
analogy and probability.’
In former editions of this work from 1832 to 1853, I did
not venture to differ from the opinion of Linnzus, that each
species had remained from its origin such as we now see it,
being variable, but only within certain fixed limits: The
mystery in which the origin of each species was involved
seemed to me no greater than that in which the beginning
of all vital phenomena on the earth is shrouded. But I
undertook to show that the gradual extinction of species one
after another was part of the constant and regular course of
nature, and must have been so throughout all geological
time, because the climate, and the position of land and sea,
and all the principal conditions of the organic and i inorganic
world, are always, and have been always, undergoing change.
{ pointed out how the struggle for existence among species,
and the increase and spread of some of them, must tend
R * ‘Classis et Ordo est sapientiz, {Flora eae) 2, 266, and Species
eperics nature opus.’ Din ei 0.
enus omne est naturale, in pri- § Ges tot numeramus quot di-
Phil. B
mordio tale creatum,’ &e. (( ot. versee formee in principio sunt create.’
§ 159. See also Ibid. g 162.), (Phil. Bot. § 157.)
268 BROCCHI ON THE DYING OUT OF SPECIES. ([Cu. XXXV.
to the extermination of others; and as these would dis-
appear gradually and singly from the scene, I suggested
that probably the coming in of new species would in like
manner be successive, and that there was no geological sanc-
tion for the favourite doctrine of some theorists, that large
assemblages of new forms had been ushered in at once to
compensate for the sudden removal of many others from the
scene.
Brocchi on the dying out of a species.—An Italian geologist,
Brocchi, the author in 1814 of an able work on the fossil
shells of the Subapennine Hills, endeavoured to imagine
some regular and constant law by which species might
be made to disappear from the earth gradually and in suc-
cession. The death, he suggested, of a species might depend,
like that of individuals, on certain peculiarities of constitution
conferred upon them at their birth; and as the longevity
of the one depends on a certain force of vitality, which,
after a period, grows weaker and weaker, so the duration of
the other may be governed by the quantity. of prolific power
bestowed upon the species which, after a season, may decline
in energy, so that the fecundity and multiplication of indi-
viduals may be gradually lessened from century to century,
‘until that fatal term arrives when the embryo, incapable
of extending and developing itseif, abandons, almost at the
instant of its formation, the slender principle of life by
which it was scarcely animated,—and so all dies with it.’ *
in opposition to this doctrine, I contended that there is no
‘reason to suspect that the last individuals of a species of
which the numbers are diminishing is physiologically de-
teriorated, or is in the least degree impaired in its prolific
powers; for there are known causes in the animate and in-
animate world which must in the course of ages annihilate
species, however vigorous their powers of reproduction
might remain. As the death of the last representatives of a
species would be abrupt, 1 conjectured that the birth of new
forms might be equally so, but as I had entire faith in the
doctrine that what is now going on in the natural world affords
* Broechi, Conch. Foss. Subap., tome i. 1814.
Cx. XXXV.] FIRST APPEARANCE OF NEW SPECIES. 269
a true indication of what has been and will be, I assumed that
the coming in of new species must be going on at about the
same rate as the dying out of old ones; and I therefore felt
myself called upon to explain how the birth of new species
could be always in progress, and yet the botanist and zoolo-
gist remain wholly unconscious of the occurrence of events
so wonderful, and to them of such transcendent interest.
Difficulty of establishing the first appearance of a new
species.—Assuming that species were specially created from
time to time to fill up the gaps to which the never-ceasing
changes of the animate and inanimate world must give rise,
I enquired what kind of evidence we had a right to expect
of the origin of new forms of animals and plants in the
course of the last twenty or thirty centuries. Ought we to
have been as conscious of the fact as we are of the lessening
of the numbers and the occasional extermination of par-
ticular species? It was obviously, I remarked, more easy
to prove that a species, once numerously represented in a
given district, had ceased to be, than that some other which
did not pre-exist had made its appearance—assuming always
that single stocks only of each animal and plant are origin-
ally created, and that individuals of new species do not sud-
denly start up in many different places at once. The latter
hypothesis had already been considered by Linnzus, and pro-
nounced by him to be unphilosophical because quite unneces-
sary, since, as he observed, every animal or plant, even those
which increase slowly, are capable in twenty or thirty gene-
rations of stocking a large part of the whole globe with their
descendants.
So imperfect has the science of Natural History remained
down to our own times, that, within the memory of persons
now living, the numbers of known animals and plants have
been doubled, or even quadrupled, in many classes. New
and often conspicuous species are annually discovered in
parts of the old continent, long inhabited by the most civi-
lised nations. Conscious, therefore, of the limited extent of
our information, we always infer, when such discoveries are
made, that the beings in question had previously eluded our
research ; or had at least existed elsewhere, and only migrated
270 THEORIES AS TO THE NATURE OF SPECIES, [Cu. XXXV.
at a recent period into the territories where we now find
them. It is difficult to look forward to the time when we
shall be entitled to make any other hypothesis in regard to
all the marine tribes, and to by far the greater number of
the terrestrial ;—such as birds, and insects, and a large pro-
portion of plants, especially those of the cryptogamous class,
many of which possess such unlimited powers of diffusion ag
to be almost cosmopolitan in their range.
It may perhaps be said that if new species were suddenly
called into being by special acts of creation, some forest tree
or new quadruped ought to have been seen, for the first time,
within the last ten or twenty centuries in the more populous
parts of such countries as England or France. In that
case, the naturalist might have been able to demonstrate
that no similar living form had before existed in the district.
Now, although this argument may seem plausible, its force
will be found to depend entirely on the rate of fluctuation
which we suppose to prevail in the animate world, and on
the proportion which such conspicuous subjects of the animal
and vegetable kingdoms bear to those which are less known
and escape our notice. There are perhaps more than a
million species of plants and animals, exclusive of the mi-
croscopic and infusory animalcules, now inhabiting the ter-
raqueous globe. The terrestrial plants may amount, said
De Candolle in 1820, to somewhere between 110,000 and
120,000.* Mr. Lindley, i in a letter to the author in 18386,
expressed his opinion that it eee be rash to speculate on
the existence of more than 80,000 phenogamous, in 10,000
cryptogamous plants. ‘If we tz fe he says, ‘37,000 as the
number of published phenogamous species, and then add,
r the undiscovered species of Asia and New Holland, 15,000,
10,000 in Africa, and 18,000 in America, we have 80,000
species ; and if 7,000 be the number of ‘published ery yptogamous
plants, and we allow 3,000 for the undiscovered species (mak-
ing 10,000), there would then be, on the whole, 90,000 species.’
Jr. J. Hooker, in 1859, when commenting on the varia-
bility of species and the indefinable nature of the limits by
a
* Geog. des Plantes. Dict. des Sci. Nat.
Cu. XXXV.] NUMBER OF LIVING SPECIES 271
which they are separated one from the other, observed that
by some botanists the number of known species of flowering
plants is assumed to be under 80,000, and by others over
150,000.*
Linnzeus imagined that there were four or five species of
insects in the world for each phzenogamous var but if we
may judge from the relative proportion of the two classes in
Great Britain, the number of insects must somewhat iat
that estimate; for the total number of B ich insects, ‘ ac-
cording to a census ’ made in 1833, was about 12,500. ce
The known species of mammifers, when Temminck wrote,
exceeded 800, and according to Mr. Waterhouse more than
1,200 were ascertained to exist in 1850.t Baron Cuvier estj-
mated the fishes known in his time at 6,000. Mr. Giin ther in-
forms me that specimens of more than that number of species
were already preserved in 1865 in the British Museum, and
that about 9,000 were known to the ichthyologist even before
the visit of Agassiz in 1866 to South Amer ica, where he is said
to have Do coreredl at least 1,000 new species. We have still
to add the reptiles, and all the invertebrated animals, exclu-
sive of insects.
It remains, in a great degree, mere matter of conjecture
what proportion the aquatic tribes may bear to the denizens
of the land; but the habitable surface beneath the waters
can hardly ie estimated at less than double that of the con-
tinents and islands, even admitiing that a very considerable
area is destitute of life, in consequence of great depth, cold,
darkness, and other circums ice The ocean teems with
life—the class of Polyps alone (Celentera ta) are conjectured
by Lamarck to be as stro ong in individuals as insects. Livery
tropical reef is described as covered with corals and g sponges,
and swarming with crustaceans, sea-urchins, and mollusks : ;
while almost every tide-washed rock in the world is car-
peted with Fuci, and Supports some sea-anemones (Actinie),
Corallines (Bryozoa), and Testacea. There are also para-
sitic animals without Damier, three or four o which are
* Flora of Tasmania, vol.
859.
7 Delile pb Mr..G. Gray, his genera of
birds (1834) ee aie 000 species ;
T See Catalogue of Brit, Insects, by Prince Charles Bonaparte, in 1864,
John Curtis, Esq. 8,300.
272 THEORIES AS TO THE NATURE OF SPECIES. [Cu. XXXV.
sometimes appropriated to one genus, as to the whale
(Balena), for example.
In the exploring expeditions to the arctic and antarctic
regions, marine animals, such as crustaceans, mollusks, ser-
pul, star-fish, and sponges, together with plants of the
simplest structure (Diatomacee), have been found at depths
varying from 2,000 to 9,000 feet, sometimes inhabiting the
bottom, where the temperature of the water was below the
freezing-point. Even though we concede, therefore, that the
geographical range of marine species may be more extensive
in general than that of the terrestrial (the temperature of
the sea being more uniform, and the land impeding less the
migrations of the oceanic than the ocean those of the terres-
trial species), yet 1t seems probable that the aquatic tribes far
outnumber the inhabitants of the land.
Without insisting on this point, it may be safe to assume,
that, exclusive of microscopic beings, there are between one
and two millions of species now inhabiting the terraqueous
globe; so that if only one of these were to become extinct
annually, and one new one were to be every year called into
being, much more than a million of years might be required
to bring about a complete revolution in organic life.
T have never ventured to hazard any precise hypothesis as to
the probable rate of change; but none will deny that when the
annual birth and the annual death of one species on the
globe was proposed as a mere speculation, this at least was
to imagine no slight degree of instability in the animate
creation. If we divide the surface of the earth into twenty
regions of equal area, one of these might comprehend a space
of land and water about equal in dimensions to Europe, and
might contain a twentieth part of the million of species which
may be assumed to exist in the animal kingdom. In this
region one species only would, according to the rate of mor-
tality before assumed, perish in twenty years, or only five out
of fifty thousand in the course of acentury. Butasa consider-
able proportion of the whole would belong to the aquatic
classes, with which we have a very imperfect acquaintance,
we must exclude them from our consideration; and if they
constitute half of the entire number, then one species only
Cx, XXXV_] RUDIMENTARY ORGANS. 273
might be lost in forty years among the terrestrial tribes.
Now the Mammalia, whether terrestrial or aquatic, bear so
small a proportion to other classes of animals, forming less,
perhaps, than one thousandth part of the whole, that if the
longevity of species in the different orders were equal, a vast
period must elapse before it would come to the turn of this
conspicuous class to lose one of their number. If one species
only of the whole animal kingdom died out in forty years, no
more than one mammifer might disappear in 40,000 years
in a region of the dimensions of Europe.
It is easy, therefore, to see, that in a small portion of such
an area, in countries, for example, of the size of England and
France, periods of much greater duration must elapse before
it would be possible to authenticate the first appearance of
one of the larger plants and animals, assuming the annual
birth and death of one species to be the rate of vicissitude in
the animate creation throughout the world. It would follow
from the above considerations that if Lamarck was entitled
to plead insufficiency of time when challenged to bring
forward a single case of transmutation, the advocates of
special creation were equally entitled to say that if the intro-
duction of new species goes on as slowly as the extinction of
old ones, it could not be expected that they should have wit-
nessed the first starting into being of a new animal or plant.
Geoffroy St. Hilaire and Lamarck on rudimentary organs.—
The great majority of the best naturalists and geologists who
succeeded Lamarck were content to believe with Humboldt
that the origin of species was one of those mysteries which
it was not given to natural science to penetrate, Omalius
d’Halloy, however, in his ‘Elements of Geology,’ which he
published in 1831, and in six subsequent editions, taught that
the species of animals now living were the descendants of
progenitors which have left their fossil remains in the later
Tertiary formations. I asked him in the year 1867, when
he was in his eighty-fourth year, by what facts and reasoning's
he had been led to entertain this view, and he told me that
he owed his convictions on this head to the lectures of
Geoffroy St. Hilaire, to which he had listened in the early
part of this century at Paris. That great zoologist, he said,
VOL. II. T
274 THEORIES AS TO THE NATURE OF SPECIES. [Cu. XXXV.
never lost an opportunity, when he spoke of the rudimentary
organs found in so many animals, of pointing out their
bearing on the theory of transmutation. According to him
they were clearly the relics of parts which had been service-
able in some remote ancestor and had been reduced in size by
disuse, and he rejected the idea as puerile that useless organs
had been created for the sake of uniformity of plan.
I may here remark that in my brief abstract of Lamarck’s
theory drawn up by me originally in 1832, and which for
reasons explained in the last chapter (p. 246, note) I have
now reprinted without alteration or addition, I omitted,
when referring to what he had said on the impoverishment
and final disappearance of organs by disuse, to cite many
examples which he gives in the ‘ Philosophie Zoologique’ in
illustration of this principle. Among other facts the abortive
teeth concealed in the jaws of some mammalia are mentioned,
such teeth not being required because their food is swallowed
without mastication. The discovery also by G. St. Hilaire
of teeth in the foetus of a whale is alluded to, and the small .
size of the eyes in the mole which makes scarcely any use of
its organs of vision. Allusion is also made to the aquatic
reptile cailed Proteus anguinus, inhabiting the waters of dark
subterranean caverns, which retains only the vestiges or |
rudiments of eyes.*
The question of species as treated in the ‘ Vestiges of Crea- |
tion.’—But, speaking generally, it may be said that all the .
most influential teachers of geology, paleontology, zoology,
and botany continued till near the middle of this century
either to assume the independent creation and immutability |
of species, or carefully to avoid expressing any opinion on this
important subject. In England the calm was first broken by
the appearance in 1844 of a work entitled ‘The Vestiges of
Creation, in which the anonymous author had gathered .
together and presented to the public, with great clearness and
skill, the new facts brought to light in geology and the kin- |
dred sciences since the time of Lamarck in favour of the
transmutation of species and their progressive development
* Phil. Zool. tom. i. p. 240, where other examples are also given.
Cu, XXXV.] THE ‘VESTIGES OF CREATION,’ ys
in time. He availed himself of the generalisations of paleon-
tologists on the changes observable in the fossil fauna and
flora of successive epochs of the past, showing that the
structural affinity was greatest in those which stood nearest
each other in position when the strata were arranged in
chronological order, and that there had been a gradual
approximation of the animate world as it changed from
period to period to the state of things now represented by
the living creation.
The embryological investigations of Tiedemann and others
were referred to as being in harmony with the doctrine of
transmutation; the various phases of development through
which a mammifer passes when in the foetal state representing
in succession the likeness of a fish, reptile and bird, and lastly
putting on the characters proper to the highest class of
vertebrata. It was also suggested that these metamorphoses
were comparable to the creative additions made in like
chronological order to the organic world of past ages as
revealed to us by the fossil remains preserved in the rocks,
The arguments which Lamarck and others had derived from
rudimentary organs in favour of their views were re-stated
and their validity emphatically insisted upon. The unity of
plan exhibited by the whole organic creation fossil and
recent, and the mutual affinities of all the different classes of
the animal and vegetable kingdoms, were declared to be in
harmony with the idea of new forms having proceeded
from older ones by generation, species having been gradually
modified by the influence of external conditions.
Lamarck had rendered his hypothesis very complete by
embracing without any essential change the notions of
Aristotle as to spontaneous generation. The simplest rudi-
ments or germs of life were assumed to be always coming into
being. This would account for the present abundance of
species of the lowest grades of animal and vegetable existence
in spite of the constant advance throughout past time of the
organic creation towards a more pertect state. In his eager-
ness to supply the evidence which was wanting to confirm
the reality of the working of this part of the plan of na-
ture, the author of the ‘Vestiges’ displayed an extraordinary
T 2
276 WALLACE ON SPECIES, [Cu. XXXV.
want of philosophical caution. For he cited experiments
which were supposed to prove that the action of a voltaic pile
on a solution of potash could give origin to new species of
insects. The careless way in which these experiments had
been conducted contrasted in a striking manner with the
extreme caution displayed by those who had been endeavour-
ing to test the truth or falsehood of Harvey’s dictum that
‘every living thing comes from an egg.’ The result of every
increase in the power of the microscope had been to refute
the theory of spontaneous generation, or at least to force the
abettors of the old doctrine to take refuge in the region of
the infinitely minute. Distrust of the soundness of the
author’s judgment was also engendered by a suspicion that he
was not practically versed in the study of any ene department
of natural knowledge. Every weak point, moreover, in this
treatise was exposed with unsparing severity by critics who
were impatient of the popularity it enjoyed, in spite of the
writer’s adoption of Lamarck’s doctrine that Man was not only
the last link of a long series of progressive developments, but
had been ecnnected by descent with the inferior animals.
Wallace on species.—The next important effort to determine
the manner in which new species may have originated was
made in 1855 by Mr. Alfred Wallace in the ‘Annals of
Natural History,’* in an essay entitled ‘On the Law which
has regulated the Introduction of New Species.’ The opinions
announced in this paper carried with them the authority of
one who was well versed in several departments of natural
history, especially ornithology and entomology. He had first
explored during four years, conjointly with Mr. H. W. Bates,
the valley of the river Amazons, and the neighbouring equa-
torial parts of South America, their' expedition having been
expressly undertaken to collect facts ‘towards solving the
problem of the origin of species.’+ Mr. Wallace had after-
wards spent many years in studying the zoology of the Malay
Archipelago, devoting his attention especially to the birds
and insects; and the result of his experience, aided by the
information obtained from geological writers, was summed
* Series 2, vol, xvi.
t Bates’ Preface to his ‘ Naturalist on the River Amazons.’
Cu. XXXV.] AND DARWIN ON NATURAL SELECTION. 2td
up in the following proposition, ‘that every species has come
into existence coincident both in space and time with a pre-
existing closely allied species..* Mr. Darwin,t when re-
ferring subsequently to this paper in his ‘ Origin of Species,’
has stated that he knew from correspondence with Mr. Wal-
lace that the cause to which he attributed the coincidence
here alluded to was no other than ‘ generation with modifi-
cation,’ or, in other words, the ‘ closely allied anti-type’ was
the parent stock from which the new form had been derived
by variation. All the most telling arguments which Lamarck
had brought forward, and those drawn from various sources
which the ‘Vestiges’ had superadded, in favour of species
being the result of indefinite modification, instead of special
creation, were briefly and ably summed up by Mr. Wallace ;
but it was clear that the evidence which had most powerfully
influenced his mind, was that derived from his own experience
of the geographical distribution of species, and especially of
birds and insects.
In geography, he remarked, a genus or species rarely occurs
in two very distant localities without being also found in the
intermediate space; so in geology the life of a genus or
Species is not interrupted, no species having come into
existence twice, or having been renewed after having once
died out.
For the manner in which the gradual extinction of species
had been brought about and was still in progress, Mr.
Wallace referred to my chapter on that subject in the ‘ Prin-
ciples of Geology,’ confining his speculations to the manner
in which new forms were introduced from time to time to
replace those which were lost.
Darwin on Natural Selection and on the origin of species.—~
Meanwhile Mr. Charles Darwin, well known by his < Voyage in
the Beagle,’ and various works on Geology, had been for many
years busily engaged in collecting materials for a great work
on the origin of species ; having made for that purpose a vast
series of original observations and experiments on domes-
ticated animals and cultivated plants, and having reflected
* Annals of Nat. Hist. ser, 2, vol. xvi. p. 186.
T Ist ed. p. 355; 4th ed. p. 424,
278 THEORIES AS TO THE NATURE OF SPECIES, [Cu. XXXV.
profoundly on those problems in geology and biology which
were calculated to throw most light on that question. For
eighteen years these researches had all been pointing to the
same conclusion, namely, that the species now living had been
derived by variation and generation from those which had
pre-existed, and these again from others of still older date.
Several of his MS. volumes on this subject had been read by
Dr. Hooker as long ago as 1844, and how long the ever-
accumulating store of facts and reasonings might have re-
mained unknown to the general public, had no one else
attempted to work out the same problem, it is impossible to
say. But at length Mr. Darwin received a communica-
tion, dated February 1858, from Mr. Wallace, then re-
siding at Ternate in the Malay Archipelago, entitled ‘On
the Tendency of Varieties to depart indefinitely from the
Original Type.’
The Author requested Mr. Darwin to show this essay to
me should he think it sufficiently novel and interesting.
It was brought to me by Dr. Hooker, who remarked how
complete was the coincidence of Mr. Wallace’s new views
and those contained in one of the chapters of Mr. Darwin’s
unpublished work. Accordingly, he suggested that it would
be unfair to let Mr. Wallace’s essay go to press unaccom-
panied by the older memoir on the same subject. Although,
therefore, Mr. Darwin was willing to waive his claim to
priority, the two papers were read on the same evening to
the Linnzan Society and published in their Proceedings for
1858. The title of the chapter extracted from Mr. Darwin’s
MS. ran as follows: ‘On the Tendency of Species to form
Varieties, and on the Perpetuation of Species and Varieties
by Natural Means of Selection.’
Already in the previous year, September 1857, Mr. Darwin
had sent to Professor Asa Gray, the celebrated American
botanist, a brief sketch of his forthcoming treatise on what
he then termed ‘ Natural Selection.’ This letter, also printed
by the Linnean Society together with the papers above alluded
to, contained an outline of the leading features of his theory
of selection as since explained, showing how new races were
formed by the breeder, and how analogous results might or
Cu. XXXV.] AND DARWIN ON NATURAL SELECTION. 209
must occur in nature under changed conditions in the ani-
mate and inanimate world. Reference was made in the
same letter to the law of human population first enunciated
by Malthus, or the tendency in man to increase in a geome-
trical ratio, while the means of subsistence cannot be made
to augment in the same ratio. We were reminded that in
some countries the human population has doubled in twenty-
five years, and would have multiplied faster if food could
have been supplied. In like manner every animal and plant
is capable of increasing so rapidly, that if it were un-
checked by other species, it would soon occupy the greater
part of the habitable globe; but in the general struggle for
life few only of those which are born into the world can
obtain subsistence and arrive at maturity. In any given
species those alone survive which have some advantage over
others, and this is often determined by a slight peculiarity
capable in a severe competition of turning the scale in their
favour. Notwithstanding the resemblance to each other and
to their parents of all the individuals of the same family, no
two of them are exactly alike. The breeder chooses out
from among the varieties presented to him those best suited
to his purpose, and the divergence from the original stock
is more and more increased by breeding in each succes-
sive generation from individuals which possess the desired
characters in the most marked degree. In this manner Mr.
Darwin suggests that as the surrounding conditions in the
organic and inorganic world slowly alter in the course of
geological periods, new races which are more in harmony
with the altered state of things must be formed in a state of
nature, and must often supplant the parent type.
Although this law of natural selection constituted one only
of the grounds on which Mr. Darwin relied for establishing
his views as to the origin of species by variation, yet it
formed so original and prominent a part of his theory that
the fact of Mr. Wallace having independently thought out the
same principle and illustrated it by singularly analogous ex-
amples, is remarkable. It raises at the same time a strong
presumption in favour of the truth of the doctrine. Both
writers referred to the number of the feathered tribe which
280 THEORIES AS TO THE NATURE OF SPECIES, [Cu. XXXV.
perish annually. ‘ Very few birds,’ says Mr. Wallace, ‘ pro-
duce less than two young ones each year, while many have
six, eight, or ten; and if we suppose that each pair produce
young only four times in their life, each would at this rate
increase in fifteen years to nearly ten millions, whereas we
have no reason to believe that the number of the birds of any
country increases at all in fifteen or even in 150 years. It is
evident, therefore, that each year an immense number of
birds must perish, as many in fact as are born; and as on
the lowest calculation the progeny are each year twice as
numerous as their parents, it follows that whatever be the
average number of individuals existing in any given country,
twice that number must perish annually.
‘Large broods are superfluous: on the average all above
one become food for hawks and kites, wild cats and weazels,
or perish of cold and hunger as winter comes on.’* The most
remarkable instances of an immense bird population is that
of the passenger pigeon of the United States, ‘ which lays
only one or at most two eggs, and is said to rear generally but
one young one. Why is this bird so extraordinarily abundant,
while others producing two or three times as many young
are much less plentiful? The explanation is not difficult.
The food most congenial to this species, and on which it
thrives best, is abundantly distributed over a very extensive
region, offering such differences of soil and climate, that in
one part or another of the area the supply never fails. The
bird is capable of very rapid and long-continued flight, so
that it can pass without fatigue over the whole of the district
1¢ inhabits, and as soon as the supply of food begins to fail in
one place is able to discover a fresh feeding-ground. This
example strikingly shows us that the procuring a constant
supply of wholesome food is almost the sole condition re-
quisite for ensuring the rapid increase of a given species,
since neither the limited fecundity, nor the unrestrained
attacks of birds of prey and of man, are here sufficient to
check it.’ +
When pointing out how every variation from the typical
* Journ. of Linnean Soc., vol. 111. p. 55. 1858,
Y Ibid. p. 565,
KS
Ca. XXXV.] AND DARWIN ON NATURAL SELECTION. 281
form of a species gives an advantage to some individuals
over others, Mr. Wallace shows that even a change of
colour, by rendering certain animals more or less distinguish-
able, affects their safety. He also observes that in a state of
nature, a race better fitted for changed conditions would never
revert to the form which it had displaced; although in the
case of domesticated animals allowed to run wild or become
‘feral,’ they must, to a certain extent, recover the character
which they had lost during their subjugation to man, for
reasons which will be explained in Chapter XXXVII. The
essay concluded with some judicious criticisms on Lamarck’s
notion that animals may by their own efforts promote the
development of some of their organs, or even acquire new ones.
‘Changes,’ says Mr. Wallace, ‘ have been brought about, not
by the volition of the creatures themselves, but by the sur-
vival of varieties which had the greatest facilities of obtaining
food. The giraffe did not acquire its long neck by desiring
to reach the foliage of lofty trees and by constantly stretching
out its neck for that purpose, but varieties which occurred
with a longer neck than usual had an advantage over their
shorter-necked companions, and, on the first scarcity of food,
were enabled to survive them.’ *
After the publication of the detached chapter of his book
in the Linnean Proceedings, Mr. Darwin was persuaded by
his friends that he ought no longer to withhold from the
world the result of his investigations on the nature and
origin of species, and his theory of Natural Selection. Great
was the sensation produced in the scientific world by the
appearance of the abridged and condensed statement of his
views comprised in his work entitled ‘On the Origin of
Species by means of Natural Selection, or the Preservation
of Favoured Races in the Struggle for Life.’ From the hour
of its appearance it gave, as Professor Huxley truly said, ‘a
new direction to biological speculation,’ for even where it
failed to make proselytes, it gave a shock to old and time-
honoured opinions from which they have never since re-
covered. It effected this not merely by the manner in which
* Journ. of Linnean Soe. p. 61.
282 THEORIES AS TO THE NATURE OF SPECIES. (Cu. XXXV.
it explained how new races and species might be formed by
Natural Selection, but also by showing that, if we assume
this principle, much light is thrown on many very distinct
and otherwise unconnected classes of phenomena, both in the
present condition and past history of the organic world.
Hooker on variation and selection and the formation of species
in the vegetable world.—The abandonment of the old received
doctrine of the ‘immutability of species’ was accelerated in
Hngland by the appearance, in the same year (1859), of Dr.
Hooker’s essay on the Flora of Australia. In several of his
previous writings this eminent botanist had said all that could
be said in support of the ‘ constancy of the specific character in
the vegetable world.’ He had been freely discussing for fifteen
years with Mr. Darwin, all the facts and arguments which
they could bring to bear on this question, but he stated in
his Introduction, that until the views of his friend and those
of Mr. Wallace in favour of Natural Selection had been made
known, he scarcely felt himself at liberty frankly to declare
how far, as a botanist, he was prepared to go in the same
direction. He had been occupied for more than twenty
years in the study of plants of various parts of the world,
arctic, temperate, and tropical, insular and continental. He
had personally explored the floras of several of these regions,
had described and classified thousands of species, and was
well known to unite caution with boldness in his philoso-
phical speculations. From his new essay the general public
learnt, not without surprise, how little the most experienced
botanists are agreed amongst themselves as to the limits of
species, and to what an extent these limits are a mere matter
of opinion, even amongst those who believe that species have
remained unchanged since their creation, and will remain
immutable as long as they continue on the globe.
Dr. Hooker showed that in proportion as we study the
same plant under varied conditions and in distant regions, it
becomes more and more difficult to define its precise specific
characters ; also that in the flora of every country there are
Some groups of species which are apparently unvarying,
others which on the contrary run so much one into another
that the whole group may be regarded as a continuous series
Cu. XXXV.] HOOKER ON SPECIES IN THE VEGETABLE WORLD. 283
of varieties between the terms of which no hiatus exists such
as might allow of the intercalation of any intermediate
variety. The genera Rubus, Rosa, Salix, and Saxifraga
afford conspicuous examples of these unstable forms; Ve-
ronica, Campanula, and Lobelia of comparatively stable ones.
At the same time he points out in accordance with Mr.
Darwin’s theory how the extinction of a certain number of
the intermediate races by destroying the transitional links,
would facilitate the classification of the remaining species,
and hints that we may be indebted to such extinction in
past times for whatever facility we now enjoy of resolving
plants into distinct species, genera, and orders. ‘The mutual
relations,’ he observes, ‘of the plants of each great botanical
province, and in fact, of the world generally, is just such as
would have resulted if variation had gone on operating
throughout indefinite periods, in the same manner as we see
it act in a limited number of centuries, so as gradually to
give rise in the course of time to the most widely divergent
orms.’
When we reflect that this statement was made after a
study of the characters and geographical distribution of tens
of thousands of species, we feel disposed at once to declare
that a theory which is in harmony with so many facts must
be true; but if so, we have to enquire how it happens that so
many naturalists, of undoubted ability and knowledge, have
always held and still believe that species have been constant
from the beginning. In reference to this question, Dr.
Hooker admits that species are realities and may be treated
as if they were permanent and immutable; for the forms and
characters, at least of the great majority of them, may be
faithfully transmitted through thousands of generations, and
may have remained constant within the range of our experi-
ence. ‘But our experience,’ he remarks, ‘is so limited that
it will not account for a single fact in the present geo-
graphical distribution, or origin of any one species of plant,
nor for the amount of variation it has undergone, nor will
it indicate the time when it first appeared nor the form it
had when created,’ *
* Hooker, Introductory Essay, Flora of Tasmania.
284
CHAPTER XXXVI.
VARIATION OF PLANTS AND ANIMALS UNDER DOMESTICATION
VIEWED AS BEARING ON THE ORIGIN OF SPECIES.
DOMESTIC RACES, HOWEVER DIVERGENT, BREED FREELY TOGETHER—REMOTE
ANTIQUITY OF SOME ARTIFICIALLY FORMED RACES—SELECTION, BOTH UNCON-
SCIOUS AND METHODICAL, VERY INFLUENTIAL IN FORMING NEW RACES—— -
THE CHARACTERS OF SOME RACES OF THE DOMESTICATED PIGEON OF GENERIC
VALUE—REVIVAL OF LONG-LOST CHARACTERS IN THE OFFSPRING OF CROSS-
BREEDS——MULTIPLE ORIGIN OF THE DOG—INHERITED INSTINCTS—VARIATION
OF THE GOLD FISH AND SILKWORM—MAN CAUSES PARTICULAR PARTS OF AN
ANIMAL OR PLANT TO VARY WHILE OTHER PARTS CONTINUE UNALTERED—
MAIZE—CABBAGE—ARE THERE ANY LIMITS TO THE VARIABILITY OF A
SPECIES ?—OBEDIENCE TO MAN UNDER DOMESTIC se ahi! OFTEN MERELY A
NEW ADAPTATION OF A NATURAL INSTINCT—‘ FERAL’ VARIETIES DO NOT
REVERT TO THE EXACT LIKENESS OF THE ORIGINAL WILD STOCK—-HOW FAR
DO DOMESTIC RACES DIFFER FROM WILD SPECIES IN THEIR CAPACITY TO INTER-
BREED ?—HYBRIDIS: ATION OF ANIMALS AND PLANTS—HERMAPHRODITE PLANTS
NOT USUALLY SELF-FERTILISED—-WHETHER THE DISTINCTNESS OF SPECIES
CAN BE TESTED BY HYBRIDITY—TENDENCY OF DIFFERENT RACES OF DOMESTIC
CATTLE AND SHEEP TO HERD APART—PALLAS ON DOMESTICITY ELIMINATING
STERILITY—-CORRELATION OF GROWTH.
DOMESTIC RACES, HOWEVER DIVERGENT, BREED FREELY
TOGETHER.— We have seen that the indefinite modifiability of
species in the course of thousands of generations, and under
gradually altered conditions in the organic and inorganic
world, is a question which has been seriously entertained
by naturalists ever since the beginning of the present
century. The changes brought about by the breeder and
horticulturist, and the new races to which they have given
origin, have always been appealed to in support of this theory
of unlimited variability. It may be said that man, in every
stage of his social progress, has been engaged in conducting,
with much patience and at enormous cost, a grand series of
experiments to ascertain how far it is possible to make the
descendants of common parents, both in the anima! and
vegetable kingdoms, deviate from their original type. In pur-
OY
Cu. XXXVI.] ANTIQUITY OF ARTIFICIALLY FORMED RACES. 285
suing this course he has by no means confined his attention
to plants and animals which minister to his wants, but he has
sometimes gone on for thousands of years simply for his amuse-
ment, trying how far he could alter certain species—the pigeon,
for example, or some flowering plants such as the rose.
‘The opponents of the doctrine of transmutation have
always objected to arguments founded on the results of such
experiments, that, in spite of the skill and perseverance of the
breeder, agriculturist, and florist, man has never succeeded in
giving origin to one new species. For however far some of
the new races may have diverged from the parent stock
or from each other, they have always continued to breed
freely together and produce fertile offspring, whereas the
hybrids which result from the union of two distinct species
in nature are always sterile.
Before we can decide on the weight which we must
attach to such an objection, we must consider not only the
nature and extent of the changes which have been effected in
species under domestication and culture, but also the facility
of obtaining hybrid plants and animals of wild species, and
the different degrees of sterility of the hybrids when obtained.
The whole subject of the variation of domesticated animals
and cultivated plants has been lately treated of, with so much
ability and in such detail, by Mr. Darwin in a new work
just published,* that I cannot do better than refer the
reader to his clear statements of the facts and of their bearing
on his theory of the ‘ Origin of Species.’ In this chapter,
besides repeating much that I advanced in former editions,
I shall allude briefly to some of the valuable observations
and experiments which he has made, and the theoretical
conclusions to which they point.
Remote antiquity of some artificially formed races.—The ex-
plorations go actively carried on within the last fifteen
years in the Swiss lake-dwellings, and an examination
of the remains of animals and plants there preserved, have
shown that domesticated races of the dog, the ox, and the
sheep, and cultivated varieties of several cereals and of many
fruits, had been formed in Central Hurope in the Neolithic
2
* The Variation of Plants and Animals under Domestication : 1867.
286 VARIATION OF PLANTS AND ANIMALS. [Cu. XXXVI.
age, or before the use of metals was yet known. The
antiquity which we are thus called upon to assign to the
culture of certain plants need not surprise us, if Mr. Darwin
is correct in his opinion, that man in a barbarous state is
naturally led to discover the useful properties of all wild
plants by the frequently recurring famines to which all savage
tribes are exposed; for when in danger of starving he ig
compelled to try as food every kind of fruit, leaf, and root.
By this means the nutritious, stimulating, and medical
qualities of the most unpromising species are brought to light.
It might have been thought that the seeds of wild grasses
were too minute to afford much temptation for men in a rude
state of society to cultivate them for food; but it seems that
both Barth and Livingstone* observed the natives ini different
parts of Africa collecting the seeds of wild grasses, and
eating them ; from which practice it would be an easy step to
pass to the sowing of some of them near their usual haunts,
and eventually to the selection for seed of those varieties which
yielded the largest crops. The great number of cultivated
erasses or cereals, and the difficulties which botanists en-
counter when they endeavour to trace them to their original
stocks, or to the wild species from which they have sprung,
becomes more intelligible if we suppose that they have
undergone considerable modifications under culture in pre-
historic times.
It has often been remarked that we do not owe a single
useful plant to Australia or the Cape of Good Hope, or to
New Zealand, or to America south of the Plata. On this
subject Mr. Darwin observes, that we must by no means
infer that in these countries no native plants have proved
useful to savage man. Dr. Hooker, indeed, enumerates no
less than 107 native speciest which are used even by the
Australians. But the small advantage which civilised man
has hitherto derived from the regions above alluded to simply
demonstrates that wild plants cannot compete with those
which have been improved by cultivation for a long series of
generations.
* Cited by Darwin ‘ ae Variation of + Flora of Australia, Introduction,
Animals, &c., 1867, p. 8 p. cx.
a ee ee eee a ee |” ey
D;
Cu. XXXVI.] PLANTS AND ANIMALS OF THE LAKE-DWELLERS. 287
A skilful botanist who should see for the first time our
finest varieties of apples, peaches, pears, and plums, would be
unable to guess from what species of wild trees they had
been derived.
De Candolle mentions no less than thirty-three useful
plants which we owe to Mexico, Peru, and Chili, among which
the maize and potato are conspicuous ; and Tschudi describes
two forms of maize no longer known in Peru, which were
taken from the tombs of the Incas,* and which had become
extinct before the arrival of the Spaniards in South America.
But strange to say, no botanist has yet been able to trace the
maize, which had evidently been cultivated from a very re-
mote period, to any wild aboriginal parent stock.
The slowness with which improved varieties of native plants
have been brought into existence may be inferred from the
researches of Oswald Heer with respect to the fruits belonging
to the Swiss lake-dwellers of the later Stone period. They
had collected wild crabs, sloes, bullaces, elderberries, hips of
roses and beech-mast differing but slightly from those which we
know in a wild state. They had also five kinds of wheat and
three of barley, mostly inferior in size to ours. Among them
was the wheat commonly called Egyptian ; a fact leading to
the inference that the lake-dwellers had either come originally
from the south or had intercourse with some southern people.
So in regard to the domesticated animals of the same lake-
dwellers, they do not agree exactly with any of our breeds.
hus for example, they had two kinds of cattle which are
considered as modifications of two species or races which then
existed in a wild state—namely, Bos primigenius and Bos longi-
frons ; but, although they were modifications of these original
types, they cannot be identified with any existing Huropean
breeds. Their dog also differed from ours, or from that of the
later Bronze period, and according to Riitimeyer was of a
middle size, and equally remote from the wolf and the jackal.
They had also a small breed of sheep with thin and tall legs
and with horns like those of a goat, which was not exactly
similar to any one of the races now known.
* Cited by Darwin ‘On Variation,’ &c., p. 320.
288 VARIATION OF PLANTS AND ANIMALS. [Cu. XXXVI,
Selection, both unconscious and methodical, very influential
in forming new races.— When the art of the breeder has been
ereatly perfected, he is able to bring about very important
changes in a short time. He has no power either of causing
or preventing the numerous varieties which nature presents
to him among individuals born of the same parents. But
he can choose those which best suit his purpose, and breed
from them, while he destroys those varieties which are less
valuable. In the next generation he again picks out those
individuals which possess the desired qualities in a somewhat
more marked degree; and so goes on accumulating these
differences till he produces a breed which answers to some
preconceived idea formed by him. He can discriminate
trifling variations both in animals and plants which an unedu-
cated eye cannot appreciate. The variations which are thus
intensified become fixed by inheritance, and permanent races
are formed—a process technically called selection. But there
is another kind of selection, termed ‘unconscious’ by Mr.
Darwin, which perhaps acts more powerfully in the long run, -
both in a rude and civilised state of society. The savage,
when pressed by hunger, is often driven to feed on his dogs ;
in which case, if he is able to retain any of them, he preserves
such as are most useful to him in the chase. So in a very
early state of agriculture, the seeds and fruits of those varie-
ties which offer some advantage over others, by the abundance
of their produce or the quality or flavour of the nutriment
they afford, will be sown by preference, whereas the seeds of
less prized varieties will be consumed. For man is always
called upon to decide which individuals shall be spared as a
stock from which to breed, so many more being always born
into the world than there is room or food for. Mr. Darwin
supposes that, even in the most advanced state of society,
the influence of unconscious selection acts more powerfully
than methodical selection.
Our present bull-dogs, he observes, are different from those
formerly used for baiting bulls, being of smaller size and
altered in shape, now that the old sport has been given up.
Our fox-hounds differ from the old English hound, and our
ereyhounds have become lighter. Our enormous dray-horses
Cu. XXXVI] GREAT DIVERGENCE OF TYPE IN THE PIGEON. 289
have been produced from some ancient bulky race through
the unconscious selection, carried on during many generations
in Flanders and England, of the most powerful and heaviest
horses, without the least intention or expectation of creating
our present elephant-like breed.* After the introduction
into England of some Arab horses, the methodical selection
of the swiftest individuals gradually produced the English
race-horse. But even this change has been partly effected
unconsciously, by the general wish to breéd as fine horses as
possible, without any intention to give to them their present
character. .
The characters of some races of the domesticated pigeon of
generic value.-—Domestic pigeons afford a most striking illus-
tration of the great divergence from the original type, the
rock pigeon (Columba Livia), which man hag brought about in
the course of time. These birds have been domesticated for
thousands of years in Egypt and India, and they afford
remarkable facilities for the production of distinct breeds, as
the male and female birds can be easily mated for life, and
the different varieties kept together in the same aviary.
More than 150 distinct races have received names, all breed-
ing true; and at least a score of these, says Mr. Darwin,
might be named, which, if shown to an ornithologist, and he
was told they were wild birds, would be ranked by him as
well-defined species, while some of them, such as the carrier,
short-faced tumbler, pouter and fan-tail, would not even be
placed in the same genus. From historical ‘details which
have come down to us of the principal races of the pigeon
as they were known in India before the year 1600, it appears
that these races, although they might have been classed in
the same groups as our present breeds, had not
so great a degree from their aboriginal common
wild rock pigeon.
Pigeon-fanciers in forming new varieties
attention to external characters—such
beak, the number or length of the tail
the plumage, and the general
diverged in
parent, the
have confined their
as the length of the
feathers, the colour of
shape of the body, yet they
* Darwin On Variation,’ ch
ap. XX.p. 212, j
Vou. Il. U
290 VARIATION OF PLANTS AND ANIMALS, [Cu. XXXVI.
have sometimes unintentionally produced modifications in |
the internal bony framework of the species. Thus while )
they have given a longer body to the pouter, they have unin-
tentionally augmented the number of its sacral and caudal
vertebrae, and the breadth of the ribs as well as the size of |
the breast-bone. In the fan-tail they have increased con-
siderably the length and number of the caudal vertebra ; and, |
what is still more worthy of note, in several breeds the whole |
skull differs in its proportions and outline from that of the
rock pigeon.
So many passages have been traced between the most di-
vergent varieties above alluded to and the wild Columba
Livia, that ornithologists do not hesitate to recognise this
species as the common progenitor of them all. Another
curious proof of such a derivation is afforded by crossing dis-
tinct breeds and finding in the offspring some peculiar cha-
racters of the rock pigeon, especially in the plumage, which
neither of the parent races possessed.* Thus the blue slaty
colour, or dark bars, on the wings and tail, and the white
edging of the outer tail feathers of the original Columba
Iivia, are produced in the mongrel offspring of the carrier
and fan-tail, although all these characters have often been
in abeyance in both of the parent stocks for a hundred or
more generations. Mr. Darwin has tested the truth of this
singular principle of atavism, by experiment, in the case of
pigeons, and has also obtained analogous results, by pairing
some of the most distinct varieties of the common fowl;
as, for example, a black Spanish cock and a white silky hen,
two ancient and pure breeds in which there was not a trace
of the red colour proper to the plumage of the wild Gallus
bankiva, a Himalayan species, which has always been sup-
posed to be the original of our domestic fowls. In many
of the young obtained from such a cross the peculiar orange-
red colour was conspicuous.t
Revival of long-lost characters in the offsprings of cross-breeds,
—Why the act of crossing should tend to evoke characters
which had long been lost in each of the parent races, is
* Darwin ‘On Variation,’ vol. i, p. 200. f Ibid. p. 241.
Cu. XXXVI.] REVIVAL OF CHARACTERS IN CROSS-BREEDS. 291
one of the most wonderful enigmas which the attributes of
inheritance present to us. By what favourable combination
of circumstances can we suppose these characters, which must
have been lying latent in so many intermediate generations,
to be thus made again to manifest themselves? In some
cases they are developed alternately in successive genera-
tions, in others at longer intervals.
The composition of the molecules which form the everm-
cells of animals and plants, and their mode of multipli-
cation and transmission from one generation to another, has
been a favourite subject of speculation ever since the time of
Buffon and Bonnet. More recently (1849), Professor Owen
has treated of this subject iu his Memoir on ‘ Parthenogene-
sis,’ and Mr. Herbert Spencer has speculated on the man-
ner in which the atoms or physiological units composing the
fertilised germ of an animal or plant may unfold into orga-
nisms and become the means of transferring the qualifica-
tions of the parent to the offspring.* The new hypothesis
suggested by Mr. Darwin, and which he has called < Pange-
nesis,’ coincides in many respects with that of Mr. Spencer,
and cannot be fully understood without reference to the
luminous and detailed explanations of it given by Darwin in
the concluding chapters of his new work.t He assumes that
the germ-cells of animals and plants are capable of generating
minute bodies, termed by him cell-gemmules, which become
diffused through all parts of an organism, and are capable of
multiplying and uniting with others like themselves, and
when this union does not occur, may remain in a dormant
state. Their increase may take place after the usual man-
ner of growth in all living beings, according to which entize
limbs are sometimes reproduced in the lower animals after
they have been cut off, or as wounds are healed by the form-
ation of new flesh, or as a portion of the leaf of a plant may
be developed into a perfect individual. The cell-gemmules re-
maining undeveloped for many generations, may be compared
to seeds lying dormant in the earth, or to rudimentary organs
which, though useless, may be inherited for an indefinite
* Principles of Biology, vol. i. chaps. iv. and viii.
+ Darwin ‘On Variation,’ chaps. xxxvii. and xxxviii.
a2
292 VARIATION OF PLANTS AND ANIMALS. ([Cu. XXXVI.
succession of generations, or as long as an entire species
endures on the earth.
Before this new hypothesis was started, it was sufficiently
difficult to conceive how a microscopic cell or ovule, so minute
as to be often invisible to the naked eye, and in some cases
requiring the aid of a powerful microscope to be made visible,
should contain within it not only the characters of the species
but many of the peculiarities of one or both parents, including ~
some of their acquired individual habits and instincts. But
now we are called upon, in addition, to imagine that there
are innumerable other molecules, in each germ or ovule, in
which the characteristics of remote progenitors may also be
present. As bearing on the question of the possible minute-
ness of particles of organic matter, I shall have to refer in a
future chapter, p. 387, to the ten million sporules of a single
fungus which were counted by Fries. A still more lively idea
of the possible diminutiveness of material atoms may be
gained by reflecting on the manner in which the air is often
perfumed or tainted throughout large spaces by the odour
of a plant or animal, and how the contagious particles of
certain diseases float unseen in the atmosphere, until they are
at last received within a human body, where they rapidly
increase and act powerfully.
Assuming, then, that the number of cell-gemmules in an
undeveloped embryo may be almost infinite in number, we
have to explain how some of these, after having been long
transmitted in a latent state, may suddenly multiply and gain
an ascendancy when individuals belonging to two distinct
races are crossed. Among other facts which are somewhat
analogous, we are reminded that, although there is frequently
in the offspring a fusion of all the characters of the parents,
et occasionally some of the characters of one parent are
exclusively transmitted to one of the children and those of
the other parent to another. The characters of one parent
sometimes prevail in all the offspring to the exclusion
of those of the other. When Giirtner crossed white and
yellow-flowered varieties and species of mullein (verbascum),
these colours never became blended, but the offspring bore
either pure white or pure yellow blossoms. This must depend
Cu. XXXVI] MULTIPLE ORIGIN OF THE DOG, 293
on some principle of the affinity of similar and the repul-
sion of dissimilar atoms. The cell-germs derived from two
individuals of distinct races may not readily unite or not
in sufficient numbers for the reproduction of the character-
istic attributes of the two parents ; they may be antagonistic
and neutralise each other’s power in such a way as to allow
the gemmules derived from a remote progenitor to multiply
suddenly, gaining such an ascendancy as to revive certain
peculiarities of the original stock which had remained long
in abeyance.
Multiple origin of the dog.—In regard to the origin of the
various canine races which have been domesticated by man
in all parts of the world, there is still no small diversity of
opinion. Mr. Darwin, after an elaborate analysis of all that
has been written on the subject, inclines to the belief which
Pallas entertained of the multiple origin of the dog, more
than one wild species having been blended together to pro-
duce the very distinct races which we now possess. The
celebrated John Hunter maintained that the wolf, the dog,
and the jackal were all of one species ; because he had found,
by two experiments, that the dog would breed both with the
wolf and the jackal; and that the mule, in each case, would
breed again with the dog. In these cases, however, it may
be observed, that there was always one parent at least of
pure breed, and no proof was obtained that a true hybrid
race could be perpetuated.
It was formerly supposed that the period of gestation in
the dog and the wolf differed slightly; but experiments
have not borne out this opinion; and Professor Owen has
been unable to confirm the alleged difference in the struc-
ture of a part of the intestinal canal. It seems scarcely to
admit of a doubt that both the jackal, and more than
one species of wolf, have been occasionally crossed with
the dog.
The main argument in favour of the different breeds of the
dog being the descendants of distinct wild stocks is their
resemblance, says Darwin, in various countries to indigenous
* Darwin ‘On Variation,’ chap. i. p. 20.
294 VARIATION OF PLANTS AND ANIMALS. [Cu. XXXVI.
species still existing there.* Thus the domestic dogs of the
American Indians resemble North American wolves. The
shepherd-dog of Hungary is very like the European wolf;
the domestic dog of Asia resembles the jackal.
But although the intercrossing of several original wild stocks
may have increased the total number and diversity of our
breeds, it cannot, says Darwin, explain the origin of such ex-
treme forms as thoroughbred greyhounds, bloodhounds, bull-
dogs, Blenheim spaniels, terriers and pugs, none of which are
known to have been kept by savages, and which are the
product of breeding in civilised countries. The difference
in the form of the skulls in some of these races is admitted
by Cuvier to be sometimes more than generic; in some
varieties there is an additional pair of molars in the upper
jaw; and some, like the Turkish dogs, are deficient in the
number of their molars; the mamme also vary from seven to
ten in number. Dogs have properly five toes in front, and four
behind, but a fifth toe is often added, together with a fourth
cuneiform bone. Man, says Darwin, if he had cared about
the number of their molar teeth, mamme or digits, could, by
selection, have fixed these characters, in the same way as he
has given additional horns to certain breeds of sheep, and an
additional toe and feathers to the Dorking fowl; but at
present these peculiarities have merely accompanied changes
in form, fleetness, size, strength, and other characters which
the breeder has purposely fixed.
Inherited imstincis.—It is evident that these new races
could not be artificially produced if the individual pecu-
larities of one generation were not transmitted by inheritance
to the next. Hven newly acquired habits and instincts are
often so transmitted, as was beautifully illustrated by a race
of dogs employed for hunting deer in the platform of Santa
Fé, in Mexico. The mode of attack, observes M. Roulin,
which they employ consists in Seizing the animal by the belly
and overturning it by a sudden effort, taking advantage of
the moment when the body of the deer rests only upon the
fore-legs. The weight of the animal thus thrown over is
* Darwin ‘On Variation,’ chap. i. p. 20,
i! -- e e P
Cx. XXXVI._] INHERITED INSTINCTS OF DOGS. 295
often six times that of its antagonist. The dog of pure
breed inherits a disposition to this kind of chase, and never
attacks a deer from before while running. Even should the
deer, not perceiving him, come directly upon him, the dog
steps aside and makes his assault on the flank; whereas
other hunting dogs, though of superior strength, and general
sagacity, which are brought from Europe, are destitute of
this instinct. For want of similar precautions, they are
often killed by the deer on the spot, the vertebra of their
neck being dislocated by the violence of the shock.”
A new instinct has also become hereditary in a mongrel
race of dogs employed by the inhabitants of the banks ot
the Magdalena almost exclusively in hunting the white-
lipped pecari. The address of these dogs consists in re-
straining their ardour, and attaching themselves to no animal
in particular, but keeping the whole herd in check. Now,
among these dogs some are found, which the very first time
they are taken to the woods, are acquainted with this mode
of attack; whereas, a dog of another breed starts forward at
once, is surrounded by the pecari, and, whatever may be his
strength, is destroyed in a moment.
Some of our countrymen, engaged about the year 1825
in conducting one of the principal mining associations in
Mexico, that of Real del Monte, carried out with them some
English greyhounds of the best breed, to hunt the hares
which abound in that country. The great platform which
is here the scene of sport is at an elevation of about
9,000 feet above the level of the sea, and the mercury in
the barometer stands habitually at the height of about nine-
teen inches. It was found that the greyhounds could not
support the fatigues of a long chase in this attenuated
atmosphere, and before they could come up with their prey,
they lay down gasping for breath; but these same animals
have produced whelps which have grown up, and are not in
the least degree incommoded by the want of density in the
air, but run down the hares with as much ease as the fleetest
of their race in this country.
The fixed and deliberate stand of the pointer has with
* M. Roulin, Ann. des. Sci, Nat., tom. xvi. p. 16. 1829.
296 VARIATION OF PLANTS AND ANIMALS. [Cx, XXXVI.
propriety been regarded as a mere modification of a habit,
which may have been useful to a wild race accustomed to
wind game, and steal upon it by surprise, first pausing for an
instant, in order to spring with unerring aim. The faculty
of the retriever, however, may justly be regarded as more
inexplicable and less easily referable to the instinctive
passions of the species. M. Majendie, says a French writer
in a recently published memoir, having learnt that there was
a race of dogs in England which stopped and brought back
game of their own accord, procured a pair, and, having
obtained a whelp from them, kept it constantly under hig
eyes, until he had an opportunity of assuring himself that,
without having received any instruction, and on the very
first day that it was carried to the chase, it brought back
game with as much steadiness as dogs which had been
schooled into the same mancuvre by means of the whip and
collar.
The power of man to produce new races of animals by
selection, has been by no means confined to the mammalia
and birds. The Chinese have kept gold fish (Oyprinus awra-
tus) for ornament or curiosity from a remote period, and
it is suspected that the golden colour is not characteristic
of the species in a state of nature. Yarrell mentions that
descriptions and coloured drawings of no less than 89 varie-
ties have been given by Sauvigny, some destitute of dorsal
fins, others having a double anal fin or a triple tail. Of
these, many, says Darwin, may be called monstrosities, for
it is difficult to draw a strict line between a variation and a
monstrosity.
If we turn from the vertebrata to the invertebrata, we find
here again that selection is capable of producing distinct
races in the class of insects, as in the case of the common
silk-moth (Bombyw mori), which is believed to have been do-
mesticated in China nearly 3,000 years before our era. It
was brought to Constantinople in the sixth century, whence
it was carried into Italy, and in the year 1494 into France.*
* Godron ‘De I’Espéce,’ 1859, tom. i. p. 460; and see Darwin ‘On Varia-
tion,’ vol. i, p. 800.
Cx. XXXVI_] PARTICULAR PARTS ONLY ALTERED. 29e
The nature of the food given to the caterpillar influences to
a certain extent the character of the breed. reat care is
taken in India and Europe in the selection of the eggs of
moths the caterpillars of which have produced the best
cocoons. The silk is usually yellow, but sometimes white,
and, by careful selection, in the course of sixty-five genera-
tions the proportion of yellow cocoons in France was greatly
reduced. The abdominal feet ofthe caterpillars which yield
white cocoons are, according to Quatrefages, always white,
while the feet of those which give yellow cocoons are in-
variably yellow, and there is a corresponding difference in the
tint of the eggs ;
Man causes particular parts of an animal or plant to vary
while other parts may continue unaltered.—The possibility of
obtaining particular breeds and fixed varieties of animals and
plants depends on the fact that variations occur in almost
any required direction if a vast number of individuals are
produced. It is also found that one form of variation may
usually be accumulated in successive generations by selection,
without the other characters of the species being materially
affected. Cows are wanted which may give us an increased
quantity of milk, sheep which may yield finer wool, poultry
which may have a habit of continually laying eggs; and these
qualities are often obtained without perceptibly changing in
any other respect the habits or organisation of the same
races.
In the case of the maize and the vine, we alter the seed
and the fruit without changing the leaves, whereas in the
foliage of the mulberry, cultivated for the sake of the silk-
worm, new varieties have been formed, the fruit remaining
the same. In the cabbage the leaves have undergone
_ wonderful transformations, as have the tubers in the potato
and the roots in the carrot, while the characters of the flowers
in all have remained unaltered. The modifications produced
in the seeds of the maize deserve especial notice. The
different races vary in height from eighteen inches to as
many feet, and the whole ear in one variety is more than
four times as long as in another dwarf kind. The seeds
are coloured white, pale yellow, orange, red, violet, or
298 VARIATION OF PLANTS AND ANIMALS. [Cu. XXXVI,
streaked with black. Mr. Darwin found that a single
grain in one variety equalled in weight seven graing of
another. The tall kinds grown in southern latitudes and
exposed to great heat require from six to seven months
to ripen their seed, whereas the dwarf kinds grown in
northern and colder climates require only from three to four
months. *
In North America the maize has been gradually cultivated
farther and farther northward, in which case the changes
induced by an alteration of climate have been added to
those due to selection. In this plant the results of in-
herited acclimatisation are very striking. Metzger obtained
the seed of a variety called Zea altissema from the warmer
parts of America, and raised it in Germany, and the first
year the plants were twelve feet high and few seeds were
perfected. The lower seeds in the ear kept true to their
proper form, but the upper ones became slightly changed.
In the second generation the plants were from nine to ten
feet in height, and the seeds had changed from white to yellow
and were more rounded in form. In the third generation
nearly all resemblance to the original and very distinct
parent form was lost. In the sixth generation this maize,
which continued to be cultivated near Heidelberg, could
only be distinguished from the common Kuropean kind by
a somewhat more vigorous growth. ‘The fact,’ says Mr.
Darwin, ‘affords the most remarkable instance known to me
of the direct and prompt action of climate on a plant.’
Several hundred varieties of the vine, each characterised
by differences in their fruit, have been reared in hothouses,
or cultivated for wine, while the mulberry, both in France
and India, has given rise to as many varieties in the texture
and quality of the leaves, characters which have been ren-
dered constant by selection. If man had reversed this treat-
ment he might doubtless have produced endless changes
in the leaves of the vine, the grapes remaining unaltered,
and a great many races characterised by different fruits in
the mulberry, while the leaves, being neglected, would not
*
Metzger die Getreidearten, 1841, p. 206, cited by Darwin ‘On Variation,’
vol. i. p. 321.
Cu. XXXVI.] CHANGES PRODUCED IN CULTIVATED PLANTS. 299
have undergone any marked modification from the type of
the original plant.
A bitter plant (Brassica oleracea), with wavy green sea
leaves, having a flower like mustard or wild charlock, has been
taken from the sea-side, and transplanted into the garden,
where it has lost its saltness, and has been metamorphosed
into many distinct vegetables, among others the red cabbage
and the cauliflower, which are as unlike each other as is
each to the parent plant. In certain countries plants belong-
ing to the order of Cruciferee which are generally herbaceous
become developed into trees, so the cabbage in the island of
Jersey has acquired a woody stem not unfrequently from ten
to twelve feet in height. The stalk of one which measured
sixteen feet in height had its spring shoots at the top occu-
pied by a magpie’s nest. The wood of the same variety
is sometimes used for walking sticks, and even for rafters.
These effects result from particular culture and peculiarities
of climate. What is worthy of note, says Darwin, is the very
trifling difference in the flowers, seed-pods, and seeds of the
cabbage which accompanies the wonderful metamorphosis
which man has brought about in the shape, size, colour, and
growth of the leaves and stem. What a contrast is here
presented to the changes in the corresponding parts in the
varieties of maize and wheat. ‘The explanation is obvious:
the seeds alone are valued in our cereals, and their variations
have been selected ; whereas the seeds, seed-pods, and flowers
have been utterly neglected in the cabbage, whilst’ many
useful variations in their leaves and stems have been noticed
and preserved from an extremely remote period, for cabbages
were cultivated by the old Celts. ’*
Among the changes in external conditions of which florists
avail themselves in order to produce new varieties those of
the soil must not be overlooked. The production of blue
instead of red flowers in the Hydrangea hortensis, illustrates
the immediate effect of certain soils on the colours of the
calyx and petals. In garden-mould or compost, the flowers
are invariably red; in some kinds of bog-earth they are
*
* Darwin ‘On Variation,’ vol. i. p. 324.
300 VARIATION OF PLANTS AND ANIMALS. [Cu. XXXVI,
blue ; and the same change is always produced by a particular
sort of yellow loam.
Whether there are definite lmits to the variability of a
species.—In former editions of this work (from 1831 to 1853),*
T contended that there are limits to that deviation from an
original type of which species are susceptible. My argu-
ment was founded chiefly on the rapid rate at which we may
bring about considerable modifications in a brief period in
domesticated animals and cultivated plants, and the slow
progress which we can afterwards make in modifying the
same races when our experiments are persevered in for a
great many generations. In illustration of this principle I
observed, that when man uses force or stratagem against
wild animals, the persecuted race soon becomes more
cautious, watchful, and cunning ; new instincts seem often to
be developed, and to become hereditary in the first two or
three generations: but let the skill and address of man in-
crease, however gradually, no farther variation can take place,
no new qualties are elicited by the increasing dangers. The
alteration of the habits of the species has reached a point
beyond which no ulterior modification is possible, however
indefinite the lapse of ages during which the new circum-
stances operate. Hxtirpation then follows, rather than such
a transformation as could alone enable the species to perpe-
tuate itself under the new state of things.
But in the first place Mr. Darwin has shown that even
in those species such as the pigeon, our common cattle,
sheep or pigs, which have been made to vary by selection
from the remotest periods, there are no signs of a positive
limit having been reached beyond which no farther change
can be brought about. All have been altered within quite
modern times, and ‘ the tendency to general variability seems
unlimited.’+
It has also been pertinently remarked by Mr. Wallace that
the amount of change in any one direction may at first be
comparatively rapid; as when in the case of the race-horse,
* *Principles of Geology,’ Ist edi- 9th edjgion, chap. xxxy. p. 592.
tion, 1831, vol. ii. chap. iii. p. 37, and f+ Darwin ‘On Variation,’ &c., p. 416.
Cu. XXXVI.] OBEDIENCE TO MAN OFTEN AN INSTINCT. 301
we begin to select certain varieties with a view of increasing
speed, and afterwards fail in our efforts materially to raise the
standard, for how ever many years we may expend wealth and
energy in the attempt. The real question, he observes, is
not whether indefinite and unlimited change in any or all
directions is possible, but whether man can bring about such
differences as do occur in nature by accumulating variations
or by selection. <‘ All the swiftest animals—deer, antelopes,
hares, foxes, lions, leopards, horses, zebras, and many others—
have reached very nearly the same degree of speed. Although
the swittest of each must have been for ages preserved and the
slowest must have perished, we have no reason to believe that
there is any advance of speed. The possible limits under
existing conditions, and perhaps under possible terrestrial
conditions, has been long reached.’* Butin the English race-
horse we have been enabled to produce a variety surpassing
in swiftness its own wild progenitor and all the other equine
species.
Obedience to man under domestication often a mere adaptation
of a natural instinct.— We may also very easily exaggerate the
amount of change which seems to be brought about in a few
generations. Frederick Cuviert has clearly pointed out one
source of deception relating to alterations which we may fancy
we have wrought in the instincts and dispositions of animals.
An animal in domesticity, he observes, is not essentially in a
different situation, inregard to the feeling of restraint, from one
left to itself. It lives in society without constraint, because,
without doubt, it was a social animal; and it conforms itself to
the will of man, because it had.a chief, to which, in a wild
state, it would have yielded obedience. There is nothing in
its new situation that is not conformable to its propensities ;
it is satisfying its wants by submission to a master, and
makes no sacrifice of its natural inclinations. All the social
animals, when left to themselves, form herds more or less
numerous; and all the individuals of the same herd know
each other, are mutually attached, and will not allow a strange
Wallace, Shar 7 ourn. of Science, Jameson, Ed. New Phil. Journ., Nos. 6
Teli 1867, p. 4 7 8,
¢ Mém. du it, @Hist. Nat.;
302 VARIATION OF PLANTS AND ANIMAIS. [Cu. Xxxyr.
individual to join them. ‘In a wild state, moreover, they
obey some individual, which, by its superiority, has become
the chief of the herd. Our domestic species had, originally,
this sociability of disposition ; and no solitary species, how-
ever easy it may be to tame it, has yet afforded true domestic
races. We merely, therefore, develope, to our own advantage,
propensities which propel the individuals of certain species
to draw near to their fellows.
The sheep which we have reared is induced to follow us, as
it would be led to follow the flock among which it was
brought up; and, when individuals of gregarious species
have been accustomed to one master, it is he alone whom
they acknowledge as their chief—he only whom they obey,
‘The elephant allows himself to be directed only by the
carnac whom he has adopted; the dog itself, reared in solitude
with its master, manifests a hostile disposition towards all
others; and everybody knows how dangerous it is to be in
the midst of a herd of cows, in pasturages that are little fre-
quented, when they have not at their head the keeper who
takes care of them.
‘ Everything, therefore, tends to convince us, that formerly
men were only, with regard to the domestic animals, what
those who are particularly charged with the care of them
still are—namely, members of the society which these animals
form among themselves; and, that they are only distinguished,
in the general mass, by the authority which they have been
enabled to assume from their superiority of intellect. Thus,
every social animal which recognises man as a member, and
as the chief of its herd, is a: domestic animal. It might even
be said, that, from the moment when such an animal admits
man as a member of its society, it isdomesticated, as man could
not enter into such a society without becoming the chief of it.*
But the ingenious author whose observations I have here
cited, admits that the obedience which the individuals of
many domestic species yield indifferently to every person, is
without analogy in any state of things which could exist
previously to their subjugation by man. Each troop of wild
horses, it is true, has some stallion for its chief, who draws
* Mém. du Mus. d’Hist. Nat.
Cu. XXXVI_] ORIGINAL TAMENESS OF ANIMALS. 3038
after him all the individuals of which the herd is composed ;
but, when a domesticated horse has passed from hand to
hand, and has served several masters, he becomes equally
docile towards any person, adopting as it were the whole
human race as his leader.
Every troop of wild elephants has a leader who directs
their movements with much caution, and takes care that
none of them straggle from the herd. In India this animal
rarely breeds in captivity, although, according to Mr. Craw-
furd, in Ava, where the females are allowed to roam some-
what freely in the forests, they breed in a half-domestic
state. In general it is found to be the best economy to
capture full-grown individuals in a wild state, and in a few
years after they are taken, sometimes, it is said, in a few
months, their education is completed. They who have had
opportunities of observing them in their native forests are
y no means surprised at the sagacity which they display
after they have accommodated themselves to the society of
man, to whom they render obedience, not by acquiring any
new instincts, but simply in conformity to faculties proper to
them in a wild state.
The tameness of some animals, in the case of cattle,
goats, and deer for example, after they have been reclaimed
and improved by selection for two or three generations, is
another change of which we may be in danger of overrating
the importance. The first savages who wandered into new
districts probably found most of the animals free from any
apprehension of danger from man. Mr. Darwin relates that
in the islands of the Galapagos archipelago, placed directly
under the equator, and nearly 600 miles west of the American
continent, all the terrestrial birds, as the finches, doves,
awks, and others, are so tame that they may be killed with
a switch. One day, says this author, ‘a mocking-bird
alighted on the edge of a pitcher which I held in my hand,
and began quietly to sip the water, and allowed me to lift
it with the vessel from the ground.’ Yet formerly, when
the first Europeans landed, and found no inhabitants in these
islands, the birds were even tamer than now: already they
are beginning to acquire that salutary dread of man which
304 VARIATION OF PLANTS AND ANIMALS. [Cu. XXxyt,
in countries long settled is natural even to young birds,
which have never received any injury. So in the Falkland
Islands, both the birds and foxes are entirely without fear of
man; whereas, in the adjoining mainland of South America,
many of the same species of birds are extremely wild; for
there they have for ages been persecuted by the natives.*
Dr. Richardson informs us, in his able history of the
habits of the North American animals, that, ‘in the retired
parts of the mountains where the hunters had seldom pene-
trated, there is no difficulty in approaching the Rocky Moun-
tain sheep, which there exhibit the simplicity of character so
remarkable in the domestic species ; but where they have been
often fired at, they are exceedingly wild, alarm their com-
panions, on the approach of danger, by a hissing noise, and
scale the rocks with a speed and agility that baffle pursuit.’+
‘Feral’ varieties do not revert to the exact likeness of the
original stock.—It is an old and received opinion that if any
domesticated animals or cultivated plants are abandoned by
man and allowed to run wild or become ‘ feral,’ they will
revert to the exact likeness of their aboriginal parent stock.
But this seems to be only true to a limited extent. It was
before remarked (p. 281) that such ‘feral’ animals can only
compete with their fellows in the struggle for life by losing
most of the characters which they have acquired in a state
of domesticity.
Our quickly fattening pigs, says Mr. Wallace, our short-
legged sheep, cattle without horns and pouter pigeons, would
soon be annihilated if man’s protection was withheld from
them. Ina few generations the boar when compelled to search
for food recovers his long tusks-and the full exercise of all his
organs ; reverting in the general shape of his body, the length
of his legs and of his muzzle, to the type of the wild boar.
His reversion to the likeness of the parent stock, says
Darwin, is probably more complete than that of other
domesticated animals which run wild, but there is no evl-
dence to show that it is ever perfect. There are two main
types of the domestic pig—one supposed to come from the
* Darwin’s Journ. in Voyage of H.M.S. + Fauna Boreali Americana, Pp. 273.
Beagle, p. 475.
Pn ME on so ME eet
4
oF
y—%
ae
Cu. XXXVI.] THE HYBRIDISATION OF PLANTS. 305
European Sus scrofa, and the other from the Indian Sus
Indica. These varieties or species seem not yet to have been
distinctly recognised in a feral state, and the feral pigs of S.
America, Jamaica, and New Granada have each some pecu-
liarities.* Under new climatal and other conditions they vary,
but they can only stand their ground by reacquiring many
lost characters which belonged to the original wild species.
It is very commonly believed that when the seeds of fruit-
trees and garden vegetables spring up in uncultivated soils, the
plants revert to the likeness of the original wild stock; but Dr.
Hooker observes that this is not strictly true. ‘They degene-
rate and sometimes die out; sometimes they become stunted,
and so far resemble their wild progenitors, but they do not re-
vert to the original type. Thus the Scotch kail and Brussels
sprouts, if neglected, become as unlike the wild Brassica Ole-
racea as they are unlike one another; and our finer kind of
apples, if grown from seed, degenerate and become crabs, but
in so doing, they become crab states of the varieties to which
they belong, and do not revert to the original wild crab-apple ;
and the same is true to a great extent of cultivated roses,
and of the raspberry, strawberry, and most garden fruits.’ +
This experienced botanist therefore concludes that the cha-
racters of a variety are never so entirely obliterated that it
has no longer a claim to be considered a variety.
How far do domestic races difer from wild species in their
capacity to interbreed— Hybridisation of animals and plants.—
It is now time to return to a question which was mooted at
the commencement of thig chapter, namely, the freedom with
which all artificially produced races breed together, and how
far this clearly constitutes a rea] difference between them and
the most closely allied wild Species.
There are no less than 2
family (Columbide) ; + yet,
experiments have yet been tried,
in this respect a marked contras
which, as before stated (p. 289)
pair together, presenting
t to those domestic races
» would, if found wild, have
* Darwin ‘On Variation,’ chap, iii. Lae
T Hooker, ‘Flora of Australia,’ p. ix, ‘On Vv
VOT IT,
- Bonaparte, cited by Darwin
aviation,’ p. 133
x
306 VARIATION OF PLANTS AND ANIMALS. [Cu. XxxvI
been ranked by ornithologists as true species, yet which pair
freely and produce fertile offspring.
All the different races of domestic dogs breed together,
and John Hunter’s opinion has already been cited, that the
jackal and wolf must be classed as of the same species
because when crossed they produce fertile mules. A ¢a-
pability of thus breeding together has often been proposed,
as the best practical test of a real distinctness of species.
The experiment with which we are most familiar relates +o
the mixed offspring of the horse and the ass; and in this
ease it is well established that the he-mule can generate, and
the she-mule produce. Such cases occur in Spain and Italy,
and much more frequently in the West Indies and New
Holland; but these mules have never bred in cold climates,
seldom in warm regions, and still more rarely in temperate
countries. But no instance is known of two such mules,
male and female, having bred together.
The hybrid offspring of the she-ass and the stallion, the
ywvos of Aristotle, and the hinnus of Pliny, differs from the
mule, or the offspring of the ass and mare. In both cases,
says Buffon, these animals retain more of the dam than of
the sire, not only in the magnitude, but in the figure of the
body ; whereas, in the form of the head, limbs, and tail, they
bear a greater resemblance to the sire. It seems rarely to
happen that any hybrids are truly intermediate in character
between the two parents. Thus Hunter mentions that, in
his experiments with the dog and the wolf, one of the
hybrid pups resembled the wolf much more than did the rest
of the litter; and we are informed by Wiegmann, that, in a
litter obtained in the Royal Menagerie at Berlin, from a white
pointer anda she-wolf, two of the cubs resembled the common
wolf-dog, but the third was like a pointer with hanging ears.
The phenomena of hybridity in plants present a remarkable
parallel to those in the animal kingdom; and we have learnt
more from the cultivators of plants, because they have been.
able to conduct their experiments on a grander scale, sowing
great numbers of the two species which they desire to cross;
and taking small account of failures, provided that some of
the results of crossing are successful.
from th:
Cu. XXXVI.] THE HYBRIDISATION OF PLANTS. 307
The first accurate experiments in illustration of this curious
subject appear to have been made by Kolreuter, who ob-
tained a hybrid from two species of tobacco, Nicotiana rustica
and N. paniculata, which differ greatly in the shape of their
leaves, the colour of the corolla, and the height of the stem.
The stigma of a plant of N. rustica was fertilised with the
pollen of a plant of N. paniculata. The seed ripened, and
produced a hybrid which was intermediate between the two
parents, and which, like all the hybrids which this botanist
brought up, had imperfect stamens. He afterwards impreg-
nated this hybrid with the pollen of N. paniculata, and
obtained plants which much more resembled the last. This
he continued through several generations, until, by due per-
severance, he actually changed the Nicotiana rustica into the
Nicotiana paniculata.
The plan of crossing adopted, was the cutting off of the
anthers of the plant intended for fructification before they
had shed pollen, and then laying on foreign pollen upon the
stigma. The same experiment has since been repeated with
success by Wiegmann, who found that he could bring back
the hybrids to the exact likeness of either parent, by crossing
them a sufficient number of times, with individuals of one of
the pure stocks.
The blending of the characters of the parent stocks, in
many other of Wiegmann’s experiments, was complete ; the
colour and shape of the leaves and flowers, and even the
scent, being intermediate, as in the offspring of the two
Species of verbascum. An intermarriage, also, between the
common onion and the leek (Allium cepa and A. porrum) gave
a mule plant, which, in the character of its leaves and flowers,
approached most nearly to the garden onion, but had the
elongated bulbous root and smell of the leek.
The same botanist remarks, that vegetable hybrids, when
not strictly intermediate, more frequently approach the female
than the male parent species ; but they never exhibit characters
foreign to both. A re-cross with one of the origi
pring sometimes con-
tinuing to exhibit the character of a full hybrid.
Xa
308 VARIATION OF PLANTS AND ANIMALS. [Cu. XXXVI.
Girtner, in his work on the hybridisation of plants, has
shown that some pure species which can be united with
unusual facility, will produce sterile hybrids, while others
which are crossed rarely, or with extreme difficulty, produce
hybrids which are very fertile, as for example in different
species of the genus Dianthus or pink. The same botanist
_ repeatedly crossed the common red and blue pimpernels,
Anagallis arvensis and A. cerulea, which, says Darwin, the
best naturalists rank as mere varieties of one species, and
found them absolutely sterile. These plants, besides their
distinctness in colour, differ slightly in the nervation of their
leaves and in the shape of their petals; and botanists who
attach importance to the test of sterility, conclude that they
are specifically distinct, although scarcely any of them would
have come to such an opinion before the experiment of cross-
ing had been tried.
Wiegmann diversified as much as possible his mode of
bringing about these irregular unions among plants. He
often sowed parallel rows, near to each other, of the species
from which he desired to breed; and, instead of mutilating,
after Kélreuter’s fashion, the plants of one of the parent
stocks, he merely washed the pollen off their anthers. The
branches of the plants in each row were then gently bent
towards each other and intertwined; so that the wind, and
numerous insects, as they passed from the flowers of one to
those of the other species, carried the pollen and produced
fecundation.
When we consider how busily many insects are engaged
in conveying anther-dust from flower to flower, especially
bees, flower-eating. beetles, and the like, it seems a most
enigmatical problem how it can happen that promiscuous
alliances between distinct species are not perpetually oc-
curring.
How continually do we observe the bees diligently em-
ployed in collecting on their hind legs the red and yellow
powder by which the stamens of flowers are covered, and
after passing from one flower to another, carrying it t0
their hive for the purpose of feeding their young! In
thus providing for their own progeny, these insects assist
=m wo ld
of cross.
mode of
nts, It
1e specie
utilating
of one 0
produes
Cu. XXXVI.] THE HYBRIDISATION OF PLANTS. 309
materially the process of fructification.* Few persons need
be reminded that the stamens in certain plants grow on
different blossoms from the pistils ; and, unless the summit of
the pistil be touched with the fertilising dust, the fruit does
not swell, nor the seed arrive at maturity. It is by the help
of bees, moths, and other insects, that the development of
the fruit of many such species is secured, the powder which
they have collected from the stamens being unconsciously
left by them in visiting the pistils.
A vast majority of plants are hermaphrodite, yet Mr.
Darwin, following up the views suggested by Andrew Knight,
has proved experimentally that even with such plants the
intermarriage of two separate individuals gives more vigour
and fertility to the offspring than if the female organs are
fertilised by the pollen of males of the same individual. The
whole arrangement of the flower may seem to be made for
the purpose of close interbreeding, and yet insects and other
means are employed by nature for crossing the hermaphrodite
with another individual of the same species.
How often, during the heat of a summer’s day, do we see
the males of dicecious plants, such as the yew-tree, standing
separate from the females, and sending off into the air, upon
the slightest breath of wind, clouds of buoyant pollen! That
the zephyr should so rarely intervene to fecundate the plants
of one species with the anther-dust of others, seems almost to
realise the converse of the miracle believed in by the credulous
herdsmen of the Lusitanian mares—
re omnes verse in Zephyrum, stant as altis
Exceptantque leves auras: et seepe sine u
Conjugiis, vento gravid, mirabile dictu. ‘
Mr. Darwin has discovered that when aflower is fertilised
by the wind, it never has a gaily coloured corolla ; but when
its Piation depends on the aid of insects, the over are
conspicuous in colour and size, evidently in order to attract
their observation.+
When we Ppesides the facility with which the skilful
* See Barton ‘On Geography of + Geor 73.
Plants,’ p. 67. t Origin eee 4th edition, p. 239.
310 VARIATION OF PLANTS AND ANIMALS. (Cu. XXXVI.
gardener produces hybrid races, it seems strange that we do
not oftener meet with hybrids ina state of nature. But it
must be remembered that the conditions in the two cases are
very different.
The stigma imbibes, slowly and reluctantly, the granules
of the pollen of another species, even when it is abundantly
covered with it; and if it happen that, during this period,
ever so slight a quantity of the anther-dust of its own species
alight upon it, this is instantly absorbed, and the effect of the
foreign pollen destroyed. Besides, it does not often happen
that the male and female organs of fructification, in different
species, arrive at a state of maturity at precisely the same
time. Even where such synchronism does prevail, so that a
cross impregnation is effected, the chances are very numerous
against the establishment of a hybrid race.
The greater part even of those seeds of wild plants which
are well ripened are either eaten by insects, birds, and other
animals, or decay for want of room and opportunity to ger-
minate. Unhealthy plants are the first which are cut off by
causes prejudicial to the species, being usually stifled by more
vigorous individuals of their own kind. If, therefore, the re-
lative fecundity or hardiness of hybrids be in the least degree
inferior, they cannot maintain their footing for many gener-
ations in a wild state. In the universal struggle for existence,
the right of the strongest must eventually prevail; and the
strength and durability of a race depends in a great degree
on its prolificness, in which hybrids are acknowledged to be
generally deficient.
It is admitted on all hands, that in proportion as the species
of animals and plants are remote from each other in structure
they are averse to sexual union ; and that species which the
zoologist and botanist would usually class as distinct, most
commonly refuse to unite, and if they can be crossed and
produce new offspring, the hybrids are sterile. Whenever we
find that two races regarded by many as true species will
produce fertile hybrids, we are reduced to the dilemma of
choosing between two alternatives; either to reject the test
of hybridity, or to declare that the two species, from the
union of which the fruitful progeny has sprung, were mere
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Cu, XXXVI.] DIFFERENT RACES OF CATTLE HERD APART. S11
varieties. If we prefer the latter, we are compelled to ques-
tion the reality of the distinctness of all other supposed
species which differ no more than the parents of such pro-
lific hybrids ; for although we may not be enabled immedi-
ately to procure, in all such instances, a fruitful offspring,
yet experiments show, that sometimes after repeated failures,
the union of two.recognised species may at last, under very
favourable circumstances, give birth to a fertile progeny.
Two kinds of pheasant, our common species, Phasianus
colchicus, and P. torquatus, breed together, and the hybrids
are perfectly fertile.* The two pimpernels, as before stated
(p. 8308), cannot be crossed.
Tendency of different races of domestic cattle and sheep to herd
apart.—Although more than one species of wolf as well as the
jackal have been crossed with the dog, and this mixture is sup-
posed to have contributed somewhat to the great diversity
of our artificial breeds, yet these same wolves and the jackal
keep distinct in a wild state. So also more than one of the
aboriginal races or subspecies of Huropean wild cattle, which
kept distinct in prehistoric times, have now been blended
and confounded together, and even the humped cattle of
India have been crossed with our domestic varieties and have
produced fertile offspring. Two species of wild pig, as before
stated, the Huropean Sus Scrofa and the Sus Indica, have also
been confounded together in some of our domestic races.
Yet there is every reason to believe that such mixtures would
not have occurred in a state of nature. This may be ex-
plained simply by the preference which animals exhibit to
unite with others of the same race rather than with those
which differ considerably from them.
In Paraguay the horses have much freedom, and those of
the native race of the same colour and size prefer associating
together rather than with other imported horses. Three
distinct sub-races of the horse in Circassia, whilst living nearly
a free life, refrain almost always from crossing. It has
been observed in a district stocked with heavy Lincoln-
shire and light Norfolk sheep, that both kinds will, when
* Origin of Species, 4th edition, p. 300.
312 VARIATION OF PLANTS AND ANIMALS. [Cu. XXXVI.
they are all turned out together, ‘in a very short time separ-
ate to a sheep ;’ the Lincolnshires drawing off to the rich
soil, and the Norfolks to their own dry light soil ; and as long
as there is plenty of grass ‘ the two breeds keep themselves ag
distinct as rooks and pigeons. In this case different habits
of life tend to keep the races distinct.’*
The origin of a new race of sheep, recorded in the Phij-
losophical Transactions for 1813, also illustrates the disposi-
tion of even closely related varieties to herd apart, and has
also been cited by Professor Huxley as proving the strong
tendency which there is in a newly arisen variety to be per-
petuated. ‘A farmer in Massachusetts possessed a flock of
fifteen ewes and a ram of the ordinary kind. In the year
1791 one of the ewes presented her owner with a male lamb,
differing from its parents by a proportionally long body and
short bandy legs, whence it was unable to emulate its rela-
tives in those sportive leaps over the neighbouring fences, in
which they were in the habit of indulging much to the good
farmer’s vexation. His neighbours imagined that it would
be an excellent thing if all his sheep were endued with the
stay-at-home tendencies enforced by nature upon the newly
arrived ram, and they advised Wright to kill the old patriarch
of his fold and instal the Ancon ram in his place. The result
justified their sagacious anticipations. The young lambs
were almost always pure Ancons or pure ordinary sheep, and
when sufficient Ancon sheep were obtained to interbreed with
one another, it was found that the offspring was always pure
Ancon. In this well-authenticated instance we have a dis-
tinct race established at once or by a leap, and that race
breeding true. When the Ancon sheep were herded with
other sheep they kept together, so that it was believed that
this breed might have been indefinitely protracted, had it not
been superseded by the introduction of the Merino sheep,
which were not only superior to the Ancons in wool and
meat, but were equally quiet and orderly.’
Pallas on domesticity eliminating sterility. Correlation of
* Darwin ‘On Variation,’ chap. xvi. Article on Darwin ‘On the Origin of
p- 102, who cites Marshall. Species.’
t Huxley, Westminster Review, 1860.
Cu. XXXVI_] DOMESTICITY ELIMINATES STERILITY. OL
growth.— Pallas has remarked that domesticity eliminates the
tendency to sterility which belongs to nearly allied species
in a state of nature. As bearing on this subject, Mr. Darwin
observes that there are many animals which, when tamed or
subjugated to man, refuse to breed in captivity although
they enjoy perfect health, as the tiger, for example, in India,
and parrots in Europe, and the elephant except when allowed,
as in Assam, to range in a half-wild state in the woods; a fact
showing how easily sterility may be superinduced when habits
long fixed, as well as many of the conditions of existence in
a wild state, are interfered with. But those species which
more readily accommodate themselves to new circumstances
arising out of their association with man, and which can be
carried by him to all climates, exhibit the same plasticity of
character in reference to the reproductive organs.
It cannot, however, be pretended that a satisfactory expla-
nation can be offered of the tendency of domestication to in-
crease the prolificness of animals and plants. In reference to
the opposite effect of a return to the wild state, the following
fact is worthy of mention. About the year 1419 some rabbits
were introduced into the island of Porto Santo, where they
multiplied exceedingly, and have flourished ever since in a
feral state. In many of their characters they constitute a
marked race, which is smaller than the original parent stock.
When two of the males were brought to the London Zoologi-
cal Gardens, they refused to pair with any varieties of domes-
tic rabbits, isolation for many generations under peculiar
geographical conditions having apparently superinduced an
aversion to cross even with such nearly allied races.
If two wild species, such as the wolf and the jackal, can by
the intervention of man be made to breed together and the
offspring proves fertile, such a result must shake our faith
in the theory that species have been specially endowed with
mutual sterility in order to keep them distinct. It is certainly
very strange that when domesticated races have been made
to differ to such an extent that if wild they would have been
referred by naturalists to different genera, there should still
be scarcely any well-attested examples even of an approach
to sterility in their mongrel offspring. It is all the more
314 VARIATION OF PLANTS AND -ANIMALS. [Cu. XXXVI.
strange if we are persuaded of the truth of Mr. Darwin’s
view, that the whole organisation of an animal is so tied to-
gether, that when even slight variations occur in any one part
other parts usually become modified.
Among many other illustrations which he gives of this
principle, called by him in the ‘Origin of Species’ ‘ correlation
of growth,’ and in his last work ‘ correlated variability,’ he
mentions that pigeons with feathered feet have skin between
their outer toes, pigeons with short beaks have small feet, and
those with long beaks large feet ; and some instances of corre-
lation, he remarks, are quite whimsical: thus, cats which are
entirely white and have blue eyes are generally deaf. One
case is recorded where the blue iris at the end of four months
began to grow dark-coloured, and then the cat began to
hear.*
If the sterility of the mule offspring be due, as the same
naturalist suggests, to the imperfection of their reproductive
organs arising from the blending together of two different
structures and constitutions, which causes a disturbance and
interferes with the development of the embryo, we might
have expected that differences affecting permanently not
only the external form and shape, but even the shape of the
skull in many vertebrate animals, as well as their instincts
and habits, would have been accompanied, when such fixed
varieties were crossed, with a disturbance in the reproductive
rgans and consequent sterility in the hybrids.
At the same time we must remember that the greatest
changes in races have been brought about by selection, and
it has never been the object of man to modify the reproduc-
tive organs with a view of producing two races mutually
sterile, nor if he wished to make such an experiment, would
he know in what manner to proceed. Moreover, we have
seen how possible it is to alter the foliage of plants without
their seeds varying, or to change their seeds, fruit, or flowers
without the character of the root or leaves being affected.
It is in fact established, in spite of‘ correlation,’ that we may
cause some organs to be greatly modified, while another
to which we have not directed our attention may continue
* Dr. Sichet, cited by Darwin ‘ On Variation,’ p. 329.
Ne same
oductive
different
ance and
e might
ntly not
w of the
instincts
ich fixed
oductire
jon,
Cu. XXXVI_] CORRELATION OF GROWTH. 315
almost or entirely unaltered. In the next chapter, when we
treat of Natural Selection, we shall have again to consider
in what way the varieties of wild species may be supposed
to have departed so far in the course of ages from the parent
stock and from each other as to be incapable of being crossed,
notwithstanding the fact which seems directly opposed to
such a result, that a slight amount of variation in indi-
viduals of the same species when they are intermarried in-
fuses fresh uigour and increased fertility into the offspring.
316
CHAPTER XXXVII.
NATURAL SELECTION.
NATURAL AS COMPARED TO ARTIFICIAL SELECTION—TENDENCY IN EACH
SPECIES TO MULTIPLY BEYOND THE MEANS OF SUBSISTENCE —TERMS * SELEC-
De Ose
VARIABLE AND COMPARATIVELY MODERN—ALTERNATE GENERATION DOES
NOT EXPLAIN THE ORIGIN OF NEW SPECIES.
NATURAL AS COMPARED TO ARTIFICIAL SELECTION.—In
the last chapter we have spoken of the great changes which
man has brought about in the course of many generations
in the form and characters of animals and plants, by selecting
certain useful varieties of a species, and breeding from them
to the exclusion of other varieties less profitable or pleasing
to him. In this way he has gone on accumulating differ-
ences in successive generations until new races have been
formed as distinct in outward Shape, and sometimes in the
internal structure of important organs, as are most of the
species which we meet with in nature; the races, however,
thus artificially produced being distinguishable from wild spe-
cies by the fertility of the offspring produced by their union.
We may next consider the modification of species effected
by variation and what Mr. Darwin has called ‘ natural gelec-
tion,’ of which we gave a brief analysis in Chap. XXXV.
How far do the breeder, the agriculturist, and gardener,
when they form new races, simply imitate a process by which,
in a much greater lapse of time, nature causes still more
important deviations from the original type ?
Cu. XX XVII. ] RAPID INCREASE OF ANIMALS. 317
Of the laws which may govern the variety-making power
we are, as Mr. Darwin admits, profoundly ignorant; and if,
as seems probable, these laws embrace the principle of pro-
gressive development explained in the first volume (Chap.
IX.), they must be of so high and transcendental a nature
that we may well despair of ever gaining more than a dim
insight into them. But granting what is undeniable, that
there is a tendency in all animals and plants to possess
individual peculiarities by which they differ slightly from
their parents and from each other, are there not forces in
operation in the organic and inorganic world, which, in the
course of thousands or millions of generations, may cause new
races, varying more and more in a particular direction, until
at length they constitute new species? If there be such a
process in nature, it will most nearly resemble that kind of
human selection which has been called ‘ unconscious,’ and
which for reasons explained in the last chapter is even more
effective in the long run than that which is intentional.
Tendency in each species to multiply beyond the means of
subsistence.—It has already been stated that if all the progeny
of each animal and plant which are born into the world were
allowed to come to maturity, a single species would soon fill
the whole of the habitable land or water. Malthus long ago
pointed out, that in the case of man, if his capability of in-
crease were not checked by scarcity of food, the earth would
soon fail to afford standing room for the descendants of a single
pair. The elephant, says Darwin, although reckoned the
slowest breeder of all known animals, would nevertheless so
multiply, if we assume that it only begins to have young when
thirty years old, and brings forth three pair between that age
and the age of ninety, that if all its descendants were to live
out the term of their natural life, at the end of five centuries
there would be fifteen million elephants descended from a
single pair.
In the severe struggle for existence which is always going
on, those varieties or species which have any even the slight-
est advantage over others inhabiting the same district will be
the survivors. They may be able to bear a degree of cold or
heat, moisture or dryness, which others cannot endure; they
318 | NATURAL SELECTION, [Cu. XXXVIL.
may have strength or agility to escape foes to which otherg
must fall victims ; but the great trial, as before hinted, con-
sists in the capacity of maintaining their ground at that
season of the year when food is scarcest.
Term ‘ Natural Selection’ or ‘ Survival of the fittest’—Mr.
Herbert Spencer has proposed to substitute for ‘ Natural Selec-
tion’ the term ‘ Survival of the fittest ;’* an expression which
is often very appropriate, and which some naturalists prefer,
because the various causes which in the natural world enable
one variety or race to prevail over another, act according
to fixed laws, and do not imply a conscious choice like the
selection of the breeder. But the metaphor employed by
Darwin appears to me legitimate and often useful, as remind-
ing us of the close analogy which exists between the manner
in which new races are formed by man and the way in which
it is supposed by Darwin and Wallace that they are slowly
produced by nature. Professor Huxley in his comments on
this subject observes, that the winds and waves of the Bay of
Biscay in the district called the Landes near Bordeaux have
spread out over a wide area great heaps of sand all the erain
of which are below a certain size. These grains have been
separated from the larger gravel with as much precision as
if by the aid of a sieve. That which the wind and the sea
are to a sandy beach the sum of all the influences which we
term the conditions of existence is to living organisms. The
weak are sifted out from the strong. A frosty night selects
the hardy plants in a plantation from among the tender ones
as effectually as if the intelligence of a gardener had been
operative in cutting the weaker organisms down.t
Number of conditions on which the constancy or the variation
of a species depends.—If the reader will reflect on the changes
in the earth’s physical geography and climate which were
alluded to in the first volume (Chapters XI. and XII.), as
having occurred in the course of geological periods, he will
not fail to perceive that the new conditions to which plants
and animals inhabiting any given province must be exposed
will be far more important in the ageregate than the change
* Principles of Biology, p. 444.
t Nat. Hist. Rey. ‘On Origin of Species,’ p. 578.
ployed j
, a8 renin
the Mane
AY In whic
"are slow}
mmments «
' the Bay
dean har
I] the gran.
: have bea
yrecision #
ind the #!
ag which ®
isms. DP
ght sel
tender
r bad s
1, variate
ic . A
Cu. XXXVIT.] CONDITIONS OF EXISTENCE. 819
of circumstances to which man can in a few thousand years
subject any animal or plant under domestication.
Were we to attempt to enumerate all the conditions which
Mr. Herbert Spencer has concisely termed the ‘ environment’
of a species, they would be almost endless. They would com-
prise not only the mean temperature of the air or water, but
the extreme heat or cold in the different seasons of the year,
the quantity and intensity of sunshine at different periods,
the number of clear and of rainy days, the quantity of ice and
snow, the direction and strength of the wind, the pressure
of the atmosphere and its electrical state, the nature of the soil,
its elevation above the sea, the habits, instincts, and properties
of hundreds of contemporary animals and plants, some of them
friendly others inimical, the comparative abundance or rarity
of those species on which the food of a given animal or plant
may depend,—circumstances, many of them, wholly beyond
the control of the breeder or horticulturist. All of them,
moreover, are brought into play by natural selection with a
uniformity and persistency which man cannot emulate.
Dr. Hooker ascertained that the average range in vertical
height : of flowering plants in the Himalayan mountain
amounted to 4,000 feet, and the upper and lower limits
of some species are even distant from each other as much
as 8,000 feet. If we transplant individuals which inhabit
the higher limits in these mountains into our British
gardens, we find that they are hardier, and better able to
stand the cooler climate of England, than those taken from
the inferior or warmer stations. This acclimatisation h
been the result of natural selection during thousands of eene-
rations. The physiological constitution of the plant has
been acted upon, and a hardy race established, although
the change may not have been sufficient to cause it to rank
as more than a variety. It may sometimes be more dwarfed
in size than individuals of the same species living in the
moist and hotter region far below. Tt may
slightly in the colour of its flowers, and,
the period of shedding its leaves or
of growth. Yet
sufficiently distin
as
perhaps vary
if deciduous, in
in its. general habits
its characters may not be on the whole
ct to induce the botanist to rank it as
320 NATURAL SELECTION, [Cu. XX XVII
more than what is called a geographical variety. In arriving
at such an opinion he may perhaps be chiefly guided by
his ability to trace in the individuals inhabiting all the
intermediate heights a gradual passage from one extreme
of the series to another.
Intercrossing of slight varieties beneficial.—It would be
an interesting experiment, and one which has not yet been
made, to cross individuals taken from the lowest station with
those hardier races which have been formed by acclimatisa-
tion in the upper regions of the mountain, and ascertain
whether they would produce as much seed as individuals
fertilised by the pollen of plants of the same station. If.
there were any signs of comparative sterility in such crosses,
it would afford an indication of the commencement under
nature of that character which distinguishes wild species
from artificially formed races. There is good reason, how-
ever, to believe that before any difficulty of crossing, or any
deficiency of prolific power in the offspring, would be appa-
rent, the races must depart so widely from each other that
their distinctness as species would already be a debateable
question with the naturalist. And this brings us to the
principal obstacle which we encounter when we endeavour to
refer the gradual formation of a new species to variation
and natural selection. If some degree of sterility was found
in the offspring of slight varieties, and this want of prolific
power went on augmenting in proportion as the deviation from
a common stock became more and more marked, the fact that
closely allied species inhabiting the same region keep distinct
would be intelligible. But the phenomena are precisely the
reverse. Instead of any reluctance being exhibited by slight
variations to intermarry and propagate their kind, their in-
termixture, on the contrary, takes place freely and infuses
fresh vigour and fertility into the species. Individuals of
the normal type are always the most numerous, and slight
varieties are usually ‘soon merged in the general average, so
that the new characters disappear. In some cases where
the races are so wide apart as to be thought by some
to belong to distinct species, it is only necessary to cross
their mongrel or hybrid offspring with pure individuals
|
|
ng, or aly
| be appe-
other that
lebateabk
us to th
leavour tv
variation
was found
Cu. XXXVII.1 BREEDING IN AND IN INJURIOUS. 321
of one of the two parent stocks for six or sometimes eight
generations in succession, and every trace of the foreign ad-
mixture will be lost. The mutual absorption in this manner
of the European and negro races the one into the other, by
a certain number of intermarriages with one of the two stocks,
has been frequently verified. The efficacy of the principle
above adverted to, in causing species to breed true for ages,
and checking lawless divergence, in spite of the numerous
varieties which occur in every generation, is obvious; the
only difficulty is to conceive how, if there be such proneness
in each aberrant form to merge into the normal type, a new
and permanent species can ever be established. It would
seem to require prolonged isolation under altered conditions,
such as may occur in different parts of the same continent, or
still more frequently in different islands of the same archi-
pelago. But we have yet to learn what degree of divergence
must be attained in two races sprung from the same stock
before a decided disinclination to breed together will arise,
and how much farther this must be carried before the off.
spring of the cross, if produced, will be sterile.
Breeding in and in injurious.—It has already been stated
that certain domestic races prefer breeding with their own
kind ; on the other hand, it is well ascertained that too much.
breeding in and in has an injurious effect.
The half-wild cattle which have been kept for four or five
centuries or more in British parks, as in those of Lord
Tankerville and the Duke of Hamilton, where the tota]
number varies from sixty to eighty, are relatively far legs
fertile than the enormous herds of half-wild cattle in South
America. But even in the latter case it is believed that the
occasional introduction of animals from distant localities is
necessary to prevent degeneration in size and fertility.*
The decrease in bulk from ancient times of the British cattle
alluded to must, says Darwin, have been prodigious, as ac-
cording to Riitimeyer they are the descendants of the gigantic
Bos prvmigenius. The Chillingham cattle are white, but
this is partly due to selection, as dark-coloured calves are
Bey eee bs ‘
* Darwin ‘On Variation,’ chap. xvii., who cites Azara.
VOL. Il. Y
822 NATURAL SELECTION. [Cu. XXXVII.
occasionally destroyed. In the Pampas in Texas, or in
Africa, where cattle have run wild in large herds, they have
acquired a nearly uniform dark-brownish red.* <A breed
called Niatas, seen by Darwin on the banks of the Plata,
has a short and broad forehead and other peculiarities in the
shape of the skull and in the projection and curvature of
the lower jaw. In this variety scarcely a single bone agrees
exactly in shape with that of the common ox. This breed,
which has existed for at least a century, is a good illustration
of the manner in which a marked variety may be formed in
a nearly wild state, and of the tendency of such a new race,
when brought into contact with other breeds, to keep distinct.
Such a tendency may point to the manner in which, in the
course of many generations, if man did not interfere, a greater
divergence from a common original and a more decided
aversion to sexual union might be superinduced. If the lapse
of time necessary for such transformations be very great, the
extinction of intermediate races will take place, by which a
new bar to the commingling of the nearest allied types will
be raised.
In speculating on this subject, Mr. Darwin reminds us
that a slight change in the conditions of life is found to be
very generally advantageous to cultivated animals and plants,
although we know that great changes are injurious. So, in
the case of man, the invalid whose constitution will be
benefited by.going from England to the South of France or
Madeira, may perish if transferred to Fernando Po. We
may easily imagine, that, although the crossing of most of
the varieties of cultivated plants and animals imparts strength
and fertility to them, yet under nature, and in the course of
ages, the variation may be carried so far as to modify the
reproductive organs, and render the formation of a fertile
hybrid germ impossible.t+
The refusal of many tamed animals to breed in captivity,
has been alluded to, and it demonstrates the susceptibility of
the reproductive system to be affected by a change in the
* Azara and others, cited by Darwin f~ Darwin ‘On Variation,’ chap.
‘On Variation,’ p. 86. xVill.
pat
Vol. : “Ong,
Pp,
ii,
eminds i
ound tole
and plats
ns. 82
‘
atom
Cu, XXXVII.] LINNAEUS ON PROTEAN GENERA. 523
natural conditions of life. That changes greater in degree or
even equal, but continuing uniformly in force for many thou-
sands of generations, should bring about the mutual sterility
of two allied races or species, is quite conceivable.
If this point of divergence had been reached by the breeder
or horticulturist, the derivability of a new species by gradual
deviation from an old type would almost have ceased to be a
debateable question in natural history.
Allusion has been made to the extinction of intermediate
varieties. This would happen the more readily on the prin-
ciple well pointed out by Darwin, that in order that a given
area should support the greatest number of individuals, these
ought to belong to a great many widely dissimilar types ; and
‘what is true of genera, must sometimes be true of the races
of a species. There may be room for those which represent
the extreme terms of a series, and no equally advantageous
place for those of intermediate characters.
Wild hybrid plants, and opinions o if Linneus on protean genera.
—If wild species were not averse to intermarry, or if their
hybrid offspring were not almost always sterile, it is obvious
that in a few generations there would be a blending together
of all existing types, and we should behold everywhere that
state of confusion which we now only meet with in certain
exceptional cases.
To the occasional occurrence of protean or polymorphous
genera, as they have sometimes been called, where a great
number of closely allied Species occur, Linneus makes
frequent allusion in his writings. He was evidently unable
to reconcile the phenomena with his dogma of the immu-
tability of primordially created Species. In an address to
the University of Upsala in 1751,* he gave a list of nearly
thirty ‘prolific’ genera of plants, in which the species
were of doubtful or suspicious value; enumerating, among
others, the willows and
Saxifrages in Europe, the oaks and
asters in North Amer
heaths and everlastin
1ca, the cactuses in South America, the
gs at the Cape; in each of which there
were sO many intermediate gradations between what are
* Linneus, ‘ Plante Hybride,’ 32nd Dissertation of the Amenitates Academic,
vol. ili. pp. 28-62, :
x 2
324 NATURAL SELECTION. [Cu. XXXVII,
commonly called allied species, as to make their origin a
curious subject of enquiry. He considered how far hybri-
disation could explain the enigma, and having his new dis-
covery of the sexuality of plants uppermost in his mind, he
was disposed to exaggerate the extent to which that cause
might have been efficacious in originating new forms. Hy-
brids, he says, are not always sterile, and not ie hac ae
even genera, may have arisen from this source.* But in a
ereat many instances, when he speaks of one species being
derived from an older one, and when he calls allied species,
which inhabit distant countries, ‘ sisters,’ as being of common
origin, and when he remarks of several forms that they had
their first origin from one and the same source, he is evidently
speculating on the origin of species by variation. In this
spirit he avowedly groups many forms of Ophrys, Valerianella,
Myosotis, Medicago, and other genera under single collective
specific names, because, he says, after a comparison of a great
number of them, all the forms will be seen to have had their
origin from one source. He even throws out the idea
that the day may come when botanists may hold that all
the species of the same genus may have sprung from the same
mother.t
The occurrence of some hybrids in a state of nature is
admitted by all botanists, although they are rare. Centawrea
hybrida is produced, according to Herbert, by the frequent
intermixture of two well-known species of Centaurea ; but this
hybrid race never seeds. Ranunculus lacerus, also sterile, has
been produced accidentally at Grenoble, and near Paris, by
the union of two ranunculi; but this occurred in gardens.}
Mr. Darwin has lately (in the summer of 1867) satisfied him-
self by experiment that the common oxlip is a natural hybrid
between the primrose and cowslip, and these two last he
considers to be distinct species. Mr. Herbert, in one of his
* «Novas species, immo et genera ex and Lovén, have kindly pointed out to
copula div ersarum spec ierum in then me these and many other passages 1
Vegetabili oriri, ete —Ameen. Academ. which Linnzus shows that he had fr eely
orig. ed. ee ed. Holm.1749,vol.i. p.70. speculated on bse Risse: and trans-
‘¢ oO
bat
t species dici congeneres quot sary ition of s
eadem matre sint progenite.—Ameeni- { Hon. and Rev. Ww, Herbert, Hort.
tates Academice, vol. vi. p. 12. Two emi- Trans. ,;VOl.iv. p. 4
nent Swedish naturalists, Professors Fries
aleriandh,
> collectin
ofa oreat
> had ther
> the ide
\d that d
n the salt
’ nature 3
Centaur
o freque
a; but ths
Cx, XXXVIUI.] DE CANDOLLE’S OPINIONS. 325
ingenious papers on mule plants, endeavours to account for
their rare occurrence in a state of nature, from the circum-
stance that all the combinations that were likely to occur
have already been made many centuries ago; but in our
gardens, he says, whenever species, having a certain degree
of affinity to each other, are transported from different coun-
tries, and brought for the first time into contact, they give
rise to hybrid species.*
De Candolle’s opirions.— Auguste De Candolle, in his Hssay
on Botanical Geography, published in 1820, observes, that
the varieties of plants range themselves under two general
heads: those produced by external circumstances, and those
formed by hybridity. After adducing various arguments to
show that neither of these causes can explain the permanent
diversity of plants indigenous in different regions, he says, in
regard to the crossing of races, ‘ I can perfectly comprehend,
without altogether sharing the opinion, that, where many
species of the same genera occur near together, hybrid species
may be formed, and I am aware that the great number of
species of certain genera which are found in particular regions
may be explained in this manner; but I am unable to conceive
how anyone can regard the same explanation as applicable to
species which live naturally at great distances. If the three
larches, for example, now known in the world, lived in the
same localities, I might then believe that one of them was the
produce of the crossing of the two others; but I never could
admit that the Siberian species has been produced by the
crossing of those of Europe and America. TI see, then, that
there exist, in organised beings, permanent differences which
cannot be referred to any one of the actual causes of varia-
tion, and these differences are what constitute species.’+ In
this passage De Candolle assumes that the actual causes of
variation have their strict and definite limits; an hypothesis
which the advocates of transmutation say, and not without
reason, is quite as arbitrary as the opposite or rival assump-
tion of indefinite modifiability.
Hybridity will not account for special instincts. —As to the
* Hon. and Rev. W. Herbert, Hort. Trans., vol. iv. p. 41.
t Essai Elémentaire, &c. 3idme partie.
326 NATURAL SELECTION. (Cu. XXXVI,
derivation of species in general from the mixture of a limited
number of original stocks, differing widely from each other,
all our experience is against such an hypothesis; for between
plants or animals of very distinct genera we can obtain
no cross-breeds. Nor is it easy to comprehend how species
of intermediate character between two divergent types could
give rise to a mongrel offspring having qualities and instincts
fitting them to hold their ground in the struggle for life.
If we take some genus of insects, such as the bee, we find
that each of the numerous species has some difference in its
habits, its mode of collecting honey, or constructing its
dwelling, or providing for its young, and other particulars,
In the case of the common hive bee, the workers are described,
by Kirby and Spence, as being endowed with no less than
thirty distinct instincts.* So also we find that, amongst a
most numerous class of spiders, there are nearly as many
aifferent modes of spinning their webs as there are species.
When we recollect how complicated are the relations of
these instincts with co-existing species, both of the animal
and vegetable kingdoms, it is scarcely possible to imagine
that a bastard race could spring from the union of these
species, and retain just so much of the qualities of each
parent stock as to preserve its ground in spite of the dangers
which surround it.
The theory of the origin of species by variation and natural
selection, would be untenable unless we could assign very
different degrees of antiquity to the generic and specific
types now existing. Some of them must date from remote
geological periods, others must be comparatively modern.
Of this last class are those forms of which the living re-
presentatives run so much the one into the other that
scarcely any two naturalists can agree as to where the lines
of demarcation between the Species ought to be drawn.
The British roses present a familiar illustration of this
ambiguous state of things, Mr. Bentham making only five
species of them, and Dr, Babington seventeen. Mr. Darwin
sees in this abundance of closely allied species an active
* Intr. to Entom, vol. ii. p. 504, ed. 1817,
Organis
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Cu. XXXVII.] ALTERNATE GENERATION, 327
manufacture of new races, and a want of time since their
origin to bring about the extinction of the varieties which
still link together the divergent members of the series, and
he remarks that the species of these polymorphous genera
are unusually variable. When the reader has reflected
on what will be said in Chapter XLII. on the extinction
of species, he will understand why, as a general rule, there
are so many missing links, and why ‘ protean’ genera are
the exception. No clue to this enigma is afforded by the
hypothesis of special creation. On the other hand, if it had
been found that fertile hybrids could spring from animals
and plants which are remote in their organisation, the oc-
currence of protean genera might certainly be explained ; but
in that case they ought to have been universal, and the
present condition of the animal and vegetable world would
then be a greater mystery than ever.
Alternate generation.—The discovery in certain classes of
invertebrate animals of what has been called ‘alternate
generation,’ has suggested to some zoologists a possible
mode by which nature may usher abruptly into the world
not only new organisms but even types of being of a higher
grade than any which pre-existed in the same class. Certain
sertularian polyps give birth to other polyps like themselves,
and these again produce other individuals of the same form
and structure, and this may continue for many generations
till at last one of the series gives birth to a more highly
organised creature called a4 Medusa. Formerly naturalists
regarded this Medusa as belonging to a distinct genus or
even family, of decidedly higher or more complex organi-
sation than the Sertularie. If then it is said, under a
change of conditions the Sertularia and the Medusa should
each of them go on for an indefinite number of generations
producing, according to the more ordinary rules of inherit-
ance, offspring like themselves, we should have an example of
the coming into existence of a new and higher form without
the disappearance of the lower one from which it had been
evolved; but, unfortunately for such speculations, nothing
of the kind has ever been witnessed. The Sertularia, although
it is hatched from an egg, never produces one, but simply
0328 NATURAL SELECTION. [Cu. XXXVII)
gives birth to other polyps by what is termed internal
gemmation, and when at length the male and female Medusz,
after sexual union, produce eggs from which the Sertu-
larie are born, the whole cycle of changes returns into
itself, just as do the metamorphoses of an insect. The same
may be said of certain aphides which, coming from an
egg, give birth by gemmation to a sexual offspring, and these
again to others like themselves, till at length some of their
descendants produce perfect and winged males and females,
from whose union eggs proceed, and then the cycle of trans-
formation recommences.
Even if there had been any indication of the Sertularia
and Medusa becoming each of them independent of the
other, this phenomenon would not afford an illustration of
what is usually meant by special creation, as the new form
would still be evolved out of the older one by descent. In
truth there are only as yet two rival hypotheses, between
which we have our choice in regard to the origin of species
—namely, first, that of special creation and, secondly, that of
creation by variation and natural selection. In the next
four chapters I shall treat of the light thrown by the geo-
graphical distribution of animals and plants on the claims
of these two rival hypotheses to our acceptance.
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CHAPTER XXXVIITI.
ON THE GEOGRAPHICAL DISTRIBUTION OF SPECIES.
GEOGRAPHICAL DISTRIBUTION OF ANIMALS—BUFFON ON SPECIFIC DISTINCT-
NESS OF QUADRUPEDS OF THE OLD AND NEW WORLDS—DOCTRINE OF ‘NATURAL
BARRIERS ’—AUSTRALIAN MARSUPIALS—GEOGRAPHICAL RELATION OF EXTINCT
FOSSIL FORMS TO THEIR NEAREST ALLIED LIVING GENERA AND SPECIES—
GEOGRAPHICAL PROVINCES OF BIRDS ACCORDING TO DR. SCLATER—THEIR
APPLICABILITY TO ANIMALS AND PLANTS GENERALLY—NEOTROPICAL REGION—
NEARCTIC—PALZARCTIC—ETHIOPIA N—INDIAN—AUSTRALIAN WALLACE ON
THE LIMITS OF THE INDIAN AND AUSTRALIAN REGIONS IN THE MALAY ARCHI-
PELAGO
GEOGRAPHICAL DISTRIBUTION OF ANIMALS.—Although in
speculating on ‘philosophical possibilities,’ said Buffon,
writing in 1755, ‘the same temperature might have been ex-
pected, all other circumstances being equal, to produce the
same beings in different parts of the globe, both in the
animal and vegetable kingdoms, yet it is an undoubted fact,
that when America was discovered, its indigenous quadrupeds
were all dissimilar to those previously known in the Old
World. The elephant, the rhinoceros, the hippopotamus,
the camelopard, the camel, the dromedary, the buffalo, the
horse, the ass, the lion, the tiger, the apes, the baboons, and
a number of other mammalia, were nowhere to be met with
on the new continent; while in the old, the American species,
of the same great class, were nowhere to be seen—the tapir,
the lama, the pecari, the jaguar, the couguar, the agouti, the
paca, the coati, and the sloth.’
These phenomena, although few in number relatively to
the whole animate creation, were so striking and so positive
in their nature, that the great French naturalist caught sight
at once of a general law in the geographical distribution of
organic beings, namely, the limitation of groups of distinct
species to regions separated from the rest of the globe by
certain natural barriers, It was, therefore, in a truly philo-
330 GEOGRAPHICAL DISTRIBUTION OF SPECIES. (Cu. XXXVIII.
sophical spirit that, relying on the clearness of the evidence
obtained respecting the larger quadrupeds, he ventured to
call in question the identifications announced by some con-
temporary naturalists of species of animals said to be common
to the southern extremities of Amerié¢a and Africa.*
In order to appreciate the importance and novelty of the
doctrine, that separate areas of land and water were the abodes
of distinct species of animals and plants, we must look back
to the times of Buffon and see in what crude conjectures
even so great a naturalist as his illustrious contemporary
Linneeus indulged, when speculating on the manner in which
the earth may first have become peopled with its present in-
habitants. The habitable world was imagined by the Swedish
philosopher to have been for a certain time limited to one
small tract, the only portion of the earth’s surface that was
as yet laid bare by the subsidence of the primeval ocean.
In this fertile spot the originals of all the species of plants
which exist on this globe were congregated together with
the first ancestors of all animals and of the human race.
‘In qua commodé habitaverint animalia omnia, et vegetabilia
leté germinaverint.’? In order to accommodate the various
habits of so many creatures, and to provide a diversity of
climate suited to their several natures, the tract in which the
creation took place was supposed to have been situated in
some warm region of the earth, but to have contained a lofty
mountain range, on the heights and in the declivities of
which were to be found all temperatures and every climate,
from that of the torrid to that of the frozen zone.t There
are still perhaps some geologists who adhere to a notion once
very popular, that there are signs of a universal ocean at a
remote period after the planet had become the abode of
living creatures. But few will now deny that the proportion
of sea and land approached very nearly to that now estab-
lished long before the present species of plants and animals
had come into being.
The reader must bear in mind that the language of Buffon,
* Buffon, vol. v. 1755.—On the Vir- also Prichard, Phys. Hist. of Mankind,
ginian Opossum, vol. i. p. 17, where the hypotheses of
+ ‘De terrd habitabili incremento ;’ different naturalists are enumerated.
Cx. XXXVIII.] THE DOCTRINE OF ‘SPECIFIC CENTRES,’ ool
in 1755, respecting ‘natural barriers’ which has since been
so popular, would be wholly without meaning had not the
geographical distribution of organic beings led naturalists
to adopt very generally the doctrine of specific centres, or, in
other words, to believe that each species, whether of plant or
animal, originated in a single birthplace. Reject this view,
and the fact that not a single native quadruped is common
to Australia, the Cape of Good Hope, and South America,
can in no ways be explained by adverting to the wide extent
of intervening ocean, or to the sterile deserts, or the ereat
heat or cold of the climates, through which each species
must have passed, before it could migrate from one of those
distant regions to another. It might fairly be asked of
one who talked of impassable barriers, why the same kan-
garoos, rhinoceroses, or lamas, should not have been created
simultaneously in Australia, Africa, and South America?
The horse, the ox, and the dog, although foreign to these
countries until introduced by man, are now able to support
themselves there in a wild state; and we can scarcely doubt
that many of the quadrupeds at present peculiar to Australia,
Africa, and South America, might have continued in like
manner to inhabit all the three continents, had they been in-
digenous in each, or could they once have got a footing there
as new colonists.
We have seen in the passage already cited that Buffon
called attention to the fact that the apes and baboons of the
Old World were nowhere to be found in America. Now that
SO many new forms of quadrumana have been brought to
light in both continents, the want of agreement in the ana-
tomical and many other characters of the two groups has
been rendered even still more prominent.
The Old-World apes and monkeys have been called Catar-
rhini because they have a narrow division between the nos-
trils; those of the New World, Platyrrhini because their
332 GEOGRAPHICAL DISTRIBUTION OF SPECIES. [Cu. XXXVIII.
in man, whereas in all the Platyrrhine monkeys they are
36, for they have four additional false molars. This marked
distinctness in their dentition is accompanied by many other
differences ; such as the prehensile tails belonging exclusively
to so many of the American monkeys, and the cheek-pouches
peculiar to the Old-World quadrumana.
Australian marsupials.—The adherence to certain peculiar
types of structure observable in the animals inhabiting dis-
tinct geographical provinces was illustrated in a still more
striking manner, some time after the publication of Buffon’s
great work, by the discovery in Australia of a group of mam-
malia so unlike those of the Old World as to be referable
even to a distinct sub-class called the Marsupial, of which
there was only one genus previously known on the globe,
namely, the Opossum (Didelphis) of America. Some of these
pouched animals, like the kangaroo, were herbivorous, others,
like the Tasmanian wolf (Thylacinus) carnivorous, and on the
whole they presented a parallel series in which were found
representatives of nearly all the grand divisions of the pla-
cental mammalia of the rest of the world. Mr. Waterhouse
has described about 140 species proper to the mainland of
Australia, and about 9 others inhabiting New Guinea and
some neighbouring. islands of the Malay archipelago.
Among these, only one species, the flying opossum (Petaurus
ariel), is common to one of the islands and the continent.
Geographical relation of extinct fossil forms to the nearest
allied living genera and species—When we speculate on the
meaning of this restriction of a peculiar division of the verte-
brata to a single province of the land, and try, by aid of it, to
gain some insight as to the plan which nature has followed in
peopling the earth with new species, we find ourselves in
some degree precluded from attributing the peculiarity of the
fauna to the nature of the climate, soil, and vegetation of
Australia. It has at least been ascertained experimentally
that when placental mammalia of various orders, whether
herbivorous or carnivorous—such as the ox, the horse, the dog,
and the cat—run wild in Australia,they are not only a match
for the native animals, but often obtain a mastery over them
and multiply greatly at their expense. How, then, does it
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Cu XXXVIII.] FOSSIL FORMS RELATED TO LIVING GENERA. 333
happen that the marsupials ever became dominant and
gained so complete an ascendancy over the placentals in the
struggle for life? The answer seems to be, that the more
highly organised placentals were never able to gain access to
Australia since it emerged from beneath the sea. It is cer-
tain that the marsupial fauna of that continent is of great
antiquity, for when we examine the bone-caves and super-
ficial alluvium of that part of the world, we find in them, as
in formations of corresponding age in Europe, the remains of
extinct quadrupeds; but, instead of being referable to the
placental class, as in the Old World, the Australian fossils
consist of lost species of kangaroo, wombat, thylacine, and
other marsupials. One of these, the Diprotodon of Owen,
allied to the kangaroo, is of the size of a large rhinoceros ;
another, Nototherium of Owen, not much inferior in bulk.
They are associated with extinct species of Dasywrus, besides
many of smaller dimensions, such as Phalangers and Potoroos.
In like manner, when we turn to the geological records of
South America, we find among the fossil remains of an age im-
mediately antecedent to the present, entombed in cavern and
alluvial deposits, the skeletons of Megatherium, Megalonyx,
Glyptodon, Mylodon, Toxodon, and Macrauchenia, extinct
forms generically allied to the existing sloth, armadillo, cavy,
capybara, and lama. In the caves also of Brazil we meet
with extinct monkeys associated with the above, and they are
referable to the genera Cebus and Callithrix, both belonging
to the Platyrrhine or New-World type of quadrumana before
mentioned. Thirdly, if we turn to the EKuropxo-Asiatic and
African province—a region which comprises Hurope, Asia,
and the north of Africa—geology teaches us, in like manner,
that where the rein-deer, musk-ox, elephant, rhinoceros,
hippopotamus, horse, and many other Old-World types now
prevail, there also extinct species of the same genera abounded
formerly at a very modern geological period. In the pre-
sent state of science we cannot speak of the fossil quad-
rumana of the same great province, because the Pliocene
maimmalia of tropical regions have ag yet been so imperfectly
investigated, and it is only within the tropics that the ape
and monkey tribe is at present met with. But it is worthy
334 GEOGRAPHICAL DISTRIBUTION OF SPECIES. [Cu. XXXVIII,
of notice that the extinct fossil monkeys which have been
discovered in Hurope and India, all of them of Miocene age,
are referable to Old-World forms or to the Catarrhine division,
such as the Semnopithecus and the Gibbons.
Professor Owen and Mr. Darwin have dwelt emphatically
on this manifest relationship between the living and the dead
—between peculiar genera and families of mammalia now in-
habiting certain parts of the world and the fossil representa-
tives of the same families found in corresponding regions.*
No hypothesis, therefore, respecting the origin of species will
be satisfactory unless it renders some account of the two
classes of phenomena already alluded to in this chapter.
First, species, and often genera and still larger groups, have
such a range in space as implies that they have spread in all
directions from a limited area called a ‘ centre of creation,’
until their progress was stopped by some natural barriers,
or conditions in the organic and inorganic world, hostile to
their farther extension. Secondly, the restriction of peculiar
generic forms to certain parts of the globe is not confined to
the present period, but may be traced back to an antecedent
geological epoch, when most of the species of mammalia were
different from those now living. The significance of this last-
mentioned fact can hardly be overrated. If we find Latin
inscriptions of ancient date most common in the country
where Italian is now spoken, Greek inscriptions most abundant
where they now talk modern Greek, and Heyptian hierogly-
phics inscribed on ancient monuments where for centuries
after the Christian era the kindred Coptic tongue was still in
use, we recognise at once that there is a geographical con-
nection between the three dead and the three living or
modern languages, which even if the entire intervening
history of those countries were lost, could not be questioned.
In this case it would afford-a powerful argument in favour of
the derivative origin of the three modern languages, each of
them having a nearer relationship to the extinct tongues
than to any other lost forms of speech known to us by tradition
or history as having been used elsewhere on the globe. So the
* Owen, British Mammals and Birds; and Darwin, Journal of South America.
pread ina]
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Cu. XXXVIIL] GEOGRAPHICAL PROVINCES OF ANIMALS. 335
intimate connection between the geographical distribution
of the fossil and recent forms of mammalia points to the
theory (without absolutely demonstrating its truth) that the
existing species of animals and plants, like the above-men-
tioned modern forms of speech, are of derivative origin and
not primordial or independent creations.
Geographical provinces of animals.—It has been ascertained
that the sea as well as the land may be divided into what
have been called distinct provinces, each inhabited by certain
species of animals and plants, there being a considerable
coincidence in the range of species in the two grand
divisions of the organic world. The six principal regions
sketched out in 1857 by Dr. Sclater for birds (referring
rather to the genera and families in the class Aves than to
the species),* are applicable, with some slight exceptions,
to quadrupeds, reptiles, insects, and landshells, and to a
great extent even to plants. The regions alluded to are as
follows:—1. the Neotropical, comprising South America,
Mexico, and the West Indies. 2. The Nearctic, including
the rest of America. 38. The Palearctic, composed of Hurope,
Northern Asia as far ag Japan, and Africa north of the
Sahara. 4. The Ethiopian, which contains the rest of Africa
and Madagascar. 5. The Indian, containing Southern Asia
and the western half of the Malay archipelago. 6. The
Australian, which comprises the eastern half of the Malay
islands, Australia, and most of the Pacific islands.
Neotropical region.—To begin with the Neotropical, compre-
hending the West Indies and South America, The bird
fauna of this division is, according to Dr. Sclater, the richest
and most peculiar on the globe, and the mammalia are, as
Buffon remarked, singularly unlike those of the Old World. I
have already spoken of the Platyrrhine monkeys of South
America, as well ag the sloths and armadilloes of that country,
and I might add the vampires or true blood-sucking bats
(Phyllostomide) , also the capybara, the largest of the rodents,
the carnivorous coati-mondi (Naswa), with a great many other
forms.
If there be any truth in the theory which refers the origin
* Paper read to Linnwean Society, June, 1857.
336 GEOGRAPHICAL DISTRIBUTION OF SPECIES. [Cua. XXXVIITI,
of species to variation or eradual transmutation, we should
expect that South America would contain a terrestrial fauna
very distinct from that of other lands; for we are taught by
geology that the present continents and oceanic basins are
of very high antiquity,* and the southern part of the Ame-
rican continent is separated by a wide expanse of sea from
Africa, Asia, and the land of the Antarctic regions. We
cannot suppose South America to have had a free land commu-
nication with any other of the great continents in the Pliocene
or scarcely perhaps in the Miocene epoch; so that even the
genera of quadrupeds in Europe must have changed several
times, while this Neotropical region has continued almost
as isolated as it is now.
In Peru and Chili, says Humboldt, the region of the grasses
is inhabited at an elevation of from 12,300 to 15,400 feet by
crowds of lama, guanaco, and alpaca. These quadrupeds,
which here represent the genus camel of the ancient conti-
nent, have not extended themselves either to Brazil or Mexico,
because, during their journey, they must necessarily have
descended into regions that were too hot for them.+ In this
passage, published in 1814, it will be seen that already the
doctrine of specific centres was tacitly assumed.
I have already stated that extinct genera of the lama,
sloth, armadillo, and many other families of South American
quadrupeds, have been found in the same region in a fossil
state. But it is remarkable that, in some points, the fossil
fauna is not so unlike that of the rest of the world as is the
recent. <A species of horse, for example, has been found
fossil in the Pampas, and of elephant (Mastodon Andiwm), in
the mountains of Peru. So also the horse, mastodon, and
Siberian mammoth occur fossil throughout a considerable
area in North America, although there were no represen-
tatives of any of these genera extant in the New World when
it was first colonised by Europeans.
The former wide range of these quadrupeds implies @
migration of Old-World forms into the New World, perhaps
by way of the Andes, in Pliocene times; but how this in-
* See above, Vol. I. p. 253.
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Cu. XXXVIII.] ANIMALS OF THE NEOTROPICAL REGION. 337
vasion was brought about, and by what causes the Old-World
species were again exterminated, we cannot conjecture. It
may, however, be affirmed that we are by no means entitled,
in the present state of our knowledge, to wonder at the
extinction of any species. A small insect, which lays its
eggs in the navels of horses, cattle, and dogs, when first born,
makes it impossible, says Darwin, for any of these animals
to run wild in Paraguay ;* and we are extremely ignorant as
to the various animals and plants, on the coexistence of
which the well-being of any one species may depend.
Besides, as geologists, we must remember that the horse
tribe and the elephants have been waning groups since the
Miocene and Pliocene periods in the northern hemisphere.
In northern India alone, the fossil remains of the Sewalik
hills have shown us that there were in the Upper Miocene
Period no less than seven distinct Species of proboscidians of
the genera Hlephas, Mastodon, and Stegodon (as defined by
Falconer), and besides these several Species of mastodon
flourished contemporaneously in Europe. There are now only
two living representatives of the whole group, viz. Hlephas
Indicus and E. Africanus. In like manner no less than twelve
equine species referred by Leidy to seven genera, have been
already detected in the Pliocene and Post-Pliocene forma-
tions of the United States, no one of which survived in
America at the time when it was first visited by Europeans.+
It has been objected that the insect fauna of Chili, although
to a great extent peculiar to South Temperate America,
contains also many generic forms of butterfijes and beetles,
such as Colias, Carabus and others, which are common to the
northern hemisphere, and are not found in the intermediate
tropical region. These insects, however, may well be sup-
posed to have passed from north to south along the higher
region of the Andes, during the cold of the Glacial Period ;
and almost all of them seem to have been so modified in
their character, that the allied forms of the north and south
are not specifically identical. As to the marsupial opossums of
* Darwin, ‘Origin of Species,’ 4th
edition, p. 83.
{ See Leidy and Hayden on Ne-
VOL. Il.
braska Fossil Remains, Proc. of Acad.
Nat. Sci. Philadelp. 1858, p. 89.
. e
x
‘
388 GEOGRAPHICAL DISTRIBUTION OF SPECIES. [Cu. XXXVIII.
America having Australian affinities, it has been justly
remarked by Mr. Wallace that as the genus Didelphis existed
in Europe in the Hocene and Lower Miocene periods, the
American species are much more likely to have been derived
from that source, assuming the origin of species by variation,
than from Australia, where the genus in question has not
hitherto been met with, whether in a fossil or living state.
In this great province, the Neotropical, as indeed in every
other to which we shall afterwards allude, the larger part of
the species are separable from each other by lines of demar-
cation, whether in the animal or vegetable kingdoms, suf-
ficiently clear to enable naturalists to agree for the most part
in their systems of classification; but exceptions could be given
in every great division, whether of the vertebrate or inverte-
brate class, where species occur which pass one into the other
by so many intermediate gradations that scarcely any two
naturalists take exactly the same views as to their relation-
ship. Thus for example, Mr. Bates observed in the valley of
the Amazons swarms of a gregarious species of butterfly of
the elegant genus Heliconius, which is peculiar to tropical
America. It abounds in the shades of the forests presenting
clusters of allied species and varieties, as well as some better
marked forms. - A conspicuous member of the group is H.
Melpomene of Linnzeus, which is found throughout Guiana,
Venezuela, and parts of New Granada. It is very common
at Obydos on the north side of the Amazons, and reappears
on the south side of the river, in the dry forests behind
Santarem. But it is absent from other parts of the valley,
where a nearly allied species, H. Thelwiope, of the same size
and shape, but differing in colour, takes its place. Both
species have the same habits, and they have always been con-
sidered by entomologists as specifically distinct; but Mr.
Bates came to the conclusion that one was simply a modifi-
cation of the other; for he found that in those forest tracts
which were intermediate in character between the dryer air of
Obydos and the moister air of the rest of the great valley the
individuals of these Heliconii were transitional forms between
the two reputed species alluded to. He observed them to
pass by very slight variations from one extreme to the other,
|
|
ould be i
< OF inves
nto the othe
ely any ty
heir relate
the valley
f butterlr:
r to tropis
ts presenti
; some bet
group i!
yout Gus
Cu. XXXVIII.] MAMMALIA OF THE NEOTROPICAL REGION. 309
and yet the inference that they were hybrids produced by the
intercrossing of H. Melpomene and H. Thelxiope was not
admissible; for the two butterflies were never seen to pair
with each other, and the intermediate varieties are unknown
in several places where the two forms come in contact. If the
whole district which they inhabit is contemplated, the inter-
mediate forms are incomparably more rare than the two ex-
treme terms of the series, and these last must, says Mr. Bates,
be treated as good and true species, because they exhibit cha-
racters usually regarded as sufficient for such a distinction,
and, amongst others, an aversion to pair together. A similar
course of reasoning induced the same naturalist to believe
in the derivation of H. Vesta from H. Melpomene, H. Vesta
having a very wide range, and extending into the central
valleys of the Andes.
The highest class of the mamuinalia, or the monkeys of the
same region, might afford us another equally apposite illus-
tration. There are two distinct species of Cebus, or Capuchin
monkey, the Caiarara (C. albifrons, Spix), and that called
Prego (C. cirrhifer, St. Hilaire), both found on the Amazons,
which differ in form and disposition. They are not local
varieties, for they sometimes coexist in the same district.
But there are so many sub-species and varieties of this same
monkey in equatorial America, which spread over thousands
of miles of wild country, and connect together the two forms
above mentioned, that, after comparing the whole, Mr. Bates
affirms that a zoologist cannot separate, by any well-defined
line, the two extremes of the series.*
The naming of these varieties has often been a subject of
great perplexity in the Zoological Gardens in London, and
equally so in the museums at Paris, as anyone may satisfy
himself by consulting the printed catalogue, drawn up by
Isidore Geoffroy St. Hilaire. Nor are the Capuching the only
platyrrhine monkeys whose classification ig embarrassing, as
appears by the same official document. To those who adopt
Mr. Darwin’s views, these transitional forms are preci
what we ought to encounter, for they simply i
hinted, p. 323, that some genera and species ar
sely
mply, as before
€ comparatively
* Bates, Naturalist on the Amazons, vol. ii. p. 101.
Zz 2
340 GEOGRAPHICAL DISTRIBUTION OF SPECIES. ([Cu. XXXVIqq.
modern, so that there has not been time for the causes of
extinction to make gaps in the series of new varieties.
Nearctic region.—We have next to pass to the Nearctic
region, extending from the centre of the table-land of Mexico
to the North Pole. If we compare the southern limits of
this great province with the nearest lands on the east and
west, the north of Africa on the one side and China on the
other, we find a complete dissimilarity between the fauna of
the American and that of the African and Asiatic continents;
but, the farther we go north and enter those latitudes where
the three continents approach each other, the more the dis-
cordance in genera and species diminishes. It has often, in-
deed, been said that the whole circumpolar region forms one
province; but some of the American species formerly iden-
tified with the Huropean—the badger, for example—have
been found to differ on closer examination, and the musk-ox
(Ovibos moschatus) is peculiar to America, although the same
animal formerly ranged, as we know from its fossil remains,
over Germany, France, and England.
The predominant influence of climate over all the other
causes which limit the range of species in the mammalia is
perhaps nowhere so conspicuously displayed as in the region
now under consideration. It will be observed that on this
continent between the Rocky Mountains and the Atlantic
there are no great geographical barriers running east and
west, such as high snow-clad mountains, barren deserts, or
wide arms of the sea, capable of checking the free migration
of species from north to south. Yet the arctic fauna, so ad-
mirably described by Sir John Richardson, has scarcely any
species in common with the fauna of the state of New York,
which is 600 miles farther south, and comprises about forty
distinct mammifers. If again we travel farther south about
600 miles, and enter another zone, running east and west, in
South Carolina, Georgia, Alabama, and the contiguous states,
we again meet with a new assemblage of land " quadeupeds,
and this again differs from the fauna of Texas farther to the
south, where frosts are unknown. But notwithstanding the
distinctness of those zones of indigenous mammalia, there
are some species, such as the buffalo (Bison Americanus), the
Ugg (
a
nple—hay,
e musk
1 the sam:
i] remain
the othe
ymmalia 5
the regi
at on thi
e Atlant
r east ns
Cu. XXXVIII.] MAMMALIA OF THE PALZZXARCTIC REGION. 34]
racoon (Procyon lotor), and the Virginian opossum (Didelphis
Virginiana), which have a wider habitation, ranging almost
from Canada to the Gulf of Mexico ; but they form exceptions
to the general rule. The opossum of Texas (Didelphis caneri-
vora) is different from that of Virginia, and other species of
the same genus are found westward of the Rocky Mountains,
in California, for example, where almost all the mammalia
differ specifically from those in the United States.
Palearctic region.—We next come to the third or Palearctic
region, comprising Hurope and Northern Asia as far as J apan,
and also including Africa north of the desert of the Sahara.
Selecting our examples here, as before, chiefly from the
mammalia, we may first mention the extraordinary range from
east to west of the Huropean species of quadrupeds ; for no
less than 44 of these, out of 58, are common to Europe and
Amoorland, or that part of North-eastern Asia which lies
between latitude 45° and 55° north. In the same group
there are some species which have not so wide a range
east and west, but which extend for great distances in
a north and south direction. Thus the tailless hare, or Pica,
passes far into the Arctic latitudes, and the tiger, Felis Tigris,
into the tropical, even as far south as Java.
The propriety of considering Morocco, Algeria, and Tunis
as part of the same province as Kurope and Northern Asia,
has been questioned, but only with reference to the mammals ;
for the birds, reptiles, insects, and plants are all decidedly
of Palearctic forms. As to the mammala, Mr. Wallace has
given a table showing that no less than thirty-three of the
Algerian species are absolutely identical with Huropean or
West- Asiatic quadrupeds; fourteen more are representatives
of European genera, and ten belong to genera of Western
Asia and Siberia. But, on the other hand, seven or eight
species have been Supposed to give an Ethiopian or extra-
Kuropean character to the North-African highlands. They
are all desert-haunting species—an antelope, a monkey
(Macacus Inwus}, the same as that which inhabits the rock
of Gibraltar, a lion, leopard, cerval, and hunting leopard.
These same large feline species range through the whole of
Africa from the Mediterranean to the Cape, and may, says
342 GEOGRAPHICAL DISTRIBUTION OF SPECIES. [Cu. XXXVI.
Mr. Wallace, very probably have crossed the desert in the
tracks of caravans. If we confine our attention to the
genera instead of species, we find that out of thirty-one only
three are common to the Palearctic and Ethiopian regions,
From what we have said in the first volume (p. 562) of
the submarine ridge between Gibraltar and the nearest part
of Africa or Tangiers (a ridge twenty-two miles long and
from five to seven miles broad, and nowhere covered by a
depth of water exceeding 220 fathoms), we learn that the
union of Southern Hurope with Africa does not imply a
great change in the relative level of land and sea. The
geologist at least is familiar with the fact that the rising
and sinking of land and of the bed of the Mediterranean
within the Newer Pliocene Period has, in Sicily and else-
where, far exceeded the amount which would be required
to unite the coasts on the opposite side of the Straits of
Gibraltar. <A change of level of about 70 fathoms would
unite Malta and Gozo with Sicily, and one of 200 fathoms
would join Malta to Tripoli by an isthmus 170 miles long.
A similar change would connect Italy with Sicily, and the
latter with Africa by the Adventure Bank. We can only
explain, by this and other analogous land communications of
modern geological date, the remarkable resemblance of the
fauna and flora of the islands of the Mediterranean and the
nearest mainland, notwithstanding the general depth of that
sea. Some of the mountainous islands, it is true, of the
Egean are inhabited by peculiar species of landshells, as was
ascertained by the late Edward Forbes and Captain Spratt;
but these mountains may perhaps have been insulated from
a remote period, as freshwater strata of Miocene age occur
in parts of them, and the surrounding sea is of vast depth.
The remains of the African elephant and of the EHlephas
antiquus, and of an extinct hippopotamus in Sicily, and,
what is more wonderful, of several species of elephant, and
an hippopotamus in caverns in the small island of Malta,
bear testimony to great geographical changes in compara-
tively modern or Pliocene times.
As to the distinctness above alluded to of the North-
African fauna from that south of the Sahara, we know that
<
Ae
iit) my)
. Imply
ry t
editeran,
ly and dl
be requ
@ Straits (
homs wil
200 fathos
) miles lay.
ily, and tt
Ve can oi
nications!
lance of
‘ 4 id
ean ant
Cu. XXXVIII.] MAMMALIA OF THE ETHIOPIAN REGION. 3438
the Great Desert was submerged beneath the sea in the
Pliocene Period; so that assuming that species have only
one birthplace, we can account for their distinctness in
these two regions, which were separated first by a barrier of
water and afterwards by one of sand.
The geographical distribution of reptiles agrees as a
general rule with that of the mamimalia and birds; but a
discrepancy has been pointed out in the Palearctic region.
Although the batrachians of Japan are all Palearctic, the
snakes agree in genera and species with those of the more
southern parts of Asia or the Indian region, which we
shall have presently to consider. Mr. Wallace suggests
the following explanation of this apparent anomaly: he
reminds us that Dr. Giinther has shown that snakes are a
preeminently tropical group, decreasing rapidly in the tem-
perate regions, and absolutely ceasing at 62° N., whereas
the batrachians are almost as largely developed in northern
as in tropical latitudes, being able to support, partly by aid
of hybernation, a very cold climate. We may therefore
suppose Japan to have once formed a part of Northern Asia,
with which it is even now almost connected by two chains
of islands ; in which ease it might have received its birds,
mamials, and batrachians from the Palearctic region,
whereas it could have derived but few or no snakes from the
same quarter, since the great cold extends to a much lower
latitude in Eastern Asia than in Western Europe. If ata
subsequent period Japan became connected with Southern
Asia through the Loo-choo and Majicosima islands, it might
then have been colonised by snakes of Indian origin, which
would easily establish themselves in a region unoccupied by
any representatives of the same class. Batrachians, on the
contrary, as well as the birds and mammals of Southern Asia.
would find a firmly established Palearctic population ready
to resist the invasion of all intruders.*
Ethiopian region.—The next or fourth zoological province
is the Ethiopian, including Africa south of the Great Desert,
and the island of Madagascar. That this part of Africa
* Wallace on Zoological and Botanical Geography, Nat. Hist. Rey. 1864, p. 114.
344 GEOGRAPHICAL DISTRIBUTION OF SPECIES. [Cu. XXXVIII.
should be characterised by a peculiar indigenous fauna is a
fact in perfect accordance with Buffon’s theory of natural
barriers.
We have already stated that the sea even in post-tertiary
times covered the space now occupied by the Sahara, so that
Africa was for vast periods surrounded by water on every side
but the north-east, where it was connected by an isthmus
with Asia. Such a connection might explain why there are
some few species, such as the lion, dromedary, and jackal,
common to Africa and Asia, and algo why many Asiatic
genera are represented by allied African species. The ele-
phant, for example, of Africa, though so nearly resembling that
of India, is distinct, being smaller, having a rounder head and
larger ears than the Indian one, and having only three instead
of four toes on each hind foot. There are three African
species of rhinoceros, all differing from the three Indian ones.
The genus hippopotamus is now represented by two species
exclusively African, although it occurred in India in the Mio-
cene Period, and in Europe in the Pliocene and Post-Pliocene.
Also the giraffe, the gorilla, the chimpanzee, the blue-faced
baboon, the four-fingered monkey (Colobus), and many carni-
vora, such as Proteles, allied to the hyena. In proportion
as we advance towards the southern part of the Hthiopian
region we find in the temperate zone other forms, many of
them agreeing generically with those inhabiting the zone of
corresponding climate north of the equator in Asia. Among
these are the quagga and the zebra; answering to the horse,
the ass, and the jiggetai of temperate Asia. Amongst
pachydermatous animals the hyrax is peculiar, amongst the
ruminantia the Cape buffalo and many antelopes, such as the
springbok, the oryx, the gnu, the leucophoé, the pygarga,
and several others.
Separated from Africa by the Mozambique channel, which
is 800 miles wide, Madagascar forms, with two or three small
islands in its immediate vicinity, a zoological sub-province,
of which all the species except one, and nearly all the genera,
are peculiar. The one exception alluded to consists of a small
insectivorous quadruped (Centetes), found algo in the Mauri-
tius, to which place, however, it is supposed to have been
Y an ju
thy Mei,
y ‘ 7 a
y+ and Jacky
many Aaias
Ss The g
semblino ty
der head
three insta
hree Afni
Indian ox
¥ two spats
a in the Mi
ost-Phiocer
1@ blue-fiee
many cal
} propor
e Ethiow
ms, mall!
the zou!
ia, Ape
0 the hors
Ante
mons”
euch a 4
Ox. XXXVIIT. | MAMMALIA OF: ETHIOPIAN REGION. 545
taken in ships. The most characteristic feature of this
remarkable fauna consists in the number of quadrumana of
the Lemur family, no less than six genera of those monkeys
being exclusively met with in this island, and a seventh
genus of the same, called Galago, which alone has any foreign
representative, being found, as we might from analogy
have anticipated, on the nearest mainland. Madagascar is
nearly as large as Great Britain, and being in the same lati-
tude as the adjoining part of the continent of Africa, enjoys
a similar climate. Had the species of quadrupeds in Mada-
gascar agreed with those of Africa, as do those of England
with the rest of Europe, the naturalist would have inferred
that there had been a land communication since the period
of the coming in of the existing quadrupeds, whereas we may
now conclude that the broad Mozambique channel has con-
stituted an insuperable barrier to the fusion of the conti-
nental fauna with that of the great island during the whole
period that has elapsed since the living species of mammalia
came into being.
The period when Madagascar was united to some part of
Africa was probably as remote as the Upper Miocene era,
at which time we know that the outline of the land in Europe
varied materially from that which it now exhibits; so that we
may readily suppose the arm of the sea constituting the
Mozambique channel to have been dry land at that period.
Some of the peculiar Miocene genera may have survived on
the island after they became extinct on the continent, and a
still greater number of species. Other families, such as the
Lemurs, may have multiplied more in the island than on the
continent; but in spite of such changes the two faunas
continental and insular (assuming the origin of species by
variation and natural selection) would continue to bear the
mark of having sprung from a common source at a compa-
ratively modern era. They would continue to have more
affinity with each other than with any more distant region,
such as the Indian or Australian. On the other hand, the
hypothesis of special creation helps us in no way to account
for such generic and family ties as bind together these two
sets of animals in each of which all the species are distinct.
346 GEOGRAPHICAL DISTRIBUTION OF SPECIES. (Cx. Xxxvqqz.
Indian region.— We have next to consider the Indian region,
comprising Southern Asia and the western half of the Malay
archipelago. Its boundary on the side of Arabia has not yet
been well defined, as that country seems at present to be
regarded by zoologists as debateable ground between the
Kthiopian, Indian, and Palearctic regions. Although the
Indian species are very distinct from those of Africa, a great
many of the genera of quadrupeds are common to both con-
tinents. There are, however, some forms which are peculiar
to the Indian region ; such as the sloth-bear (Prochilus), the
musk-deer (Moscus), the nylghau, the gibbon or long-armed
ape, and some others.
The elephant and tapir of Sumatra and Borneo are the
same as the Indian species, and the rhinoceros of Sumatra and
that of Java are each of them respectively common to Bengal
and Malacca. One of the gibbons or long-armed apes
(Hylobates lewciscus) is common to the Malay peninsula and the
islands of Java and Borneo, though wanting in Sumatra.
The wild ox of Java also occurs on the Asiatic continent.
None of these large animals, says Mr. Wallace, could possibly
have passed over the arms of the sea which now separate
these countries ; so that they point clearly to the existence of
a land communication between the islands and the mainland
since the origin of such mammalia.
Between 80 and 90 mammals inhabit Java, and nearly as
many occur in Sumatra; more than half of these species are
common to the two islands. Borneo, which is much less ex-
plored, has yielded already upwards of 60 species, and more
han half of these are not met with either in Java or Sumatra.
As each island contains not only many species but some genera
peculiar to itself, the date of their former union can only be
spoken of as modern when we understand the term in a geo-
logical sense. We may feel sure, for example, that it occurred
during some part of the Pliocene epoch; and this speculation
is rendered the more probable by the fact that a difference of
level of 50 fathoms, or only 300 feet, would unite Borneo,
Java, and Sumatra with the mainland or with Malacca and
Siam,* and a rise of 100 fathoms would include the Philippine
Me r . . .° 864
* Wallace, Physical teography of Malay Archipelago, Geogr. Soc. Journ. 1864.
umatra ap)
1 to Beng
r med aps
ula and th
1 Sumatn,
continent
ild possi
W separa
xistenc (
» mainlan
| nearly #
species ar
ch Jess od F
and Bm
Cru. XXXVIIT.] MAMMALIA OF AUSTRALIAN REGION. 347
Islands and. Bali or the whole of the Indian region (see map,
fig. 132). To this question of a modern geographical change
we shall again refer.
In regard to the birds of the mainland, the genus Huploca-
mus of the pheasant family affords a good illustration of a
variable form. Thus LH. melanotus, or black-backed kalige of
s
~
° .*
-
7 o>
WCE ES
NN
\ SS
SSS
CELEB
x \
ae wv
Ete . S$
ll FLORIS yee ee o* £
ay
So
W6WwwWW
eee
Map showing the boundaries of two great zoological provinces, the Indian and
the Australian, as defined by Alfred B. Wallace, Esq. The lands which are shaded
belong to the Australian, the unshaded to the Indian region.
ab. Line exceeding 100 fathoms in depth and Papuan races, showing their near coinci-
separating the Indian and Australian zoologi- dence with the range of species of the inferior
cal region. animals (see Chap. XLIII.).
¢d. Boundary line between the Malayan
Sikkim, is found to pass by numerous varieties in the inter-
mediate Aracan country into the F. lineatus of Tenasserim and
Pegu. The varieties are considered by Dr. Sclater not to be
hybrid forms.
Australian region—and Mr. Wallace on its limits with the
Indian region in the Malay archipelago.—Lastly, we come to
the sixth or Australian region, which, as we have before men-
348 BOUNDARY OF THE INDIAN (Cu. XXXVIIT.
tioned, is inhabited by mammalia belonging almost exclusively
to the marsupial sub-class. The only associated and indi-
genous placental species are a few rodents and bats. Al-
though the mainland of Australia is very isolated, yet when the
whole geological province is considered, there seems at first
sight to be no natural barrier sufficiently strong in a north-east
direction to account for the marked line of separation in the
islands of the Malay archipelago between the species belonging
to the Australian and those proper to the Indian region.
The geographical distribution of the two faunas, which are
remarkably distinct, is shown in the annexed map, all the lands
which are shaded belonging to the Australian and those which
are unshaded to the Indian region. Mr. Wallace has also
pointed out that the line a b, which divides two different
assemblages of mammalia and birds, coincides very nearly with
the line ¢ b, which divides two of the best characterised races
of mankind, the Malayan and the Pacific, in which last are
included the Papuans, Australians, and Polynesians.*
The Straits of Lombok, through which the line a } passes
between the island of that name and Bali, are only fifteen
miles across, less wide than the Straits of Dover, and yet the
contrast of the animals of various classes on both sides of this
narrow channel is as great as that between the Old and the
New Worlds. In other words, the discordance, not only in
species but in genera, equals that which is usually caused by
a wide ocean rather than by straits which allow of one shore
being easily seen from the other. It has already been stated
(p. 343) that all those islands of the Malay archipelago which
are only separated from the mainland of Asia by a depth of
water of less than 100 fathoms contain a fauna which is strictly
Indian. Mr. Wallace, in commenting on this fact, has pointed
out the obvious relation of the present distribution of animals
and plants with changes in the position of land and sea
which must be assumed to have taken place in comparatively
modern times.
The reader has already been told (Chapters XII., XIV., and
XXX.) of the elevation and depression of the crust of the earth
* See below, Chap. XLIILI.
WO diffs
early vii
ferised ma
hich last it
ins.*
e ab pas
only fife
and yet
sides of ti
Old and
not oat?
y causal
f ope st
D 2
asst
pp?
y
ae
ad
Cu. XXXVIII.] AND AUSTRALIAN REGIONS. 349
and the conversion of land into sea and sea into land, with
which geology has made us acquainted, and of the accompany-
ing fluctuations in the state of the organic world. Taking
these for granted, we may expect to find proofs that some
islands were once united with each other or with the neigh-
bouring continents at comparatively recent periods. Where
this has happened, the same species of animals and plants
will be found to be common to the lands now disjoined, and
the seas which divide them will usually be shallow. But if
the natural productions are dissimilar, we may safely speculate
on the separation having taken place at a more remote epoch,
as in the case before mentioned of Madagascar and Africa,
where we have seen that the intervening sea is very deep.
The line a b in the map, fig. 132, indicates a line of sound-
ing exceeding 100 fathoms, the sea to the westward of this
line having everywhere a depth of less than 100 fathoms ; and
here we find the limits of the two faunas, the Indian and the
Australian, very sharply defined. When speaking of the
contrast of the animals inhabiting the two regions Mr.
Wallace says: ‘In Australia there are no apes or monkeys, no
cats or tigers; no wolves, bears, or hyeenas ; no deer, or sheep,
or oxen ; no elephant, horse, squirrel, or rabbit ; none, in short,
of those familiar types of quadrupeds which are met with on
the Indian area. Instead of these Australia has its marsupials,
kangaroos, opossums, and wombats, and the representatives of
a still lower division of the mammalia, the duck-billed Platy-
pus (or Ornithorynchus), and the Echidna. Its birds,’ he
continues, ‘are almost as peculiar: it has no woodpeckers and
no pheasants, families which exist in every other part of the
world. But instead of them it hag the mound-making brush-
turkeys, the honeysuckers, the cockatoos, and the brush-
tongued Lories, which are found nowhere else upon the globe.’*
If we cross the straits from Lombok to Bali, which we may
do in two hours, we find on the western side a complete con-
trast in animal life. We meet, for example, with barbets,
fruit-thrushes, and woodpeckers; instead of honeysuckers
and brush-turkeys. In like manner, if we travel from Java
Wallace,
Rae all Physical Geography of Malay Archipelago, Journal of Geogra-
phical Society, 1864.
350 BOUNDARY OF THE INDIAN [Cu. XXXVI.
or from Borneo, and pass over to Celebes, the Moluccas, and
New Guinea, the difference is almost equally striking. In Java
or Borneo the forests abound in monkeys of many kinds, and
wild cats, deer, civets, otters, and squirrels are constantly met
with. In Celebes or the Moluccas, none of these occur, but
the prehensile-tailed opossum is the terrestrial animal most
seen. Some pigs, however, and deer of Indian types, probably
introduced by man, are met with.
Mr. Wallace moreover reminds us that the diversity in the
natural productions of the two great regions does not corre-
spond to any of the physical or climatal divisions of the
surface. On both sides of the line of demarcation we find in
the same latitude islands of voleanic origin similar in soil,
elevation, moisture, dryness, and fertility, and equally covered
with forests. How then are we to explain the distinctness
of the two faunas ? The greater depth of the sea which sepa-
rates the lands east of the line a b (fig. 132) from those to
the west of it would lead us to speculate on a longer period
of separation. Still it may be asked, how is it possible to
conceive that a channel in one place only fifteen miles wide
should have been so effective in arresting the migration of
species from one region into the other? Before we give an
account of Mr. Wallace’s speculations on this head, we must
state, that marked as is the contrast on the opposite sides of
the line a b, some colonisation from one province to the other
has already begun, although less perhaps than along any one
of the points of contact of the five great zoological provinces
before described. In Lombok there are several mammalia
of the placental class. The largest of them is the ape called
Macacus cynomolgus. As to the wild pig it may have been
introduced by man, and the same may be said of the Moluccan
deer, which occurs in the island of Timor. The Paradoxurus
musanga of the weasel tribe, also found in many of these
islands east of the line a b, is an animal often domesticated.
But a shrew-mouse and a feline animal, Felis megalotus,
peculiar to Timor, are less easily explained; unless, indeed,
our acquaintance with the mammalia of Java is still defective,
a supposition by no means improbable. The squirrels extend
from Lombok eastward as far as Sumbawa, but no farther.
Rt
, Probab},
y iQ the
Ot com,
DS of th,
We find
aT iD gai
Ly covery
stinctney
uich a0
those ti
rer pen
ossible ti
niles wil
oration i
re give w
a
a
Cu. XXXVIITI.] AND AUSTRALIAN REGIONS. 351
Tn the case of Borneo and Celebes there seems to have
been a partial fusion of the mammalia at some remote period,
as there is a species of baboon, a wild cat, and a squirrel in
Celebes, all belonging to Indian genera; but that so few of the
mammals of Borneo should have reached Celebes, and that
there should be hardly a land-bird in common and very few
insects, is, perhaps, says Mr. Wallace, even more extraordi-
nary than the distinctness of the fauna of Bali and Lombok ;
for the two latter islands being wholly of volcanic origin, may
be comparatively modern, whereas Borneo and Celebes must
from their great size and altitude be very ancient. Between
the latter also, although the sea is much wider than in the
Straits of Lombok, there is a great extent of opposing coasts
which would be very favourable to mutual immigration.
it is a singular fact that there are distinct species of
wild pig in almost every large island, as in Sumatra, Borneo,
Java, New Guinea, and Timor, and one or more other
species are said to inhabit Gilolo. Some of these may
have been introduced by man at so remote a period as to
have varied greatly from the parent stock; for if the pre-
vailing opinion be correct, that the Japanese pigs, of which
specimens were lately exhibited in our Zoological Gardens,
be mere varieties of the domesticated Sus Indica, we may
imagine a little more divergence to be sufficient to constitute
a true species. We shall see in the next chapter that pigs
have been known, when swept by a flood into the sea, to swim
for great distances, so that some of them may have passed
in this manner from island to island.
That so few quadrupeds, birds, and insects have obtained
a footing on the opposite sides of such channels as those or
Lombok or the Macassar Straits, seems the more strange,
when we reflect on well-known instances of birds even of
weak flight having sometimes been carried by the wind
during heavy gales over wide spaces of sea. But the power
of preoccupancy is great in enabling the old indigenous in-
habitants to prevent stray individuals of foreign species
from effecting a permanent settlement. As to the Straits of
Lombok, they are very narrow, but there is so rapid a marine
current always running through them, that it might easily
302 BOUNDARY OF THE INDIAN | [Cu. XX XVIII.
prevent quadrupeds and reptiles from swimming across from
shore to shore.
To assist us in accounting for the marked separation
between the Indian and Australian faunas, as well as for
many partial exceptions to the distinctness of the two
groups of animals in some of the islands of the Malay
archipelago, Mr. Wallace has suggested an imaginary
parallel, of which I can only give a brief outline. Suppose
the bed of the Atlantic to be gradually converted into land,
partly by the deposition of large bodies of sediment poured
down by rivers, and partly by slow upheaval and volcanic
action. Let the two continents of Africa and America be
thus more and more extended, so that the ocean, which now
separates them, should at last be reduced to an arm of the
sea a few hundred miles wide. Let us, at the same time,
imagine several islands to be upheaved in mid-channel, and
that, while the subterranean forces varied in intensity and
shifted their points of greatest action, these islands became
sometimes connected with the main land on one side of the
strait, and sometimes with the land on the other side. Two
or more of the islands also might occasionally be joined to-
cether and then broken up again, till at last, after many ages
of such intermittent action, with many a long intervening
period of comparative tranquillity, we might have an irre-
cular archipelago of islands filling up the ocean channel of
the Atlantic, in whose appearance and arrangement we could
discover nothing to tell us which had been connected with
Africa and which with America. But the animals and plants
inhabiting these islands would certainly reveal this portion of
their former history. On those islands which had ever formed
a part of the South American continent we should be certain
to find such common birds, as chatterers, toucans, macaws,
and humming-birds, and some peculiar quadrupeds, such as
spider-monkeys, pumas, tapirs, ant-eaters, and sloths; while,
on the islands which had been separated from Africa, we
should be equally sure to meet with horn-bills, orioles, and
honeysuckers, and some quadrupeds contrasting strongly
with those of South America, such as baboons, lions, ele-
phants, buffaloes, and giraffes. Those intermediate islands
and Toleay
| Americy k
i, Which Loy
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& Same tin:
channel, ai
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Cu, XXXVIIL]
AND AUSTRALIAN REGIONS. 353
which at different times had had a temporary connection
with either continent, would contain a certain amount of
mixture in their living inhabitants. Such seems to Mr.
Wallace to have been the case with the islands of Celebes
and the Philippines. Other islands, again, though in such
close proximity as Bali and Lombok, might each exhibit an
almost unmixed sample of the productions of the continents
of which they had directly or indirectly once formed a part.
In the Malay archipelago we have indications of a vast
Australian continent which once reached westward to the
island of Celebes, and was characterised by a very peculiar
fauna and flora; the western part of this continent was
afterwards broken up gradually and irregularly into islands.
At the same time Asia, which at first was separated from the
Australian continent by a wide ocean, appears to have been
extending its limits in a north-east direction in an unbroken
mass, so as to include Sumatra, Java, and Borneo, and pro-
bably reaching as far as the present 100 fathom line of
soundings, or as far as the boundary line a b, map, fie. 132.
Afterwards the south-eastern portion of this land was sepa-
rated into islands as we now see it, some of them coming
into almost actual contact with the scattered fragments of
the great Southern or Australian land.
There are some peculiarities in the distribution of animals
and plants in oceanic islands which have a more direct and
obvious bearing on the question of the origin of species by
variation than the grouping of species on continental tracts.
I shall therefore consider that subject in a separate chapter ;*
but as I shall be unable to reason on the somewhat ex-
ceptional facts which these islands present in relation to
theories of the origin of species, without constantly adverting
to the relative powers of migration which different species
enjoy, I shall treat of this latter subject first in order, and
then allude to the insular faunas and floras,
* Chapter XLI.
CHAPTER XXXIX.
ON THE MIGRATION AND DIFFUSION OF TERRESTRIAL ANIMALS,
MIGRATION OF QUADRUPEDS—MIGRATORY INSTINCTS—DRIFTING OF ANIMALS
ON ICE-FLOES—MIGRATION OF BIRDS—-MIGRATION OF REPTILES—INVOLUN-
TARY AGENCY OF MAN IN THE DISPERSION OF ANIMALS.
MIGRATION OF QUADRUPEDS.—Before we consider the geo-
graphical distribution of aquatic animals, it may be useful to
enquire what facilities the terrestrial species enjoy of spread-
ing themselves over the surface of the earth. The tendency
of each species to multiply is so great, that unless checked
it would soon extend its range over as wide an area as is ac-
cessible to it. Whether it feed on plants or prey on other
animals, it will not cease to enlarge the boundaries of its
habitation until its progress is arrested by some rival species
better fitted to the soil, climate, and organic conditions of
the country ; or by some lofty and unbroken chain of moun-
tains which it cannot scale, or by a desert, or the sea, or by
cold or heat, or some other barrier.
Mr. Wallace and Mr. Bates have shown that large rivers
such as the Amazons and Rio Negro are capable of forming
effective barriers to the farther spread of many species of
monkeys. This happens even where the same kind of forest
occurs on the opposite banks. Mr. Darwin also mentions
that the biscacha, a rodent somewhat resembling a large
rabbit, which abounds in the Pampas, although it has crossed
the broader river Parana, has never been able to extend its
range across the Uruguay. Geology teaches us that the
present continents have been formed by the union of large
pre-existing islands; and what were formerly straits of the
sea have often become, under a new arrangement of the land,
broad valleys and the channels of great rivers such as the
Amazons, the Orinoco, and the La Plata. It is therefore
—— Se CO
VO rr SP
AM,
AT
“SNny.
the a,
etl 4
of Spal
tender
$ chek
Cu. XXXIX.] DIFFUSION OF QUADRUPEDS 355
probable that the real obstacle to the farther spread of many
species is not their inability to swim over large rivers, but
the pre-occupancy of the land on the farther side by an assem-
blage of animals fitted for all the stations which the region
affords. If an intruder attempts to colonise he is overpowered
by a rival species already established in great numbers.*
But for such resistance scarcely any quadrupeds would be
stopped by rivers and narrow friths; for the greater part of
them swim well, and few are without this power when urged
by danger and pressing want. Thus, amongst beasts of
prey, the tiger is seen swimming about among the islands
and creeks in the delta of the Ganges, and the jaguar tra-
verses with ease the largest streams in South America.+
The bear, also, and the bison, cross the current of the Missis-
sippi. The popular error, that the common swine cannot
escape by swimming when thrown into the water, has been
contradicted by several curious and well-authenticated in-
stances during the floods in Scotland of 1829. One pig, only
six months old, after having been carried down from Garmouth
to the bar at the mouth of the Spey, a distance of a quarter
of a mile, swam four miles eastward to Port Gordon, and
landedsafe. Three others, of the same age and litter, swam,
at the same time, five miles to the west, and landed at
Blackhill.
In an adult and wild state, these animals would doubtless
have been more strong and active, and might, when hard
pressed, have performed a much longer voyage, especially if
aided by powerful tides and currents. Hence islands many
miles distant from a continent may obtain inhabitants by
casualties which, like the storms of 1829 in Morayshire, may
only occur once in many centuries, or thousands of years,
under all the same circumstances.
The late Edward Forbes told me that when he was on
board a surveying vessel commanded by Lieutenant Graves,
R. N. in the Grecian archipelago, the sailors amused them-
selves with setting a terrier at a domestic pig which they
had recently purchased. The animal being worried, threw
* Andrew Murray. Geographical Distribution of Mammalia, 1866, p. 18.
+ Buffon, vol. v. p. 204.
ee Ae,
356 MIGRATION AND DIFFUSION (Cu. XXXIX.
himself overboard and made for the nearest land in sight,
which was many miles distant. As the pig was more fit for
the table than for feats of agility, and as the reputation of
his tribe for swimming stood very low, the sailors were
slow in getting out the boat to give chase, so that the
animal having a fair start, landed soon after sunset, just as
they came up to him, and further pursuit in the dark was
impossible.
The power of crossing rivers is essential to the elephant in
a wild state, for the quantity of food which a herd of these
animals consumes renders it necessary that they should be
constantly moving from place to place. The elephant crosses
the stream in two ways. If the bed of the river be hard, and
the water not of. too great a depth, he fords it. But when he
crosses great rivers, such as the Ganges and the Niger, the
elephant swims deep, so deep that the end of his trunk only
is out of the water; for the complete immersion of his body
is a matter of indifference to him, provided he can bring the
tip of his trunk to the surface, so as to breathe the external
alr.
Animals of the deer kind frequently take to the water,
especially in the rutting season, when the stags are seen
swimming for several leagues at a time, from island to island,
in search of the does, especially in the Canadian lakes ; and
in some countries where there are islands near the sea-shore,
they fearlessly enter the sea and swim tothem. In hunting
excursions, in North America, the elk of that country is
frequently pursued for great distances through the water.
The large herbivorous animals, which are gregarious, can
never remain long in a confined region, as they consume 80
much vegetable food. The immense herds of bisons (Bos
Americanus) which often, in the great valleys of the Mississippi
and its tributaries, blacken the surface of the prairie lands,
are continually shifting their quarters, followed by wolves,
which prowl about in their rear. ‘It is no exaggeration,’
says Mr. James, ‘to assert, that in one place, on the banks
of the Platte, at least ten thousand bisons burst on our sight
in an instant. In the morning we again sought the living
ae
ee Peg —:
} shonli ald | |,
4
n bring t
Cu. XXXIX.] OF QUADRUPEDS 357
picture; but upon all the plain, which last evening was so
teeming with noble animals, not one remained.’ *
Migratory instincts.—Besides the disposition common to the
individuals of every species slowly to extend their range in
search of food, in proportion as their numbers augment, a
migratory instinct often developes itself in an extraordinary
manner, when, after an unusually prolific season, or upon a
sudden scarcity of provisions, great multitudes are threatened
with famine. It may be useful to enumerate some examples of
these migrations, because they may put us upon our guard
against attributing a high antiquity to a particular species
merely because it is diffused over a great space: they show
clearly how soon, in a state of nature, any species might spread
itself in every direction, from a single point, and how the
territory of one animal may be invaded by another, leading
occasionally to the extermination of the weaker species.
In very severe winters, great numbers of the black bears of
America migrate from Canada into the United States; but in
milder seasons, when they have been well fed, they remain
and hybernate in the north.t The rein-deer, which in Scan-
dinavia, scarcely ever ranges to the south of the sixty-fifth
parallel, descends, in consequence of the greater coldness of
the climate, to the fiftieth degree in Chinese Tartary, and
often roves into a country of more southern latitude than any
part of England.
In Lapland, and other high latitudes, the common squirrels,
whenever they are compelled, by want of provisions, to quit
their usual abodes, migrate in amazing numbers, and travel
directly forwards, allowing neither rocks nor forests, nor the
broadest waters to turn them from their course. In like
manner the small Norway rat sometimes pursues its migrations
in a straight line across rivers and lakes ; and Pennant informs
us, that when the rats, in Kamtschatka, become too numerous,
they gather together in the spring, and proceed in great bodies
westward, swimming over rivers, lakes, and arms of the sea.
Many are drowned or destroyed by water-fowl or fish. As
* Expedition from aha to the ft Richardson’s Fauna Boreali-Ame-
Rocky Mountains, vol. i ricana, p. 16.
358 MIGRATION AND DIFFUSION (Cu. XXXIX,
soon as they have crossed the river Penginsk, at the head of
the gulf of the same name, they turn southward, and reach
the rivers Judoma and Okotsk by the middle of July ; a district
more than 800 miles distant from their point of departure.
The lemings, also, a small kind of rat, are described as
natives of the mountains of Kolen, in Lapland; and once
or twice in a quarter of a century they appear in vast numbers,
advancing along the ground and ‘ devouring every green
thing.’ Innumerable bands march from the Kolen, through
Northland and Finmark, to the Western Ocean, which they
immediately enter; and after swimming about for some time,
Fig. 1338.
SSE,
XS :
The Leming or Lapland Marmot (Mus Lemmus, Linn.)
perish. Other bands take their route through Swedish
Lapland, to the Bothnian Gulf, where they are drowned in
the same manner. They are followed in their journeys by
bears, wolves, and foxes, which prey upon them incessantly.
They generally move in lines, which are about three feet from
each other, and exactly parallel, going directly forward
through rivers and lakes ; and when they meet with stacks of
hay or corn, gnawing their way through them instead of
passing round.* These excursions usually precede a rigorous
winter, of which the lemings seem in some way forewarned.
Vast troops of the wild ass, or onager of the ancients, which
inhabit the mountainous deserts of Great Tartary, feed, during
the summer, in the tracts east and north of Lake Aral. In
the autumn they collect in herds of hundreds, and even
thousands, and direct their course towards the north of India,
and often to Persia, to enjoy a warm retreat during winter.t
Bands of two or three hundred quaggas (a species of wild ass)
are sometimes seen to migrate from the tropical plains of
* Phil. Trans., vol. ii. p. 872. ft Wood’s Zoography, vol. i. p. 11.
Se i ————— ee 8
—s — ——_—_—
bees)
h Swe
Cu. XXXIX.] OF QUADRUPEDS 359
Southern Africa to the vicinity of the Malaleveen River.
During their migrations they are followed by lions, who
slaughter them night by night.*
The migratory swarms of the springbok, or Cape antelope,
afford another illustration of the rapidity with which a species
under certain circumstances may be diffused over a continent.
When the stagnant pools of the immense deserts south of the
Orange River dry up, which often happens after intervals of
three or four years, myriads of these animals desert the parched
soil, and pour down like a deluge on the cultivated regions
near the Cape. The havoc committed by them resembles that
of the African locusts; and so crowded are the herds, that
‘the lion has been seen to walk in the midst of the compressed
phalanx with only as much room between him and his victims
as the fears of those immediately around could procure by
pressing outwards.’ +
Dr. Horsfield mentions a singular fact in regard to the
geographical distribution of the Mydaus meliceps, an animal
intermediate between the polecat and badger. It inhabits
Java, and is ‘confined exclusively to those mountains
which have an elevation of more than 7,000 feet above the
level of the ocean; and there it occurs with the same regu-
larity as many plants. The long-extended surface of Java,
Fig. 134.
Mydaus meliceps, or badger-headed Mydaus. Sice tay, ytidiediae the tail, 16 inches.
abounding with isolated volcanos with conical points which
exceed this elevation, affords many places favourable for its
resort. On ascending these mountains, the traveller scarcely
fails to meet with this animal, which, from its peculiarities,
the authority of Mr. Campbell. + Cuvier’s cae Kingdom by Grif-
ee of Entert. Know., ih sine fiths, vol. ii. p. 109. Libr a of eat
vol. i
Know. iy. oly 1.
360 DRIFTING OF ANIMALS [Cu. XXXIX,
is universally known to the inhabitants of these elevated tracts,
while to those of the plains itis as strange as an animal from
a foreign country. In my visits to the mountainous districts,
T uniformly met with it; and, as far as the information of the
natives can be relied on, it is found on all the mountains,’ *
Now, if asked to conjecture how the Mydaus arrived at the
elevated regions of each of these isolated mountains, we might
say that, before the island was peopled by man, by whom their
numbers are now thinned, they may occasionally have multi-
plied so as to be forced to collect together and migrate: in
which case, notwithstanding the slowness of their motions,
some few would succeed in reaching another mountain, some
twenty, or even, perhaps, fifty miles distant; for although the
climate of the hot intervening plains would be unfavourable
to them, they might support it for a time, and would find there
abundance of insects on which they feed. Volcanic eruptions,
which, at different times, have covered the summits of some of
those lofty cones with sterile sand and ashes, may have
occasionally contributed to force on these migrations.
Drifting of animals on ice-~floes.—The power of the terrestrial
mammalia to cross the sea is very limited, and it was before
stated that the same species is scarcely ever common to
districts widely separated by the ocean. If there be some
exceptions to this rule, they generally admit of explanation ;
for there are natural means whereby some animals may be
floated across the water, and the sea may in the course of ages
wear a wide passage through a neck of land, leaving indi-
viduals as a species on each side of the new channel. Polar
bears are known to have been frequently drifted on the ice
from Greenland to Iceland: they can also swim to considerable
distances, for Captain Parry, on the return of his ships
through Barrow’s Straits, met with a bear swimming in the
water about midway between the shores, which were about
forty miles apart, and where no ice was in sight. ‘Near
the east coast of Greenland,’ observes Scoresby, ‘ they have
been seen on the ice in such quantities, that they were com-
pared to flocks of sheep on a common; and they are often
* Horsfield, Zoological Researches in t+ Append. to Parry’s Second Voyage,
Java, No. ii, from which the figure is years 1819-20.
taken.
"Prien
uld Hd te
Ue raps
ts of om
- q
may he
100,
he terres
t was be?
Cu. XXXIX.] ON ICE-FLOES. , . 361
found on field-ice, above two hundred miles from the shore.’ *
Wolves, in the arctic regions, often venture upon the ice near
the shore, for the purpose of preying upon young seals, which
they surprise when asleep. When these ice-floes get detached,
the wolves are often carried out to sea; and though some may
be drifted to islands or continents, the greater part of them
perish, and have been often heard in this situation howling
dreadfully, as they die by famine.t
During the short summer which visits Melville Island,
various plants push forth their leaves and flowers the moment
the snow is off the ground, and form a carpet spangled with
the most lively colours. These secluded spots are reached
annually by herds of musk-oxen and rein-deer, which, migra-
ting from the North-American continent, traverse the ice for
hundreds of miles to graze undisturbed on these luxuriant
pastures.{ The rein-deer often pass along in the same manner,
by the chain of the Aleutian Islands, from Behring’s Straits
to Kamtschatka, subsisting on the moss found in these islands
during their passage.§ But the musk-ox, notwithstanding
its migratory habits, and its long journeys over the ice, does
not exist either in Asia or Greenland.|
On floating islands of drift-wood.— Within the tropics there
are no ice-floes; but, as if to compensate for that mode of
transportation, there are floating islets of matted trees, which
are often borne along through considerable spaces. These are
sometimes seen sailing at the distance of fifty or one hundred
miles from the mouth of the Ganges, with living trees standing
erect upon them. The Amazons, the Orinoco, and the Congo
also produce these verdant rafts, which are formed in the
manner already described when speaking of the great raft of
the Atchafalaya, an arm of the Mississippi, where a natural
bridge of timber, ten miles long, and more than two hundred
yards wide, existed for more than forty years, supporting a
luxuriant vegetation, and rising and Sinking with the water
which flowed beneath it.
* Account of the Arctic Regions, of Discovery, p. 189.
vol. i. p. 5 . § Godman’s American Nat. Hist.,
i Turton in a note to Goldsmith’s vol. i. p. 22.
Nat. Hist., vol. iii. p. 43. | Dr. Richardson, Brit. Assoc. Re-
{ Supplement to Parry’s First Voyage port, vol. v. p. 161
362 DRIFTING OF ANIMALS [Cu. XXXIX,
On these green islets of the Mississippi, young trees take
root, and the water-lily or nenuphar displays its yellow
flowers: serpents, birds, and the cayman alligator come to
repose there, and all are sometimes carried to the sea, and
engulphed in its waters.
Spix and Martius relate that, during their travels in Brazil,
they were exposed to great danger while ascending the
Amazons in a canoe, from the vast quantity of drift-wood con-
stantly propelled against them by the current; so much SO,
that their safety depended on the crew being always on the
alert to turn aside the trunks of trees with long poles. The
tops alone of some trees appeared above water, others had
their roots attached to them with so much soil that they
might be compared to floating islets. On these, say the travel-
lers, we saw some very singular assemblages of animals,
pursuing peacefully their uncertain way in strange companion-
ship. On one raft were several grave-looking storks, perched
by the side of a party of monkeys, who made comical gestures,
and burst into loud cries, on seeing the canoe. On another
was seen a number of ducks and divers, sitting by a group
of squirrels. Next came down, upon the stem of a large
rotten cedar-tree, an enormous crocodile, by the side of a tiger-
cat, both animals regarding each other with hostility and
mistrust, but the saurian being evidently most at his ease, as
conscious of his superior strength.*
Similar green rafts, principally composed of canes and
brushwood, are called ‘camelotes’ on the Parana in South
America; and they are occasionally carried down by in-
undations, bearing on them the tiger, cayman, squirrels, and
other quadrupeds, which are said to be always terror-stricken
on their floating habitation. No less than four tigers (pumas)
were landed in this manner in one night at Monte Video, lat.
35° §., to the great alarm of the inhabitants, who found them
pr eine about the streets in the morning.t
‘In a memoir published in the United Service Journal (No.
XXIV. p. 697) a naval officer relates that, as he returned from
* Spix and Martius, Reise, &c., vol. _p. 187, and Robertson’s latins on Pa-
ii pp. LOL, 1013. raguay, p. 220.
~ Sir W. Parish’'s Buenos Ayres,
|
|
|
|
he tran
Panic.
Cu. XXXIX.] ON FLOATING ISLANDS. 365
China by the eastern passage he fell in, among the Moluccas,
with several small floating islands of this kind, covered with
mangrove-trees interwoven with underwood. ‘The trees and
shrubs retained their verdure, receiving nourishment from a
stratum of soil which formed a white beach round the margin
of each raft, where it was exposed to the washing of the waves
and the rays of the sun. The occurrence of soil in such situa-
tions may easily be explained ; for all the natural bridges of
timber which occasionally connect the islands of the Ganges,
Mississippi, and other rivers, with their banks, are exposed
to floods of water, densely charged with sediment.
The late Admiral W. H. Smyth informed me, that, when
cruising in the Cornwallis amidst the Philippine Islands, he
saw more than once, after those dreadful hurricanes called
typhoons, floating masses of wood, with trees growing upon
them; the ships have sometimes been in imminent peril,
as these islands were often mistaken for terra firma, when, in
fact, they were in rapid motion.
It is highly interesting to trace, in imagination, the effects
of the passage of these rafts from the mouth of a large river
to some archipelago, raised from the deep by the operations
of the volcano and the earthquake. If a storm arise, and
the frail vessel be wrecked, still many a bird and insect may
succeed in gaining, by flight, some island of the newly-formed
group, while the seeds and berries of herbs and shrubs, which
fall into the waves, may be thrown upon the strand. But if
the surface of the deep be calm, aud the rafts are carried
along by a current, or wafted by some slight breath of air
fanning the foliage of the green trees, it may arrive, after a
passage of several weeks, at the bay of an island, into which
its plants and animals may be poured out as from an ark, and
thus a colony of several hundred new species may at once be
naturalised.
Although the transportation of such rafts may be of ex-
tremely rare and accidental occurrence, and may happen only
once in thousands or tens of thousands of years, they may yet
account in tropical countries for the extension of some species
of mammalia, birds, insects, landshells, and plants to lands
which without such aid they could never have reached.
364 MIGRATION OF BIRDS. [Cu. XXXIX,
Migration of birds.—It was before stated that birds, not-
withstanding their great locomotive powers, form no excep-
tion to the general rule, that groups of distinct species are
circumscribed within definite limits.
In parallel zones of the northern and southern hemispheres,
a great general correspondence of form is observable, both in
the aquatic and terrestrial birds; but there is rarely any spe-
cific identity: and this phenomenon is remarkable, when we
consider the readiness with which some birds, not eifted with
great powers of flight, shift their quarters to different regions,
and the facility with which others, possessing great strength
of wing, perform their aérial voyages. Many species migrate
periodically from high latitudes, to avoid the cold of winter,
and the accompaniments of cold,—scarcity of insects and
vegetable food. For this purpose, they often traverse the
ocean for thousands of miles, and recross it at other periods,
with equal security.
Periodical migrations, no less regular, are mentioned by
Humboldt, of many American water-fowl, from one’ part of the
tropics to another, in a zone where there is the same tempe-
rature throughout the year. Immense flights of ducks leave
the valley of the Orinoco, when the increasing depth of its
waters and the flooding of its shores prevent them from
catching fish, insects, and aquatic worms. They then betake
themselves to the Rio Negro and the Amazons, having passed
from the eighth and third degrees of north latitude to the first
and fourth of south latitude, directing their course south-
south-east. In September, when the Orinoco decreases and
reenters its channel, these birds return northwards.*
The insectivorous swallows which visit our island would
perish during winter, if they did not annually repair to
warmer climes. It is supposed that in these aérial excursions
the average rapidity of their flight is not less than fifty miles
an hour; so that, when aided by the wind, they soon reach
warmer latitudes. Spallanzani calculated that the swallow
can fly at the rate of ninety-two miles an hour, the rapidity
of the swift being much greater.t Bachman says that the
. . . . . oe 9
* Voyage aux Régions Equinoxiales, f+ Fleming, Phil. Zool., vol. ii. p. 49+
tom. vil. p. 429.
—~ ot FF > §& DR jG we HH cH
a ath tet AF et met ma
ae ae ae |
her peri
entionel |
T art oft
ane tell
ducks kr
Cu, XXXIX.] MIGRATION OF REPTILES. 365
hawk, wild pigeon (Columba migratoria), and several species
of wild ducks, in North America, fly at the rate of forty miles
an hour, or nearly a thousand miles in twenty-four hours.*
It is well known that many European birds are carried every
winter during violent gales of wind from Europe to the
Azores. Some of them are supposed to be blown from Great
Britain to those islands.¢ In performing such flights no great
exertion of muscular power may be required if they have
simply to extend their wings and allow themselves to be car-
ried through the air in the direction of the wind. If they
advance at the rate even of twenty miles an hour, they would
reach the islands in forty-eight hours, a period not exceeding
that during which many birds can sustain life without food
(see below, p. 414).
hen we reflect how easily different species, in a great
lapse of ages, may be each overtaken by gales and hurricanes,
and, abandoning themselves to the tempest, be scattered at
random through various regions of the earth’s surface, where
the temperature of the atmosphere, the vegetation, and the
animal productions might be suited to their wants, we shall
be prepared to find some species capriciously distributed, and
to be sometimes unable to determine the native countries of
each. Admiral Smyth, when engaged in his survey of the
Mediterranean, encountered a gale in the Gulf of Lyons, at
the distance of between twenty and thirty leagues from the
coast of France, which bore along many land-birds of various
species, some of which alighted on the ship, while others were
thrown with violence against the sails. In this manner
islands may become tenanted by species of birds inhabiting
the nearest mainland.
Migration of reptiles.—Turtles migrate in large droves from
one part of the ocean to another during the Ovipositing sea-
son; and they find their way annually to the island of
Ascension, from which the nearest land is about 800 miles
distant. Dr. Fleming mentions, that an individual of the
hawk’s bill turtle (Chelonia wmbricata), so common in the
American seas, has been taken at Papa Stour, one of the
ee)
* Silliman’s Amer. Journ. No. 61, p. t Mr. F. Du Cane Godman, Ibis, vol.
3.
iil. 1866, New Series.
566 AGENCY OF MAN [Cu. XXXIX,
West Zetland Islands;* and, according to Sibbald, ‘the
same animal came into Orkney.’ Another was taken, in
1774, in the Severn, according to Turton. Two instances,
also, of the occurrence of the leathern tortoise (C. coriacea), on
the coast of Cornwall, in 1756, are mentioned by Borlase,
These animals of more southern seas can be considered only
as stragglers attracted to our shores during uncommonly warm
seasons by an abundant supply of food, or carried by the
Gulf-stream, or driven by storms to high latitudes.
Some of the smaller reptiles lay their eggs on aquatic
plants; and these may often be borne rapidly by rivers, and
thus conveyed to distant regions. .
But that even the larger ophidians may be transported
across the seas, is evident from the following most interesting
account of the arrival of one at the island of St. Vincent. I+
is worthy of being recorded, says Mr. Guilding, ‘ that a noble
specimen of the Boa constrictor was lately conveyed to us
by the currents, twisted round the trunk of a large sound
cedar-tree, which had probably been washed out of the bank
by the floods of some great South-American river, while its
huge folds hung on the branches, as it waited for its prey.
The monster was fortunately destroyed after killing a few
sheep, and his skeleton now hangs before me in my study, put-
ting me in mind how much reason I might have had to fear
in my future rambles through the forests of St. Vincent, had
this formidable reptile been a pregnant female, and escaped
to a safe retreat.’ +
Involuntary agency of man in the dispersion of animals.—In a
future chapter I shall speak of the transportation by man to
distant regions of quadrupeds and birds which are useful to
him, and of the effect of such colonisation in limiting the
range and sometimes extirpating indigenous species of plants
and animals. I shall merely consider in this place the invo-
Juntary or unintentional aid which we frequently lend to the
dissemination of species, many of them not only unservicable
but noxious and injurious to us.
Thus we have introduced the rat, which was not indigenous
* Brit. Animals, p. 149, who cites Sibbald.
+ Zool. Journ. vol. ii. p. 406. Dec. 1827.
eee
for its jr
illing a #
y study, f#
Cr. XXXIX.] IN DISPERSION OF ANIMALS. 367
in the New World, into all parts of America. They have
been conveyed over in ships, and now infest a great multitude
of islands and parts of that continent. In like manner the
Norway rat (Mus decwmanus) has been imported into Eng-
land, where it plunders our property in ships and houses.
Among birds, the house-sparrow may be cited as a species
known to have extended its range with the tillage of the
soul. During the last century it has spread gradually over
Asiatic Russia towards the north and east, always fol-
lowing the progress of cultivation. It made its first ap-
pearance on the Irtisch in Tobolsk, soon after the Russians
had ploughed the land. It came in 1735 up the Obi to
Beresow, and four years after to Naryn, about fifteen degrees
of longitude farther east. In 1710, it had been seen in the
higher parts of the coast of the Lena, in the government of
Irkutzk. In all these places it is now common, but is not
yet found in the uncultivated regions of Kamtschatka.*
The great viper (Fer de lance), a species no less venomous
than the rattlesnake, which now ravages Martinique and St.
Lucia, was accidentally introduced by man, and exists in no
other part of the West Indies.
Many parasitic insects which attack our persons, and some
of which are supposed to be peculiar to our species, have
been carried into all parts of the earth, and have as high a
claim as man to a wniversal geographical distribution.
A great variety of insects have been transported in ships
from one country to another, especially in warmer latitudes.
The European house-fly has been introduced in this way into
all the South Sea Islands. Notwithstanding the coldness of
our climate in England, we have been unable to prevent the
cockroach (Blatta orientalis) from entering and diffusing
itself in our ovens and kneading-troughs, and availing itself
of the artificial warmth which we afford. It is well known
also that beetles, and many other kinds of ligniperdous
insects, have been introduced into Great Britain in timber ;
especially several North-American species. ‘The commercial
relations,’ says Malte-Brun,+ ‘between France and India,
* Gloger, Abind. der Végel, Pp
. 108 ; Pallas, Zoog. Rosso-Asiat., tom. ii. Delon
t Syst. of Geog., vol. viii. p. 169.
368 DIFFUSION OF TERRESTRIAL ANIMALS. [Cu. XXXIX:
have transported from the latter country the aphis, which
destroys the apple-tree, and two sorts of Neuroptera, the
Lucifuga and Flavicola, mostly confined to Provence and the
neighbourhood of Bordeaux, where they devour the timber
in the houses and naval arsenals.
Among mollusks we may mention the Teredo navalis, which
is a native of equatorial seas, but which, by adhering to the
bottom of ships, was transported to Holland, where it has
been most destructive to vessels and piles. The same species
has also become naturalised in England, and other countries
enjoying an extensive commerce. Bulimus undatus, a land
species of considerable size, native of Jamaica and other
West Indian islands, has been imported, adhering to tropical
timber, into Liverpool; and, as Mr. Broderip informed me,
is now naturalised in the woods near that town.
In all these and innumerable other instances we may re-
gard the involuntary agency of man as strictly analogous to
that of the inferior animals. Like them, we unconsciously
contribute to extend or limit the geographical range and
numbers of certain species, in obedience to general rules in
the economy of nature, which are for the most part beyond
our control.
——
, tropie] ;
med ne
» may Be
OOUS ti
nsclousy
t beyaal
369
CHAPTER XI.
ON THE GEOGRAPHICAL DISTRIBUTION AND MIGRATION OF
SPECIES—continued.
GEOGRAPHICAL DISTRIBUTION AND MIGRATION OF FISH—OF TESTACRA——
DISTRIBUTION OF PLANTS—-AGENCY OF MAN, BOTH VOLUNTARY AND INVOLUN-
TARY, IN THE DISPERSION OF PLANTS
GEOGRAPHICAL DISTRIBUTION AND MIGRATION OF FISH.—
Although we are less acquainted with the habitations of
marine animals than with those of terrestrial species, yet it
is well ascertained that their distribution is governed by the
same general laws.
On comparing the freshwater fish of Europe and North
America, Sir John Richardson remarks, that the only species
which is unequivocally common to the two continents is the
pike (sox lucius) ; and itis curious that this fish is unknown
to the westward of the Rocky Mountains, the very coast which
approaches nearest to the old continent.* According to the
same author the genera of freshwater fish in China agree
closely with those of the peninsula of India, but the species
are not the same. ‘As in the distribution, > he adds, ‘of
marine fish, the interposition of a continent stretching from
the tropics far into the temperate or colder parts of the ocean,
separates different ichthyological groups ; so with respect to
the freshwater species, the intrusion of arms of the sea
running far to the northwards, or the interposition of a lofty
mountain-chain, effects the same thing. The freshwater
fish of the Cape of Good Hope and the South-American
ones, are different from those of India and China.’ +
Cuvier and Valenciennes, in their ‘ Histoire des Poissons,’
* Brit. Assoc. Reports, vol. v. p. 203.
~ Report to the Brit. Assoc., 1845, p. 192.
VOL. Il. B
370 GEOGRAPHICAL DISTRIBUTION AND (Ca. XE,
observe that very few species of marine fish cross the Atlantic,
But a great many species are common to the opposite sides of
the Indian Ocean, inhabiting alike the Red Sea, the eastern
coast of Africa, Madagascar, the Mauritius, the southern seag
of China, the Malay archipelago, the northern coasts of Aus-
tralia, and the whole of Polynesia ! * This very wide diffu-
sion, says Sir J. Richardson, may have been promoted by
chains of islands running east and west, which are wanting
in the deep Atlantic. An archipelago extending far in lon-
gitude, favours the migration of fish by multiplying the
places of deposit for spawn along the shores of islands, and
on intervening coral banks; and in such places, also, fish
find their appropriate food.
Although the marine shells on the opposite side of the
Isthmus of Panama are scarcely any one of them the same,
yet nearly a third of the marine fishes, or 48 out of 158
species, have recently been ascertained by Dr. Ginther to be
common to the Pacific Ocean and Caribbean Sea. It has
been said in explanation of the species of Testacea being
distinct, that the coast on the east side of the isthmus is
low, and the sea shallow, whereas the west or Pacific coast
is abrupt with perpendicular cliffs. The fish would be
much more independent of the physical geography of the
coast, and their eggs might be transported from one side
of the isthmus to the other by birds.t
The flying fish are found (some stragglers excepted) only
between the tropics: in receding from the line, they never
approach a higher latitude than the fortieth parallel. The
course of the Gulf-stream, however, and the warmth of its
water, enable some tropical fish to extend their habitations
far into the temperate zone; thus the chetodons, which
abound in the seas of hot climates, are found among the
Bermudas on the thirty-second parallel, where they are pre-
served in basins inclosed from the sea, as an important ar-
ticle of food for the garrison and inhabitants. Other fish,
following the direction of the same great current, range
from the coast of Brazil to the banks of ae
* Richardson, Brit. Assoc. Reports, .1867, p
1845, p. 190 t Sir ishanon, Brit. Assoc.
TG oe s Chronicle, Feb. 28, Reports, 1845, p.
|
|
|
|
|
Ca. XL] MIGRATION OF SPECIES. 371
All are aware that there are certain fish of passage which
have their periodical migrations, like some tribes of birds.
The salmon, towards the season of spawning, ascends the
rivers for hundreds of miles, leaping up the cataracts which
it meets inits course, and then retreats again into the depths
of the ocean. The herring and the haddock, after frequenting
certain shores, in vast shoals, for a series of years, desert
them again, and resort to other stations, followed by the
species which prey on them. LHels are said to descend into
the sea for the purpose of producing their young, which are
seen returning into the fresh water by myriads, extremely
small in size, but possessing the power of surmounting every
obstacle which occurs in the course of a river, by applying
their slimy and glutinous bodies to the surface of rocks, or
the gates of a lock, even when dry, and so climbing over it.*
Before the year 1800 there were no eels in Lake Wener, the
largest inland lake in Sweden, which discharges its waters
by the celebrated cataracts of Trolhittan. But according to
Professor Nilsson, when a canal was opened uniting the river
Gotha with the lake by a series of nine locks, eels were ob-
served in abundance in the lake. It appears, therefore, that
though they were unable to ascend the falls, they made their
way by the locks, by which in a very short space a difference
of level of 114 feet is overcome.
Gmelin says, that the Anseres (wild geese, ducks, and
others) subsist, in their migrations, on the Spawn 6f fish ;
and that oftentimes, when they void the spawn, two or three
days afterwards, the eggs retain their vitality unimpaired.+
hen there are many disconnected freshwater lakes in a
mountainous region, at various elevations, each remote from
the other, it has often been deemed inconceivable how they
could all become stocked with fish from one common source ;
but it has been suggested, that the minute egos of these
animals may sometimes be entangled in the feathers of
waterfowl. These, when they alight to wash and plume
themselves in the water, may often unconsciously contribute
to propagate swarms of fish, which, in due season, will supply
them with food. Some of the water-beetles, also, as the
* Phil. Trans. 1747, p. 395. ft Ameen. Acad., Essay 75.
BB2
O72 GEOGRAPHICAL DISTRIBUTION AND [Cx. XL.
Od
Dyticidee, are amphibious, and in the evening quit their lakes
and pools; and, flying in the air, transport the minute ova
of fishes to distant waters. In this manner some naturalists
account for the fry of fish appearing occasionally in small
pools caused by heavy rains.
GEOGRAPHICAL DISTRIBUTION AND MIGRATIONS OF
TESTACHA.
The Testacea are a class of animals of peculiar importance
to the geologist ; because their remains are found in strata
of all ages, and generally in a higher state of preservation
than those of other organic beings.
Some forms are exclusively confined to warm, others to cold,
latitudes. Marine currents flowing permanently in certain
directions, and the influx at certain points of great bodies of
fresh water, limit the extension of many species. Those
which love deep water are arrested by, shoals; others, fitted
for shallow seas, cannot migrate across unfathomable abysses.
The nature also of the ground has an important influence on
the testaceous fauna, both on the land and beneath the waters.
Certain species prefer a sandy, others a gravelly, and some a
muddy sea-bottom. On the land, limestone is of all rocks
the most favourable to the number and propagation of species
of the genera Helix, Clausilia, Bulimus, and others. Pro-
fessor'E. Forbes has shown, as the result of his labours in
dredging in the Mgean Sea, that there are eight well-marked
regions of depth, each characterised by its peculiar testaceous
fauna. The first of these, called the littoral zone, extends
to a depth of two fathoms only; but this narrow belt 18
inhabited by more than 100 species. The second region,
of which ten fathoms is the inferior limit, is almost equally
ace
be-
populous; and a copious list of species is given as char
teristic of each region down to the seventh, which lies
tween the depths of 80 and 105 fathoms, all the inhabited
space below this being included in the eighth province, wh
no less than 65 species of shell-fish or mollusca have b
taken. The majority of the shells in this lowest zone are
white or transparent. Only two species are common to
ere
een
eS eee.
portans
D sth
§ To cul
Cu. XL. MIGRATION OF TESTACHA, 370
all the eight regions, namely, Arca lactea and Certthiuin
lima.*
Great range of some provinces and species.—In Hurope con-
chologists distinguish between the arctic fauna, the southern
boundary of which corresponds with the isothermal line of
32° F., and the Celtic, which, commencing with that limit as
its northern frontier, extends southwards to the mouth of the
English Channel and Cape Finisterre,in France. rom that
point begins the Lusitanian fauna, which, according to the
observations of Mr. M‘Andrew in 1852, ranges to the Canary
Islands. The Mediterranean province is distinct from all
those above enumerated, although it has some species in
common with each.
The Indo-Pacific region is by far the most extensive of all.
It reaches from the Red Sea and the eastern coast of Africa,
to the Indian archipelago and adjoining parts of the Pacific
Ocean. To the geologist it furnishes a fact of no small
interest, by teaching us that one group of living species of
mollusca may prevail throughout an area exceeding in mag-
nitude the utmost limits we can as yet assign to any assem-
blage of contemporaneous fossil species. Mr. Cuming ob-
tained more than 100 species of shells from the eastern coast
of Africa identical with those collected by himself at th
Philippines and in the eastern coral islands of the Pacific
Ocean, a distance of 12,000 miles, equal, says Darwin, to that
from pole to pole.
Certain species of the genus Ianihina have avery wide
range, being common to seas north and south of the equator.
They are all provided with a beautifully contrived float, which
renders them buoyant, facilitating their dispersion, and
enabling them to become active agents in disseminating other
species. Captain King took a specimen of Ianthina fragilis
alive, a little north of the equator, so loaded with barnacles
(Pentelasmis) and their ova that the upper part of its shell was
invisible.
Helix putris (Succinea putris, Lam.) has a wide range in
Europe, occurs also in Siberia, and is said to inhabit New-
@. iD
ot
* Report to the Brit. Assoc. 1848, p. 130.
tT Quart. Journ, Geol, Soe., 1846, vol. ii. p. 268.
O74 GEOGRAPHICAL DISTRIBUTION AND [Carxe
foundland and parts of North America. It was found by:
Captain Hutton in Afghanistan.* As this animal inhabits
constantly the borders of pools and streams where there igs
much moisture, it is not impossible that different water-
fowl have been the agents of spreading some of its minute
egos, which may have been entangled in their feathers. The
freshwater snail, Lymneus palustris, so abundant in English
ponds, ranges uninterruptedly from Hurope to Cashmere, and
thence to the eastern part of Asia. Heliaz aspersa, one of
the commonest of our larger land-shells, is found in St.
Helena and other distant countries. Some conchologists have
conjectured that it was accidentally imported into St. Helena
in some ship; for it is an eatable species.
As an illustration of the power of such mollusca to retain
life during a long voyage without air or nourishment, I may
mention that four individuals of a large species of landshell
(Bulimus), from Valparaiso, were brought to England by
Lieutenant Graves, who accompanied Captain King in his
expedition to the Straits of Magellan. They had been packed
up in a box, and enveloped in cotton: two for a space of
thirteen, one for seventeen, and a fourth for upwards of
twenty months: but when they were exposed by Mr.
Broderip to the warmth ofa fire in London, and provided with
tepid water, I saw them revive and feed greedily on lettuce
leaves.
Perhaps no species has a better claim to be called cosmo-
polite than one of our British bivalves, Saxicava rugosa. It
is spread over all the north-polar seas, and ranges in one
direction through Europe to Senegal, occurring on both sides
of the Atlantic; while in another it finds its way into the
North Pacific, and thence to the Indian Ocean. Nor do its
migrations cease till it reaches the Australian seas.
A British brachiopod, named Terebratula caput serpentis, 1s
common, according to Professor H. Forbes, to both sides of
the North Atlantic, and to the South-African and Chinese
seas.
Mode of diffusion of Testacea._-Notwithstanding the pro-
* J. Gwyn Jeffreys, British Conchology, p. 152.
|
|
|
|
Cu. XL.] MIGRATION OF TESTACEA. 375
AL | , ;
Mba verbially slow motion of snails and mollusks in general, and
her, - although many aquatic species adhere constantly to the same
Mate, rock for their whole lives, they are by no means destitute of
Ling, provision for disseminating themselves rapidly over a wide
a area. ‘ Some Mollusca,’ says Professor H. Forbes, ‘ migrate
ta in their larva state, for all of them undergo a metamorphosis
Pe either in the egg or out of the egg. The Gasteropoda com-
kn mence life under the form of a small spiral shell, and an
' rial animal furnished with ciliated wings, or lobes, like a pteropod,
my by means of which it can swim freely, and in this form can
ot hay migrate with ease through the sea.’*
Hey We are accustomed to associate in our minds the idea of
the greatest locomotive powers with the most mature and
vi | et
ET Fig. 135.
andsle)
land by
g in bi
n packs
space
iF 5 a
br lt The young fry of a cockle oo pygmeeum), from Loven’s Kongl. Vetenskaps
ielvi m. Handling, 1848.
A. The young just hatched, magnified 100 can filamentous appendage b.
n Jetta diameters. . The rudimentary intestine.
B. The same farther advanced. d The rudimentary shell.
a. The ciliated organ of locomotion with
| perfect state of each species of invertebrate animal, especially
poet when they undergo a series of transformations; but in all
; ne the Mollusca the reverse is true. The young of the cockle,
oth 3 for example (Cardiwm), possess, when young or in the larva
spt? Y state, an apparatus which enables them both to swim and to
x do? be carried along easily by a marine current. (See fig. 135.)
These small bodies here represented, which bear a con-
lit? j siderable resemblance to the fry of univalve, or gasteropodous
sl shells, above mentioned, are so minute at first as to be just
cuit visible to the naked eye. They begin to move about from the
: moment they are hatched, by means of the long cilia, a, a,
y pf placed on the edges of the locomotive disk or velum. This
* Kdin. New Phil. Journ. April, 1844.
346 GEOGRAPHICAL DISTRIBUTION AND
(Ca, a
disk shrinks up as they increase in size, and gradually dis-
appears, no trace of it being visible in the perfect animal.
Some species of shell-bearing Mollusca lay their eges in a
sponge-like nidus, wherein the young remain enveloped for a
time after their birth ; and this buoyant substance floats far
and wide as readily as sea-weed. The young of other vivi-
parous tribes are often borne along entangled in sea-weed.,
Sometimes they are so light, that, like grains of sand, they
can be easily moved by currents. Balani and Serpule are
sometimes found adhering to floating cocoa-nuts, and even to
fragments of pumice far out at sea. It is probable, indeed,
that the porous and sponge-like texture of pumice causes it
to be a vehicle for the transport of eggs of mollusks and
insects and of the seeds of plants far more effective in many
regions than has been hitherto suspected. Mr. Bates saw
pieces of it floating on the river Amazon 1,200 miles from its
source, the nearest voleanos of the Andes. He also observed
other fragments 900 miles lower down the river, which in the
rainy season are floated at the rate of from three to five miles
an hour.* They must often reach the sea, and be carried by
currents for hundreds of miles farther from their point of
departure.
In rivers and lakes, on the other hand, aquatic univalves
usually attach their eges to leaves and sticks which have
fallen into the water, and which are liable to be swept away,
during floods, from tributaries to the main streams, and from
thence to all parts of the same basin. Particular species
may thus migrate during one season from the head waters
of the Mississippi, or any other great river, to countries bor-
dering the sea, at the distance of many thousand miles. An
illustration of the mode of attachment of these egos will be
seen in the annexed cut (fig. 186).
A lobster (Astacus marinus) was taken alive covered with
living mussels (Mytilus edulis); + and a large female crab
(Cancer pagurus), covered with oysters, and bearing also
Anomia ephippium, and Actiniz, was also taken in 1832, off
the English coast. The oysters, seven in number, included
* Naturalist of the Amazons, vol. ii. p. 170.
t The specimen is preserved in the Museum of the Zool, Soe. of London.
hy .
lly a
7 in.
: fe, L
lo Yaty te
Indes
Ct,
PaLISAg i
wit
mivalré
ch bat
pt ani
nd fn?
Cu. XL.] MIGRATION OF INSECTS. Oe
individuals of six years’ growth, and the two largest were four
inches long and three inches and a half broad.*
From this example we learn the manner in which oysters
may be diffused over every part of the sea where the crab
Eggs of freshwater Mollusks.
ae 1. Eggs of Ampullari ta ovata (a fluviatile a dead leat ly at under w vater
) fixed t lsprig which had fallen Fig. 3. Eggs the common Limn ae
into the wate vulgar is), ere to a dead stick under water
Fig. 2. tend ‘of Planorbis albus, attached to
wanders; and if they are at length carried to a spot where
there is nothing but fine mud, the foundation of a new oyster-
bank may be laid on the death of the crab. In this instance
the oysters survived the crab many days, and were killed at
last only by long exposure to the air.
GEOGRAPHICAL DISTRIBUTION AND MIGRATIONS OF INSECTS.
The entomological provinces coincide very closely with
those of the higher animals as already described. Few species
have a very wide range, but there are exceptions to this
rule, and among them may be mentioned our painted lady
butterfly eriove cardu), which re-appears at the Cape
of Good Hope and in New Holland and Japan with scarcely
* Mr. Broderip observed that this have stated that the species moults
h was apparently in per- annually, without limiting the moulting
tly
foot health, could not have cast her shell period to the early stages of the erowth
for six years, whereas some naturalists of the animal.
878 GEOGRAPHICAL DISTRIBUTION AND (Cu. XI,
a varying streak.* The same species is said to be one of
the few insects which are universally dispersed over the
earth, being found in Hurope, Asia, Africa, America, and
Australia. Its wide range seems to imply a capacity enjoyed
by few species, of enduring a great diversity of tempera-
ture, and is the more interesting because of the migratory
instinct which it sometimes displays.
A vast swarm of this species, forming a column from ten
to fifteen feet broad, was, in 1826, observed in the Canton de
Vaud: they traversed the country with great rapidity from
north to south, all flying onwards in regular order, close
together, and not turning from their course on the approach
of other objects. Professor Bonelli, of Turin, observed, in
March of the same year, a similar swarm of the same species,
also directing their flight from north to south, in Piedmont,
in such immense numbers that at night the flowers were
literally covered with them. They had been traced from
Coni, Raconi, Susa, &c. <A similar flight at the end of the
last century is recorded by M. Louch, in the Memoirs of the
Academy of Turin. The fact is the more worthy of notice,
because the caterpillars of this butterfly are not gregarious,
but solitary from the moment that they are hatched; and
this instinct remains dormant, while generation after gene-
ration passes away, till it suddenly displays itself in full
energy when their numbers happen to be in excess.
The European hive-bee (Apis mellifica), although not a
native of the New World, is now established both in North
and South America. It was introduced into the United
States by some of the early settlers, and has since overspread
the vast forests of the interior, building hives in the decayed
trunks of trees. ‘The Indians,’ says Irving, ‘ consider them
as the harbinger of the white man, as the ‘buffalo i is of the
red man, and say that in proportion as the bee advances the
Indian and the buffalo retire. It is said,’ continues the
same writer, ‘that the wild bee is seldom to be met with at
any great ateass from the frontier, and that they have
ae been the heralds of civilisation, preceding it as it
advanced from the Atlantic borders. Some of the ancient
* Kirby and Spence, vol. iv. p. 487; and other authors.
Pe
oe ee
Cu. XL. ] MIGRATION OF INSECTS, 379
settlers of the west even pretend to give the very year when
the honey-bee first crossed the Mississippi.* The same species
is now also naturalised in Van Diemen’s Land and New
Zealand.
As almost all insects are winged, they can readily spread
themselves wherever their progress is not opposed by un-
congenial climates, or by seas, mountains, and other physical
impediments; and these barriers they can sometimes sur-
mount by abandoning themselves to violent winds, which, as
i shall afterwards state when speaking of the dispersion of
seeds (p. 386), may in a few hours carry them to very consider-
able distances. On the Andes some sphinxes and flies have
been observed by Humboldt, at the height of 19,180 feet above
the sea, and which appeared to-him to have been involuntarily
carried into these regions by ascending currents of air.t
Inundations of rivers, observes Kirby, if they happen at
any season except in the depth of winter, always carry down a
number of insects, floating on the surface of bits of stick,
weeds, &c.; so that when the waters subside, the entomolo-
cist may generally reap a plentiful harvest. In the dissemi-
nation, moreover, of these minute beings, as in that of plants,
the larger animals play their part. Insects are, in number-
less instances, borne along in the coats of animals, or the
feathers of birds; and the eggs of some species are capable,
like seeds, of resisting the digestive powers of the stomach,
and after they are swallowed with herbage, may be ejected
again unharmed in the dung.
White mentions a remarkable shower of aphides which
seem to have emigrated, with an east wind, from the great
hop plantations of Kent and Sussex, and blackened the
shrubs and vegetables where they alighted at Selborne,
spreading at the same time in great clouds all along the
vale from Farnham to Alton. These aphides are sometimes
accompanied by vast numbers of the common lady-bird
(Coccinella septempunctata), which feed upon them.t
It is remarkable, says Kirby, that many of the insects
which are occasionally observed to emigrate, as, for instance,
* Been Irving’s Tour in the govcg tate Brun, vol. v. p. 379.
Prairies, ch, i + Kirby and Spence, Cor ip;
if an of the Equatorial Re- 1817.
380 GEOGRAPHICAL DISTRIBUTION AND (Cx: XT,
A
the Libellule, Coccinelle, Carabi, Cicade, &c., are woh.
usually social insects; but seem to congregate, like swallows, 1
merely for the purpose of emigration.* Here, therefore, we f
have an example of an instinct developing itself on certain t
rare emergencies, causing unsocial species to become gre- H
garious and to venture sometimes even to cross the ocean, :
The armies of locusts (Gryllus migratorws), which darken f
the air in Africa and traverse the globe from Turkey to our
southern counties in England, are well known to all, and their
vast geographical range will again be alluded to (Chap. XLII), | :
When the western gales sweep over the Pampas they bear :
along with them myriads of insects of various kinds. Asa
proof of the manner in which species may be thus diffused, I :
may mention that when the Creole frigate was lying in the i
outer roads off Buenos Ayres, in 1819, at the distance of 4
six miles from the land, her decks and rigging were suddenly Ic
covered with thousands of flies and grains of sand. The :
sides of the vessel had just received a fresh coat of paint, bi
to which the insects adhered in such numbers as to spot 4
and disfigure the vessel, and to render it necessary partially b
to renew the paint.t The late Admiral W. H. Smyth was P
obliged to repaint his vessel, the Adventure, in the Mediterra- b
nean, from the same cause. He was on his way from Malta ?
to Tripoli, when a southern wind blowing from the coast of
Africa, then one hundred miles distant, drove such myriads
of flies upon the fresh paint, that not the smallest point was
left unoccupied by insects.
Moths seen flying 300 miles from land. —Captain Henry
Toynbee has put on record some striking examples of the
great distance from land at which the larger Lepidoptera are
occasionally seen on the wing. <A female of the large
Sphynx Convolvuli flew on board his ship, the Hotspur, Hast
Indiaman, in lat. 12° 09’ N. and long. 21° 17’ W., a point 300
miles from the nearest coast of Africa, and about 210 miles
from the Cape de Verde Islands, from which last it is
supposed to have come, as the prevailing winds at the time
were north-westerly. Two individuals of the common Death’s
* Kirby and Spence, vol. ii. p. 9. + Iam indebted to Lieutenant Graves,
1817. R.N. for this information.
coast
yrs
pint
Cu. XL.] MIGRATION OF PLANTS. 3881
“Head Moth (Acherontia atropos) also flew on board the Hotspur
during the same homeward voyage, in lat. 40° 29’ N. long.
15° W., or 260 miles from the nearest land (the coast of
Portugal) after an easterly gale. They had already traversed
more than two-thirds of the distance from Hurope to Madeira,
and the case affords a good illustration of the manner in
which islands far out at sea may be peopled with insects
from the nearest continents.*
To the southward of the river Plate, off Cape St. Antonio,
and at the distance of fifty miles from land, several large
dragon-flies alighted on the Adventure frigate, during
Captain King’s expedition to the Straits of Magellan. If
the wind abates when insects are thus crossing the sea,
the most delicate species are not necessarily drowned ; fox
many can repose without sinking on the water. The slender
long-legged Tipule have been seen standing on the surface
of the sea, when driven out far from our coast, which took
wing immediately on being approached.t Exotic beetles are
sometimes thrown on our shore, which revive after having
been long drenched in salt water; and the periodical ap-
pearance of some conspicuous butterflies amongst us, after
being unseen some for five, others for fifty years, has been
ascribed, not without probability, to the agency of the winds.
BOTANICAL GEOGRAPHY.
Searcely 1,400 species of plants appear to have been
known and described by the Greeks, Romans, and Arabians.
At present, more than 3,000 species are enumerated as
natives of our own island.{ In other parts of the world
there have been now collected more than 100,000 reputed
species, specimens of which are preserved in European her-
bariums. It was not to be supposed, therefore, that the
ancients should have acquired any correct eOHOnE. respecting
what has been called the geography of plants, although
* Both the above-mentioned insects of my friend, the late Mr. John Curtis,
were shown at a meeting of the Zoo- the able eDtors logist.
logical Society by Mr. Flower, May 22, { Barton ‘Lectures on the Geography
1866. of Planta p. 2.
~ Istate this fact on the authority
3.99 GEOGRAPHICAL DISTRIBUTION AND [Cu XL
the influence of climate on the character of the vegetation
could hardly have escaped their observation.
Antecedently to investigation, there was no reason for
presuming that the vegetable productions, growing wild in
the eastern hemisphere, should be unlike those of the western,
in the same latitude; nor that the plants of the Cape of
Good Hope should be unlike those of the south of Europe ;
situations where the climate is little dissimilar. The contrary
supposition would have seemed more probable, and we might
have anticipated an almost perfect identity in the plants
which inhabit corresponding parallels of latitude at equal
heights above the sea. The discovery, therefore, that each
separate region of the globe, both of the land and water, is
occupied, in the vegetable as well as in the animal world, by
distinct groups of species, and that most of the exceptions to
this general rule are referable to disseminating causes now
in operation, is eminently calculated to prepare us to receive
with favour any hypothesis respecting the first introduction
of species which may be reconcilable with such phenomena.
Botanical regions.—Humboldt was among the first to pro-
mulgate philosophical views on the distinctness of the vegetable
productions of different regions of the globe. Every hemi-
sphere, he said, is inhabited by different species of plants,
and it is not by the diversity of climates that we can attempt
to explain why equinoctial Africa has no Laurinee, and
the New World no Heaths;* or why the Calceolarie are
found only in the southern hemisphere.
‘We can conceive,’ he adds, ‘that a small number of the
families of plants, for instance, the Musacee and the Palms,
cannot belong to very cold regions, on account of their m-
ternal structure and the importance of certain organs; but
we cannot explain why no one of the Melastomas (a family
allied to the Myrtles) vegetates north of the parallel of
thirty degrees ; or why no rose-tree belongs to the southern
hemisphere. Analogy of climates is often found in the two
continents without identity of productions.’+
* The common heath (Erica vulgaris, | Massachusetts north of Boston; but this
L.) has, since Humboldt wrote, been case is quite exceptional.
found growing wild in one spot in ft Pers. Nar., vol. v. p. 180.
Cu. XL] MIGRATION OF PLANTS. 383
The luminous essay of Auguste De Candolle on ‘ Botanical
Geography ’ (1820) presents us with the fruits of his own
researches and those of Humboldt, Brown, and other eminent
botanists, so arranged, that the principal phenomena of the
distribution of plants are exhibited in connection with the
causes to which they are supposed to be referable.* <Tt
might not, perhaps, be difficult,’ observes this writer, ‘to find
two points, in the United States and in Hurope, or in equi-
noctial America and Africa, which present all the same
circumstances: as, for example, the same temperature, the
same height above the sea, a similar soil, an equal dose of
humidity; yet nearly all, perhaps all, the plants in these two
similar localities shall be distinct. A certain degree of
analogy, indeed, of aspect, and even of structure, might very
possibly be discoverable between the plants of the two
localities in question ; but the species would in general be
different. Circumstances, therefore, different from those
which now determine the stations, have had an influence on
the habitations of plants.’
It may be as well to define in this place the technical sense
in which the words printed in italics are here used: station
indicates the peculiar nature of the locality where each species
is accustomed to grow, and has reference to climate, soil,
humidity, light, elevation above the sea, and other analogous
circumstances; whereas, by habitation is meant a general
indication of the country where a plant grows wild. Thus
the station of a plant may be a salt-marsh, a hill-side, the
bed of the sea, or a stagnant pool. Its habitation may be
Kurope, North America, or New Holland, between the tropics.
The study of stations has been styled the topography, that
of habitations the geography, of botany. The terms thus
defined, express each a distinct class of ideas, which have
been often confounded together, and which are equally appli-
cable in zoology.
In farther illustration of the principle above alluded to,
that difference of longitude, independently of any influence
of temperature, is accompanied by a great, and sometimes a
* Essai Elémentaire de Géographie Botanique. Extrait du 18me vol. du Dict.
des Sci. Nat. 1820,
384 GEOGRAPHICAL DISTRIBUTION AND [Cu. XL,
complete, diversity in the species of plants, De Candolle
observed, that, out of 2,891 species of pheenogamous plants
described by Pursh as known in 1820 in the United States,
there were only 385 common tonorthern or temperate Europe,
On comparing New Holland with Europe, Mr. Brown as-
eertained that, out of 4,100 species, then discovered in
Australia, there were only 166 common to Europe, and of
this small number there were some few which may have
been transported thither by man. Almost all of the 166
species were cryptogamic, and the rest consist, in nearly
every case, of phenogamous plants which also inhabit in-
tervening regions.
But it is still more remarkable that there should be an
almost equal diversity of species, in distant parts of the
ancient continent between which there is an uninterrupted
land communication. Thus there is one assemblage of species
in China, another in the countries bordering the Black Sea
and the Caspian, a third in those surrounding the Mediter-
ranean, a fourth on the great platforms of Siberia and Tartary,
and so forth.
The distinctness of the groups of indigenous plants, in
the same parallel of latitude, is greatest, as in the case of
animals before mentioned, where continents are disjoined
by a wide expanse of ocean. In the northern hemisphere,
near the pole, where the extremities of Europe, Asia, and
America unite or approach near to one another, a consider-
able number of the same species of plants are found, common
to the three continents. But it has been remarked, that
these plants, which are thus so widely diffused in the arctic
regions, are also found in the chain of the Aleutian islands,
which stretch almost across from America to Asia, and which
may probably have served as the channel of communication
for the partial blending of the floras of the adjoining regions.
De Candolle enumerated twenty great botanical provinces,
inhabited by indigenous and aboriginal plants; and his son
Alphonse, a distinguished living botanist, has made a further
subdivision into twenty-seven provinces, between which the
lines of demarcation are by no means ill-defined.*
* Alph. De Candolle, Monogr. des Campanulées. Paris, 1880.
i te, WP
eS NS ee a ee
Cu. XL] MIGRATION OF PLANTS. 385
There are, however, not a few species which are common
to two or more than two of these provinces, and often repre-
sentative forms which some naturalists would class as mere
geographical varieties. The six ornithological divisions of
the globe before alluded to (p. 335), four of them-in the Old
World and two in the New, are not on the whole inapplicable
to plants, if we wish to take a more large and comprehensive
view of the leading features in their geographical distribution,
especially as regards genera and families.
This holds true, particularly of the Neoarctic and Neo-
tropical regions, each of which contains a distinct assem-
blage of peculiar vegetable forms. Those of the table-land
of Brazil, which has an elevation of from 2,000 to 4,000 feet,
are described by Sir Charles Bunbury, after he had explored
the district, as belonging for the most part to generic types,
little known except to botanists, for they have not been
cultivated in Europe. But when he descended from the
Brazilian uplands towards the south, or to the grassy plains
of Uruguay and La Plata, he found plants still belonging to
the predominant South-American types, though represented
by different and local species. Such affinity between the
specific forms proper to the more elevated and to the lower
stations agrees well with the idea of certain original types
having been gradually adapted by variation and natural
selection to all the diversified conditions of the surface of the
land. ;
The Pampas and banks of the Plata are also remarkable
for the extraordinary manner in which some foreign European
plants, especially the thistles and trefoils, have overpowered
the indigenous vegetation.* The intruders have been intro-
duced by man sometimes unintentionally, and, having na-
turalised themselves, have become more conspicuous than any
of the native products of the soil. They illustrate a principle
before laid down, that the organic beings of each great region
which man finds in possession of wide areas are not those
which are most fitted of all contemporary species to flourish
there to the exclusion of all others. They appear to be
* Sir C. Bunbury, ‘Characters of S. American Vegetation,’ Fraser’s Magazine,
July, 1867.
VOL. II. co
386 GEOGRAPHICAL DISTRIBUTION AND [Cu. XL
simply the modified descendants of such an older fauna and
flora as happened to preexist under a somewhat different
phase of the earth’s physical geography, or they are the
offspring of colonists which by natural means were able to
reach those lands. But the same organisms are powerless
to maintain their ground in the struggle for life if brought
into competition with species from distant regions which
would never without the aid of man have come into contact
with them.
Marine plants.—The vegetation of the sea, like that of the
land, is divisible into different provinces each inhabited by
distinct species, but these provinces are fewer in number
because the temperature of the ocean is more uniform than
that of the atmosphere, and because the area of land bears a
small proportion to that of water, so that the migration of
marine plants is not so often stopped by barriers of land as is
that of the terrestrial species of the ocean. It is a remark-
able fact that Dr. Hooker has been able to identify no less
than a fifth part of the antarctic Algw, excluding the New
Zealand and Tasmanian groups, with British species. Yet
there is a much smaller proportion of cosmopolite species
among the Alge than among the terrestrial cellular crypto-
gams, such as lichens, mosses, and Hepatice.
Dispersion of plants.—The fact last alluded to, of the ubi-
quitous character of cryptogamous plants, deserves special
attention. Linnus observed that, as the germs of plants of
this class, such as mosses, fungi, and lichens, consist of an
impalpable powder, the particles of which are scarcely visible
to the naked eye, there is no difficulty in accounting for their
being dispersed throughout the atmosphere, and carried to
every point of the globe, where there is a station fitted for
them. Lichens in particular ascend to great elevations,
sometimes growing on bare rocks two thousand feet above
the line of perpetual snow, where the mean temperature is
nearly at the freezing point. This elevated position must
contribute greatly to facilitate the dispersion of those buoy-
ant particles of which their fructification consists.*
* Linn., Tour in Lapland, vol. ii. p. 282.
Cu. XL.] MIGRATION OF PLANTS. 387
Some have inferred, from the springing up of mushrooms
whenever particular soils and decomposed organic matter are
mixed together, that the production of fungi is accidental,
and not analogous to that of perfect plants. But Fries,
whose authority on these questions is entitled to the highest
respect, has shown the fallacy of this argument in favour of
the old doctrine of equivocal generation. ‘The sporules of
fungi,’ says this naturalist, ‘are so infinite, that in a single
individual of Reticularia maxima, I have counted above ten
millions, and so subtile as to be scarcely visible, often resem-
bling thin smoke; so light that they may be raised perhaps
by evaporation into the atmosphere, and dispersed in so
many ways by the attraction of the sun, by insects, wind,
elasticity, adhesion, &c., that it is difficult to conceive a
place from which they may be excluded.’ *
The club-moss called Lycopodium cernuum affords a strik-
ing example of a cryptogamous plant universally distributed
over all equinoctial countries. It scarcely ever passes be-
yond the northern tropic, except in one instance, where it
appears around the hot-springs in the Azores, although it is
neither an inhabitant of the Canaries nor of Madeira. Doubt-
less its microscopic sporules are everywhere present, ready
to germinate on any spot where they can enjoy throughout
the year the proper quantity of warmth, moisture, light, and
other conditions essential to the species.
Almost every lichen brought home from the southern
hemisphere by the antarctic expedition under Sir James
Ross, amounting to no less than 200 species, was ascer-
tained to be also an inhabitant of the northern hemisphere,
and almost all of them European.
When we contrast the cosmopolite character of this class
of plants with the comparatively limited range of most of the
phenogamous species, we cannot fail to perceive how inti-
mately the geographical distribution of each is related to
their powers of dispersion. But, in order to see a con-
nection between these phenomena, we must first assume that
each species has one birthplace, and that it has radiated
* Fries, cited by Lindley, Introd. to Nat. Syst. of Botany.
cc 2
388 GEOGRAPHICAL DISTRIBUTION AND [Cu. XL
in all directions in which it is possible for it to spread from
the original point or centre where it was first formed.
The most active of the inanimate agents provided by na-
ture for scattering the seeds of plants over the globe, are
the movements of the atmosphere and of the ocean, and the
constant flow of water from the mountains to the sea. To
begin with the winds: a great number of seeds are furnished
with downy and feathery appendages, enabling them, when
ripe, to float in the air, and to be wafted easily to great dis-
tances by the most gentle breeze. Other plants are fitted
for dispersion by means of an attached wing, as in the case
of the fir-tree, so that they are caught up by the wind as
they fall from the cone, and are carried to a distance.
Amongst the comparatively small number of plants known
to Linneus, no less than 138 genera are enumerated as
having winged seeds.
As winds often prevail for days, weeks, or even months to-
gether, in the same direction, these means of transportation
may sometimes be without limits ; and even the heavier grains
may be borne through considerable spaces, in a very short
time, during ordinary tempests ; for strong gales, which can
sweep along grains of sand, often move at the rate of about
forty miles an hour, and if the storm be very violent, at the
vate of fifty-six miles.* The hurricanes of tropical regions,
which root up trees and throw down buildings, sweep along
at the rate of ninety miles an hour; so that, for however
short a time they prevail, they may carry even the heavier
fruits and seeds over friths and seas of considerable width,
and doubtless are often the means of introducing into islands
the vegetation of adjoining continents. Whirlwinds are also
instrumental in bearing along heavy vegetable substances
to considerable distances. Slight ones may frequently be ob-
served in our fields, in summer, carrying up haycocks into
the air, and then letting fall small tufts of hay far and wide
over the country; but they are sometimes so powerful as to
dry up lakes and ponds, and to break off the boughs of trees,
and carry them up in a whirling column of air.
* Annuaire du Bureau des Longitudes.
months}
nsportata
avier pris
very sit
which @
Cu. XL.] MIGRATION OF SPECIES. 389
Dr. Franklin tells us, in one of his letters, that he saw, in
Maryland, a whirlwind which began by taking up the dust
which lay in the road, in the form of a sugar-loaf with the
pointed end downwards, and soon after grew to the height
of forty or fifty feet, being twenty or thirty in diameter. It
advanced in a direction contrary to the wind ; and although
the rotatory motion of the column was surprisingly rapid,
its onward progress was sufficiently slow to allow a man to
keep pace with it on foot. Franklin followed it on horse-
back, accompanied by his son, for three quarters of a mile,
and saw it enter a wood, where it twisted and turned round
large trees with surprising force. These were carried up in
a spiral line, and were seen flying in the air, together with
boughs and innumerable leaves, which, from their height, ap-
peared reduced to the apparent size of flies. As this cause
operates at different intervals of time throughout a great
portion of the earth’s surface, it may be the means of bear-
ing not only plants but insects, land testacea and their eggs,
with many other species of animals, to points which they
could never otherwise have reached, and from which they
may then begin to propagate themselves again as from a
new centre.
Agency of rivers and currents.—In considering, in the
next place, the instrumentality of the aqueous agents of dis-
persion, I cannot do better than cite the words of one of
our ablest botanical writers. ‘The mountain stream or
torrent,’ observes Keith, ‘washes down to the valley the seeds
which may accidentally fall into it, or which it may happen
to sweep from its banks when it suddenly overflows them.
The broad and majestic river, winding along the extensive
plain, and traversing the continents of the world, conveys to
the distance of many hundreds of miles the seeds that may
have vegetated at its source. Thus the southern shores of
the Baltic are visited by seeds which grew in the interior of
Germany, and the western shores of the Atlantic by seeds
that have been generated in the interior of America.’* Fruits,
moreover, indigenous to America and the West Indies, such
* System of Physiological Botany, vol. ii. p. 405.
390 GEOGRAPHICAL DISTRIBUTION AND (Cu. XL.
as that of the Mimosa scandens, the cashew-nut, and others,
have been known to be drifted across the Atlantic by the Gulf-
stream, on the western coasts of Europe, in such a state that
they might have vegetated had the climate and soil been
favourable. Among these the Gwilandina Bonduc, a legu-
minous plant, is particularly mentioned, as having been raised
from a seed found on the west coast of Ireland.*
Sir Hans Sloane states, that several kinds of beans cast
ashore on the Orkney Isles, and Ireland, but none of which
appear to have naturalised themselves, are derived from trees
which grow in the West Indies, and many of them in Jamaica.
He conjectures that they might have been conveyed by rivers
into the sea, and then by the Gulf-stream, to greater distances.
The absence of liquid matter in the composition of seeds
renders them comparatively insensible to heat and cold, so
that they may be carried without detriment through climates
where the plants themselves would instantly perish. Such
is their power of resisting the effects of heat, that Spal-
lanzani mentions some seeds that germinated after having
been boiled in water.t Sir John Herschel informs me that
he has sown at the Cape of Good Hope the seeds of the
Acacia lophanta after they had remained for twelve hours in
water of 140° Fahrenheit, and they germinated far more
rapidly than unboiled seeds. He also states that an emi-
nent botanist, Baron Ludwig, could not get the seeds of a
species of cedar to grow at the Cape till they were thoroughly
boiled.
When, therefore, a strong gale, after blowing violently off
the land for a time, dies away, and the seeds alight upon the
surface of the waters, or wherever the ocean, by eating away
the sea-cliffs, throws down into its waves plants which would
never otherwise reach the shores, the tides and currents
become active instruments in assisting the dissemination of
various classes of the vegetable kingdom. The pandanus and
many other plants have been distributed in this way over the
islands of the Pacific.
In a collection of 600 plants from the neighbourhood
* Brown, Append. to Tuckey, Ne. v. + System of Physiological Botany,
p: 481. vol. il. p. 408.
rough dimix
perish,
at, that by
after lun
peed of B
rele boas
ted far
that a
be web
oe thon?
Cu. XL.] MIGRATION OF SPECIES. 391
of the river Zaire, in Africa, the late Dr. Robert Brown
found that thirteen species were also met with on the oppo-
site shores of Guiana and Brazil. He remarked that most
of these plants were found only on the lower parts of the
river Zaire, and were chiefly such as produced seeds capable
of retaining their vitality a long time in the currents of the
ocean. Dr. J. Hooker informs me that after an examination
of a great many insular floras, he has found that no one of
the large natural orders is so rich in species common to other
countries, as the Leguminose. The seeds in this order,
which comprises the largest proportion of widely diffused
littoral species, are better adapted than those of any other
plants for water-carriage.
Mr. Darwin has made a series of experiments to ascertain
the number of days for which the seeds and fruits of various
plants could be immersed in salt water without injury, and
he found that out of 87 kinds, 64 germinated after they had
been 28 days in salt-water, and some survived an immersion
of 37 days. According to the average rate at which oceanic
currents run, he came to the conclusion that a large number
of seeds might be carried uninjured for nearly 1,000 miles
across the sea.*
Currents and winds in the arctic regions drift along ice-
bergs covered with an alluvial soil, on which pine-saplings
and a variety of herbaceous plants are seen growing, all of
which may continue to vegetate on some distant shore where
the ice-island may be stranded.
Dispersion of marine plants.—With respect to marine ve-
getation, the seeds, being in their native element, may remain
immersed in water without injury for indefinite periods, so
that there is no difficulty in conceiving the diffusion of species
wherever uncongenial climates, contrary currents, and other
causes do not interfere. All are familiar with the sight of
the floating sea-weed ;
lung from the rock on ocean’s foam to sail,
Where’er the surge may sweep, the csi s breath prevail.
I have before called attention (p. 386) to the interesting
fact that one-fifth of all the alge found in the antarctic
regions in 1841-8, by Dr. J. Hooker, were of species common
* Origin of Species, chap. xi.
392 GEOGRAPHICAL DISTRIBUTION AND [Cu. XL,
to the British seas. He has suggested that cold currents
which prevail from Cape Horn to the equator, and are there
met by other cold waters, may by their direct influence, as
well as by their temperature, facilitate the passage of ant-
arctic species to the Arctic Ocean. |
Remarkable accumulations of that species of sea-weed
generally known as gulf-weed, or sargassum, occur north of
the equator in the Northern Atlantic. Columbus and other
navigators, who first encountered these banks of alge, com-
pared them to vast inundated meadows, and stated that they
retarded the progress of their vessels. This mass of floating
vegetation, exceeding the British Isles in area, lies between
latitudes 20° and 35° to the south-west of Europe.
Sir Hans Sloane stated in 1696 that this weed grows on the
rocks about Jamaica, and is known to be ‘ carried by the
winds and current towards the coast of Florida and thence
into the North-American ocean, where it lies very thick on
the surface of the sea.’ *
Humboldt first suggested that it occupies an eddy in that
part of the Atlantic where the Gulf-stream is met by the
current from the north; and Maury gives a similar explana-
tion of another large bank of kelp and drift-weed in the
North Pacific, to the northward of the Sandwich Islands,
and of another in the Southern Ocean around Kerguelen’s
Land between lat. 40° and 54°.f
The late Robert Brown inclined to the opinion that the
original source of the gulf-weed might be some parts of the
coasts of the Gulf of Florida. When floating on the ocean
it propagates itself rapidly by new fronds which are contin-
ually pushed out from the old ones; and the larger portion of
it being produced under such peculiar circumstances, the
plant may perhaps become so modified as not to be easily
identifiable with the original stock from which it is derived.
The late Edward Forbes conceived that this weed first grew
on an old coast-line since submerged; this coast having
* Phil. Trans. 1696. t R. Brown, Mode of Propagation of
+ See map of Sargassum seas, taken Gulf-weed, Miscell. Works, vol. 1. Bay
from Maury by Andrew Murray, Geog. Society, 1866.
Dist. of Mammals, 1866.
Cu. XL.] MIGRATION OF SPECIES. 393
formed the western extremity of the continent of Europe and
Northern Africa, which then extended far into the Atlantic.*
But the great depth of the ocean, ranging from 1,000 to
10,000 feet, and often of still greater depth, which prevails over
a great part of the area assumed by this hypothesis to have
been turned from land into sea, since the Miocene epoch,
makes me consider it far more probable that, instead of
growing on a bank which has sunk down, the gulf-weed has
been drifted from some part of America.
As proof of the extent to which sea-weed is drifted, I may
mention that along the northern edge of the Gulf-stream Dr.
Hooker found Fucus nodosus and F’, serratus, which he traced
all the way from lat. 36° N. to England. The hollow pod-
like receptacles in which the seeds of many algze are lodged,
and the filaments attached to the seed-vessels of others, seem
intended to give buoyancy. It may also be remarked that
these hydrophytes are in general proliferous, so that the
smallest fragment of a branch can be developed into a per-
fect plant. The seeds, moreover, of the greater number of
species are enveloped with a mucous matter like that which
surrounds the eggs of some fish, and which not only protects
them from injury, but serves to attach them to floating bodies
or to rocks.
Agency of animals in the distribution of plants—But we
have as yet considered part only of the fertile resources of
nature for conveying seeds to a distance from their place of
erowth. The various tribes of animals are busily engaged
in furthering an object whence they derive such important
advantages. Sometimes an express provision is found in the
structure of seeds to enable them to adhere firmly by prickles,
hooks, and hairs to the coats of animals, or feathers of the
winged tribe, to which they remain attached for weeks, or
even months, and are borne along into every region whither
birds or quadrupeds may migrate. Linnzus enumerates
fifty genera of plants, and the number now known to botanists
is much greater, which are armed with hooks, by which, when
ripe, they adhere to the coats of animals. Most of these
vegetables, he remarks, require a soil enriched with dung.
* KE, Forbes, Fauna and Flora, &c., 1846, vol. i. p. 849.
394 GEOGRAPHICAL DISTRIBUTION AND [Cu. XL.
Few have failed to mark the locks of wool hanging on the
thorn-bushes, wherever the sheep pass, and it is probable that
the wolf or lion never give chase to herbivorous animals
without being unconsciously subservient to this part of the
vegetable economy.
A deer has strayed from the herd when browsing on some
rich pasture, when he is suddenly alarmed by the approach
of his foe. He instantly takes to flight, dashing through
many a thicket, and swimming across many a river and lake.
The seeds of the herbs and shrubs which have adhered to his
smoking flanks, and even many a thorny spray, which has
been torn off, and has fixed itself in his hairy coat, are
brushed off again in other thickets and copses. Even on the
spot where the victim is devoured many of the seeds which
he had swallowed immediately before the chase may be left
on the ground uninjured, and ready to spring up in a new
soil.
The passage, indeed, of undigested seeds through the
stomachs of animals is one of the most efficient causes of the
dissemination of plants, and is, of all others, perhaps the most
likely to be overlooked. Few are ignorant that a portion of
the oats eaten by a horse preserve their germinating faculty
in the dung. The fact of their being still nutritious is not
lost on the sagacious rook. To many, says Linneus, it seems
extraordinary, and something of a prodigy, that when a field
is well tilled and sown with the best wheat, it frequently
produces darnel or the wild oat, especially if it be manured
with new dung; they do not consider that the fertility of
the smaller seeds is not destroyed in the stomachs of
animals.*
Some birds of the order Passeres devour the seeds of plants
in great quantities, which they eject again in very distant
places, without destroying its faculty of vegetation: thus a
flight of larks will fill the cleanest field with a great quantity
of various kinds of plants, as the melilot trefoil (Medicago
lupulina), and others whose seeds are so heavy that the
wind is not able to scatter them to any distance.t In like
* Linneus, Amen. Acad., vol. ii. + Ameen. Acad., vol. iv. Essay 79.
409. § 8.
Cu. XL.] MIGRATION OF SPECIES. 395
manner, the blackbird and misselthrush, when they devour
berries in too great quantities, are known to consign them
to the earth undigested in their excrement.”
Pulpy fruits serve quadrupeds and birds as food, while
their seeds, often hard and indigestible, pass uninjured
through the intestines, and are deposited far from their
original place of growth in a condition peculiarly fit for
vegetation.t So well are the farmers, in some parts of
England, aware of this fact, that when they desire to raise a
quickset hedge in the shortest possible time, they feed
turkeys with the haws of the common white-thorn (Crategus
Oxyacantha), and then sow the stones which are ejected
in their excrement, whereby they gain an entire year in the
erowth of the plant.{ Birds, when they pluck cherries, sloes,
and haws, fly away with them to some convenient place ;
and when they have devoured the fruit, drop the stone into
the ground. Captain Cook, in his account of the volcanic
island of Tanna, one of the New Hebrides, which he visited
in his second voyage, makes the following interesting obser-
vation :—‘ Mr. Forster, in his botanical excursion this day,
shot a pigeon, in the craw of which was a wild nutmeg.’$
It is easy, therefore, to perceive, that birds in their migra-
tions to great distances, and even across seas, may transport
even heavy seeds to new isles and continents.
The sudden deaths to which great numbers of frugivorous
birds are annually exposed must not be omitted as auxiliary
to the transportation of seeds to new habitations. When
the sea retires from the shore, and leaves fruits and seeds on
the beach, or in the mud of estuaries, it might, by the
returning tide, wash them away again, or destroy them by
long immersion; but when they are gathered by land birds
which frequent the sea-side, or by waders and water-fowl,
they are often borne inland; and if the bird to whose crop
they have been consigned is killed, they may be left to grow
up from the sea. Let such an accident happen but once
* Amen. Acad., vol. vi. § 22. to me by Professor Henslow, of Cam-
{ Smith’s Introd. to Phys. and Syst. _ bridge.
Botany, p. 304. 1807. § Book iii. ch. iv.
$ Thisinformation was communicated
396 GEOGRAPHICAL DISTRIBUTION AND (Ca. XL)
in a century, or a thousand years, it will be sufficient to
spread many of the plants from one continent to another ; for
in estimating the activity of these causes, we must not consider
whether they act slowly in relation to the period of our obser-
vation, but in reference to the duration of species in general.
Let us trace the operation of this cause in connection with
others. A tempestuous wind bears the seeds of a plant
many miles through the air, and then delivers them to the
ocean; the oceanic current drifts them to a distant continent ;
by the fall of the tide they become the food of numerous
birds, and one of these is seized by a hawk or eagle, which,
soaring across hill and dale to a place of retreat, leaves, after
devouring its prey, the unpalatable seeds to spring up and
flourish in a new soil.
Mr. Darwin found that fresh-water fish eat the seeds of many
land and water plants, and as the same fish are often devoured
by birds, such seeds may be readily transported by them to
ereat distances. The same naturalist observed also that the
earth adhering to the feet of birds, often contains a variety
of seeds of plants; and he mentions one case where from a
ball of earth taken from the leg of a partridge he raised more
than 80 individual plants belonging to species both of
monocotyledons and dicotyledons.* Insects are probably in-
strumental like birds in disseminating plants, for proofs have
lately been obtained (see Chapter XLI.) of the germinating
power of seeds swallowed by locusts and rejected in their dung.
The machinery above adverted to, is so capable of dissemi-
nating seeds over almost unbounded spaces, that were we
more intimately acquainted with the economy of nature, we
might probably explain nearly all the instances of plants
inhabiting two points very remote from each other and not
found in places intermediate; but some difficulties must
remain in accounting for the range of species so long as the
botanist confines his speculations to the present state of the
earth’s physical geography and climate. For the geologist
can show that great changes have taken place in the height
of the land and in the position of land and sea since the
* Origin of Species, 4th edition, p. 432.
Cu. XL.] MIGRATION OF SPECIES. 397
ereater number of the living species of plants came into
being. And we shall see in the Forty-second Chapter how
much the rarity, or even the entire extinction, of species is
promoted by these changes.
Agency of man in the dispersion of plants.—But in addition
to all the agents already enumerated as instrumental in
diffusing plants over the globe, we have still to consider man
—one of the most important of all. He transports with him,
into every region, the vegetables which he cultivates for his
wants, and is the involuntary means of spreading a still
greater number which are useless to him, or even noxious.
‘Whenthe introduction of cultivated plants,’ says De Candolle,
‘is of recent date, there is no difficulty in tracing their origin ;
but when it is of high antiquity, we are often ignorant of
the true country of the plants on which we feed. No one
contests the American origin of the maize or the potato ; nor
the origin, in the Old World, of the coffee-tree, and of wheat.
But there are certain objects of culture, of very ancient
date, between the tropics, such for example as the banana,
of which the origin cannot be verified. Armies, in modern
times, have been known to carry, in all directions, grain and
cultivated vegetables from one extremity of Europe to the
other; and thus have shown us how, in more ancient times,
the conquests of Alexander, the distant expeditions of the
Romans, and afterwards the crusades, may have transported
many plants from one part of the world to the other.’*
But, besides the plants used in agriculture, the number
which have been naturalised by accident, or which man
has spread unintentionally, is considerable. One of our old
authors, Josselyn, gives a catalogue of such plants as had, in
his time, sprung up in the colony since the English planted
and kept cattle in New England. They were two-and-twenty
in number. The common nettle was the first which the
settlers noticed ; and the plantain was called by the Indians
. Hngishman’s foot,’ as if it sprung from their footsteps.t
We have introduced every where,’ observes De Candolle,
some weeds which grow among our various kinds of wheat,
: a Candolle, Essai Elémen. &c. ft Quarterly Review, vol. xxx. p. 8.
p. 50.
GEOGRAPHICAL DISTRIBUTION AND [Cu. XL.
and which have been received, perhaps, originally from Asia
along with them. Thus, together with the Barbary wheat,
the inhabitants of the south of Europe have sown, for many
ages, the plants of Algiers and Tunis. With the wools and
cottons of the East, or of Barbary, there are often brought
into France the grains of exotic plants, some of which
naturalise themselves. Of this I will cite a striking example.
There is, at the gate of Montpellier, a meadow set apart for
drying foreign wool, after it has been washed. There hardly
passes a year without foreign plants being found naturalised
in this drying-ground. I have gathered there Centaurea
parviflora, Psoralea palestina, and Hypericum crispum. This
fact is not only illustrative of the aid which man lends
inadvertently to the propagation of plants, but it also demon-
strates the multiplicity of seeds which are borne about in the
woolly and hairy coats of wild animals.
The same botanist mentions instances of plants naturalised
in seaports by the ballast of ships ; and several examples of
others which have spread through Europe from botanical
gardens, so as to have become more common than many
indigenous species.
It is scarcely a century, says Linnzus, since the Canadian
Erigeron, or flea-bane, was brought from America to the
botanical garden at Paris; and already the seeds have been
carried by the winds so that it is diffused over France, the
British Islands, Italy, Sicily, Holland,and Germany.* Several
others are mentioned by the Swedish naturalist, as having
been dispersed by similar means. The common thorn-apple
(Datura Stramonium), observes Willdenow, now grows as 2
noxious weed throughout all Europe, with the exception of
Sweden, Lapland, and Russia. It came from the East Indies
and Abyssinia to us, and was thus universally spread by
certain quacks, who used its seeds as an emetic.t The same
plant is now abundant throughout the greater part of the
United States, along road-sides and about farm-yards. The
yellow monkey-flower, Mimulus luteus, a plant from the north-
* Essay on the Habitable Earth, t Principles of Botany, p. 389.
Ameen. Acad., vol. ii. p. 409.
“entauny
ne Thi
an Jeni;
0 demo.
nat in the
turalisel
|
mples i
tani
Cu. XL.] MIGRATION OF SPECIES. 399
west region of America, has now established itself in various
parts of England, and is spreading rapidly.
In hot and ill-cultivated countries, such naturalisations
take place more easily. Thus the Chenopodium ambrosiordes,
sown by Mr. Burchell on a point of St. Helena, multiplied so
fast in four years as to become one of the commonest weeds
in the island, and it has maintained its ground ever since
1845.*
The mostremarkable proof, says De Candolle, of the extent
to which man is unconsciously the instrument of dispersing
and naturalising species, is found in the fact, that in New
Holland, America, and the Cape of Good Hope, the European
species exceed in number all the others which have come from
any distant regions ; so that, in this instance, the influence of
man has surpassed that of all the other causes which tend to
disperse plants over remote regions. About a fifth of the
British flowering plants are supposed to be naturalised
species, and a large proportion of them would perish with the
discontinuance of agriculture.
Although we are but slightly acquainted, as yet, with the
extent of our instrumentality in naturalising species, yet the
facts ascertained afford no small reason to suspect that the
number which we introduce unintentionally exceeds all those
transported by design. Nor is it unnatural to suppose that
the functions, which the inferior beings extirpated by man
once discharged in the economy of nature, should devolve
upon the human race. If we drive many birds of passage
from different countries, we are probably required to fulfil their
office of carrying seeds, eggs of fish, insects, mollusks, and
other creatures, to distant regions : if we extirpate quadrupeds,
we must replace them not merely as consumers of the animal
and vegetable substances which they devoured, but as disse-
minatorsof plants,and of the inferior classes of theanimal king-
dom. I donot mean to insinuate that the very same changes
which man brings about, would have taken place by means of
the agency of other species, but merely that he supersedes a
certain number of agents; and so far as he disperses plants
* Principles of Botany, p. 389.
400 GEOGRAPHICAL DISTRIBUTION AND (Cu. XL,
unintentionally, or against his will, his intervention isstrictly
analogous to that of the species so extirpated.
I may observe, moreover, that if, at former periods, the
animals inhabiting any given district have been partially
altered by the extinction of some species, and the introduction
of others, whether by new creations or by immigration, a
change must have taken place in regard to the particular
plants conveyed about with them to foreign countries. As,
for example, when one set of migratory birds is substituted
for another, the countries from and to which seeds are trans-
ported are immediately changed. Vicissitudes, therefore,
analogous to those which man has occasioned, may have
previously attended the springing up of new relations between
species in the vegetable and animal worlds.
It may.also be remarked, that if man is the most active
agent in enlarging, so also is he in circumscribing, the geo-
eraphical boundaries of particular plants. He promotes the
migration of some, he retards that of other species ; so that,
while in many respects he appears to be exerting his power
to blend and confound the various provinces of indigenous
species, he is, in other ways, instrumental in obstructing the
fusion into one group of the inhabitants of contiguous
provinces.
Botanists are well aware that garden plants naturalise
and diffuse themselves with great facility in comparatively
unreclaimed countries, but spread themselves slowly and with
difficulty in districts highly cultivated. There are many
obvious causes for this difference : by drainage and culture the
natural variety of stations is diminished, and those stray
individuals by which the passage of a species from one fit
station to another is effected, are no sooner detected by the
agriculturist than they are uprooted as weeds. The large
shrubs and trees, in particular, can scarcely ever escape obser-
vation, when they have attained a certain size, and will rarely
fail to be cut down if unprofitable.
The same observations are applicable to the interchange
of the insects, birds, and quadrupeds of two regions situated
like those above alluded to. No beasts of prey are permitted
to make their way across the intervening arable tracts. Many
tity
TE tan. |
here |
lay hays
betray ;
St actin
the oe
yotes the
30 that, i
is pore
ligenoas
Cu. XL.] MIGRATION OF SPECIES. 401
birds, and hundreds of insects, which would have found some
palatable food amongst the various herbs and trees of the
primeval wilderness, are unable to subsist on the olive, the
vine, the wheat, and a few trees and grasses favoured by
man. In addition, therefore, to his direct intervention, man,
in this case, operates indirectly to impede the dissemination
of plants, by intercepting the migration of animals, many of
which would otherwise have been active in transporting seeds
from one province to another.
We shall see in the sequel that species belonging to genera,
previously foreign to the province into which they are intro-
duced, often make their way more readily than plants of those
genera and species which are indigenous, a fact which has a
very important bearing on the theory of the origin of species.
It is unfavourable to the doctrine that new species have been
specially created in each station as best fitted of all possible
organisms to flourish there, while it agrees perfectly with the
view that new lands or stations are first colonised by such
plants and animals as can gain access to them without
violating the fixed and immutable laws which govern the
diffusion of species. Once introduced, they may become
adapted by variation and selection to all the peculiar condi-
tions of the new region; but they may still be less fitted for
it than some other organisms which may coexist on the globe,
and which may be prevented by impassable barriers from
reaching the same country so: as to assert their superiority
in the battle of life.
VOL. II. DD
CHAPTER XLI.
INSULAR FLORAS AND FAUNAS CONSIDERED WITH REFERENCE
TO THE ORIGIN OF SPECIES.
VOLCANIC ORIGIN AND MIOCENE AGE OF THE ATLANTIC ISLANDS—ISLANDS
ONCE FORMED HAVE NOT BEEN SINCE SUBMERGED, NOR UNITED WITH OTHER
ISLANDS—ARGUMENTS AGAINST CONTINENTAL EXTENSION—-MAP SHOWING
THE GREAT DEPTH OF THE OCEAN BETWEEN THE VOLCANIC ARCHIPELAGOS
CEOUS FAUNA OF THE BRITISH ISLES AND THAT OF THE ATLANTIC ISLANDS
—MODE IN WHICH AN OCEANIC ISLAND MIGHT BECOME PEOPLED WITH
LANDSHELLS—VARIABILITY OF SPECIES NOT GREATER IN ISLANDS THAN ON
CONTINENTS.
In the present chapter I shall consider the characteristic
features of the fauna and flora of islands remote from con-
tinents. It has been truly said, that the distribution of
species in such peculiar situations affords perhaps the severest
test by which the theory of Variation and Natural Selection
can be tried. ‘
I have already stated that as a general rule, when islands
are near a continent, especially if they are only divided from
it by a shallow sea, less, for example, than 100 fathoms in
depth, their flora and fauna are identical with that of the
mainland. But when an island, like Madagascar, 1s of large
size, and is divided from the mainland by a deep channel of
the sea several hundred miles wide, the species of quadrupeds
differ from those on the continent, although nearly all the
genera are the same, while of the other members of the animal
and vegetable kingdom there is a greater or less identity
-according to the class to which they belong.
If we then go a step farther, and contemplate small islands
haracten
re frow a
tribatit
the ger
al get
+ ER
Cu. XLL] INSULAR FLORAS AND FAUNAS CONSIDERED. 403
far from land and surrounded by a deep ocean, we find that
they are remarkable for the number of peculiar species of
animals and plants which they contain, even a single island of
the same group being sometimes inhabited by many species
exclusively belonging to it. Yet even in such localities an
affinity can be traced between the insular forms considered
as a whole, and those of the nearest continent—a relationship
exceeding that which connects them with the fauna and flora
of more distant parts of the globe.
Volcanic origin and Miocene age of the Atlantic islands.—I
shall refer chiefly to the Madeiras and Canaries as types of
oceanic archipelagos, as I have myself visited them and
studied their geological structure, without a knowledge of
which the speculations and theories of a zoologist or botanist
as to the mode in which they may have been peopled with living
beings must necessarily be most imperfect. For in the first
place we require information as to the period of the past to
which the origin of the islands can be traced back, and then we
have still to enquire whether they are fragments of a pre-
existing continent, or were formed in mid-ocean by volcanic
eruptions.
If we find evidence that in the case of the Atlantic
islands the latter conclusion is true, we have still to learn
whether each of them has continued above water during
the whole course of its growth by successive eruptions, or
whether it may have undergone oscillations of level, by alter-
nate upheaval and subsidence. ‘To most of these questions
we are fortunately able to give a satisfactory answer. It
may be affirmed that the earliest eruptions took place in that
part of the Middle Tertiary period which I have called Upper
Miocene. As soon as the first solid lavas raised their heads
above water, they were exposed to the action of the waves,
and fragments of volcanic rocks were detached and rounded
on the shore, and some of them swept into the adjoining
deeper parts of the sea, so as to form pebble beds, or con-
glomerates, or sands and sandstones, in which corals and
shells of Miocene species were imbedded. By far the larger
number of these species are now extinct. Their fossil re-
mains have been rendered visible to us by their having been
DD 2
AOA INSULAR FLORAS AND FAUNAS WITH (Cu. XLI.
uplifted in various islands to great heights, especially in the
Grand Canary, Madeira, and Porto Santo, where they some-
times reach elevations of from 1,500 to 2,000 feet above the
level of the sea. The movement of elevation was, I believe,
very gradual, and went on during the whole period which
witnessed the piling up on these islands of several thousand
feet of basaltic and trachytic lavas, just as I have described
the gradual rise of the Marine Pliocene strata, which con-
stituted the foundations of Mount Etna during the accumu-
lation of the subaérial superstructure of the great cone.*
Nowhere could I detect, in any of the Atlantic islands
which I visited, any signs of subsidence, or even of the tem-
porary submergence of old terrestrial surfaces. In Madeira
there are hundreds of thin horizontal layers of a red-brick
colour, dividing those sheets of ancient lava which are seen
in the sea-cliffs or in precipices in the interior. They exactly
resemble a layer of burnt vegetable mould near Catania, already
described (p. 13), as having been overflowed in the year 1669
by a great lava-current, and all of them seem to be ancient
soils formed by the decomposition of lava and volcanic sand.
They bear testimony to the reiterated obliteration and renewal
of old habitable surfaces, unaccompanied by any signs of sub-
mergence or the intervention of the sea. The movements of
upheaval, on the other hand, seem to have been always partial
and confined within the limits of the separate islands in
which we find the marine strata uplifted. The 100 fathom
line is always near to the shore,t+ and outside of this line the
depth of water increases very rapidly, so that it is highly
improbable that any of the principal islands were united
and afterwards disjoined. Madeira would, indeed, be con-
nected with the Dezertas,{ if the sea was to sink 100 fathoms ;
but there is no geological reason for presuming that the
intervening ridge, over which there is, in one part, more
than 400 feet of water, ever formed an unbroken isthmus
joining Chao to the south-eastern extremity of Madeira.
The great antiquity of the Canaries and Madeiras is at-
tested by the twofold evidence of the height and magnitude
of the islands themselves, and the age of the fossil organic
* Vol, ii. p. 5. + See Map, p. 400, + See Map.
red-brig
L are ey |
ey exadh |
a, ala
year Li
be ance
ani¢ saul
d rene
ns of sil
ements
8 pare
Cx. XLI.] REFERENCE TO THE ORIGIN OF SPECIES. 405
remains (of Miocene date) already alluded to as having been
imbedded in the products of early eruptions.
In Madeira the voleanic accumulations rise to the height
of 5,000 feet, and in the Grand Canary to 6,000 feet. The
highest crater in Teneriffe rises to an elevation of more than
12,000 feet above the sea-level. We know that violent erup-
tions are usually separated by long intervals of time; and
from the history of the Canaries and volcanic archipelagos in
Fig. 137.
DerertaAd®\
Grande\\s.
ae
Ney
\eRS
4)
Biu ay,
: \ a”
Map of the Madeiran Archipelago.
a. The Styx reef, 72 feet under wate
T.
b. The Falcon reef, 26 feet under water.
general, we may infer that when one island is in a state of
unusual volcanic activity, the other adjoining islands enjoy
comparative repose. Moreover, in one and the same island,
different sets of vents have been in eruption in succession; as,
for example, in Madeira, where the series of cones which now
constitute the highest and central ridge, is not the most
406 INSULAR FLORAS AND FAUNAS WITH (Ca; Xie
ancient, for lavas proceeding from those vents, and flowing
southwards, have overwhelmed the products of an older series
of eruptions.*
Scarcely any progress has been made as yet in tracing in
any of the archipelagos the passage from a Miocene to a
recent fauna and flora by aid of fossil remains preserved in
voleanic tuff; but Mr. Hartung and I were fortunate enough
to discover in 1854 at San Jorge in Madeira, in a deep ravine
at the height of 1,000 ft. above the sea, a layer of lignite con-
taining impressions of the leaves of forest trees and some
ferns. They appear to belong to some part of the Pliocene
period, and are certainly of great antiquity, for the nume-
rous beds of lava and layers of volcanic ash piled over them
are about 1,100 feet thick. Sir C. F. Bunbury, and after
him Professor Heer, have shown that these fossil leaves prove
Madeira to have been clothed, at the period when they were
imbedded (possibly in the mud at the bottom of an old crater)
with evergreens and other laurel-like trees, such as Lawrus
and Oreodaphne mixed with species of European genera,
together with ferns, such as Woodwardia—in fact, with just
such forests and such an undergrowth as we now find charac-
teristic of the native vegetation of the island. Some of the
species, however, according to Heer, differ from any now living
in Madeira.t
It isa favourite opinion of some naturalists, and one advo-
‘ated by the late Edward Forbes; that the Azores, Madeiras,
and Canaries are the last remaining fragments of a contin-
uous area of land, which once connected them with the West
of Europe and North Africa. In order to explain my reasons
for dissenting from this hypothesis, I may refer the reader to
the adjoining map, partly based on a chart in Maury’s Physi-
cal Geography of the Sea, and partly on Admiralty charts, for
an analysis of which I am indebted to Mr. T. Saunders. A
elance at this map will satisfy the reader that the theory of
continental extension involves an amount of change of level
so vast, that to assume its occurrence since the close of the
Miocene epoch, is quite inconsistent with what we know of the
vol. x. p. 326, and ‘Lyell’s Ele-
* See ‘ Lyell’s Elements,’ p. 639. 1854, \
+ See Bunbury, Geol. Quart. Journ. ments,’ 6th edit. p. 642.
Cu. XLI-J REFERENCE TO THE ORIGIN OF SPECIES. A407
constancy of the position of continents and oceanic basins
throughout long geological periods. The Azores, in which
the oldest fossiliferous rocks, like those of the Madeiras and
Canaries, are of Upper Miocene date, are everywhere sur-
rounded * by a zone of ocean more than 10,000 feet deep.
There is, indeed, one line of soundings having a depth of more
than 15,000 feet between the Azores and Portugal, showing
Fig. 138.
} PORTUGAL
30 fa) / i MER O OF GR.
Map, showing the depth of the ocean between the eastern volcanic archipelagos
of the North Atlantic and the Mainland.
The ocean is tinted cee to its depth, thus:
depth of 1,000 feet lightly
From 1,000 feet to 10,000 feet . - darker
— 10 fhe feet ery darkly B=
The line of 1,00 LTA. 8. a the line of a mie feet C. D.
that a land communication would imply, first, the sinking of
a great continental area down to the sea-level, and then a
further depression of the same from the sea-level to a depth
* See Map.
408 INSULAR FLORAS AND FAUNAS WITH [Cu. XLI.
of from 10,000 to 15,000 feet and upwards, all since the close
of the Miocene period. The Madeiran archipelago, it will be
seen, 1s near the line C D, which expresses a depth of 10,000
feet, and the same may be said of the eastern portion of the
Canarian archipelago. On the western side of this last, the
ocean has a depth of several thousand feet, dividing Fuerta-
ventura and Lanzerote from the mainland. The general
abruptness of the cliffs of all the Atlantic islands, coupled
with the rapid deepening of the sea outside the 100 fathom
line, are characters which favour the opinion that each island
was formed separately by igneous eruptions in a sea of ereat
depth. No geologist can doubt that the beds of lava and
volcanic ash originally sloped down gradually towards the
shore, and that the abrupt precipices now so general and often
from 1,000 to 2,000 feet in perpendicular height facing the
Atlantic, have been caused by the undermining action of the
waves.
Submarine volcanic eruptions of the present century.—From
what we know of the modern history of volcanic action in the
basin of the Atlantic, we can be at no loss to conceive the
manner in which such groups as the Azores or Canaries
originated. I have already mentioned that the foundations
of a future archipelago seem now in the act of being Jaid
midway between St. Helena and Ascension, which are about
600 miles distant from each other.* Here in mid-ocean no
less than 1,200 miles from the nearest part of Africa, un-
equivocal signs of submarine eruptions are occasionally wit-
nessed. On this spot, so far out of sight of land, we may
expect on some future day that a cone and crater will be
built up as was Sabrina in 1811, in the sea off St. Michael’s,
one of the Azores, or as was Graham’s Island, which in 1831+
rose up in a deep part of the Mediterranean, thirty miles
from the nearest land, the south coast of Sicily. Although
both these islands were gradually swept away by the waves,
they have left reefs of solid rock in that part of the sea from
which, on some future occasion, a new voleanic cone may
arise.
* See above, p. 64. t See above, p. 60.
OWands fh
y and ofa
| facing th |
ction of th
ary — Fon |
etionintk
Cu. XLI.] REFERENCE TO THE ORIGIN OF SPECIES. 409
Even in the present year (November 1867) a submarine
yoleano has burst out in the South Pacific at a point 1,200
geographical miles from New Zealand and 1,809 from Aus-
tralia, between two of the most easterly islands of the Samoa
or Navigator’s Group, an archipelago where there had been
no tradition of an eruption within the memory of man. This
outburst was preceded by numerous shocks of earthquakes.
Jets of mud and dense columns of volcanic sand and stones,
rising 2,000 feet, and the fearful crash of masses of rock
hurled upwards and coming in collision with others which
were falling, attested the great volume of ejected matter,
which accumulated in the bed of the ocean, although there
was no permanent protrusion of a new volcano above its level.
General inferences to be deduced from the endemic and other
species of animals and plants in the Atlantic Islands.— Whether
therefore we consider the composition of the rocks and struc-
ture of the Atlantic islands, or their comparatively modern
origin, or the vast depth and extent of the sea which separates
them from the nearest continent, all these characters conspire
to lead to the belief that they have been formed in mid-ocean
by volcanic agency ; and we shall find, if I mistake not, that the
geographical distribution of the species, both of animals and
plants, contained in them is far more in accordance with such
an hypothesis than with that of continental extension. If,
when the first islands were formed, the earliest colonists con-
sisted of plants and animals which arrived as waifs and strays
from the nearest land, they must have consisted of species
which inhabited Hurope and the North of Africa in Upper
Miocene times. Fortunately we have made considerable pro-
gress in ascertaining what was the character of the fauna and
flora of that epoch, differing widely as it did from that now
existing in the same regions. We know, for example, that the
Miocene flora of Europe had a strong generic affinity to the
vegetation now characterising North America, much greater
than to that of any other part of the globe in our own period;
so that, if we find American forms in these Atlantic islands,
it does not violate the general law that the animate creation
in oceanic archipelagos bears always most resemblance to that
of the nearest adjoining mainland, for these American forms
410 INSULAR FLORAS AND FAUNAS WITH [Cx XE
are doubtless the remnants of a flora derived from an ancient
and adjoining Miocene continent. But we must also re-
member that the Miocene fauna and flora of Hurope eradu-
ally gave place to another of Plocene date, and all these
fluctuations in the animate world must have made themselves
felt in the oceanic islands in which the successive destruction
and renovation of the terrestrial surfaces would facilitate the
settling in them of new species brought to them by the
winds, marine currents, and various agents of transport, or-
ganic and inorganic. New sheets of lava would in particular
weaken the barrier which preoccupancy opposes to new colo-
.nists; for the melted matter first annihilates every living
thing over the strip of land, more or less broad, which extends
from the volcanic orifice to the sea-coast, and then, after many
years, when the lava has decomposed, it affords a fresh and
virgin soil on which new immigrants may settle. Volcanic
ejections and movements of upheaval, by causing perpetual
variations in the surface-level of each island above the sea,
would also promote fluctuations in the fauna and flora. That
low portion of Africa which is marked in our map (fig. 188,
p. 407), as the Sahara, was probably under water during the
Miocene period. It is also possible that some volcanic islands
may, during or since the Miocene era, have been formed and
again destroyed within the area embraced in this map. They
may have played an important part in promoting the inter-
change of species between different archipelagos, or between
them and the continent.
It will be seen that at present, about half way between
Madeira and the Canaries, there are some isolated rocks
called the Salvages, which attain a height of 100 feet above
the sea. The largest of them which, like the rest, is unin-.
habited, is about a mile long. They rise from a deep ocean,
and their steep cliffs show that they have been much reduced
in size by the waves. The plants, insects, and landshells
found upon them belong in part to those peculiar types called
‘ Atlantic,’ probably the relics of a Miocene fauna and flora.
The foregoing remarks on the geography and geology of
the Atlantic islands are indispensable to a reader who would
follow us in our speculations on the manner in which they
oT i
REFERENCE TO THE ORIGIN OF SPECIES. 411
Cu. XLI.]
may have become peopled with the animals and plants now
inhabiting them. The absence or abundance of each class,
the number of species common to the nearest continent, the
range, whether limited or extensive, of each species through
different islands or through different archipelagos, may throw
light on the question whether species have been independently
created, or whether they are modifications of pre-existing
forms, the products of Variation and Natural Selection.
Mammalia.—The first great fact for which we have to
account, is the entire absence of all indigenous Mammalia
except bats. Palma, one of the Canaries, is inhabited by an
indigenous bat, the progenitors of which may have migrated
to, that island in Miocene or Pliocene times.
When we have travelled over large and fertile islands,
thirty miles or more in diameter, such as the Grand Canary
and Teneriffe, and have seen how many domestic animals,
such as camels, horses, asses, dogs, sheep and pigs, they now
support, we cannot but feel amazed that not even the smaller
wild animals, such as squirrels, field-mice, and weasels, should
be met with in a wild state. The reader may ask how such
quadrupeds could have reached an island ike Madeira, more
than 360 miles from the nearest mainland ; but such a ques-
tion at once implies the admission, that an arbitrary exer-
tion of creative power does not give origin to Mammalia in
every region where conditions favourable to their support
may happen to exist.
Tt was long ago remarked by Dr. Prichard,* that among
the various groups of fertile islands in the Pacific, no quadru-
_peds, with the exception of a few bats, have been met with,
which might not be supposed, like the dog, the hog, and the
‘Tat, to have been conveyed thither from New Guinea by the
natives in canoes. What is more extraordinary, even the
large island of New Zealand, when first explored by Euro-
peans, was found to be destitute of indigenous Mammalia,
except one species of rat and two bats, said to be different
from any found elsewhere. Bats have been seen wandering
by day far over the Atlantic ocean, and two North American
* Prichard, Phys. Hist. of Mankind, vol. i. p. 76.
412 INSULAR FLORAS AND FAUNAS WITH Rea ah
species visit the Bermudas at the distance of 600 miles from
the mainland.* Mr. Darwin has therefore emphatically
dwelt on the absence of Mammalia in islands far from con-
tinents, as strongly confirmatory of his theory of the origin
of all species by descent from pre-existing closely allied
species. The absence of Mammalia also supplies us with an
argument against the doctrine of continental extension.
Had a large tract of land stretching from Europe to the
Atlantic islands been gradually submerged, so that at last
no vestige of it remained above water, except the tops of
certain volcanic mountains, the Mammalia would have re-
treated into such spots, for the smaller species at least might
have found subsistence there. It has been suggested by the
advocates of continental extension, that if Java should sink
down several thousand feet, no land would be left except the
summits of a series of lofty volcanic cones, round which
there would be everywhere a deep ocean. But these same
cones, as we have seen (p. 356), would each of them be in-
habited by its peculiar Mydaus, and no doubt other species of
Mammalia would take refuge there. Had any quadrupeds
been able to swim to the Azores, Madeiras, or Canaries in the
Miocene epoch, there is no ground for supposing that their
descendants would not still survive; for, as before stated, each
island seems during its whole growth to have afforded a
habitable surface to terrestrial beings. |
The rapid multiplication of goats when allowed to run
wild in St. Helena, and of both goats and dogs in Juan Fer-
nandez when introduced by the Spaniards, and of rabbits in
Porto Santo, from a single brood imported there in 1418,
prove the fitness of small islands to maintain wild quadrupeds,
if they can once make their way into them.
The total dearth of Batrachians (frogs, toads, and newts),
has also been pointed out by Darwin, as a characteristic of
oceanic islands; yet he remarks that frogs, when taken to
Madeira, the Azores, and Mauritius, have thriven to such a
degree as to become a nuisance. If their spawn were
carried down by a river to the sea, it would at once be de-
* Origin of Species, p. 469.
Cu. XLI.J REFERENCE TO THE ORIGIN OF SPECIES. 4158
stroyed by the saltwater, as has been ascertained by experi-
ment, and it is not of a nature to adhere to the feet of birds,
as Mr. Darwin has found by observation.
A strong current which flows from the north, and passes
between the Atlantic archipelagos and the mainland, may
perhaps have prevented Mammalia and reptiles from reach-
ing even the Canaries, one of which, Fuertaventura, is now
only fifty miles from Africa, though possibly it was more
distant when the Sahara was still under water. The same
current may have prevented canoes from being drifted to
Madeira, which is so isolated in mid-ocean, and on the shores
of which no human being is believed to have ever landed
until the year 1419. Madeira now supports a population
of about 80,000 souls, and when we consider the great beauty
and fertility of the island, and that it has existed ever since
the Miocene epoch, we are not merely called upon to explain
the absence of inferior animals, but why, if we adopt the
theory of special creation, no race of mankind was formed
expressly to inhabit such a paradise.
Birds.—For the same reason that bats, being provided with
wines, form an exception to the general rule of the absence
of Mammalia in oceanic islands, so we might expect that
the feathered race would, of all classes of Vertebrata, be
most fully represented. Accordingly we not only find this to
be the case, but what is still more significant, as bearing
on the theory of transmutation, almost all the birds in the
Atlantic islands are absolutely identical in species with
those of the nearest mainland. Thus in the Canaries and
Madeiras, all the species except three or four are European.
Of the 99 Madeiran species, there is only one peculiar to that
island, and it is closely related to a European form; the
other two non-Huropean species are common to the Canaries.
In the Azores, there are only two peculiar species, out of
51, and these two, a chaffinch and a bullfinch, are closely
allied to Huropean and North African birds.*
We learn from Mr. Du Cane Godman, as before cited (p. 3865),
that every winter some birds are driven by violent gales over
1,000 miles of ocean from England to the Azores. The same
* Ibis, vol. ii, 1866, new series.
414 INSULAR FLORAS AND FAUNAS WITH —[Cu, xu.
observer informs us that the species are most numerous in the
easternmost islands, and that the number diminishes rapidly
as we examine those lying farther west, showing that the
wearied and hungry voyagers drop down on the first land
they discern. It is only by this frequent arrival of new-
comers that we can explain the specific identity of the insular
and continental fauna, the tendency to variation and in-
definite divergence being checked in the manner explained
at p. 321, by the absorption of the insular into the conti-
nental types, with which they are continually crossed. There
are no American birds in the Azores, which cannot be entirely
explained by the greater distance of that continent, because
no less than sixty species are known to have crossed the
Atlantic as stragglers, and to have reached the British Islands.
The fact simply proves that strong winds blowing continu-
ously in the right direction, are indispensable to enable birds
to colonise remote islands.
The Bermudas, which are 700 miles from the coasts of
America, are stocked with species all belonging to that conti-
nent. Of three Huropean stragglers mentioned by Baird, two
are common to Greenland, and may have come from the
north, Newfoundland having served as an intermediate
halting-place ; and the third, our common sky-lark, a rare and
occasional visitor, is so often carried in ships to America, that
it may perhaps sometimes escape from a cage, and alight on
the first land which presents itself.
The number of days for which land-birds can fast would
more than suffice for their flight from Europe or even from
America to the Azores. Mr. Bartlett informs me that a par-
tridge sent from the London Zoological Gardens to the
country remained accidentally in the box in which it was
enclosed for five days without food or water ; when discovered,
it was alive, and being fed was soon restored to its usual
vigour.
The avifauna of the volcanic archipelago of the Galapagos
presents in some respects a contrast to that of the Atlantic
islands; for although the distance from the nearest mainland
is scarcely more than half that which separates the Azores
from Europe, four-fifths of the land-birds are of species found
contin.
ble bin
soasts of
at cont
—"
S
SS,
SE NS
Cu. XLI.] REFERENCE TO THE ORIGIN OF SPECIES. 415
nowhere else in the world. Out of twenty-six species all but
three or four are peculiar to these islands, at the same time
that the whole of them are of South American types. What
is still more worthy of note, several of these land-birds are
peculiar to a single island of the group.* To explain this
we may suppose that continuous gales have rarely blown
from South America to the Galapagos since these islands
first lifted their heads above the waves, and for this reason
stragglers have only arrived after long intervals, some on
one island, and some on another. Once established, they
have remained isolated, without communication with birds
of the parent stock on the South American mainland, or with
settlers of the same stock on other parts of the archipelago.
On this subject Mr. Godman remarks, that while in the
Azores, winds are constantly blowing from all points of
the compass so that land-birds are carried during storms
from one island to another, in the Galapagos there are no
such violent gales, but usually uninterrupted calms. He
also adds, that while the marine currents in the Azores flow
in varying directions, those of the Galapagos are strong,
and always in the same direction. As to the web-footed
birds or waders of the Galapagos, Mr. Darwin found that
out of 11 species all except two consist of species common
to the nearest continent.t This fact agrees well with the
very wide range of this order of birds in all parts of the
world, and is in accordance with their migratory habits.
The relationship of the birds of the Atlantic islands to
those of Europe and North Africa is nearly the same as that
usually observed in a continuous continent. <A few excep-
tional and peculiar types may in some cases have arisen
from Variation and Natural Selection, since they first arrived,
and some of them may perhaps be the descendants of Miocene
species or genera which have died out in the mother con-
tinent.
Insecits.—The insects of Madeira, the Salvages, and the
Canaries, unlike the birds, exhibit a large proportion of
indigenous species, and a great many genera peculiar to the
* Darwin, Origin of Species, p. 465. eal:
416 INSULAR FLORAS AND FAUNAS WITH [Cu. XLI,
Atlantic islands, represented in each separate archipelago by
distinct species. Mr. T. V. Wollaston, in his ‘ Coleoptera
Atlantidum,’ has described no less than 1,449 species of beetles
belonging to the three groups of islands above mentioned.
Nearly all of these have been collected by himself, and of the
whole number more than1,000 are of species hitherto unknown
as inhabiting any other region, although there is no doubt that
a great many of them will hereafter be discovered in lands
bordering the Mediterranean. The distinctness of the fauna
of different archipelagos is shown by the fact that out of
1,007 species obtained from the Canaries, and 661 from the
Madeiras, only 238 are common to the two groups. Hven
of these it is suspected that the larger number have been
introduced by man, and it is quite certain that 38 species
have been so imported in very modern times.
Nearly every detached island adds some distinct species or
marked variety to the general list, and one half of the 24
species found on the rocks called the Salvages, before men-
tioned, are peculiar, some of them belonging to those forms
which have been called Atlantic types. ‘ If, says Wollaston,
‘we exclude those beetles which have probably been natura-
lised by human agency, there are marvellously few species,
which permeate the whole of the archipelagos, yet with few
exceptions the genera are common to the whole.’ Among the
dominant forms the weevils, or Curculionide, preponderate
ereatly, and certain families of them are of essentially
Atlantic types. No less than 50 species and varieties feed
exclusively on the Euphorbias which are so abundant and
diversified in form in the Canaries. Some fossil plants of
the genus Euphorbia occur in the Miocene strata of (Eninghen
in Europe, and the parent stock both of these plants and of
the Atlantic Ourculionide may perhaps have been derived from
the old Miocene continent. It has been already proved, by the
researches of Heer and others, that the Miocene Coleopterous
Fauna of Central Europe was actually richer than that now
living in the same latitudes ; * so that we may well imagine
that the various means of transport already alluded to (p. 379),
* See ‘Lyell’s Elements of Geology,’ p, 254,
Specks wr
of the 24
Ore Mel-
ye form -
‘ollastan,
4
Cu. XLI.] REFERENCE TO THE ORIGIN OF SPECIES. 417
by which insects are often carried seaward, may have been
the means of introducing into the oceanic islands some of the
progenitors of the present insular fauna.
The inferior facilities enjoyed by insects as compared to
birds of crossing the sea, affords probably the true explana-
tion of the marked difference in the relationship of the two
faunas to that of the mother continent, and also the compara-
tively small number of insects common to different islands of
the same group. In proportion as the interchange of species
is an event of rare occurrence, Variation and Natural Selec-
tion will be efficacious in forming distinct races in separate
islands.
A recent examination of the beetles collected in the Azores
by Mr. Godman, and described by Mr. Crotch,* shows that
that archipelago presents the same phenomena as the Ca-
naries and Madeiras, although the proportion of Atlantic
types is smaller, and the living European forms more pre-
dominant.
Plants.—Dr. Hooker, in his admirable essay on Insular
Floras,t remarks that in Madeira, besides the numerous culti-
vated plants which have been introduced by man, and the
poppies, fumitories, groundsels, and other weeds which he
has brought with him unintentionally, there are other native
varieties of Huropean species, and sometimes representative
genera, which indicate a relationship to the nearest continent.
He also observes that whereas we find on ascending moun-
tains in Great Britain or on the continent of Kurope, from
the height of 2,000 feet and upwards, species proper to more
northern latitudes, and differing from those flourishing at
lower levels, we do not meet with any such boreal forms in
Madeira even at the height of 4,000 feet, and from that to
6,000. The species become fewer as we ascend, but they con-
tinue to be the same as those which flourish at inferior eleva-
tions. Had the theory of continental extension been true,
we might have expected the Atlantic islands to have bor-
rowed their upland flora from higher latitudes during the
Glacial period.
: Azorean Coleoptera, Zool. Proc. t+ Lecture to Brit. Assoc. Notting-
1867 ; pt. ii. p. 359. ham, 1866 ; Gardener’s Chronicle, 1867.
VOL. II. EE
418 INSULAR FLORAS AND FAUNAS WITH [Cu. XLI.
A botanist, wholly ignorant of the plants which lived on
the continent of Europe in Miocene times when the first
volcanos were beginning their eruptions in the Canaries,
Madeiras, and Azores, would be in no small degree perplexed
at the presence in these archipelagos of such Atlantic types
as Clethra and Persea, of which living representatives exist
in no part of the world nearer than the continent of North
America. It would seem to be a violation of the general
law according to which the organic productions of islands
bear most resemblance to those of the nearest continent.
But fortunately the labours of Unger, Heer, and Goppert
on the fossil botany of the tertiary strata have shown us
that Europe, when the Atlantic volcanos first reared their
crests above the waves, was covered with an exceedingly rich
vegetation.
No less than 900 species of these fossil plants have been
detected in the strata of a single locality at Ginimghen m
Switzerland.* The most conspicuous feature, says Heer, in
this ancient flora, is the large number of genera of plants
now peculiar to America; whereas those having Huropean
affinities only hold the second rank, those of Asia the third,
of Africa the fourth, and those of Australia the fifth. Among
the prevailing American forms are Clethra and Persea, above
alluded to, genera common to Madeira, the Canaries, and
Azores. Regarded as relics of a Miocene flora, they are just
such forms as we should naturally expect to have come from
the adjoining Miocene continent. Another plant of a sin-
gularly aberrant form, and which we may well imagine to be
the last survivor of a Miocene type, is the Monizia edulis,
belonging to a genus which has now no representative else-
where in the world. This conspicuous shrub is an umbellife-
rous plant with a stem like an inverted elephant’s trunk,
crowned with a huge tuft of parsley-like foliage. A fine
specimen of it may now (1867) be seen growing in the green-
house of the Botanical Garden at Kew. It is peculiar to one
of the rocky islands of the Dezertas,t where it probably owes
its preservation to the exceptional conditions which it has there
* Fora brief sketch of the Miocene 6th ed. chap. xv.
flora and fauna, see ‘ Lyell’s Elements,’ + See Map, fig. 137, p. 400.
ed thei
0.
Cu. XLI.] REFERENCE TO THE ORIGIN OF SPECIES, 4ig
enjoyed cut off from all communication with other islands, into
which new colonists, both of the animal and vegetable worlds,
have been able more freely to penetrate.
Dr. Hooker reminds us that the extinction of so many
species and of some genera which flourished in the Miocene
period in Europe, is fully accounted for by the great change
of climate which the temperate latitudes of the northern
hemisphere experienced in Pliocene and Glacial times. The
old subtropical species, which had long flourished in Central
Europe and in the regions bordering the Mediterranean,
gave way before a more southern flora, but many plants and
nota few of the insects, which were extirpated on the con-
tinent, may well have survived in oceanic islands which
enjoyed a milder and more equable temperature. To this
source we may probably refer those peculiar ‘ Atlantic types’
above alluded to, which pervade all the archipelagos. We
are informed by Dr. Hooker that the seeds of the West
Indian bean-like climber Entada were floated to the Azores
3,000 miles by the Gulf-stream. These seeds, after such
long immersion in salt water, although they could not stand
the climate of the Azores, germinated in the Garden at Kew;
from which fact we learn how easily seeds of the Miocene
period may have been carried uninjured by currents from the
Mediterranean region to any one of the Atlantic islands,
as none of them are so far from Europe as are the Azores
from the West Indies. But it is probably to birds more
than to marine currents that new islands owe the plants
which clothe them. We have already seen (p. 894) how
many seeds which have been swallowed by birds and ejected
in their dung, germinate freely, and these, if carried by a
land-bird driven to a new voleanic island, would soon cover
the unoccupied ground, until other species brought by a
similar mode of transport came to dispute their monopoly.
It is not easy to conjecture how many different modes of
transport nature may have employed in peopling some At-
lantic islands. Even icebergs may have played their part in
carrying plants to the Azores in the Glacial period, for they
are now sometimes floated to latitudes farther south than
that archipelago, as we have already stated (Vol. I. p. 246),
EE2 ’
420 INSULAR FLORAS AND FAUNAS WITH [Cu. XLI,
Mr. Hartung found fragments of rock in the Azores which he
regarded as erratics or of iceborne origin. When, indeed,
we consider all the changes in climate, and in the direction
of winds and currents, and in the species of birds which have
occurred in the lapse of millions of years since the Miocene
epoch, to say nothing of the incessant transformations under-
gone by the volcanic islands themselves, we must feel that
the colonisation of the several archipelagos has been the
result of such a complexity of causes and conditions, that
the distribution of species is not more anomalous or ca-
pricious in its character than we might reasonably have
anticipated. If we find a plant or animal peculiar to a
single island, we may suppose it to have been first brought
there as a straggler from the adjoining continent, and it may
never have been able to spread to any other island; or it
may have had a wider range until dispossessed of most of its
former stations by new intruders, or by volcanic eruptions ;
or lastly, the parent stock may still flourish in some one of
the islands or archipelagos, but the descendants may have
gone on diverging from the original type, until, in the lapse
of millions of generations, the amount of difference may be
of specific value. When it is said that the Atlantic types,
whether of plants or insects, are common to the Azores,
Madeiras, and Canaries, it is only the genera which are
spoken of, for the species are almost always distinct in each
archipelago.
Mr. Darwin had said in his ‘Origin of Species,’* that we
probably still remain ignorant of many means of transoceanic
migration which will one day be discovered. These antici-
pations have been singularly verified even since the appear-
ance of the last edition of his celebrated work. Hearing that
many new plants had been observed to spring up in Southern
Africa in districts which had been invaded by locusts, he
procured from a correspondent, Mr. Weale, residing in Natal,
a small packet of dry locust dung, weighing less than half
an ounce. Seeds were extracted from the middle of several
pellets, and their true nature ascertained by dissection, and
* Chap. xi. 4th ed. p. 483. 1866.
Cu. XLI.] REFERENCE TO THE ORIGIN OF SPECIES. 421
others were sown, and when they had germinated, no less
than seven individuals belonging to at least two kinds of
erasses were obtained. A locust of the migratory species
blown from the coast of Africa was taken on one occasion by
Mr. Darwin himself when at sea, at a distance of 370 miles
from the nearest land, or somewhat farther than is Madeira
from Africa. The same naturalist observed in 1867 some
mud adhering firmly to the foot of a woodcock, which
weighed when dry nine grains. He extracted from it the
seed of the Juncus Huphonicus, which germinated. This fact
throws much light on the colonisation of new islands by
plants, for of all orders even of wading birds the woodcocks
are perhaps the most migratory, and there is scarcely a remote
island which they do not sometimes reach.
When we compare the flora of any one of the Atlantic archi-
pelagos—that of the Madeiras for example—with that of the
British Islands, the difference in the number of indigenous
species and in the proportion of plants common to the
nearest continent is truly marvellous. In the British area
there is only a single peculiar plant of the phenogamous
class, one of the orchids, Spiranthes gemmipora, out of 1,500
species. In the Madeiras there are hundreds of indigenous
species, although the entire flora is not half so numerous as the
British. On the other hand, all the British plants are species
common to the continent of Europe, except two, the Spiranthes
above mentioned, and a North American water-plant, Hrio-
caulon septangulare.
Landshells—I have reserved to the last my comments
on the landshells, as their geographical distribution in
the Atlantic islands is more singular and instructive than
that of any other class of living beings. In the Ma-
deiran archipelago especially, as was long ago pointed out
by the Rev. R. T. Lowe, every island has its distinct species,
and the whole fauna differs almost entirely from that of
every other archipelago as well as from that of Europe and
Africa. Moreover, it is when we contemplate these air-
breathing mollusks that we find the contrast between the
Atlantic and British islands to have reached its climax;
for in Great Britain no one of the different islands is charac-
422 INSULAR FLORAS AND FAUNAS WITH (Cu. XLI.
terised by peculiar species, and the insular and adjoining con-
tinental faunas are the same.
Mr. Lowe, in the year 1834, described 71 species of land-
shells of the genera Helix, Bulimus, Achatina, &c., from the
Madeiran archipelago, 44 of which were new. He then
stated that but few of these were common to the Canaries,
and, what was still more astonishing, only two were common
to the islands of Madeira and Porto Santo, divided by a
sea only 30 miles wide. Since his memoir was published
his own further investigations, and those of Mr. Wollaston
and others, have augmented the list of species, and taught
us that some few of those before known had a wider range
than was at first supposed; but notwithstanding these
additions to our knowledge, the general conclusions an-
nounced in 1834 hold good, or are even rendered more
striking. The instruction derived from this fauna is greatly
enhanced by the occurrence, both in Madeira and in Porto
Santo, of large assemblages of fossil shells which reveal to
us the state of this part of the animal creation in the Newer
Pliocene period. Some few of the fossil species are extinct,
but most of them are the same as those now inhabiting
Madeira and Porto Santo respectively ; consequently the two
ancient groups of shells are as dissimilar as are the two
recent ones. From this we learn that in the Newer Pliocene
period the two islands must have been disjoined, as they are
now. It is also clear that at that period neither island was
united with the continent of Europe; for scarcely any of the
fossil species are European, and the absence of these confirms
the general opinion of naturalists that almost all the species
now living in this archipelago and common to the continent
have been introduced by man since the beginning of the
fifteenth century. During my short stay in Madeira there
was found in the earth of a single flower-pot in which a
garden plant had been sent from Lisbon no less than three
species of Portuguese Helices, showing us how unconsciously
the horticulturist is busied in alloying the purity of the
native fauna. Most of the European shells have been found
in the gardens of Funchal, from which principal town as
from a centre they radiate for greater or less distances.
Cu, XLI.] REFERENCE TO THE ORIGIN OF SPECIES. 4238
At the time of my visit in 1854 the known living species
of Madeira proper, excluding the modern intruders above
alluded to, amounted to 56, and those of Porto Santo to 42;
only 12 of the whole being common to both islands; and,
what is of no small significance, even some of these 12
being represented in the two islands by distinct varieties.
In truth, the discordance is more like that of two of the
six great zoological provinces of the globe before described,
than of two islands of the same province in sight of each other.
If we then refer to the fossil groups, we find 36 species in
Madeira and 35 in Porto Santo, only 8 being common to
the two islands, and 5 of these 8 being represented by
distinct varieties in each island respectively. It was to be
expected that as Porto Santo is much less cultivated than
Madeira, and has onlya small human population, the fossil and
living species should agree much more with each other than.
do those of Madeira; and the fact that they do so encourages
us to reject as spurious or as modern interlopers those
landshells now living in Madeira which are missing in the
fossil group of that island. These fossils occur at Canigal
near the eastern extremity of Madeira,* in prodigious
numbers, imbedded in a superficial deposit of calcareous
sand and mud. Among the most common is a conspic-
uous species of an unusual form named Helia delphinula
(from its resemblance to the marine genus Delphinula),
which has entirely disappeared from the Atlantic islands.
Another smaller but very characteristic shell, Heliz tia-
rella, must have swarmed in the Newer Pliocene period,
but it has now became so extremely rare that for a long
time it was supposed to be extinct, until a few surviv-
ing individuals were detected by Mr. Wollaston, in 1855,
at a great height on some precipitous and nearly inac-
cessible rocks in the interior of Madeira. Two species of
Achatina and two of Pupa, also fossil at Canigal, are supposed
to have disappeared from the living creation, but as they are
of small dimensions they may possibly have been overlooked,
although, if extant, they must have become very scarce.
* See Map, fig. 137, p. 405.
424 INSULAR FLORAS AND FAUNAS WITH [Cu. XLI.
Tn the shelly sand of Porto Santo a conspicuous shell,
Helia Lowet, is very abundant. It is of so large a size that
it could. hardly have escaped detection if it still existed on
either of the principal islands, but lately a few individuals
of this species have been detected on the rock called Itheo
di Cima off Porto Santo.* By some conchologists Helix
Lowet is regarded as a gigantic variety of the living H.
Porto sanctana, which also occurs fossil in the same sands.
If this opinion be correct, it offers by no means the only
example in the fauna of this archipelago of the same distinct
races being found both fossil and recent, and in both cases
without any intermediate varieties. One of the two forms
may possibly represent the parent stock, and the other the
extreme of divergence. There must once have existed,
according to the theory of Natural Selection, all the transi-
tional forms between the two extremes. But these forms
may have died out for want of favourable conditions, or may
have been absorbed into one or other of the extremes, which
last may be able to maintain their ground on the principle
before alluded to (p. 323), according to which more plants or
animals find support in a limited area if they are of many
different genera then if they all belong to one genus. There
are however in the Madeiran archipelago some polymorphous
species, such as Helix polymorpha, in which the transitional
links between the extremes are not missing, and they remind
us of the varieties of the English brambles and roses ; but
such cases are the exception to the rule, for reasons to be
explained in the next chapter.
I have alluded to Helix tiarella in Madeira; an allied re-
presentative of the same peculiar form, H. coronata, abounds
in a fossil state in Porto Santo, and is also still living in
that island, though it israre. Another, or third closely allied
species, H. coronula, was first found fossil in Bugio, one of
the Dezertas, and it probably still exists on some part of those
inaccessible rocks, for a few living individuals have lately been
found on the nearest adjoining coast of Madeira. They
may supply an example of the smaller island having yielded
one of its indigenous species to Madeira; for the absence
* See Map, fig. 137, p. 400.
Cu. XLI.] REFERENCE TO THE ORIGIN OF SPECIES. 425
of this shell among the fossils of Canical seems to imply
that it has only recently gained access to Madeira proper.
These three distinct though kindred forms of a’ peculiar
division of the Helicide belonging to Madeira, Porto Santo,
and the Dezertas remind us of the representative species
of some genera found in Asia, Hurope, and America.
Having alluded to the Dezertas, I may add that 19 species
of landshells have been found on them, 12 of which, or about
two-thirds of the whole, are common to Madeira, and only
5 to Porto Santo. The nearer affinity of the fauna to
Madeira was to be expected, not only because of its greater
proximity, but because, as will be seen by our map, Madeira
and the Dezertas stand within the same 100 fathom line,
and the channel between them may once have been narrower,
although there is no reason for believing that the land was
ever continuous, or even that Chao, Dezerta Grande, and
Bugio were ever united; for each of these rocks has some
species of shells as well as some varieties peculiar to itself.
It is worth remarking, as showing the limited range of
species when the whole archipelago is considered, that there
are only two species of landshells common to all the three
faunas of Madeira, the Dezertas, and Porto Santo.
The antiquity of the fossils of Madeira and Porto Santo
is unmistakable, although they are more modern than the
newest lava streams; for to say nothing of the time required
to annihilate several species and greatly to alter the relative
numbers of others, there are proofs of local geographical
changes of subsequent date. Since the accumulation of
the voleanic sand and mud, in which the landshells are
enveloped, there has been much undermining of the sea-cliffs,
both in the narrow promontory in which Canical is situated
and on the northern coast of Porto Santo. Some of the
shelly formation of the last-mentioned island consists of
sand-dunes which have been cut off abruptly in the vertical
cliffs, and must once have extended farther in a seaward
direction. The whole island, indeed, of Porto Santo has
suffered great denudation, and some rocks indicated by the
letters a b in our map (fig. 137), one of them called the Falcon,
now covered by only 26 feet of water, and the other the
426 INSULAR FLORAS AND FAUNAS WITH (Cu. XLI.
Styx by 72 feet, may perhaps mark the site of isolated
volcanic cones which once rose above the sea-level. But that
the whole space within the 100 fathom line* was ever con-
tinuous land, I can by no means conceive. Such an ex-
tension would give to Porto Santo five times its present
dimensions. The proportion of extinct species as compared
to the living ones in Madeira and Porto Santo is about 8
per cent., which may perhaps be slightly diminished by the
future discovery of some of the smaller species ; but the real
discordance between the ancient and modern fauna will never
disappear, for it is even greater than is expressed by the
numerical statements above given, some species formerly
most dominant being now very feebly represented, and some
fossil races as well as species having become extinct.
The landshells of the Canaries, when we exclude those
which have probably been introduced by man, are very
distinct from those of Madeira. The different islands in the
Canaries have more species in common than the Madeiras,
but this fusion may be partly owing to the remote and un-
known period at which the aboriginal inhabitants, the
Guanchos, settled there.
Contrast of the testaceous fauna of the British isles and that
of the Atlantic islands.—I shall now revert to the extraordinary
contrast between the distribution of landshells in the At-
lantic and British islands. If a curved line be drawn from
the Azores through Madeira to the Canaries, its length would
be about 750 miles, or about equal to a line drawn from the
Shetland islands through Scotland and England to the Scilly
islands. The British archipelago contains more than 200
islands, when we include the Shetlands, Orkneys, Hebrides, and
others. In all of these the landshells are the same, whereas
in the Atlantic archipelagos it 1s not only the principal or
habitable islands, but almost every uninhabited rock off the
coast, which supplies the conchologist with peculiar species
or varieties. Inthe British area, it would seem at first sight,
as if the land-snails had never had any difficulty in crossing
the sea, whereas in the Atlantic archipelagos the narrowest
* See Map, fig. 137, p. 406.
Cu. XLL] REFERENCE TO THE ORIGIN OF SPECIES. 427
marine channels have formed in most.cases impassable barriers.
The Scilly islands are as far from Cornwall as is Madeira
from Porto Santo, yet in them the conchologist obtains no
distinct species, nor even any marked races, whereas, on
crossing from Madeira to Porto Santo, he finds four-fifths
of the species different, besides some peculiar races, even of
those shells which are common to the two sides of the
channel. It may, no doubt, be said that the southern parts of
England display a richer fauna, and contain certain species
(about eight), which do not range farther northwards than
Yorkshire. These are; Heliz pomatia, H. cartusiana, H.
revelata, H. Pisana, H. obvoluta, Bulimus montanus, Clausilia
Rodolphi, and OC. biplicata. It is more difficult to name
species which are peculiar to the north, Vertigo alpestris
affording perhaps a solitary example.*
In what manner, then, can we explain or refer to one and
the same law of distribution the apparently incongruous
phenomena exhibited in the two regions above compared ?
Some zoologists who have been struck with the unusual
number of endemic species and marked varieties observed
in oceanic islands, have suggested that the terrestrial mol-
lusca must be more variable than other classes of the
animal kingdom. But this idea is wholly inadmissible, for
we need go no farther than the fossil faunas of Madeira and
Porto Santo, above alluded to, to prove the remarkable con-
stancy and persistency of form of the genera Heli, Pupa, Acha-
tina, and Clausilia, from the Newer Pliocene era to our own
times. To solve the enigma we must appeal to the immense
difference in the lapse of time, during which the islands of
the British and those of the Atlantic archipelagos have
remained separate from each other and from the nearest con-
tinents. In the one case we have to deal with thousands, in
the other with millions, of years.t In the one case there
has been everywhere a land communication between every
part of the archipelago since the commencement of the
Glacial period, when the species of marine and terrestrial
testacea were everywhere the same as they are now; in the
r. J. Gwyn Jeffreys, British + See above, Vol. I. p. 300.
eililicy, 1866-67.
428 INSULAR FLORAS AND FAUNAS WITH [Cu. XLI.
other there has been no land communication since the
Miocene epoch, when the whole fauna and flora of the globe
bore but a distant resemblance to that now established. Our
map (p. 407) will satisfy the reader, that if the bed of the
Atlantic were everywhere uplifted 100 fathoms, all the
principal archipelagos and islands would remain as dis-
connected as they are now, whereas we know that a similar
upward movement would unite every one of the 200 British
islands with each other and with the continent. Indeed,
nearly all of them would be joined to the mainland and to
each other with a change of level of less than 400 feet.* That
there have been great movements of oscillation in the British
area since the Glacial period is proved by independent geo-
logical evidence, whereas there are no signs, as before stated,
of any general movements of like magnitude in the Atlantic
area, but only here and there some evidence of partial
upheaval. .
I have already remarked that had Porto Santo been united
with Madeira proper in the Newer Pliocene period, the two
fossil faunas would have been fused together, instead of
being as different as are the living native shells of the two
islands. In Great Britain, also, we have a fossil fauna of
terrestrial shells associated with the bones of the Mammoth
and other extinct mammalia in ancient drift; and this enables
us to carry back the comparison of the Atlantic and British
archipelagos one step farther. We recognise in the British
fossils the same uniformity, or wide range of species, as
in the actual or recent fauna. No less than 48 species
of fossil landshells were collected by the late Mr. John
Brown from the Post-Pliocene drift of Copford in Essex, and
with the exception of two Helices, (which still survive on the
continent,) all are of living British species. But if England
had been submerged a few hundred feet, and divided into
islands, even since the Pliocene period, we might have ex-
pected the shells associated with extinct quadrupeds in
different counties to display some marked want of agreement
in species and varieties. There is however no such contrast.
* See Map, fig. 41, ‘ Antiquity of Man,’ by the author, p. 279.
Cx. XLI.] REFERENCE TO THE ORIGIN OF SPECIES. 429
If, for example, we compare the landshells of the Wilt-
shire drift, near Salisbury, of the age of the Mammoth, with
those of Essex before mentioned, places twice as far apart
as are Madeira and Porto Santo, they exhibit no difference
whatever in the species of fossil landshells. From this fact
we may infer that although the British area has been partially
submerged since the commencement of the Glacial period,
yet its normal state has been a continental one.
Mode in which an oceanic island might become peopled with
landshells—The reader may well ask, if Madeira and Porto
Santo have made so little progress in interchanging their
respective species of landshells in the course of that vast
lapse of ages which has occurred since the Newer Pliocene
period, how could any of the Atlantic archipelagos ever have
become peopled by migration from Europe or Africa? The
enigma is certainly perplexing, and we must assume that the
arrival of landshells, as waifs and strays from a continent, is
an exceedingly rare event. It has been suggested that birds
may transport across the sea the eggs of these mollusks in
mud attached to their feet. But if so, why have the birds
which fly freely across the channel, only 30 miles wide, be-
tween Madeira and Porto Santo, allowed the fauna of these
two islands to remain so distinct? or why have those birds
which arrive every year from the continent in the Atlantic
islands introduced so few landshells? Hitherto the naturalist
has not witnessed the arrival of a new continental Helix on
any remote oceanic island, except by the aid of man; and to
those who are unwilling to abandon in despair all hope of
solving the problem, it is satisfactory that such should be
the case. How inexplicable would be the dearth of land
quadrupeds in the Atlantic islands if some members of
this class were seen occasionally to swim across the ocean
from Europe to the Azores !
If hereafter we should discover the mode in which air-
breathing mollusks can sometimes traverse a wide expanse
of ocean, we may be sure that the occasions of transport will
be few and far between, so that a continental species when
it colonises a new island has time to vary and to give rise
to one or two new races, before other representatives of the
430 INSULAR FLORAS AND FAUNAS WITH [Cu. XLI.
original continental type follow in the same direction, so as
to cross with the first settlers and check divergence.
If floating timber, or land-birds, or insects, or any other
causes organic or inorganic, serve as the means of transport,
their agency must be so casual and irregular as to cause the
results to appear capricious in the extreme.
The first Miocene Helix which reached Madeira may have
been of a different species from the first which reached Porto
Santo. It has been imagined that Helix infleza Martens, an
extinct Miocene form of Europe, may have been the parent
stock of H. port tana, of which the gigantic H. Lowe
may be a variety, but the last-mentioned form seems never to
have reached Madeira. The extinct H. Raymondi, so common
in the French Faluns or Upper Miocene strata, is supposed
to have been the ancestral type of another common shell,
H. Bowditchiana Pfeiffer, found both fossil and recent in
Madeira and Porto Santo.
Let us assume that certain Miocene species, nearly all
of them long since extinct, were carried as waifs and strays
to separate islands by a concurrence of circumstances so
rare as to happen once only in several hundred thousand
years, other combinations of circumstances almost equally
rare might be required to convey a species from one island
to another. A volcanic eruption, for example, which might
only occur once in the whole course of the building up of
an archipelago, at exactly the same season of the year, or
at the same height above the sea, with equal violence and
when the wind or marine currents were in the same direction.
Such a convulsion might cause the dispersion of some
Helices from one part of an archipelago to another in a
manner altogether without parallel during the antecedent
or subsequent history of the same region. If the reader will
refer to our description of the birth of Monte Nuovo, Vol. I.
p- 608, near Naples, in 1538, he will see that while many
land-birds were killed, those which escaped and flew terrified
from the scene of the catastrophe, must, like the human
inhabitants, have been covered with mud which was showered
In the beginning of such
down so as to envelope all things.
an eruption trees, shrubs, and vegetable soil, in which the
Cu. XLI.] REFERENCE TO THE ORIGIN OF SPECIES. 431
eggs of landshells must sometimes be included, were hurled
up into the air by the aqueous vapour. The eggs of a pupa
are sometimes so minute and their terminal velocity in air so
slight that they might be carried many miles by the wind
before alighting on the ground—as far perhaps as from Ma-
deira to the Dezertas. There is no reason for supposing
that the tendency of species to form new varieties is greater
in an oceanic island than on a continent. But if islands be
separated from each other throughout so long a period as
would be sufficient on the continent to change most of the
species, then it is evident that there will be a greater manu-
facture of new species in the islands: Let us suppose a band
of emigrants to have gone from some Huropean country a
thousand years ago and to have formed colonies in the Azores,
Canaries, and Madeiras, and that all communication between
them and the mother country and between the different
archipelagos was cut off for a thousand years, there would then
be in all probability four languages spoken between the
mother country and her three colonies all different from the
original tongue of the ninth century. The population of
the three archipelagos, like the area of land formed by the
whole of them, might be very insignificant compared with
that of the country from which the first emigrants pro-
ceeded, yet the smaller number of islanders, in consequence of
their isolation, would have given rise to three new languages,
and the inhabitants of the continent to one only. Not that
the invention of new terms and idioms or the disuse of old
ones would have gone on at a greater rate in the islands,
but because each archipelago being separated from every other
one and from the rest of the world, had formed an independent
linguistic centre. In like manner the distinctness of the
landshells in the Canaries, Madeiras, and Azores, and in
many of the separate islands of each, are the results of the
prolonged isolation of small fragments of land in mid-ocean,
not of a greater tendency in the testacea inhabiting such
islands to vary.
In conclusion I may observe, that the extent to which the
species of mammalia, birds, insects, landshells, and plants,
(whether flowering or cryptogamous,) agree with continental
INSULAR FLORAS AND FAUNAS CONSIDERED. [Cu. XLI.
species, or the degree in which those of different archipe-
lagos or of different islands of the same group agree with
each other, has an unmistakable relation to the known faci-
lities enjoyed by each class of crossing the ocean. Such a
relationship accords well with the theory of Variation and
Natural Selection, but with no other hypothesis yet suggested
for explaining the origin of species.
433
CHAPTER XLII.
EXTINCTION OF SPECIES.
CONDITIONS WHICH ENABLE EACH SPECIES OF PLANT TO MAINTAIN ITS
v M IN THE NUMBER OF SPECIES HOW
PRESERVED—AGENCY OF INSECTS IN PRESERVING THIS EQUILIBRIUM—DEVAS-
TATIONS CAUSED BY LOCUSTS—EFFECT OF OMNIVOROUS ANIMALS IN PRESERV-
ING THE EQUILIBRIUM OF SPECIES—RECIPROCAL INFLUENCE OF AQUATIC AND
TERRESTRIAL SPECIES—HOW CHANGES IN PHYSICAL GEOGRAPHY AFFECT THE
DISTRIBUTION OF SPECIES—EXTENSION OF THE RANGE OF ONE SPECIES
THE POLAR BEAR INTO ICELAND—INCREASE OF REIN-DEER IMPORTED INTO
ICELAND—INFLUENCE 9 IN DERANGING THE NUMERICAL STRENGTH
OF I INDIGENOUS QUADRUPEDS AND BIRDS EXTIRPATED IN GREAT
oO Ab ME
QUADRUPEDS OVER THE AMERICAN CONTINENT—POWER OF EXTERMINATING
SPECIES NO PREROGATIVE OF MAN—CONCLUDING REMARKS ON EXTINCTION.
CONDITIONS WHICH ENABLE EACH SPECIES OF PLANT TO
MAINTAIN ITS GROUND AGAINST OTHERS.—I propose in this
chapter to treat of the various causes to which the continual
extinction of species, both in the animal and vegetable
creation, are due.
Every naturalist is familiar with the fact, that although in
a particular country, such as Great Britain, there may be
more than 3,000 species of plants, 12,000 insects, and a
great variety in each of the other classes; yet there will
not be more than 100, perhaps not half that number, in-
habiting any given locality. There may be no want of
space in the supposed limited area: it may be a large
mountain, or an extensive moor, or a great river-plain,
containing room enough for individuals of every species in
our island; yet the spot will be occupied by a few to the
exclusion of many, and these few are enabled, throughout
long periods, to maintain their ground successfully against
every intruder, notwithstanding the facilities which species
VOL. II. FR
484 EXTINCTION OF SPECIES. [Cu. XLII.
enjoy, by virtue of those powers of diffusion already men-
tioned (Chapters XXXVIII., XXXTX., XL.), of invading
adjacent territories.
The principal causes which enable a certain assemblage of
plants thus to maintain their ground against all others de-
pend, as is well known, on the relations between the physio-
logical nature of each species, and the climate, exposure,
soil, and other physical conditions of the locality, and the
power of each to compete with other organic beings in the
struggle for life. Some plants live only on rocks, others in
meadows, a third class in marshes. Of the latter, some
delight in a fresh-water morass,—others in salt marshes,
where their roots may copiously absorb saline ‘particles.
Some prefer an alpine region in a warm latitude, where,
during the heat of summer, they are constantly irrigated by
the cool waters of melting snows. ‘To others loose sand,
so fatal to the generality of species, affords the most proper
station. The Carex arenaria and the Elymus arenarius
acquire their full vigour on a sandy dune, obtaining an ascen-
dancy over the very plants which in a stiff clay would imme-
diately stifle them.
Where the soil of a district is of so peculiar a nature that
it is extremely favourable to certain species, and agrees ill
with every other, the former get exclusive possession of the
ground, and as in the case of heaths, live in societies. In
like manner the bog moss (Sphagnwm) is fully developed in
peaty swamps, and becomes, like the heath, in the language
of botanists, a social plant. Such monopolies, however, are
not common, for they are checked by various causes. Not
only are many species endowed with equal powers to obtain
and keep possession of similar stations,.but each plant, for
reasons not fully explained by the physiologist, has the
property of rendering the soil where it has grown less fitted
for the support of other individuals of its own species, or
even other species of the same family. Yet the same spot,
so far from being impoverished, is improved, for plants of
another family. Oaks, for example, render the soil more fertile
for the fir tribe, and firs prepare the soil for oaks. very
agriculturist feels the force of this law of the organic world,
and regulates accordingly the rotation of his crops.
Cu. XLII.] EQUILIBRIUM IN THE NUMBER OF SPECIES. 435
Equilibrium in the number of species, how preserved.— All
the plants of a given country,’ says De Candolle, in his
usual spirited style, ‘are at war with one another. The first
which establish themselves by chance in a particular spot
tend, by the mere occupancy of space, to exclude other
species—the greater choke the smaller; the longest livers
replace those which last for a shorter period; the more
prolific gradually make themselves masters of the ground,
which species multiplying more slowly would otherwise fill.’
In this continual strife, he observes, it is not always the
resources of the plant itself which enable it to maintain or
extend its ground. Its success depends, in a great measure,
on the number of its foes or allies, among the animals and
plants inhabiting the same region. Thus, for example, a
herb which loves the shade may multiply, if some tree with
spreading boughs and dense foliage flourish in the neigh-
bourhood. Another, which, if unassisted, would be over-
powered by the rank growth of some hardy competitor, is
secure because its leaves are unpalatable to cattle ; which, on
the other hand, annually crop down its antagonist, and rarely
suffer it to ripen its seed. .
Oftentimes we see some herb which has flowered in the
midst of a thorny shrub, when all the other individuals of the
same species, in the open fields around, are eaten down, and
cannot bring their seed to maturity. In this case, the shrub
has lent his armour of spines and prickles to protect the
defenceless herb against the mouths of the cattle ; and thus
a few individuals which occupied, perhaps, the most unfavour-
able station in regard to exposure, soil, and other circum-
stances, may, nevertheless, by the aid of an ally, become the
principal source whereby the winds are supplied with seeds
which perpetuate the species throughout the surrounding
tract.* Thus, in the New Forest in Hampshire, the young
oaks which are not consumed by the deer, or uprooted by
the swine, are often indebted to the holly for their escape.
In the above examples we see one plant shielding another
from the attacks of animals ; but instances are, perhaps, still
* Amen, Acad, vol. vi. p. 17, § 12.
FF 2
436 EXTINCTION OF SPECIES. (Cu. XLII,
more numerous, where some animal defends a plant against
the enmity of some other subject of the vegetable kingdom.
Scarcely any beast, observes Linneeus, will touch the nettle,
but fifty different kinds of insects are fed by it.* Some of
these seize upon the root, others upon the stem ; some eat
the leaves; others devour the seeds and flowers: but for this
multitude of enemies, the nettle (Urtica dioica) would anni-
hilate a great number of plants. The same naturalist tells
us, in his ‘Tour in Scania,’ that goats were turned into an
island which abounded with the Agrostis arundinacea, where
they perished by famine; but horses which followed them
grew fat on the same plant. The goat, also, he says, thrives
on the meadow-sweet and water-hemlock, plants which are
injurious to cattle.t
Agency of msects.—EHvery plant, observes Wilcke, has its
proper insect allotted to it to curb its luxuriancy, and to
prevent it from multiplying to the exclusion of others.
‘Thus grass in meadows sometimes flourishes so as to exclude
all other plants: here the Phalena graminis (Bombyx gram.),
with her numerous progeny, finds a well-spread table; they
multiply in immense numbers, and the farmer, for some
years, laments the failure of his crop; but, the grass being
consumed, the moths die with hunger, or remove to another
place. Now the quantity of grass being greatly diminished,
the other plants, which were before choked by it, spring up,
and the ground becomes variegated with a multitude of diffe-
rent species of flowers. Had not Nature given a commission
to this minister for that purpose the grass would destroy a
great number of species of vegetables, of which the equili-
brium is now kept up.’t
In the above passage allusion is made to the ravages com-
mitted in 1740, and the two following years, in many provinces
of Sweden, by a most destructive insect. ‘The same moth is
said never to touch the foxtail grass, so that it maybe classed
as a most active ally and benefactor of that species, and as
peculiarly instrumental in preserving it in its present abun-
dance.§ A discovery of Rolander, cited in the treatise of
* Ameen. Acad., vi. p. 17, § 12. { Ibid. vol. vi. p. 17, § 11, 12.
+ Ibid. vol. vii. p. 409. § Kirby and Spence, vol. i. p. 178.
Cu. XLIT.] AGENCY OF INSECTS. 437
Wilcke above mentioned, affords a good illustration of the
checks and counter-checks which Nature has appointed to
preserve the balance of power among species. ‘The Phalena
strobilella has the fir-cone assigned to it to deposit its eggs
upon; the young caterpillars coming out of the shell consume
the cone and superfluous seed; but, lest \the destruction
should be too general, the Ichnewmon strobilelle lays its eggs in
the caterpillar, inserting its long tail in the openings of the
cone till it touches the included insect, for its body is too large
to enter. Thus it fixes its minute egg upon the caterpillar,
which being hatched, destroys it.’ * F
Entomologists enumerate many parallel cases where insects,
appropriated to certain plants, are kept down by other insects,
and these again by parasites expressly appointed to prey on
them.t Few, perhaps, are in the habit of duly appreciating
the extent to which insects are active in preserving the
balance of species among plants, and thus regulating in-
directly the relative numbers of many of the higher orders
of terrestrial animals. The peculiarity of their agency con-
sists in their power of suddenly multiplying their numbers to
a degree which could only be accomplished in a considerable
lapse of time in any of the larger animals, and then as
instantaneously relapsing, without the intervention of any
violent disturbing cause, into their former insignificance.
If, for the sake of employing, on different but rare occasions,
a power of many hundred horses, we were under the necessity
of feeding all these animals at great cost in the intervals
when their services were not required, we should greatly
admire the invention of a machine, such as the steam-engine,
which was capable at any moment of exerting the same
degree of strength without any consumption of food during
periods of inaction. Thesame kind of admiration is strongly
excited when we contemplate the powers of insect life, in the
creation of which the Author of Nature has been so prodigal.
A scanty number of minute individuals, to be detected only
by careful research, are ready in a few days, weeks, or
months, to give birth to myriads, which may repress any
* Amon, Acad. vol. vi. p. 26, § 14, + Kirby and Spence, vol. iv. p, 218.
438 EXTINCTION OF SPECIES, [Cu. XLII.
degree of monopoly in another Species, or remove nuisances,
such as dead carcasses, which might taint the air. But no
sooner has the destroying commission been executed than
the gigantic power becomes dormant—each of the mighty
host soon reaches the term of its transient existence, and
the season arrives when the whole species passes naturally
into the egg, and thence into the larva and pupa state. In
this defenceless condition it may be destroyed either by the
elements, or by the augmentation of some of its numerous
foes which may prey upon it in the early stages of its trans-
formation ; or it often happens that in the following year
the season proves unfavourable to the hatching of the ego's
or the development of the pupz.
Thus the swarming myriads depart which may have covered
the vegetation like the aphides, or darkened the air like
locusts. In almost every season there are some Species which
in this manner put forth their strength, and then, like Mil-
ton’s spirits, which thronged the spacious hall, ‘reduce to
smallest forms their shapes immense ’—
——-—— So thick the aéry crowd
Swarm’d and were straiten’d; till, the signal given
Behold a wonder! they but now who seemed
In bigness to surpass earth’s giant sons,
Now less than smallest dwarfs.
’
A few examples will illustrate the mode in which this
force operates. It is well known that, among the countless
species of the insect creation, some feed on animal, others on
vegetable matter; and, upon considering a catalogue of
8,000 British Insects and Arachnide, Mr. Kirby found
that these two divisions were nearly a counterpoise to each
other, the carnivorous being somewhat preponderant. There
are also distinct species, some appointed to consume living,
other dead or putrid animal and vegetable substances. One
female, of Musca carnaria, will give birth to 20,000 young;
and the larvee of many flesh-flies devour so much food
in twenty-four hours, and grow so quickly, as to increase their
weight two hundred-fold! In five days after being hatched
they arrive at their full growth and size, so that there was
ground, says Kirby, for the assertion of Linneus, that three
Cu. XL] AGENCY OF INSECTS. 439
flies of M. vomitoria could devour a dead horse as quickly as
a lion;* and another Swedish naturalist remarks, that so
ereat are the powers of propagation of a single species even
of the smallest insects, that each can commit, when required,
more ravages than the elephant.t
Next to locusts, the aphides, perhaps, exert the greatest
power over the vegetable world, and, like them, are sometimes
so numerous as to darken the air. The multiplication of these
little creatures is without parallel, and almost every plant has
its peculiar species. Reaumur has proved that in five gene-
rations one aphis may be the progenitor of 5,904,900,000
descendants ; and it is supposed that in one year there may
be twenty generations.t{ Mr. Curtis observes that, as among
caterpillars we find some that are constantly and unalterably
attached to one or more particular species of plants, and
others that feed indiscriminately on most sorts of herbage, so
it is precisely with the aphides: some. are particular, others
more general feeders; and as they resemble other insects in
this respect, so they do also in being more abundant in some
years than in others.§ In 1793 they were the chief, and in
1798 the sole, cause of the failure of the hops. In 1794, a
season almost unparalleled for drought, the hop was perfectly
free from them; while peas and beans, especially the former,
suffered very much from their depredations.
The ravages of the caterpillars of some of our smaller moths
afford a good illustration of the temporary increase of a
species. The oak trees of a considerable wood have been
stripped of their leaves as bare as in winter, by the caterpillars
of a small green moth (Tortria viridana), which has been ob-
served the year following not to abound. ‘The silver Y moth
(Plusia gamma), although one of our common species, is not
dreaded by us for its devastations; but legions of their cater-
pillars have at times created alarm in France, as in 1735.
Reaumur observes that the female moth lays about 400 eggs ;
so that if twenty caterpillars were distributed in a garden, and
all lived through the winter and became moths in the
succeeding May, the eggs laid by these, if half of them were
* Kirby and Spence, vol. i. BS 250. { Kirby and ee ee i. p. 174.
t+ Wilcke, Amen. Acad. ¢ § Trans. Linn. Soc
440 EXTINCTION OF SPECIES. [Cu. XLII.
female and all fertile, would in the next generation produce
800,000 caterpillars.* A modern writer, therefore, justly
observes that, did not Providence put causes in operation to
keep them in due bounds, the caterpillars of this moth alone,
leaving out of consideration the 2,000 other British species,
might soon destroy more than half of our vegetation.
In the latter part of the last century an ant most destruc-
tive to the sugar-cane (Formica saccharivora), appeared in
such infinite hosts in the island of Granada, as to put a stop
to the cultivation of that vegetable. Their numbers were
incredible. The plantations and roads were filled with them ;
many domestic quadrupeds, together with rats, mice, and
reptiles, and even birds, perished in consequence of this plague.
It was not till 1780 that they were at length annihilated by
torrents of rain, which accompanied a dreadful hurricane.+
Devastations caused by locusts—We may conclude by
mentioning some instances of the devastations of locusts in
various countries. Among other parts of Africa, Cyrenaica
has been at different periods infested by myriads of these
creatures which have consumed nearly every green thing.
The effect of the havoc committed by them may be estimated
by the famine they occasioned. St. Augustine mentions a
plague of this kind in Africa which destroyed no less than
800,000 men in the kingdom of Massinissa alone, and many
more upon the territories bordering upon the sea. It is also
related, that in the year 591, an infinite army of locusts mi-
grated from Africa into Italy ; and, after grievously ravaging
the country, were cast into the sea, when there arose a pesti-
lence from their stench which carried off nearly a million of
men and beasts.
In the Venetian territory, also, in 1478, more than 30,000
persons are said to have perished in a famine occa-
sioned by this scourge; and other instances are recorded of
their devastations in France, Spain, Italy, Germany, &e. In
different parts of Russia also, Hungary, and Poland, in Arabia
and India, and other countries, their visitations have been
periodically experienced. Although they have a preference for
* Reaumur, vol. ii. p. 337. :
t Kirby and Spence, vol. i. p. 183. Castle, Phil. Trans., xxx. 346.
Cu. XLII] DEVASTATIONS CAUSED BY LOCUSTS. 441
certain plants, yet, when these are consumed, they will attack
almost all the remainder. In the accounts of the invasions
of locusts, the statements which appear most marvellous relate
to the prodigious mass of matter which incumbers the sea
wherever they are blown into it, and the pestilence arising
from its putrefaction. Their dead bodies are said to have
been, in some places, heaped one upon another, to the depth
of four feet, in Russia, Poland, and Lithuania; and when, in
Southern Africa, they were driven into the sea, by a north-
west wind, they formed, says Barrow, along the shore, for
fifty miles, a bank three or four feet high.* But when we
consider that forests are stripped of their foliage, and the
earth of its green garment, for thousands of square miles, it
may well be supposed that the volume of animal matter pro-
duced may equal that of great herds of quadrupeds and flights
of large birds suddenly precipitated into the sea.
The occurrence of such events at certain intervals, in hot
countries, like the severe winters and damp summers return-
ing after a series of years in the temperate zone, may affect
the proportional numbers of almost all classes of animals and
plants, and probably prove fatal to the existence of many
which would otherwise thrive there ; while, on the contrary,
the same occurrences can scarcely fail to be favourable to
certain species which, if deprived of such aid, might not main-
tain their ground.
Although it may usually be remarked that the extraordinary
increase of some one species is immediately followed and
checked by the multiplication of another, yet this does not
always happen; partly because many species feed in common
on the same kinds of food, and partly because many kinds of
food are often consumed indifferently by one and the same
species. In the former case, where a variety of different
animals have precisely the same taste, as, for example, when
many insectivorous birds and reptiles devour alike some
’ particular fly or beetle, the unusual numbers of these insects
may cause only a slight and almost imperceptible augmen-
tation of each of these species of bird and reptile. In the
other instance, where one animal preys on others of almost
* Travels in Africa, p. 257. Kirby and Spence, vol. i. p. 215.
442 EXTINCTION OF SPECIES. [Cu. XLII,
every class, as, for example, where some of our English hawks
or buzzards (Buteo) devour not only small quadrupeds, as rab-
bits and field-mice, but also birds, frogs, lizards, and insects,
the profusion of any one of these last may cause all such
general feeders to subsist more exclusively upon the species
thus in excess, by which means the balance may be restored.
Agency of ommworous animalsx—The number of species
which are nearly omnivorous is considerable; and although
every animal has, perhaps, a predilection for some one de-
scription of food rather than another, yet some are not even
confined to one of the great kingdoms of the organic world.
Thus, when the racoon of the West Indies can procure
neither fowls, fish, snails, nor insects, it will attack the sugar-
canes, and devour various kinds of grain. The civets, when
animal food is scarce, maintain themselves on fruits and roots.
Numerous birds, which feed indiscriminately on insects and
plants, are perhaps more instrumental than any other of the
terrestrial tribes in preserving a constant equilibrium between
the relative numbers of different classes of animals and vege-
tables. If the insects become very numerous and devour the
plants, these birds will immediately derive a larger portion of
their subsistence from insects, just as the Arabians, Syrians,
and Hottentots feed on locusts, when the locusts devour their
crops.
Reciprocal influence of aquatic and terrestrial species—The
intimate relation of the inhabitants of the water to those of
the land, and the influence exerted by each on the relative
number of species, must not be overlooked amongst the com-
plicated causes which determine the existence of animals and
plants in certain regions. A large portion of the amphibious
quadrupeds and reptiles prey partly on aquatic plants and
animals, and in part on terrestrial ; and a deficiency of one kind
of prey causes them to have immediate recourse to the other.
The voracity of certain insects, as the dragon-fly, for example,
is confined to the water during one stage of their transfor- *
mations, and in their perfect state to the air. Innumerable
water-birds, both of rivers and seas, derive in-like manner
their food indifferently from either element ; so that the abun-
dance or scarcity of prey in one induces them either to forsake
Cu. XLII] MEANS OF EXTINCTION VERY VARIOUS. 443
or more constantly to haunt the other. Thus an intimate
connection between the state of the animate creation in a lake
or river, and in the adjoining dry land, is maintained; or
between a continent, with its lakes and rivers, and the ocean.
Tt is well known that many birds migrate, during stormy
seasons, from the sea-shore into the interior, in search of food ;
while others, on the contrary, urged by like wants, forsake
their inland haunts, and live on substances rejected by the tide.
The migration of fish into rivers during the spawning sea-
son supplies another link of the same kind. Suppose the
salmon to be reduced in numbers by some marine foes, as by
seals and grampuses, the consequence must often be, that in
the course of a few years the otters at the distance of several
hundred miles inland, will be lessened in number from the
scarcity of fish. On the other hand, if there be a dearth of
food for the young fry of the salmon in rivers and estuaries,
so that few return to the sea, the sand-eels and other marine
species, which are usually kept down by the salmon, will
swarm in greater profusion.
It is unnecessary to accumulate more illustrations in order
to prove that the stations of different plants and animals
depend on a great complication of circumstances,—on an
immense variety of relations in the state of the animate and
inanimate worlds. Every plant requires a certain climate,
soil, and other conditions, and often the aid of many animals,
in order to maintain its ground. Many animals feed on
certain plants, being often restricted to a small number, and
sometimes to one only ; other members of the animal kingdom
feed on plant-eating species, and thus become dependent on
the conditions of the stations not only of their prey, but of
the plants consumed by them.
How changes in physical geography affect the distribution of
species.— Thus by means of numerous checks and counter-
checks the state of the animal and vegetable kingdoms con-
tinues from century to century, and even perhaps for tens of
thousands of years, the same, except where man interferes ;
but independently of human intervention, neither the zoolo-
gical nor botanical provinces can remain for indefinite periods
unaltered.
444 EXTINCTION OF SPECIES. [Ca, XLII.
Nature is continually engaged in the task of sowing seeds
and colonising animals; were this not the case the depopu-
lation of a certain portion of the habitable sea and land
would, even in a few years, be considerable, so great is the
instability of the earth’s surface. Whenever a river trans-
ports sediment into a lake or sea, so as materially to diminish
its depth, the aquatic animals and plants which delight in
deep water are expelled: the tract, however, is not allowed
to remain useless; but is soon peopled by species which
require more light and heat, and thrive where the water is
shallow. Every addition made to the land by the encroach-
ment of the delta of a river banishes many aquatic species
from their native abodes; but the new-formed plain is not
permitted to lie unoccupied, being instantly covered with
terrestrial vegetation. The ocean devours continuous lines
of sea-coasts, and precipitates forests or rich pasture land
into the waves; but this space is not lost to the animate
creation ; for shells and sea-weeds soon adhere to the new-
made cliffs, and numerous fish people the channel which the
current has scooped out for itself. No sooner has a volcanic
island been thrown up than some lichens begin to grow upon
it, and it is sometimes clothed with verdure while smoke and
ashes are still occasionally thrown from the crater. The
cocoa, pandanus, and mangrove take root upon the coral reef
before it has fairly risen above the waves. The burning stream
of lava that descends from Etna rolls through the stately
forest, and converts to ashes every tree and herb which stands
in its way ; but the black strip of land thus desolated is covered
again, in the course of time, with oaks, pines, and chestnuts,
as luxuriant as those which the fiery torrent swept away.
Every fiood and landslip, every wave which a hurricane or
earthquake throws upon the shore, every stream of lava or
shower of volcanic dust and ashes which buries a country far
and wide to the depth of many feet, every advance of the
sand-flood, every conversion of salt water into fresh, when
rivers alter their main channel of discharge, every permanent
variation in the rise or fall of tides in an estuary—these and
countless other causes displace, in the course of a few
centuries, certain plants and animals from stations which
|
|
Cx. XLII.] VICISSITUDES IN THE EARTH’S SURFACE. 445
they previously occupied. If, therefore, the Author of Nature
had not been prodigal of those numerous contrivances, before
alluded to, for spreading all classes of organic beings over
the earth—if He had not ordained that the fluctuations of the
animate and inanimate creation should be in perfect harmony
with each other, it is evident that considerable spaces, now
the most habitable on the globe, would soon be as devoid
of life as are the Alpine snows, the dark abysses of the
ocean, or the moving sands and salt plains of the Sahara.
The powers, then, of migration and diffusion, conferred, as
already shown, on animals and plants, are indispensable to
enable them to maintain their ground, and would be necessary,
even though it were never intended that a species should
eradually extend its geographical range. But a facility of
shifting their quarters being once given, it cannot fail to
happen that the inhabitants of one province should occasion-
ally penetrate into some other; since the strongest of those
barriers which I before described as separating distinct regions
are all liable to be thrown down, one after the other, during
the vicissitudes of the earth’s surface.
We have seen in the Twelfth Chapter* how vast a suc-
cession of changes in the physical geography of the globe has
been revealed to us by geology. Although these changes are
incessant they proceed at so slow a rate that mankind at large
are wholly unconscious of their reality. It would not be easy
for the naturalist to take account of the advantage which one
species may gain over another in the course of a few centuries,
even at those points on the borders of two distinct provinces
where the struggle for existence is most keen. At such
points the rate of change must far outstrip the average
pace at which it proceeds in the organic world generally.
If the ocean should gradually wear its way through an
isthmus, like that of Suez, it would open a passage fe the
intermixture of the aquatic tribes of two seas (the Mediter-
ranean and Red Sea) previously disjoined, and would, at the
same time, close a free communication which the terrestrial
plants and animals of two continents had before enjoyed.
* Vol. I. p, 248,
446 EXTINCTION OF SPECIES. [Cu. XLII.
These would be, perhaps, the most important consequences, in
regard to the distribution of species, which would result from
the breach made by the sea in such a spot; but there would
be others of a distinct nature, such as the conversion of a
certain tract of land, which formed the isthmus, into the sea.
This space, previously occupied by terrestrial plants and
animals, would be immediately delivered over to the aquatic ;
a local revolution which might have happened in innumer-
able other parts of the globe, without being attended by any
alteration in the blending together the species of two distinct
provinces.
So if the narrow isthmus of Panama were to sink down
gradually, a communication would at length be established
between two seas which are now inhabited by fish, mollusks,
crustaceans, and other aquatic tribes nearly all of them speci-
fically distinct. A contest would take place between thousands
of allied species which in the course of time would give rise to
the predominance of some and the decline or total extinction
of others. If Spain were joined to Morocco, by the upheaval
and laying dry of the submarine ridge 1,000 feet deep, before
described,* the Mediterranean fauna would be separated
from that of the Atlantic, and there would be a fusion of the
terrestrial plants of Northern Africa with those of Southern
Europe. Or we may imagine a land communication to be
caused by voleanic outbursts in the straits of Lombok,t+
uniting the islands of Bali and Lombok. This would bring
about a conflict between the land-birds, insects, and plants
of the Indian and Australian provinces, which could not
fail to add. to the numerical predominance of some species
at the expense of others, while some might be exterminated.
But even such fluctuations would to a human observer appear
slow in the extreme, because a communication formed by a
new volcanic island will not simply take thousands of years, but
perhaps thousands of centuries, for its accomplishment, and
few of the species capable of profiting by the removal of the old
barrier would wait till the two islands were completely joined.
Extension of the range of one species alters that of others.—In
reference to the extinction of species it is important to bear
* See above, Vol. I. p. 562. { See Map, fig. 132, p. 347.
Cu. XLII] INCREASE OF ONE SPECIES DIMINISHES OTHERS. 447
in mind, that when any region is stocked with as creat a
variety of animals and plants as its productive powers will
enable it to support, the addition of any new species to the
permanent numerical increase of one previously established,
must always be attended either by the local extermination or
the numerical decrease of some other species.
There may undoubtedly be considerable fluctations from
year to year, and the equilibrium may be again restored with-
out any permanent alteration ; for, in particular seasons, a
greater supply of heat, humidity, or other causes, may aug-
ment the total quantity of vegetable produce, in which case
all the animals subsisting on vegetable food, and others which
prey on them, may multiply without any one species giving
way: but whilst the aggregate quantity of vegetable produce
remains unaltered, the progressive increase of one animal or
plant implies the decline of another.
All agriculturists and gardeners are familiar with the fact
that when weeds intrude themselves into the space appro-
priated to cultivated species, the latter are starved in their
growth or stifled. If we abandon for a short time a field or
garden, a host of indigenous plants,
The darnel, hemlock, and rank fumitory,
pour in and obtain the mastery, extirpating the exotics, or
putting an end to the monopoly of some native plants.
If we enclose a park, and stock it with as many deer as the
herbage will support, we cannot add sheep without lessening
the number of the deer; nor can other herbivorous species
be subsequently introduced, unless the individuals of each
species in the park become fewer in proportion.
So, if there be an island where leopards are the only beasts
of prey, and the lion, tiger, and hyena afterwards enter, the
leopards, if they stand their ground, will be reduced in num-
ber. If the locusts then arrive and swarm greatly, they may
deprive a large number of plant-eating animals of their food,
and thereby cause a famine, not only among them, but among
the beasts of prey: certain Species, perhaps, which had the
weakest footing in the island may thus be annihilated.
Although our knowledge of the history of the animate creation
448 EXTINCTION OF SPECIES. [Cu. XLII.
dates from so recent a period, that we can scarcely trace the
advance or decline of any animal or plant, except in those
cases where the influence of man has intervened ; yet we can
easily conceive what must happen when some new colony of
wild animals or plants enters a region for the first time, and
succeeds in establishing itself.
Supposed effects of the first entrance of the polar bear into
Iceland.—Let us consider how great are the devastations
committed at certain periods by the Greenland bears, when
they are drifted to the shores of Iceland in considerable num-
bers on the ice. These periodical invasions are formidable
even to man; so that when the bears arrive, the inhabitants
collect together, and go in pursuit of them with fire-arms—
each native who slays one being rewarded by the king of
Denmark. The Danes of old, when they landed in their
marauding expeditions upon our coast, hardly excited more
alarm, nor did our islanders muster more promptly for the
defence of their lives and property against the common enemy,
than the modern Icelanders against these formidable brutes.
It often happens, says Henderson, that the natives are pur-
sued by the bear when he has been long at sea, and when
his natural ferocity has been heightened by the keenness of
hunger; if unarmed, it is frequently by stratagem only that
they make their escape.
Let us cast our thoughts back to the period when the first
polar bears reached Iceland, before it was colonised by the
Norwegians in 874; we may imagine the breaking up of an
immense barrier of ice like that which, in 1816 and the
following year, disappeared from the east coast of Greenland,
which it had surrounded for four centuries. By the aid of
such means of transportation a great number of these quadru-
peds might effect a landing at the same time, and the havoc
which they would make among the species previously settled
in the island would be terrific. The deer, foxes, seals, and
even birds, on which these animals sometimes prey, would be
soon thinned down.
But this would be a part only, and probably an insignifi-
cant portion, of the aggregate amount of change brought
* Journal of a Residence in Iceland, p. 27 .
Cu. XLIT.] HABITS OF EIDER DUCKS IN ICELAND. 449
about by the newinvader. The plants on which the deer fed,
being less consumed in consequence of the lessened numbers
of that herbivorous species, would soon supply more food to
several insects, and probably to some terrestrial testacea, so
that the latter would gain ground. The increase of these
would furnish other insects and birds with food, so that the
numbers of these last would be augmented. The diminution
of the seals would afford a respite to some fish which they
had persecuted ; and these fish, in their turn, would then
multiply and press upon their peculiar prey. Many water-
fowls, the eggs and young of which are devoured by foxes,
would increase when the foxes were thinned down by
the bears; and the fish on which the water-fowls subsisted
would then, in their turn, be less numerous. Thus the
numerical proportions of a great number of the inhabitants,
both of the land and sea, might be permanently altered
by the settling of one new species in the region; and the
changes caused indirectly would ramify through all classes
of the living creation, and be almost endless.
An actual illustration of what we have here only proposed
hypothetically, is in some degree afforded by the selection of
small islands by the eider duck for its residence during the
season of incubation, its nests being seldom if ever found on
the shores of the main land, or even of a large island. The
Icelanders are so well aware of this, that they have expended
a great deal of labour in forming artificial islands, by
separating from the main land certain promontories, joined
to it by narrow isthmuses. This insular position is necessary
to guard against the destruction of the eggs and young birds,
by foxes, dogs, and other animals. One year, says Sir W.
Hooker, it happened that, in the small island of Vidoe, ad-
joining the coast of Iceland, a fox got over wpon the ice, and
caused great alarm, as an immense number of ducks were then
sitting on their eggs or young ones. It was long before he
was taken, which was at last, however, effected by bringing
another fox to the island, and fastening it by a string near
the haunt of the former, by which he was allured within shot
of the hunter.*
* Tour in Iceland, vol. i. p. 64, 2nd edit.
VOL. If. GG
450 : EXTINCTION OF SPECIES. ~ (Cx. XLII.
Increase of rein-deer imported into Iceland.—As an example
of the rapidity with which a large tract may become
peopled by the offspring of a single pair of quadrupeds, it may
be mentioned that in the year 1773 thirteen rein-deer were
exported from Norway, only three of which reached Iceland.
These were turned loose into the mountains of Guldbringé
Syssel, where they multiplied so greatly, in the course of forty
years, that it was not uncommon to meet with herds, consist-
ing of from forty to one hundred, in various districts.
The rein-deer, observes a modern writer, is in Lapland a
loser by his connection with man, but Iceland will be this
creature’s paradise. There is, in the interior, a tract which
Sir G. Mackenzie computes at not less than 40,000 square
miles, without a single human habitation, and almost en-
tirely unknown to the natives themselves. There are no
wolves ; the Icelanders will keep out the bears; and the rein-
deer, being almost unmolested by man, will have no enemy
whatever, unless it has brought with it its own tormenting
gad-fly.*
Ulloa in his voyage, and Buffon on the authority of old
writers, relate a fact which illustrates very clearly the prin-
ciple before explained, of the check which the increase of one
animal necessarily offers to that of another. The Spaniards
had introduced goats into the island of Juan Fernandez, where
they became so prolific as to furnish the pirates who infested
those seas with provisions. In order to cut off this resource
from the buccaneers, a number of dogs were turned loose into
{he island; and so numerous did they become in their turn,
that they destroyed the goats in every accessible part, after
which the number of the wild dogs again decreased.t
It is usually the first appearance of an animal or plant, in
a region to which it was previously a stranger, that gives rise
to the chief alteration; since, after a time, an equilibrium is
again established. But it must require ages before such a
new adjustment of the relative forces of so many conflicting
agents can be definitely settled. The causes in simultaneous
action are so numerous, that they admit of an almost infinite
* Travels in Iceland in 1810, p. 342
+ Buffon, vol. v. p.' 10¢
).. Ulloa’s Voyage, vol. ii. p. 220.
Cu. XLII.] CHANGES CAUSED BY MAN, 451
number of combinations; and it is necessary that all these
should have occurred once before the total amount of change,
capable of flowing from any new disturbing force, can be
estimated.
Thus, for example, suppose that once in two centuries a
frost of unusual intensity, or a volcanic eruption of great
violence accompanied by floods from the melting of glaciers,
should occur in Iceland; or an epidemic disease, fatal to the
larger number of individuals of some one species, and not
affecting others,—these, and a variety of other contingencies,
all of which may occur at once, or at periods separated by
different intervals of time, ought to happen before it would
be possible for us to declare what ultimate alteration the
presence of any new comers, such as the bear or rein-deer
before mentioned, might occasion in the animal population of
the isle.
Every new condition in the state of the organic or inorganic
creation, a new animal or plant, an additional snow-clad
mountain, any permanent change, however slight in compa-
rison to the whole, gives rise to a new order of things, and
may make a material change in regard to some one or more
species. Yet a swarm of locusts, or a frost of extreme inten-
sity, or an epidemic disease, may pass away without any
great apparent derangement ; no species may be lost, and all
may soon recover their former relative numbers, because the
same scourges may have visited the region again and again,
at preceding periods. Every plant that was incapable of
resisting such a degree of cold, every animal which was ex-
posed to be entirely cut off by an epidemic or by famine
caused by the consumption of vegetation by the locusts, may
have perished already, so that the subsequent recurrence of
similar catastrophes is attended only by a temporary change.
Hxtirpation of species by man.—That man’ is, geologically
speaking, of very modern origin we may assume, although we
have recently obtained satisfactory proofs that he was con-
temporary with the mammoth and many other extinct mam-
malia, and that he has survived considerable changes in the
physical geography of the globe.
The number of human beings now peopling the earth is
GG 2
452 EXTINCTION OF SPECIES. [Cx. XLH, |
generally supposed to amount to eight hundred millions, so |
that we may easily understand how great a number of beasts .
of prey, birds, and animals of every class, this prodigious |
population must have displaced, independently of the still
more important consequences which have followed from the
derangement brought about by man in the relative numerical
strength of particular species.
It may perhaps be said, that man has, in no small degree,
compensated for the appropriation to himself of the food of
many animals by artificially improving the natural produc-
tiveness of soils, by irrigation, manure, and a judicious inter-
mixture of mineral ingredients conveyed from different
localities. But it admits of reasonable doubt whether, upon
the whole, we fertilise or impoverish the lands which we
occupy. This assertion may seem startling to many ; because
they are so much in the habit of regarding the sterility or
productiveness of land in relation to the wants of man, and
not as regards the organic world generally. It is difficult, at
first, to conceive, if a morass is converted into arable land, and
made to yield a crop of grain, even of moderate abundance, that
we have not improved the capabilities of the habitable surface |
—that we have not empowered it to support a larger quantity
of organic life. In such cases, however, a tract, before of no
utility to man, may be reclaimed, and become of high agri-
cultural importance, though it may, nevertheless, yield a
scantier vegetation. If a lake be drained, and turned into a
meadow, the space will provide sustenance to man, and many
terrestrial animals serviceable to him, but not, perhaps, so
much food as it previously yielded to the aquatic races.
The felling of dense and lofty forests, which covered, even
within the records of history, a considerable space on the
globe, now tenanted by civilised man, must generally have
lessened the amount of vegetable food throughout the space
where these woods grew. We must also take into our
account the area covered by towns, and a still larger surface
occupied by roads.
If we force the soil to bear extraordinary crops one year,
we are, perhaps, compelled to let it lie fallow the next. But
nothing so much counterbalances the fertilising effects of
eT, Cy
hich yp
beeen
nity
nan, ani
Beult, i
and, al
nee, {hi
suriatt
re of
hat
yell!
jist
| w!
Cu. XLIL.] CHANGES CAUSED BY MAN. 453
human art as the extensive cultivation of foreign herbs and
shrubs, which, although they are often more nutritious to
man, seldom thrive with the same rank luxuriance as the
native plants of a district. Man is, in truth, continually
striving to diminish the natural diversity of the stations of
animals and plants in every country, and to reduce them all
to a small number fitted for species of economical use. He
may succeed perfectly in attaining his object, even though
the vegetation be comparatively meagre, and the total
amount of animal life be greatly lessened.
When St. Helena was discovered about the year 1506,
it was entirely covered with forests, the trees drooping over
the tremendous precipices that overhang the sea. Now, says
Dr. Hooker, all is changed; fully five-sixths of the island
are entirely barren, and by far the greater part of the vegeta-
tion which exists, whether herbs, shrubs, or trees, consists of
introduced European, American, African, and Australian
plants, which propagated themselves with such rapidity
that the native plants could not compete with them. These
exotic species, together with the goats, which being carried
to the island destroyed the forests by devouring all the
young plants, are supposed to have utterly annihilated about
100 peculiar and indigenous species, all record of which is
lost to science, except those of which specimens were collected
by the late Dr. Burchell and are now in the herbarium of Kew.”
In the district of Canterbury, New Zealand, Mr. Locke
Travers, writing in 1863, says that the spread of Huropean
and other foreign plants is surprisingly rapid. The cow-grass
(Polygonum aviculare), the common dock, and the sow thistle
grow luxuriantly, the water-cress increases in the still rivers
so as to threaten to choke them up altogether, and to put the
colonists to the expense of £300 annually in keeping open
a single stream, the Avon, which runs through Christchurch.
Stems of this water-cress have been measured 12 feet long.
and three quarters of an inch in diameter. In some mountain
districts the white clover is displacing the native grasses, and
foreign trees, such as poplars, aud willows, and the gum-
* Hooker, Insular Floras, Brit. Assoc. Nottingham, 1866.
454 EXTINCTION OF SPECIES. [Cu. XLIL
trees of Australia, are growing rapidly. In fact, the young
native vegetation appears to shrink from competition with
these more vigorous intruders.’*
Spix and Martius have given a lively description of the
incredible number of insects which lay waste the crops in
Brazil, besides swarms of monkeys, flocks of parrots, and
other birds, as well as the paca, agouti, and wild swine.
They describe the torment which the planter and the natura-
list suffer from the musquitoes, and the devastation of the
ants and blatte ; they speak of the dangers to which they were
exposed from the jaguar, the poisonous serpents, crocodiles,
scorpions, centipedes, and spiders. But with the increasing
population and cultivation of the country, say these natura-
lists, these evils will gradually diminish ; when the inhabitants
have cut down the woods, drained the marshes, made roads
in all directions, and founded villages and towns, man will,
by degrees, triumph over the rank vegetation and the noxious
animals, and all the elements will second and amply recom-
pense his activity.+
Indigenous quadrupeds and birds extirpated in Great Britain.
—Let us make some enquiries into the extent of the influence
which the progress of society has exerted during the last
seven cr cight centuries, in altering the distribution of
indigenous British animals. Dr. Fleming, in an able memoir
on the subject, has enumerated the best authenticated
examples of the decrease or extirpation of certain species
during a pericd when our population has made the most
rapid advances. I shall offer a brief outline of his results.
The stag, as well as the fallow deer and the roe, were
formerly so abundant in our island, that, according to Lesley,
from five hundred to a thousand were slain at a hunting-
match ; but the native races would already have been ex-
tinguished, had they not been carefully preserved in certain
forests. The otter, the marten, and the polecat were also in
sufficient numbers to be pursued for the sake of their fur ;
but they have now been reduced within very narrow bounds.
* Locke Travers, cited by Hooker, { Ed. Phil. Journ., No. xxii. p. 287. ;
Nat. Hist. Rev. 1864, p. 124. et. 1824.
~ Travels in Brazil, vol. i. p. 269.
824
;
|
|
Teco:
Cx, XLIL.] CHANGES CAUSED BY MAN. ADS
The wild cat and fox have also been sacrificed throughout
the greater part of the country, for the security of the poultry-
yard or the fold. Badgers have been expelled from nearly
every dis trict, which at former periods they inhabited.
Besides these, which have been driven out from their
favourite haunts, and everywhere reduced in number, there
are some which have been wholly extirpated ; such as the
ancient breed of indigenous horses, and the wild boar; of
the wild oxen a few remains are still preserved in some of
the old English parks. The beaver, which is eagerly sought
after for its fur, had become scarce at the close of the ninth
century; and, by the twelfth century, was only to be met
with, according to Giraldus de Barri, in one river in Wales,
and another in Scotland. The wolf, once so much dreaded.
by our ancestors, 1s said to have maintained its ground in
Ireland so late as the beginning of the eighteenth century
(1710), though it had been extirpated in Scotland thirty years
before, and in England at a much earlier period. The bear,
which, in Wales, was regarded as a beast of chase equal to
the hare or the boar, only perished, as a native of Scotland,
in the year 1057.*
Many native birds of prey have also been the subjects of
unremitting persecution. The eagles, larger hawks, and
ravens, have disappeared from the more cultivated districts.
The haunts of the mallard, the snipe, the redshank, and the
bittern, have been drained equally with the summer dwellings
of the lapwing and the curlew. But these species still linger
in some portion of the British Isles; whereas the larger
capercailzies, formerly natives of the pine-forests of Ireland
and Scotland, had been quite destroyed towards the close
of the last century, but were successfully reintroduced into
Perthshire about the year 1824. The egret and the crane,
which appear to have been formerly very common in Scot-
land, are now only occasional visitants.+
The bustard (Otis tarda), observes Graves, in his British
Ornithology, ‘was formerly seen on the downs and heaths
* Fleming, Ed. Phil. Journ. No, xxii. f+ Fleming, ibid., p. 292.
p. 298. + Vol. iii, London, 1821.
456 EXTINCTION OF SPECIES. (Cu. XLII.
of various parts of our island, in flocks of forty or fifty birds ;
whereas it is now (1821) a circumstance of rare occurrence
to meet with a single individual.’ Bewick also remarks,
‘that they were formerly more common in this island than
at present ; they are now found only in the open counties of
the south and veast—in the plains of Wiltshire, Dorsetshire,
and some parts of Yorkshire.’* In the few years that have
elapsed since Bewick wrote, this bird has entirely disappeared
from the British Isles. These changes, it may be observed,
are derived from very imperfect memorials, and relate only to
the larger and more conspicuous animals inhabiting a small
spot.on the globe; but they cannot fail to exalt our conception
of the enormous revolutions which, in the course of thousands
of years, the whole human species must have effected.
Hxtinction of the dodo.—The kangaroo and the emu are
retreating rapidly before the progress of colonisation in
Australia ; and it scarcely admits of doubt, that the general
cultivation of that country must lead to the extirpation of both.
The most striking example of the loss, even within the last two
centuries, of a remarkable species, is that of the dodo—a bird
first seen by the Dutch, when they landed on the Isle of France,
at that time uninhabited, immediately after the discovery of
the passage to the Hast Indies by the Cape of Good Hope. It
was of a large size, and singular form; its wings short, like
those of an ostrich, and wholly incapable of sustaining its
heavy body, even for a short flight. In its general appearance
it differed from the ostrich, cassowary, or any known bird.+
Many naturalists gave figures of the dodo after the com-
mencement of the seventeenth century; and there is a
painting of it in the British Museum, which is said to have
been taken from a living individual. Beneath the painting
* Land Birds, vol. i. p- 816, ed. 1821.
t Some have complained that inscrip-
tions on tomb-stones convey no general
information, except that individuals were
born and died, accidents which must
happen alike to all men. But the death
natural history that it deserves comme-
moration, and it is with no small interest
that we learn, from the archives of the
University of Oxford, the exact day and
year when the remains of the last speci-
men of the dodo, which had been per-
mitted to rot in the Ashmolean Museum
were cast away. The relics, we are told,
were ‘a muso subducta, annuente vice-
cancellario aliisque curatoribus, ad ea
lustranda conyoeatis, die Januarii 8vo,
A.D. 1750.’ Zeol. Journ. No, 12, p. 559.
1828
Cention
sandy
peayeeataataiee
Cu. XLIL.] EXTINCTION OF THE DODO. 457
is a leg, in a fine state of preservation, which ornithologists
are agreed cannot belong to any other known bird. In the
museum at Oxford, also, there is a foot and a head in an
imperfect state.
In spite of the most active search, during the last century,
no information respecting the dodo was obtz ained, and some
authors went so far as to pretend that it had never existed ;
but a great mass of satisfactory evidence in favour of is
recent existence has now been collected by Mr. Broderip,*
and by Mr. Strickland and Dr. Melville. Mr. Strickland,
agreeing with Professor Reinhardt, of Copenhagen, in re-
ferring the dodo to the Columbide, calls it a ‘ vulture-like
frugiverous pigeon.’ It appears, also, that another short-
winged bird of the same order, called ‘The Solitaire,’
inhabited the island of Rodrigues, 300 miles east of the
Mauritius, and has been exterminated by man, as have one
or two different but allied birds of the Isle of Bourbon.+ In
the year 1865 parts of the skeleton of the dodo were dug up
in a bog near the sea in the island of Mauritius. They were
sent to Professor Owen, and were described by him in the
Transactions of the Zoological Society for 1867. Speaking of
the extinct bird as the great ‘ground-dove’ of the Mauritius,
he speculates on this peculiar species having originated in
that uninhabited and thickly wooded island, where there was
no animal powerful enough to contend with it and from which
it would be required to escape by flight. He therefore con-
ceives that ‘ finding food enough scattered over the ground, it
ceased to exert its wings in raising the heavy trunk, and so
eradually gained bulk in the course of many generations.
Hence the organs of flight would, according to Lamarckian
principles, be atrophied by disease and diminished in size and
strength, while the hind limbs, having an increasing weight
to support and being exercised by habitual motion on the
land, would acquire larger dimensions. ’{
Rapid propagation of domestic quadrupeds over the American
continent.—Next to the direct agency of man, his indirect
influence in multiplying the numbers of large herbivorous
* Penny Cyclopedia, ‘ Dodo,’ 1837. ‘the Dodo and its Kindred.’ London,
tT Messrs. Strickland and eat: on 1848, t Zool. Soc. Trans. 1867.
458 EXTINCTION OF SPECIES. [Cu. XLII,
quadrupeds of domesticated races may be regarded as one of
the most obvious causes of the extermination of species. On
this, and on several other grounds, the introduction of the
horse, ox, and other mammalia, into America, and their
rapid propagation over that continent within the last three
centuries, is a fact of great importance in natural history.
The extraordinary herds of wild cattle and horses which
overran the plains of South America sprung from a very few
pairs first carried over by the Spaniards; and they prove
that the wide geographical range of large species in great
continents does not necessarily imply that they have existed
there from remote periods.
Humboldt observes, in his Travels, on the authority of
Azara, that it is believed that there exist, in the Pampas of
Buenos Ayres, twelve million cows and three million horses,
without comprising in this enumeration the cattle that have
no acknowledged proprietor. In the Llanos of Caraccas, the
rich hateros, or proprietors of pastoral farms, are entirely
ignorant of the number of cattle they possess. The young
are branded with a mark peculiar to each herd, and some of
the most wealthy owners mark as many as 14,000 a year.*
In the northern plains, from the Orinoco to the lake of
Maracaybo, M. Depons reckoned that 1,200,000 oxen, 180,000
horses, and 90,000 mules, wandered at large.t In some
parts of the valley of the Mississippi, especially in the country
of the Osage Indians, wild horses were immensely numerous
in the early part of this century.
The establishment of black cattle in America dates from
Columbus’s second voyage to St. Domingo. They there mul-
tiplied rapidly ; and that island presently became a kind of
nursery from which these animals were successively trans-
ported to various parts of the continental coast, and from.
thence into the interior. Notwithstanding these numerous
exportations, in twenty-seven years after the discovery of the
island, herds of 4,000 head, as we learn from Oviedo, were
not uncommon, and there were even some that amounted to
8,000. In 1587, the number of hides exported from St.
* Pers. Nar. vol. iy. ft Quarterly Review, vol. xxi. p. 335.
Cu. XLII. | CHANGES CAUSED BY MAN. A459
Domingo alone, according to Acosta’s report, was 35,444;
and in the same year there were exported 64,350, from
the ports of New Spain. This was in the sixty-fifth year
after the taking of Mexico, previous to which event the
Spaniards, who came into that country, had not been able to
engage in anything else than war.* Everyone is aware that
these animals are now established throughout the American
continent from Canada to the Straits of Magellan.
The ass has thriven very generally in the New World ; and
we learn from Ulloa, that in Quito they ran wild, and multi-
plied in amazing numbers, so as to become a nuisance. ‘They
erazed together in herds, and when attacked defended them-
selves with their mouths. If a horse happened to stray into
the places where they fed, they all fell upon him, and did not
cease biting and kicking till they left him dead.t This fact
illustrates the power of one of those barriers—namely, that of
preoccupancy, which we before alluded to (p. 351)—as being
often most effective in limiting the range of species.
The first hogs were carried to America by Columbus, and
established in the island of St. Domingo the year following
its discovery, in November, 1493. In succeeding years they
were introduced into other places where the Spaniards settled
and, in the space of half a century, they were found esta-
blished in the New World, from the latitude of 25° north, to
the 40th degree of south latitude. Sheep, also, and goats
have multiplied enormously in the New World, as have also
the cat and the rat; which last, as before stated, has been
imported unintentionally in ships. The dogs introduced by
man which have at different periods become wild in America,
hunted in packs, like the wolf and the jackal, destroying not
only hogs, but the calves and foals of the wild cattle and
horses.
Besides the quadrupeds above enumerated, our domestic
fowls have also thriven in the West Indies and America,
where they have now the common fowl, the goose, the duck,
the peacock, the pigeon, and the guinea-fowl. As these were
often taken suddenly from the temperate to very hot regions,
* Quarterly Review, vol, xxi. p. 335.
t Ulloa’s Voyage. Wood’s Zoog. vol. i. p. 9.
460 EXTINCTION OF SPECIES. [Cu. XLII.
they were not reared at first without much difficulty ; but
after a few generations, they became habituated to the cli-
mate, which, in many cases, approached much nearer than
that of Europe to the temperature of their original native
countries. ‘he fact of so many millions of wild and tame
individuals of our domestic species, almost all of them the
largest quadrupeds and birds, having been propagated
throughout the new continent within the short period that
has elapsed since the discovery of America, while no appre-
ciable improvement can have been made in the productive
powers of that vast continent, affords abundant evidence of
the extraordinary changes which accompany the diffusion
and progressive advancement of the human race over the
globe.
Power of exterminating species no prerogative of man.—When
we reflect how many millions of square miles of the fertile
land, occupied originally by a boundless variety of animal
and vegetable forms, have been already brought under the
dominion of man, and compelled, in a great measure, to yield
nourishment to him, and to a limited number of plants and
animals which he has caused to increase, we must at once be
convinced, that the annihilation of a multitude of species has
already been effected, and will continue to go on hereafter, in
certain regions, in a still more rapid ratio, as the colonies of
highly civilised nations spread themselves over unoccupied
lands.
Yet, if we wield the sword of extermination as we advance,
we have no reason to repine at the havoc committed, nor to
fancy, with the Scottish poet, that ‘we violate the social
union of nature ;’ or complain, with the melancholy Jacques,
that we
Are mere usurpers, tyrants, and what's worse,
To fright the animals and to kill them up
In their assign’d and native dwelling-place.
We have only to reflect, that in thus obtaining possession
of the earth by conquest, and defending our acquisitions by
force, we exercise no exclusive prerogative. Every species
which has spread itself from a small point over a wide area
must, in like manner, hare marked its progress by the dimi-
Cu. XLIL] CONCLUDING REMARKS ON EXTINCTION. 461
nution or the entire extirpation of some other, and must
maintain its ground by a successful struggle against the
encroachments of other plants and animals. That minute
parasitic plant, called ‘the rust’ in wheat, has, like the Hes-
sian fly, the locust, and the aphis, caused famines ere now
amongst the ‘lords of the creation.’ The most insignificant and
diminutive species, whether in the animal or vegetable king-
dom, have each slaughtered their thousands, as they dissem-
nated themselves over the globe, as well as the lion, when
first it spread itself over the tropical regions of Africa.
Concluding remarks on extinction—From what has now been
said of the effect of changes which are always going on in the
condition of the habitable surface of the globe, and the
manner in which some species are constantly extending their
range at the expense of others, it may be deduced, as a co-
rollary, that the species existing at any particular period,
must, in the course of ages, become extinct one after the
other. ‘They must die out,’ to borrow an emphatical expres-
sion from Buffon, ‘ because Time fights against them.’
Tf such then be a law of the organic world, if every species
is continually losing some of its varieties and every genus
some of its species, it follows that the transitional links which
once, according to the doctrine of Transmutation, must have
existed, will, in the great majority of cases, be missing. We
learn from geological investigations that throughout an inde-
finite lapse of ages the whole animate creation has been
decimated again and again. Sometimes a single representa-
tive alone remains of a type once dominant, or of which the
fossil species may be reckoned by hundreds. We rarely find
that whole orders have disappeared, yet even this is notably
the case in the class of reptiles, which has lost some orders
characterised by a higher organisation than any now surviving
in that class. Certain genera of plants and animals which
seem to have been wholly wanting, and others which were
feebly represented, in the Tertiary Period, are now rich in
species, and appear to be in such perfect harmony with the
present conditions of existence, that they present us with
countless varieties confounding the zoologist or botanist who
undertakes to describe and classify them.
462 EXTINCTION OF SPECIES. [Cu. XLII.
We have only to reflect on the causes of extinction enume-
rated in this chapter, and we at once foresee the time when
even in these genera so many gaps will occur, so many tran-
sitional forms will be lost, that there will no longer be any
difficulty in assigning definite limits to each species. The
blending therefore of one general or specific form into an-
other, must be an exception to the general rule, whether
in our own times or at any period of the past, because the
forms surviving at any given moment will have been exposed
for a long succession of antecedent periods to those powerful
causes of extinction which are slowly, but incessantly, at
work in the organic and inorganic worlds.
Dr. Hooker, in commenting on the loss of a hundred species
of plants in the course of the last three and a half centuries
in St. Helena,* remarks, ‘every one of these species was a
link in the chain of created beings, which contained within
itself evidence of the affinities of other species both living
and extinct, but which evidence is now irrecoyerably lost.’
It is affirmed by Darwin that genera which in the present
state of the globe are most dominant contain also the most
variable species. It is in such genera that the formation of
new races, or ‘incipient species,’ is most actively going on;
whereas in the majority of more ancient genera and families
species are fast dying out; and that such has always been the
order of Nature is proved by the fact, that while certain forms
are characteristic of every geological period, these same are
unknown or feebly represented, whether in older strata or
in formations of later date.
They who imagine that if the theory of Transmutation be
true we ought to discover in a fossil state all the intermediate
links by which the most dissimilar types have been formerly
connected together must tacitly assume that it is part of
the plan of Nature to leave to after ages permanent records
of all her works, whether animal or vegetable. Yet these
same objectors to the theory would hardly expect that the
species of plants just alluded to as having been so recently
extirpated in St. Helena have all of them left memorials of
* See above, p. 453.
Cu. XLII.] CONCLUDING REMARKS ON EXTINCTION. 463
their existence in the crust of the earth. In Chapter XTYV.
I have treated of the fragmentary nature of the geological
record,* re-affirming what I first stated in 1833, that it is
scarcely possible to exaggerate the defectiveness of our
archives. These records, like the existing species, are con-
stantly wasting away before our eyes, while new deposits,
containing the partial memorials of the modern fauna and
flora, are now in the process of formation. But as the new
strata are deposited out of sight, chiefly in the basins of seas
and lakes, their origin is not so conspicuous as is the de-
struction of the memorials of older date.
So also, as before stated (p. 269), the dying out of old forms is
more easily proved than the coming in of new ones. We might
see in a large forest a full-grown tree blown down or felled by
the axe every day in the year, and yet at the end of fifty years
find that the number and size of the trees in the forest was
the same as before, because the daily growth of timber spread
over many thousands of trees, though insensible to the eye,
may every day produce a quantity of foliage and timber equal
in the aggregate to that contained in a single full-grown
tree. In like manner, if one species die out annually, as
before hinted (p. 272), the loss may be compensated by
the amount of permanent change effected by Variation and
Natural Selection, in the course of a single year, among
thousands of species.
* Vol. I. pp. 317-820.
CHAPTER XLIII.
MAN CONSIDERED WITH REFERENCE TO HIS ORIGIN AND
GEOGRAPHICAL DISTRIBUTION.
GEOGRAPHICAL DISTRIBUTION OF THE RACES OF MAN—DRIFTING OF CANOES
TO VAST DISTANCES—-MAN, LIKE OTHER SPECIES, HAS SPREAD FROM A SINGLE
A
GE WITH THE GREAT ZOOLOGICAL PROVINCES — AMERICAN-
INDIAN COMMON TU NEOARCTIC AND NEOTROPICAL REGIONS—MAN AN OLD-
YORLD TYPE— MARKED LINE OF SEPARATION BETWEEN MALAYAN AND
PAPUAN RACES—DISTINCTNESS OF NEGRO AND EUROPEAN, AND QUESTION OF
THE MULTIPLE ORIGIN OF MAN—SIX-FINGERED VARIETY OF MAN EARING
REGROWTH OF SUPERNUMERARY
ON THE MUTABILITY OF HIS
DIGITS WHEN AMPUTATED—THESE PHENOMENA REFERRED BY DARWIN TO
REVERSION—-WHETHER MAN HAS BEEN DEGRADED FROM A HIGHER OR HAS
iN FROM A LOWER STAGE OF CIVILISATION—GRADUAL DIMINUTION OF
RY ON INTERMEDIATE FORMS
BETWEEN THE UPPER MIOCENE AND THE LIVING MAMMALIS
OF MIOCENE AND LIVING QUA RUMANA-—- OWEN
MALIA ACCORDING TO CEREBRAL DEVELOPMENT—PROGRESSIVE ADVANCEMENT
IN CEREBRAL CAPACITY OF THE
CEREBRAL CONFORMATION— WHE
THE ORDINARY LAWS OF REPRODUCTION——CAUSE OF RELUC-
TANCE TO BELIEVE IN MAN’S DERIVATIVE ORIGIN
GEOGRAPHICAL DISTRIBUTION OF THE RACES OF MAN.—
In this chapter I shall offer some observations on the 2e0-
graphical distribution of the different races of man, and con-
sider whether if we admit the doctrine of Transmutation as
most probable in the case of the inferior mammalia, we are
bound to embrace the same hypothesis when speculating on
the origin of the human s species.
Long before the geologist had succeeded in tracing back
the signs of man’s existence to a time when Kurope was in-
habited by species of ¢ yuadrupeds,
such as the elephant,
Cu. XLIII.] ORIGIN AND DISTRIBUTION OF MAN. 465
rhinoceros, bear, lion, hyena, and others long since extinct,
naturalists had already amused themselves in speculating on
the probable birthplace of mankind, the point from which,
if we assume the whole human race to have descended from
a single stock, the tide of emigration must originally have
proceeded. It has been always a favourite conjecture, that
this birthplace was situated within or near the tropics, where
perpetual summer reigns, and where fruits, herbs, and roots
are plentifully supplied throughout the year. The climate
of these regions, it has been said, is suited to a being born
without any covering, and who had not yet acquired the arts
of building habitations or providing clothes.
‘The hunter state,’ it has been argued, ‘ which Montes-
quieu placed the first, was probably only the second stage to
which mankind arrived; since so many arts must have been
invented to catch a salmon, or a deer, that society could no
longer have been in its infancy when they came into use.’ *
When regions where the spontaneous fruits of the earth
abound became overpeopled, men would naturally diffuse
themselves over the neighbouring parts of the temperate
zone; but a considerable time would probably elapse before
this event took place; and it is possible, as a writer before
cited observes, that in the interval before the multiplication
of their numbers and their increasing wants had compelled
them to emigrate, some arts to take animals were invented,
but far inferior to what we see practised at this day among
savages. As their habitations gradually advanced into the
temperate zone, the new difficulties they had to encounter
would call forth by degrees the spirit of invention, and the
probability of such inventions always rises with the number
of people involved in the same necessity.
Sir Humphry Davy, although coinciding for the most part
in the above views, has introduced one of the persons in his
second dialogue, as objecting to the theory of the human race
having gradually advanced from a savage to a civilised state,
on the ground that ‘the first man must have inevitably been
destroyed by the elements or devoured by savage beasts, so
* Brand’s Select Dissert. from the Amen. Acad., vol.1, p. 118. ~ Ibid.
Takegsl
BVEO Lee dary
466 ORIGIN AND DISTRIBUTION OF MAN. [Cu. XLIII.
infinitely his superiors in physical force.’* But this difficulty
had been met, as before stated, by assigning, as the original
seat of man, some island within the tropics, free from large
beasts of prey. Here man may have remained for a period,
peculiar to a limited area, just as some of the large anthro-
pomorphous species are now restricted to one tropical island.
In such a situation, the new-born race might have lived in
security, though far more helpless than the New Holland
savages, and might have found abundance of vegetable food.
Colonies may afterwards have been sent forth from this
mother country; and then the peopling of the earth may have
proceeded according to the hypothesis before alluded to.
In an early stage of society the necessity of hunting acts
as a principle of repulsion, causing men to spread with the
createst rapidity over a country, until the whole is covered
with scattered settlements. It has been ecaleulated that
800 acres of hunting-ground produce only as much food as
half an acre of arable land. When the game has been in
a great measure exhausted, and a state of pasturage suc-
ceeds, the several hunter-tribes, being already scattered, may
multiply in a short time into the greatest number which the
pastoral state is capable of sustaining. The necessity, says
Brand, thus imposed upon the two savage states, of dispersing
themselves far and wide over the country, affords a reason
why, at a very early period, the worst parts of the earth may
have become inhabited.
But this reason, it may be said, is only applicable in as far
the peopling of a continuous continent; whereas
the smallest islands, however remote from continents, have
almost always been found inhabited by man. St. Helena, it
is true, afforded an exception ; for when that island was dis-
covered in 1501, it was only inhabited by sea-fowl, and occa-
sionally visited by seals and turtles.t The islands also of
Madeira, Mauritius, Bourbon, Pitcairns, and Juan Fernandez,
and those of the Galapagos archipelago, one of which is
were uninhabited when first discovered, as
as regards
70 miles lone
3?
were also the Falkland Islands, which is still more remark-
‘ eaten by ‘ Bere Ka
* Sir H. Davy, Consolations in Travel, p. 74. ft See p. 463.
«
{
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ting acts
With the
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ted that
h food as
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red, may
vhich the
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ispersing
4 reason
rth may
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= ~~ er
i
Cu. XLII] DRIFTING OF CANOES TO VAST DISTANCES. 467
able, since they are together 120 miles in length by 60 in
breadth, and abound in food fit for the support of man.
Drifting of canoes to vast distances.—Very few of the nume-
rous coral islets and volcanos of the vast Pacific, capable of
sustaining a few families of men, have been found unten-
anted ; and we have, therefore, to enquire whence and by what
means, if all the members of the great human family have
had one common source, could those savages have migrated.
Captain Cook, Mr. Forster, and others, have remarked that
parties of savages in their canoes must have often lost their
way, and must have been driven on distant shores, where
they were forced to remain, deprived both of the means and
of the requisite intelligence for returning to their own
country. Thus Cook found on the island of Wateoo three in-
habitants of Otaheite, who had been drifted thither in a canoe,
although the distance between the two isles is 550 miles.
In 1696, two canoes, containing thirty persons, who had left
Ancorso, were thrown by contrary winds and storms on the
island of Samar, one of the Philippines, at a distance of 800
miles. In 1721, two canoes, one of which contained twenty-
four, and the other six persons, men, women, and children,
were drifted from an island called Farroilep to the island of
Guaham, one of the Marians, a distance of 200 miles.*
Kotzebue, when investigating the Coral Isles of Radack,
at the eastern extremity of the Caroline Isles, became ac-
quainted with a person of the name of Kadu, who was a
native of Ulea, an isle 1,500 miles distant, from which he had
been drifted with a party. Kadu and three of his country-
men one day left Ulea in a sailing boat, when a violent storm
arose, and drove them out of their course: they drifted
about the open sea for eight months, according to their
reckoning by the moon, making a knot on a cord at every
new moon. Being expert fishermen, they subsisted entirely
on the produce of the sea; and when the rain fell, laid in as
much fresh water as they had vessels to contain it. “ Kadu,’
says Kotzebue, ‘ who was the best diver, frequently went down
to the bottom of the sea, where it is well known that the
* Malte-Brun’s Geography, vol. iii. p. 419,
H H 2
468 ORIGIN AND DISTRIBUTION OF MAN. [Cu. XLIII.
vater is not so salt, with a cocoa-nut shell, with only a small
opening.’* When these unfortunate men reached the isles
of Radack, every hope and almost every feeling had died
within them ; their sail had long been destroyed, their canoe
had long been the sport of winds and waves, and they were
picked up by the inhabitants of Aur ina state of insensibility ;
but by the hospitable care of those islanders they soon re-
covered, and were restored to perfect health.+
Captain Beechey, in his voyage to the Pacific, fell in with
some natives of the Coral Islands, who had in a similar
manner been carried to a great distance from their native
country. They had embarked, to the number of 150 souls, in
three double canoes, from Anaa, or Chain Island, situated
about 800 miles to the eastward of Otaheite. They were
overtaken by the monsoon, which dispersed the canoes ; and
after driving them about the ocean, left them becalmed, so
that a great number of persons perished. 'Two of the canoes
were never heard of; but the other was drifted from one
uninhabited island to another, at each of which the voyagers
obtained a few provisions; and at length, after having wan-
dered for a distance of 600 miles, they were found and carried
to their home in the Blossom.t
Mr. Crawfurd informs me that there are several well-
authenticated accounts of canoes having been drifted from
Sumatra to Madagascar, and by such causes a portion of the
Malayan language, with some useful plants, have been trans-
ferred to that island, which is principally peopled by negroes.
The space traversed in some of these instances was so great,
hat similar accidents might suffice to transport canoes from
various parts of Africa to the shores of South America, or
from Spain to the Azores, and thence to North America ; so
chat man, even in a rude state of society, is liable to be scat-
tered involuntarily by the winds and waves over the globe, in
a manner singularly analogous to that in which many plants
* Chamisso states that the water tT Kotzebue’s es 1815- 1818.
which they brought up was ear and Quarterly Review, vol. xxvi. p. 361.
in their opinion, less salt. It is difficult t Narrative of a nee age to the
to conceive its being fresher near the Pacific, &¢., in the years 1825, 1826,
bottom, except where subm: wine springs 1827, 1828, p. 170.
may happen is rise.
I
i
a en EE. pa
—
ir hative
Souls, in
situated
hey were
oes ; and
med, so
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Tom one
voyagers
ing wal-
1 carried
ae ee
Cu, XLII] ORIGIN AND DISTRIBUTION OF MAN. 469
and animals are diffused. We ought not, then, to wonder,
that during the ages required for some tribes of the human
race to attain that advanced stage of civilisation which em-
powers the navigator to cross the ocean in all directions with
security, the whole earth should have become the abode of
rude tribes of hunters and fishers. Were the whole of man-
kind now cut off, with the exception of one family, inhabit-
ing the old or new continent, or Australia, or even some coral
islet of the Pacific, we might expect their descendants, though
they should never become more enlightened than the Austra-
lians, the South Sea Islanders, or the Esquimaux, to spread
in the course of ages over the whole earth, diffused partly by
the tendency of population to increase, in a limited district,
beyond the means of subsistence, and partly by the accidental
drifting of canoes by tides and currents to distant shores.
Man has spread from a single starting-point.—The close
affinity of all the races of mankind in their bodily conforma-
tion and in their mental and moral attributes, and the manner
in which the most divergent varieties intermarry and blend
together, requires us to believe that the species was essen~
tially in all its characters what it now is before it began to be
diffused in the manner above supposed. The more we study
the relations of man to the rest of the organic world, the
more complete do we find his subjection to the same general
laws. If, therefore, we infer that every species of animal has
had a single birthplace, it is natural to expect that we shall
find that man is no exception to the rule, and that he also
spread over all the continents and islands from a single
starting-point. But it does not follow that all are descendants
of a single pair. Indeed, if we embrace the doctrine of
Transmutation, the process by which a new species comes into
being is by no means simple, and it is not easy to form a
precise idea of its elaboration during that period of transition
when certain varieties tending in a given direction are re-
peatedly getting the better of others in the struggle for life.
nder the constant influence of the same external conditions,
the characters of such varieties become intensified during
many successive generations, and when at last they are fixed
and permanent the ancestral type may have perished, or in
A470 ORIGIN AND DISTRIBUTION OF MAN. [Cu. XLII.
some cases may survive in certain stations, the intermediate
forms having been absorbed into one or other of the two
extremes. During a period when the powers of Variation
and Selection are so active, a considerable number of in-
dividuals closely allied in their organisation will intermarry
freely and multiply within a limited geographical area, and
will transmit the same peculiarities of bodily and mental
structure to their offspring. When, by this process, a large
homogeneous population has been formed, and their characters
have become fixed by inheritance, it will be long before sub-
sequent changes of climate, soil, food, and other conditions,
and, in the case of man, customs and institutions, will cause
any marked deviations from the normal type.
That it should be so difficult for us to picture to ourselves
the manner in which a species may be elaborated by Varia-
tion and Selection, need not surprise us when we consider
how hard itis to obtain a clear idea of the growth and estab-
lishment of a new language, even when we are sure that the
same has originated only a few centuries before our time.
In the case of the English tongue, for example, it would not
be easy to fix upon the exact year or generation when it was
formed, or to follow it through its various transitional phases
when the Anglo-Saxon stock was becoming modified by incor-
porating into it French, Danish, and Latin terms and idioms,
or when new modes of pronunciation were coming into vogue
or new and original expressions invented. The unity and per-
manency of character which finally sprang out of the blend-
ing together of such heterogeneous materials is a singular
phenomenon, and the want of pliancy of the same language
when transplanted into distant regions is also remarkable.
The modifiability of the language and its tendency to vary
never ceases, so that it would readily run into new dialects
and modes of pronunciation if there were no communication
with the mother country direct or indirect. In this respect its
mutability will resemble that of species, and it can no more
spring up independently in separate districts than species
can, assuming that these last are all of derivative origin.
Whether man’s bodily frame became more stationary when his
mind became more advanced.—Mr. Wallace, when commenting
————/Ee— OO
te
|
;
ie >
Medak,
The two
Of in.
ill Cause
urselyas
y Varia-
——
aa
Cu, XLIII.] SLOW FORMATION OF RACES. 471
on the distinctness of the leading races of mankind, especially
the Caucasian and Negro, and on the constancy of characters
maintained by these last for 4,000 years as proved by old
Kgyptian paintings, suggests that at some former period man’s
corporeal frame must have been more pliant and variable
than it is now; for according to the observed rate of fluctu-
ation in modern times, scarcely any conceivable lapse of ages
would suffice to give rise to such an amount of differentiation.
He therefore concludes that when first the mental and moral
qualities of man acquired predominance his bodily form ceased
to vary. He was enabled to meet all new exigencies springing
out of new conditions of existence by inventing new weapons,
by clothing himself and building houses to protect him
against the inclemency of the weather, by making use of fire
to render palatable and nutritious animal and vegetable sub-
stances, and above all by his powers of social combination.
Instead of the form of his limbs being modified or acquiring
more agility and strength, instead of his sight or hearing
becoming more acute, his body would remain stationary while
his intellectual faculties would continually improve.*
Before, however, we embrace the views here set forth, we
must be sure that we are not underrating the vastness of the
time which it may possibly have taken for races so different
as‘the Huropean and Negro to diverge from a common type.
Broca, in his work on Anthropology, when speaking of the
paintings preserved in Hgyptian temples nearly 4,000 years
old, says that, besides Negroes and Greeks, there are repre-
Sentations of Jews, Mongols, Hindoos, and natives of the
valley of the Nile, proving that all these types were then
as distinct as they are now. He nevertheless thinks that
climate, social condition, alimentation, and mode of life may
have determined originally the diversity of races, although it
is evident that three or four thousand years is but a minute
fraction of the time required to bring about such wide diver-
gence from a common parent stock.
r. C. L. Brace, in his answer to Mr. Wallace, has re-
marked that when members of the Anglo-Saxon race have
in the course of the last two centuries colonised a distant
* Human Races, &e. Anthropological Review, May 1864, p. clyiil.
472 DISTINCT RACES OF MAN [Cu. XLITI.
country, they have, as in the United States of America, de-
viated in an appreciable degree from the original type, in
spite of the frequent intermarriage of the new-settlerg with
emigrants coming from the mother country. ‘ The form,’
he says, ‘ has become more angular and muscular, the com-
plexion darker, and the face longer and thinner. The intel-
lectual and moral powers of the Anglo-American have not
been deficient, and yet they have not preserved him fromvaria-
tion.’ It is also very commonly asserted that in a few genera-
tions the English settlers in Australia have varied somewhat
after the manner of the Anglo-Americans. Grant that even
a slight change can be superinduced in two centuries, what
may not thousands of centuries have effected when the new
settlers were wandering into zones of latitude far more distinct
than those of England, North Africa, and South Australia ?
We may, however, concede to Mr. Wallace that when first
mankind emerged from its primitive dwelling-place and began
to people the unoccupied continents and islands, the forma-
tion of marked races may have proceeded at a somewhat
faster rate than now. After having been for a long time
as strictly confined to one district as are now the chim-
panzee or orang-utan, being still in a state of ignorance and
barbarism somewhat lower than that of the Australian savage
or the Andaman islander, man may have spread in scattered
hunter-tribes over new latitudes, often encountering very
ungenial climates in regions where food was abundant. Under
such circumstances the mortality of the population would be
great, and Natural Selection very active in giving a prefer-
ence to certain varieties over others. In Great Britain and
Belgium it has been shown by statistical returns that about
one tenth of the population die before they are a month old,
and one fourth in early childhood. If in the newly settled
territories the transitions from the extremes of heat and cold
were frequent, those individuals who had weak lungs would be
the victims, whereas in other regions where the temperature
was very equable throughout the year, these same persons
might be the most healthy and most likely to grow up and
become the progenitors of the race destined to people the
newly occupied district. So of other variations—in some
f
aN
Cu. XLIII.] COINCIDENT WITH ZOOLOGICAL PROVINCES. A735
cases a darker skin, in others a lighter complexion, might be
most favourable, but many generations must pass away before
qa combination of characters best suited to the surrounding
conditions would be attained.
Coincidence of the range of the more marked human races with
the great zoological provinces.—Professor Agassiz has called
attention to the important fact, that each of the more marked
races of the human family, such as the white race, the Chinese,
the New Hollanders, the Malays, and the Negroes, is limited
to some great zoological province. This circumstance, he
remarks, shows most unequivocally the intimate relation
existing between mankind and the animal kingdom in their
adaptation to the physical world. The same naturalist, how-
ever, has scarcely laid sufficient stress on one marked excep-
tion to this rule, namely, that over the whole continent of
America south of the Arctic zone (or the region which is
inhabited by Esquimaux) all the numerous tribes of Red
Indians have the same physical character and are of one and
the same race.* Dr. Morton had already declared this to be
the case after studying the craniological characters of the
American Indians from Canada to Patagonia. Nevertheless
this continent comprises two of the great zoological regions
before defined (pp. 8335—340) as the Neoarctic and Neotro-
pical. On independent grounds Mr. Henry W. Bates has
arrived at the conclusion that the Red Indian must have
immigrated in comparatively modern times into the hot
regions of equatorial America. Even the European, he
says, bears exposure to the sun or to unusually hot weather
quite as well as the Indians, while the Negro is far better
suited to the same climate, for he escapes many epidemic
diseases incidental to hot latitudes which cause great
havock among the Indians. The latter, according to Mr.
Bates, lives as a stranger in his own country, the valley of
the Amazons. His constitution was not originally fitted, and
has not since his immigration become perfectly adapted, to
the climate of tropical America.t
* Agassiz, pe ersity of Origin of the af ee Naturalist on the Amazons,
ee Races. Christian Examiner, vol. ii. p. 200
u
474 ORIGIN AND DISTRIBUTION OF MAN. [Cu, XLII.
We haveas yet no geological data to enable us to determine
the relative antiquity of man in the Old and New World.
Some fossil remains of our species found in the valley of the
Mississippi imply, if their geological position has been cor-
rectly ascertained, that man was contemporary with many
extinct quadrupeds and inhabited that region before it under-
went some of its latest geographical changes.* But as a
matter of speculation, if we assume that mankind, like every
other species, has had but one birthplace, and if we also sup-
pose him to have been derived from some nearly allied proto-
type, we must incline to the belief that the peopling of America
took place at a later period than that of the-Old World; for
man, as has been truly said, is an ‘ Old- World type,’ his bodily
structure, as before observed (p. 231), being closely related to
that of the quadrumana of Africa and Asia, and differing
widely from all the species of the Western Hemisphere. But
the first settling of mankind in America, though a compara-
tively modern event, may still date back as far as the Paleo-
lithic period ef Western Europe. Some of the latest changes
in the valley of the Mississippi and its tributaries may have
taken place since the remains of man and of some extinct
animals were buried in superficial deposits, yet throughout the
period of these geographical changes the chain of the Andes
may have been always continuous from Canafa to Patagonia,
and may have facilitated the spread of a single race from one
end of the continent to another.
Mr. Wallace in his memoir on Man in the Malay Archipe-
lago,t has explained how nearly the line a, b (map, fig. 132,
p- 347), which separates the regions of the Indian and the
Australian faunas, agrees with the geographical boundary
line c, 6 (ibid.) dividing the habitations of the Indo-Malayan
and the Papuan races. He describes the typical Malayan
race, found almost exclusively in the western half of the archi-
pelago, as of a light reddish brown colour with a more or less
olive tint, hair black and straight, the face almost destitute
of beard, the stature below the average European, while the
Papuan race is much darker, sometimes almost as black as
the Negro, the hair growing in tufts and frizzly, the face
* Lyell, ‘ Antiquity of Man,’ p. 200. ft Read at Brit. Assoc., Newexstle, 1864.
: eS eae ml e—=e eee
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r
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Cx, XLII] DISTINCTNESS OF EUROPEAN AND NEGRO. 475
adorned with a beard, the stature equal to that of the
European. ‘The intellectual and moral characteristics of the
two races are also described as strongly contrasted. These
Papuans are found in New Guinea, while the Malays inhabit
Borneo, two large islands almost exactly agreeing in climate
and physical features, and within 800 miles of each other, and
yet in which there is as total a diversity of animal productions
as there is distinctness in the races of man. If we assume
that these two races came originally from a common stock,
we must suppose that they have been each of them separately
exposed for hundreds of generations to a distinctness of
external conditions analogous to that which, according to the
theory of Transmutation, has, in the course of a much longer
period, produced the discordance of species observed in the
Indian and Australian regions.
Distinetness of Negro and European, and question of multiple
origin of man.—It must be admitted, however, that we cannot
so easily account for the differentiation of the Papuan and
the Malay races as we can understand how the Negro ac-
quired characters so different from all other members of the
human family. For the natural barriers of the Hthiopian
province, with the ocean on three sides and the great
desert (submerged in Pliocene times) on the fourth, may well
be supposed to have cut off for an indefinite lapse of ages a
barbarous population from all intercourse with the rest of
mankind, and to have given to peculiar external conditions
an opportunity of fixing certain variations and forming a race
without parallel in other parts of the world. The divergence,
indeed, of the Negro from the European, not only in the colour
of his skin, the texture and mode of growth of his hair, his
features, the proportion of his limbs, and the average size of
the brain, has led some naturalists to maintain that he is
more than a mere variety of mankind, and ought to rank as
& Separate species.
Professor Agassiz, without going so far, believes neverthe-
less that the parent stocks from which these and other
leading varieties have descended were originally distinct.
According to him, a great number of individuals of each o
the principal races of man were called into being when the
476 ORIGIN AND DISTRIBUTION OF MAN. [Cu. XLII.
race was created possessing all those characters which their
posterity afterwards inherited; just as the same author im-
agines that a great many representatives of each species of
animal, especially species having social habits, were created
in large numbers, so as at once to people the whole region
which they were destined to inhabit. This theory has at
least the merit of being consistent with itself, and relieves the
opponents of Transmutation from the dilemma of explaining
why, if so great a divergence from a parent type as that of
the white man and negro can take place, a like modifiability
should not be able, in the course of ages, to goa step farther,
and give rise to differences of specific value. That the races
of mankind should never have diverged so far as to become
incapable of intermarrying and producing fertile offspring is
quite intelligible, if we consider the manner in which tribe
wars against tribe, and how the inhabitants of the temperate
and colder regions have continually invaded and overpowered
the more indolent and less progressive tenants of tropical
latitudes. These conquests explain the blending at the point
of contact of one race into another, which has led many
naturalists to affirm that instead of the five principal types
of Blumenbach, there are fifty, if not more than a hundred
races, each of which have had their own Adam and Eve.
Six-fingered variety of man as bearing on the mutability of
his organisation.—Ag to the supposed want of flexibility in
the bodily structure of man ever since the Paleolithic period,
we ought to bear in mind that according to the theory of
Transmutation we can only expect those parts of his organ-
isation to vary, the improvement of which would be useful to
the individual or tribe giving them an advantage in the
struggle for life. We have seen (page 297), that the experi-
ments of the breeder and horticulturist prove that one part
of the organisation of an animal or plant may be greatly
altered by selection, while other parts which are neglected
remain unchanged or do not vary in a perceptible degree.
But the organ the variation of which would be most impor-
tant in the case of man is the brain, and it is on cerebral
ra Pea | "
lopment that Natural Selection would operate most
effectively. Before considering whether, in the course of
|
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Spring ig
hich tribe
emperate
Tpowered
L
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Rae
Cu. XLII] SIX-FINGERED VARIETY OF MAN. 477
thousands of generations, some favourable modifications may
not have taken place in this organ, giving to one race an
advantage over others, it may be well to allude to a singular
deviation from the normal standard which has been observed
in man, and some other of the mammalia, and which hag
deservedly attracted much attention. This deviation consists
in the oceurrence of six, instead of five digits, of which ex-
amples are found in the dog and the cat as well as in human
beings. Mr. Darwin, after having tabulated the cases of 46
persons with extra digits on one or both hands or feet, which
he found recorded in various works or which had been
privately communicated to him, ascertained that in this
number, 73 hands and 75 feet were thus affected, proving, in
contradiction to previous opinions, that the hands are not
more frequently affected than the feet. Professor Huxley
cites in detail from Reaumur the case of a Maltese couple
named Kelleia, who, having hands and feet constructed on the
ordinary human model, had born to them a son, Gratio, who
possessed six perfectly movable fingers on each hand, and six
toes, not quite so well formed, on each foot. This son mar-
ried a woman with the ordinary pentadactyle extremities, and
of their children one had six fingers and six toes, and the
others were of the normal type. The six-fingered son had
three out of four of his children six-fingered. But what
is more remarkable, two of Gratio’s children of the normal
type having married five-fingered wives or husbands, never-
theless reproduced in the next generation the six-fingered
variety. Thus, although in each case one parent and some-
times both were five-fingered, the six-fingered variety per-
sisted down to the grandchildren of Gratio. If, observes
Professor Huxley, some of these last had been matched with
their cousins having the same abnormal structure, we cannot
doubt that a six-fingered and six-toed race would have been
perpetuated. In these cases it usually happens that the
supernumerary digit is supported on a metacarpal bone, and
furnished with all proper muscles, nerves, and vessels, being
so perfect as to escape detection, unless the fingers are
actually counted. Additional digits, says Darwin, have been
observed in negroes as well as in the white races.
478 ORIGIN AND DISTRIBUTION OF MAN. [Cu XLII.
The frequent re-growth of supernumerary digits after they
have been cut off is another extraordinary fact which must
not be lost sight of by those who are disposed to speculate on
the nature and cause of this phenomenon. In one instance,
that of a person now living, the additional finger, when the
infant was about six weeks old, was removed at the joint, and
as soon as the wound healed, the digit began to grow, on
which the operation in about three months was repeated,
when the finger was once more reproduced including a bone.
In another example cited by Dr. Carpenter of a thumb double
from the first joint, the lesser thumb being furnished with a
nail was removed, but it grew again and reproduced a nail.*
Mr. Darwin regards these supernumerary digits in man as
retaining to a certain extent an embryonic condition, and
resembling in this respect the normal digits and limbs of the
lower vertebrate classes which are so prone to reproduction.
Spallanzani cut off the tail and legs of the same salamander
six times successively, and Bonnet cut them off eight times,
and they were always renewed. The pectoral and tail-fins
of many freshwater fish having been cut off have been per-
fectly restored in about six weeks’ time. Fishes have some-
times in their pectoral fins more than five, sometimes as
many as twenty, metacarpal and phalangeal bones forming
so many rays, and occasionally bearing bony filaments, which
together clearly represent our digits with their nails. So
again in certain extinct reptiles, the Ichthyopterygia, ‘the
digits may be seven, eight, or nine in number, a significant
mark,’ says Professor Owen ‘ of piscine afiinity.’+} Mr. Dar-
win therefore suggests that the excess in number and the
power of re-growth of the supernumerary digits in man may
be an instance of reversion to an enormously remote and
multidigitate progenitor of very inferior grade.t As the
number five is so strictly adhered to in the digits of all the
higher vertebrata, and is at least never exceeded as a rule in
any living reptile, bird, or mammal, the excess above alluded
to is generally regarded as a monstrosity, the more so because,
although six is the more common variety, yet there are some-
* Darwin, Origin of Species, chap. xu. t See above, p. 291, on Darwin's
> Thid.
]
theory of Pangenesis.
oduction,
lamander
ht times,
tail-fins
een per-
re some-
times as
forming
3, which
Je So
a, ‘the
nificant
SS ,
as _ ee a
a
|
Cu. XLII] BARBARISM OF PRIMEVAL MAN. 479
times from seven to more than ten fingers or toes, more or
less perfect, on the same hand or foot, and occasionally less
than five. Certainly this deviation from the ordinary stan-
dard, as well as the re-growth of the amputated limb, does
not point in the direction of progressive improvement. If
it be looked upon as a malformation occasionally shared by
other mammalia, it only adds one more to innumerable other
bonds of connection by which the inferior animals and man
are united, whether in the perfection, or the occasional im-
perfection, of their organisation.
Whether man has been degraded from a higher or has risen
from a lower stage of cwilisation—AIl our recent investiga-
tions in Kurope into the state of the arts in the earlier stone
age, lead clearly to the opinion that at a period many
thousands of years anterior to the historical, man wag in a
state of great barbarism and ignorance, exceeding that of
the most savage tribes of modern times. They were evidently
ignorant of metals, and of the arts of polishing stone im-
plements and of making pottery. Sir John Lubbock, in
discussing the question whether our ancestors have been
degraded from an original stock which was more highly
advanced in knowledge and civilisation, or has risen from a
lower state, observes that no fragment of pottery has been
found among the natives of Australia, New Zealand, and
the Polynesian islands, any more than ancient architectural
remains, in all which respects these rude tribes now living
resemble the men of the Paleolithic age. When pottery, he
says, is known at all, it is always abundant, and though easy
to break, it is difficult to destroy. It is improbable that so
useful an art should ever have been lost by any race of man.
The theory, therefore, that the Savage races have been de-
graded from a previous state of civilisation may be rejected.
‘Civilised nations long retain traces of their ancient bar-
barism, whereas barbarous ones retain no relics of a previous
more advanced state. The stone knives used by the Egyptian
and Jewish priests in religious ceremonies, after metal was
in use for secular purposes, point to an antecedent period
when such stone implements were in general use. ‘They
480 ORIGIN AND DISTRIBUTION OF MAN. (Cx. XLUE
would long be regarded as sacred, and there would be a
reluctance to use a new substance in religious ceremonies.’ *
Some have wished to found an argument in favour of the
superior mental endowments of the earliest races of mankind,
by pointing out that the Sanscrit, and some other of the
most ancient languages of Asia, are very artificial in their
erammatical construction and rich in abstract terms. But
the nations speaking these tongues will be regarded by every
geologist as modern when compared to the men of the Paleo-
lithic age. In tracing back the course of human events we
should first find a period when scattered migratory hordes
in the hunter state were spreading over Asia, and then a still
anterior period when one small area of land (possibly now in
great part submerged in the Indian or Pacific oceans) con-
tained the primitive stock from which they all have ramified,
and we may be sure, if the theory of Transmutation be true,
that such progenitors of mankind had a scantier vocabulary
than the humblest savage known to us. They would have
been unable to count as far as the fingers on one hand, and
would not have invented a single term expressive of an
abstract idea. When the first emigrants were spreading
over a wide continent, they would separate into small com-
munities, each of which would gradually acquire a language
of its own, but as often as one tribe became more powerful
than its neighbours, it would conquer them and absorb into
itself those who were not exterminated, imposing its lan-
guage on the conquered, yet sometimes borrowing from them
some terms and expressions. It is found that the number of
independent languages spoken in a continuous tract of land
is great in proportion to the barbarism of the natives.
Dominant tribes, as they multiply and advance in civilisation
and power, spread a single language over a vast area. The
Chinese for example, several thousand years before our time,
constituting as they still do a third of the population of the
globe, imposed on nearly the whole of their empire one lan-
euage, though diverging, it is true, into many dialects. How
long a time it required for one race thus to obtain supremacy
* On the Early Condition of Man, Sir John Lubbock. British Assoc. 1867.
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ive of an
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The
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premat]
1867
a — =
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BLENDING OF RACKS. 481
Cu. XLII]
over a large part of Asia, we know not, but we may look
forward to the time when the Europeans, especially the
Anglo-Saxon race, will in like manner spread over still larger
areas, displacing the aboriginal tribes of America, and, like
their predecessors the Red Indians, spreading from the Arctic
Region to Patagonia, so that one race and perhaps one
language may eventually prevail throughout the Neoarctic
and Neotropical provinces before alluded to.
It may seem to us almost incredible now that the progress
of the arts has given us such powers of locomotion, such
facilities of traversing continents and circumnavigating the
globe, to say nothing of exchanging ideas instantaneously
with the inhabitants of the remotest regions, that nations,
even after they had advanced far in civilisation, could remain
so isolated as we know them to have done. How the Greeks,
for example, in spite of their extraordi ary genius and
their spirit of commercial enterprise, could have continued
so ignorant of the geography of countries only a few hun-
dred miles distant from the coasts of the Mediterranean
and Black Seas. The superior power which science confers
is always increasing in a geometrical ratio, so that the dis-
placement of the weaker by the more civilised nations is
accelerated to an extent without parallel in the history of
the past. Hence in future there will be a greater blending
of races, and a constant tendency towards the establishment
of one race and one language throughout the globe. It
Seems probable that the divergence from a common stock
reached its climax, physically and psychologically, in the
formation of the Caucasian and Negro races. If, therefore,
we consider this differentiation as amounting only to one of
, Tace, it seems to follow that two rational species descending
from a common parentage cannot coexist on the globe. In
embracing this conclusion, however, we are not precluded from
entertaining the opinion that the descendants of the same
rational progenitors, if compared at two very distant times,
may not differ as much as might entitle them to rank as
distinct species,
M. Gaudry on intermediate forms between the Upper Miocene
and living mammalia.—The relationship of man to a supposed.
VOL. II. ait
482 ORIGIN AND DISTRIBUTION OF MAN. (Cu. XLII.
antecedent species nearly allied in bodily structure, offers at
present to the geologist a field of somewhat unprofitable
speculation, so long as the Pliocene and Post-Pliocene for-
mations of tropical Africa and India are still unexplored.
We are only beginning, by aid of paleontology, to trace back
the passage through a series of gradational forms from
the living mammalia to those of the Pliocene and still
older Miocene period. But in this department of osteology,
the evidence already obtained since the time of Cuvier, in
favour of transmutation, is certainly very striking. By no
naturalist has its bearing been more clearly pointed out than
by M. Gaudry, who, under the influence of the great teachers
who preceded him, entered on the enquiry with a theoretical
bias directly opposed to the conclusions which he now so
ably advocates. In his luminous memoir on the fossil bones
found at Pikermi, near Mount Pentelicus, fourteen miles
east of Athens, he has pointed out the transition through
many intermediate forms of Upper Miocene species to others
of Pliocene and Post-Pliocene date, showing how each suc-
cessive discovery has enabled us to bridge over many gaps
which existed only twenty or thirty years ago. Havin
myself had the advantage of seeing the original specimens
collected by this zealous geologist and now in the museum
of Paris, and having had the connecting links supplied by
species obtained from other parts of the world laid before me,
I have been able the more fully to appreciate the force of
the evidence appealed to in favour of transmutation. But
all who study M. Gatidry’s memoir may form an independent
opinion for themselves, by a glance atthe genealogical tables
of certain family types, in which the gradation of Miocene
through Pliocene and Post-Pliocene to living genera and,
species is traced.
In the list of proboscidians, for example, we behold chro-
nologically arranged more than thirty distinct species, be-
ginning with the mastodons of the Middle Miocene Period,
found in France, and continued through those of the Upper
Miocene of Ava, the Sewalik Hills, Pikermi, and Eppelsheim,
to the Pliocene forms of Southern India, Italy, and England,
where both the mastodons and elephants occur. Finally we
at teachers
theoretica]
he now go
Ossil bones
een miles
n through
3 to others
each sue-
many gaps
Having
specimens
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SS —~ cane
—~
Cu. XLIII.] THEORY OF TRANSMUTATION, 483
are conducted to the Post-Pliocene or quaternary species of
Europe and America, till we end with the two existing
elephants of India and Africa. Again of the rhinoceros
family, besides the five living species, fifteen extinct ones are
enumerated, and in addition to these, some generic forms of
older or Eocene date, belonging to the same great family.
The fossil pedigree of the horse tribe ig equally instructive,
traced from the Middle and Upper Miocene Hipparion of
France, Germany, Greece and India, through the Pliocene
and Post-Pliocene equine species of Hurope, India, and
America, to the living horse and ass. But the twelve equine
species referred by Leidy to seven genera detected in the
valley of the Niobrara in Pliocene and Post-tertiary for-
mations,* are omitted from this table as not having been
yet described in sufficient detail, and they would certainly, if
inserted in M. Gaudry’s table, help to fill up many a hiatus
between the forms which he has recognised. The pig family,
as well as some carnivora, such as the hyena, have also
furnished ample materials in illustration of the same law of
a gradual change of structure.
Even the quadrumana are beginning to afford proofs of
the manner in which the existing apes have ramified from
their extinct prototypes, although our information respecting
them, whether from Pikermi or elsewhere, has been hitherto
almost exclusively derived from extra-tropical latitudes,
where there are now no living representatives of the order.
Only fourteen species of the ape and monkey tribe have as
yet been detected in a fossil state, and each of these has
usually furnished but a few bones of its skeleton to the
osteologist. Yet they have not failed to throw much heht
on the transmutation hypothesis. The Dryopithecus of the
Miocene era of the south of France, though specifically
distinct from any ape now existing, comes so near to the
living Gibbon, or long-armed ape, as not to deserve, in Pro-
fessor Owen’s opinion, the separate generic rank assigned to
it by Lartet. All the other fossils of Europe and Asia have
an affinity to living species or genera of the Catarrhine
* See above, p. 337.
>
484 ORIGIN AND DISTRIBUTION OF MAN. [Cu, XLIII.
division, and those of America, found in Brazilian caves, to
the Platyrrhine.
As to the Mesopithecus of Pikermi, the skeleton is almost
complete, more so than that of any other fossil ape yet brought
to light. It differs generically from any of the living Indian
forms, not so much by presenting any novel features in its
structure as by combining characters which now belong to
two distinct Indian types. For, says M. Gaudry, one might
say that the living Semnopitheci of India have borrowed
their skulls from this Miocene type, while the living Macaci
have borrowed from it their Limbs. ‘In how different a
light,’ exclaims this eminent paleontologist, ‘does the question
of the nature of species now present itself to us from that
in which it appeared only twenty years ago, before we had
studied the fossil remains of Greece and the allied forms of
other countries ; how clearly do these fossil relics point to the
idea that species, genera, families, and orders now so distinct,
have had common ancestors ! ’—‘ 'The more we advance and fill
up the gaps, the more we feel persuaded that the remaining
voids exist rather in our knowledge than in nature. A few
blows of the pickaxe at the foot of the Pyrenees, of the
limalaya, of Mount Pentelicus in Greece, a few diggings in
the sandpits of Eppelsheim, or in the Mauvaises Terres of
Nebraska, have revealed to us the closest connecting links
between forms which seemed before so widely separated !
How much closer will these links be drawn when paleon-
tology shall have escaped from its cradle! ’*
Many of the most cultivated literary critics, and some
eminent mathematicians, have shown, in the discussions which
have arisen on the origin of species, an entire incapability
of weighing and appreciating the evidence for and against
Transmutation, and this chiefly for two reasons: first, they
have never been called upon, as classifiers in natural history,
practically to decide whether certain forms, fossil or recent,
should rank as species or as mere varieties—a point on which
the most eminent zoologists and botanists often disagree ;
secondly, they are quite unconscious of the fragmentary
* Gaudry, Animaux Iossiles de Pikermi, 1866, p. 34.
|
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from that
re we had
d forms of
oint to the
0 distinct,
nee and fill
remaining
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es, of the
iggings m
Terres of
ing links
arated '
paleon-
ea
> ~—
on. oo
Cu. XLII] CEREBRAL CONFORMATION. 485
nature of the record with which the geologist has to deal.*
To one who is not aware of the extreme imperfection of this
record, the discovery of one or two missing links is a fact of
small significance ; but to those who are thoroughly imbued
with a deep sense of the defectiveness of the archives, each
new form rescued from oblivion is an earnest of the former
existence of hundreds of species, the greater part of which are
irrecoverably lost.
Progressive development in the cerebral conformation of the
vertebrata, including man.—I have already remarked when
combating the notion that man in his corporeal structure has
arrived at a fixed and stationary condition, that we have
no right to make such an assumption, until we have acquired
a more definite idea of the number of centuries which it
took for the most marked of the human races to diverge, in
different directions, so far from a common type. The rate of
change generally in the animal and vegetable kingdoms is
slow and insensible, and naturalists have never yet witnessed
the formation of any one of the wild races which they regard
as mere geographical varieties. They know not how many
thousand generations it may have required to produce such
changes; but we cannot infer in their case, or in that of man,
that the era of the immutability of species has arrived. If
the organisation of man has been modified in comparatively
modern times, it is probably, as before hinted, in his cerebral
development that variation has been manifested.
Linneus declared that he could not distinguish man
generically from the ape, and Professor Owen has spoken of
the ‘all-pervading similitude of structure—every tooth, every
bone, being strictly homologous ’—yet the same great anato-
mist considers man’s superior cerebral development as en-
titling him to be placed in a sub-class apart from all the
other mammalia. He has proposed a new classification of
the highest division of the vertebrata with reference to the
characters of their brain, and its greater or less resemblance,
in volume and structure, to that of man. Some have ob-
jected, not perhaps without reason, that every such attempt
* See above, Vol. I. p. 318.
486 ORIGIN AND DISTRIBUTION OF MAN. (Cu. XLIII,
to classify the animate creation by reference to a single
organ, or one set of characters, has failed, and that in order
to obtain a natural system of arrangement, we must duly
consider the combined claims of as large a partas possible of
the whole organisation. Nevertheless the extent to which
cerebral conformation, taken by itself, has enabled Professor
Owen to place the genera and orders of mammalia in an
ascending scale, shows how predominant is the importance of
the brain, and the intimate connection of this mysterious
organ with mental power. We see the monotremes (the
Echidna and duck-mole) take the lowest place in the scale,
followed by the marsupials, all having brains the most
dissimilar in capacity and form from that of man; while the
quadrumana take the highest place measured by the same
standard, the family to which the chimpanzee and gorilla
belong being at the head of the long list of tabulated genera
and orders. It will also be observed that the bats, instead
of maintaining the leading position among the ‘ Primates’
which they occupied in the Linnean classification, are as-
signed to a different and inferior sub-class, far more in
accordance with their relative intelligence.
If we go still farther and compare the mammalia with the
fish, or the lowest class of the vertebrata, we find a con-
tinuance of the same descending scale in accordance with a
diminution in the volume of brain, as well as in a lessened
concentration of the nervous system in one part of the
animal; for the farther we recede from the human type, the
smaller is the proportionate quantity and weight of the
brain as compared to the spinal marrow. It is true that in
attempting to apply these rules in detail the anatomist is
often at fault, because he finds that in any given group of
animals the larger species have proportionately smaller
brains, or, in other words, the mass of the brain does not
increase in the same ratio as the general bulk of the animal.
Still the general proposition before laid down holds good,
that the degree of intelligence and mental power enjoyed by
the inferior animals increases with the increase of their
cerebral capacity, and with the resemblance in the structure
of their brain to that of man.
——— yaw
the same
id gorilla
ed generg
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lessened
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|
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Cu. XLUI.] PROGRESSIVE DEVELOPMENT. 487
Tf we take the Hottentot as the least advanced variety of
the negro type, we find not only the volume of the brain to
be far below that of the average of the European, but that
the two hemispheres are more symmetrical, and that in this
nd every peculiarity in which it deviates from the Caucasian
standard, it approaches nearer in character to the Simian
brain. The theory therefore of Progressive Development
and Transmutation would lead us to anticipate that the
human skull of the Paleolithic Period would prove to be
more pithecoid than the cranium of any living race. Our
data are as yet too scanty to allow of our drawing safe con-
clusions from the fossil remains of the era in question, for
the Neanderthal skull may be an exceptional variety, as may
some other remains of a somewhat ape-like character, lately
brought to light by M. Dupont from a deposit containing
the relics of extinct mammalia in the Belgian caves. It
may also be said that there is no reason why the Paleolithic
cranium should be much if at all inferior to that of an
Australian, for the state of the arts in the Paleolithic Period
accords well with that phase of advancement which the
Australian and some other savage tribes had reached when
they first became known to Huropeans.
In the ninth chapter of the first volume, a brief summary
was given of the evidence in favour of the successive ap-
pearance in chronological order of fish, reptile, bird and
mammal, and lastly among the mammalia, the coming in of
those anthropomorphous species which most resemble man
in structure. If we then regard the advent of man as the
last and culminating point attained in this continuous series
of developments, we may well imagine that, during the tran-
sition from the quadrumanous to the human organisation,
the brain was that part which underwent the chief modifica-
tion. And when its growth and improvement had once
conferred on man a ‘decided superiority over the brutes, it
would continue to be the organ which would go on im-
proving, so as to give one race an advantage over others in
the strugele for life.
Even if the paleontologist had obtained fossil crania of
an age immediately antecedent to the Paleolithic, it might
488 ORIGIN AND DISTRIBUTION OF MAN. [Cu. XLITII.
be difficult for him to derive from them a knowledge of the
successive steps made in an ascensive scale, if, as some
physiologists suspect, the quality of the brain has often
more to do than its quantity with intellectual superiority.
But although size alone may be no safe criterion of relative
mental power, it is undeniable that the skulls of a hundred
individuals of transcendent ability would exceed in their
average dimensions the skulls of an equal number of persons
of inferior mental power. Whether the brain, like an
other organ, gains strength by exercise, and whether an
improvement thus acquired in the intellectual faculties may
be handed down to the offspring by inheritance, are still
matters of controversy. But no one is disposed to dispute
that if some modification of an organ, or instinct, be pro-
duced by what is called ‘ spontaneous variation,’ there is a
decided propensity in the new structure or attribute to
perpetuate itself by inheritance, as in the case of the six-
fingered variety of man, before mentioned (p. 476), or the
stunted legs of the Ancon sheep (p. 312
If, therefore, it be part of the plan of nature that living
beings should occasionally give birth to varieties in some
slight degree more perfect in the specialisation of their paris
and organs, or in the perfection of an organ, instinct, or
mental faculty, than had been enjoyed by any of their prede-
cessors, Natural Selection will ensure the eventual success of
such individuals in the struggle for life. When Mr. Darwin
says that he does not believe in a law of necessary develop-
ment, he means that simple and unimproved structures may
sometimes be best fitted for simple conditions of life, and that
even a degradation instead of an advance in structure may
occasionally be advantageous. Nevertheless, in the long run,
there will be a tendency, in the higher and more perfect
organisms, to survive and multiply, not at the expense of the
lower, with most of whom they will never come into competi-
tion, but at the expense of those which are most nearly allied to
them. The repeated failure of particular varieties having
organs and attributes somewhat superior to any of their pro-
genitors, by no means implies that the final predominance of
such organisms is left to chance. It suffices that there should
Ultieg thay
y are stil
{0 dispute
t, be pro.
there is
tribute to
f the six-
)), or the
hat living
in some
\eir paris
stinct, or
ir prede-
recess of
Darwin
levelop-
es may
nd that
re may
SS
ee
|
Cx, XLUL] LAW OF PROGRESS. 489
be a power in nature, capable of giving rise to individuals in
advance of all which have preceded them, and it then becomes
simply a question of time how soon the more improved
varieties will prevail. Their final success is certain, though
many adverse circumstances may retard the rate of progress.
Suppose a human infant endowed with intellectual capacity
superior to that of any one previously born into the world; it
is as liable to be cut off in childhood as one less gifted, but
it has also an equal chance of growing up, and if it attains
maturity it will promote the advancement of the tribe to which
it belongs, inventing perhaps some warlike weapon or better
laws and institutions, and there will be a great probability
of some of the children of such an individual inheriting an
amount of talent above the average of their generation. The
more civilisation advances the less will mere bodily strength
and acuteness of the senses confer social superiority. But
still, as Darwin says, there is no fixed and necessary law of
progress. The institutions of a country may be so framed
that individuals possessing moderate or even inferior abilities
may have the best chance of surviving. Thus the Holy In-
quisition in Spain may for centuries carefully select from the
thinking part of the population all men of genius, all who dare
to question received errors and who have the moral courage
to express their doubts, and may doom them by thousands
to destruction, so as effectually to lower the general standard
of intelligence. But such exceptional institutions will not
arrest the onward march of the human race. It will only
depress one nation, causing it to decline in knowledge, power,
wealth, population, and political influence, and prepare for
the day when it will be conquered by some other people in
which freer scope has been given to intellectual progress.
Objections to Darwin’s theory of Natural Selection.—The
Duke of Argyll, in his lately published work on the < Reign of
Law,’ has made some valuable criticisms on Mr. Darwin’s
theory of Natural Selection, to which, in conclusion, I shall
now allude. After observing that we know nothing of the
natural forces by which new forms of life are called into being,
he says that if there were evidence that the new could be de-
veloped from the old, he cannot see why there should be any
490 ORIGIN AND DISTRIBUTION OF MAN. [Cu. XLII.
reluctance to admit the fact.* But he denies that sufficient
evidence in support of such a theory has yet been adduced.
The introduction, he admits, of new species ‘ to take the place
of those which have passed away, is a work which has been
not only so often but so continuously repeated that it doeg
suggest the idea of having been brought about through the
instrumentality of some natural process.’+ This process, or
‘the adaptation of forces which can compass the required
modifications in animal structure in exact proportion to the
need of them, is in the nature of creation.’ But Mr. Darwin,
he says, does not pretend to explain how new forms first ap-
pear, but only how when they have appeared they acquire a
preference over others. Mr. Darwin frankly confesses that
our ignorance of the laws of variation is profound: yet, says
the Duke, he seems sometimes to forget this and to speak of
Natural Selection as if it could account for the origin of
species, whereas, according to his own definition, it ‘can do
nothing except with the materials presented to its hands.
It cannot select except among things open to selection. It
can originate nothing; it can only pick out and choose
among the things which are originated by some other law.’
To speak therefore of Natural Selection ag < producing’
certain modifications of structure or new organs, and as
‘adapting’ them, is to ascribe to it results which it can-
not bring about, and “the cause of which we cannot even
guess at.’§
To me it appears that these criticisms are fairly applicable
to those passages in Mr. Darwin’s ‘Origin of Species,’ in
which Natural Selection is spoken of as capable of bringing
about any amount of change in the organs of an animal
provided a series of minute transitional steps can be pointed
out by which the transmutation may have been effected.
Thus, for example, if some one of the invertebrate animals
has a membrane or tissue without a single nerve, yet sensi-
tive to light, while another creature such as an eagle is
furnished with a perfect eye in which there is an apparatus
for concentrating the luminous rays, and for refracting
* Reign of Law, p. 227.
tT Ibid. p. 228.
{ Reign of Law, p. 2380.
§ Ibid. p. 254.
0 speak of
origin of
it ‘can do
its hands.
ction. It
1d choose
her law.’
roducing’
s, and as
h it ca-
not evel
pplicable
eS, “ m
—
~o2— ea
—— ~. —
———
Cu. XLIII.] THEORY OF NATURAL SELECTION. 491
pictures of external objects with optic nerves to convey
these images to the brain, it is suggested that we may
understand how this perfect organ may have been ‘ formed
by Natural Selection’ if we can only find in nature a series
of animals which have organs of vision exhibiting all the
intermediate grades of structure between the two extreme
forms above mentioned. But in reality it cannot be said
that we obtain any insight into the nature of the forces
by which a higher grade of organisation or instinct is evolved
out of a lower one by becoming acquainted with the gra-
dational forms or states which have been passed through
during the transmutation. Hven if we could discover geo-
logical evidence that every modification between a mere
power of sensation like that of a sponge and the intelligence
of an elephant had been represented by every intermediate
degree of instinct and capacity, and that beings endowed
with faculties more and more perfect had succeeded each
other in chronological order according to their relative
perfection, like the successive stages in the development
of the embryo from a simple germ-cell to the infant
mammifer, still the mystery of creation would be as great,
and as much beyond the domain of science, as ever. It is
when there is a change from an inferior being to one of
superior grade, from a humbler organism to one endowed
with new and more exalted attributes, that we are made
to feel that no modification of a progenitor, no principle
of inheritance, can explain the phenomenon. The ancestor
could not bequeath to its posterity that which it did not
possess itself, still less could the causes determining the
‘survival of the fittest’ give origin to individuals more
fit to occupy a conspicuous place in the system of nature
than any which had preceded them.
The author, however, of the ‘Reign of Law’ has by no
means argued, like the majority of Mr. Darwin’s opponents,
as if nothing had been gained by the theory of Natural
Selection, merely because this principle may have had func-
tions assigned to it far higher than it can possibly discharge.
The real question at issue—that on which the ‘ Origin of
Species’ has thrown so much light—is the same as that
492 ORIGIN AND DISTRIBUTION OF MAN. [Cu. XLIITI,
discussed by us in the last ten chapters. It is not whether we
can explain the creation of species, but whether Species have
been introduced into the world one after the other, in the form
of new varieties of antecedent organisms and in the way of
ordinary generation, or have been called into being by some
other agency, such as the direct intervention of the First
Cause. Was Lamarck right, assuming progressive develop-
ment to be true, in supposing that the changes of the organic
world may have been effected by the gradual and insensible
modification of older pre-existing forms? Mr. Darwin, with-
out absolutely proving this, has made it appear in the highest
degree probable, by an appeal to many distinct and indepen-
dent classes of phenomena in natural history and geology,
but principally by showing the manner in which a multitude
of new and competing varieties are always made to survive
in the struggle for life. The tenor of his reasoning is
not to be gainsaid by affirming that the causes or processes,
which bring about the improvement or differentiation of
organs, and the general advance of the organic world from
the simpler to the more complex, remain as inscrutable to us
as ever. .
When first the doctrine of thé origin of species by trans-
mutation was proposed, it was objected that such a theory
substituted a material self-adjusting machinery for a Supreme
Creative Intelligence. But the more the idea of a slow and
insensible change from lower to higher organisms, brought
about in the course of millions of generations according to
a preconceived plan, has become familiar to men’s minds, the
more conscious they have become that the amount of power,
wisdom, design, or forethought, required for such a gradual
evolution of life, is as great as that which is implied by a
multitude of separate, special, and miraculous acts of crea-
tion.
A more serious cause of disquiet and alarm arises out of
the supposed bearing of this same doctrine on the origin of
man and his place in nature. It is clearly seen that there
is such a close affinity, such an identity in all essential points,
in our corporeal structure and in many of our instincts
7 . . a 7 mei 1
and passions, with those of the lower animals—that man is so
gedlogy,
multitude
tO Survire
soning js
processes,
lation of
rid from
ible to us
by trans-
a theory
Supreme
Jow and
|
Se
~— mL i
———— pT
a,
|
|
|
Cu. XLIII.] PALEOLITHIC MAN. 493
completely subjected to the same general laws of reproduc-
tion, increase, growth, disease, and death,—that if progres-
sive development, spontaneous variation, and natural selection
have for millions of years directed the changes of the rest of
the organic world, we cannot expect to find that the human
race has been exempted from the same continuous process of
evolution. Such a near bond of connection between man
and the rest of the animate creation is regarded by many as
derogatory to our dignity. It certainly gives a rude shock to
many traditional beliefs, and dispels some poetic illusions re-
specting an ideal genealogy which scarcely ‘appeared less than
archangel ruined.’ But we have already had to exchange
the pleasing conceptions indulged in by poets and theologians
as to the high position in the scale of being held by our
early progenitors, for more humble and lowly beginnings,
the joint labours of the geologist and archeologist having
left us in no doubt of the ignorance and barbarism of Paleo-
lithic Man.*
We are sometimes tempted to ask whether the time will
ever arrive, when science shall have obtained such an ascen-
dancy in the education of the millions, that it will be possible
to welcome new truths, instead of always looking upon them
with fear and disquiet, and to hail every important victory
gained over error, instead of resisting the new discovery, long
after the evidence in its favour is conclusive. The motion of
our planet round the sun, the shape of the earth, the existence
of the antipodes, the vast antiquity of our globe, the distinct
assemblages of species of animals and plants by which it
was successively inhabited, and lastly the antiquity and bar-
barism of Primeval Man, all these generalisations, when first
announced, have been a source of anxiety and unhappiness.
The future now opening before us begins already to reveal
new doctrines, if possible more than ever out of harmony
with cherished associations of thought. It. is therefore de-
sirable, when we contrast ourselves with the rude and super-
stitious savages who preceded us, to remember, as cultivators
of science, that the high comparative place which we have
* For remarks on Paleolithic Man sec close of Chapter XLVII.
494 ORIGIN AND DISTRIBUTION OF MAN. [Cu. XLIII.
reached in the scale of being has been gained step by step
‘by a conscientious study of natural phenomena, and by
fearlessly teaching the doctrines to which they point. It is
by faithfully weighing evidence, without regard to precon-
ceived notions, by earnestly and patiently searching for what
is true, not what we wish to be true, that we have attained
that dignity, which we may in vain hope to claim through the
rank of an ideal parentage.
a
|
CHAPTER XLIV.
ENCLOSING OF FOSSILS IN PEAT, BLOWN SAND, AND VOLCANIC
EJECTIONS.
DIVISION OF THE SUBJECT—IMBEDDING OF ORGANIC REMAINS IN DEPOSITS ON
EMERGED LAND—GROWTH OF PEAT—SITE OF ANCIENT FORESTS IN EUROPE
NOW OCCUPIED BY PEAT—BOG IRON-ORE PRESERVATION OF ANIMAL SUB-
STANCES IN PEAT—MIRING OF QUADRUPEDS—BURSTING OF THE SOLWAY
MOSS—IMBEDDING OF ORGANIC BODIES AND HUMAN REMAINS IN’ BLOWN
SAND—GREAT DISMAL SWAMP—MOVING SANDS OF AFRICAN DESERTS—BURIED
TEMPLE OF IPSAMBUL IN EGYPT—DRIED CARCASSES IN THE SANDS OF THE
DESERT—SAND-DUNES AND TOWNS OVERWHELMED BY SAND-FLOODS—IMBED-
DING OF ORGANIC AND OTHER REMAINS IN VOLCANIC FORMATIONS ON THE
LAND
THE second branch of our enquiry, respecting changes of
the organic world, relates to the processes by which the
remains of animals and plants become fossil, or are buried in
the earth by natural causes. M. Constant Prevost divided
the effects of geological causes into two great classes: those
produced during the submersion of land beneath the waters,
and those which take place after its emersion. Agreeably to
this classification, I shall consider, first, in what manner
animal and vegetable remains become included and preserved
in deposits on emerged land, or that part of the surface
which is not permanently covered by water, whether of lakes
or seas; secondly, the manner in which organic remains
become imbedded in deposits of lakes and seas.
Under the first division, I shall treat of the following
topics :—I1st, the growth of peat, and the preservation of
vegetable and animal remains therein ; 2ndly, the burying of
organic remains in blown sand; 3rdly, of the same in the
ejections and alluviums of volcanos; 4thly, in alluviums
generally, and in the ruins of landslips; 5thly, in the mud
and stalagmite of caves and fissures.
496 ENCLOSING OF FOSSILS IN PEAT, [Cu. XLIV.
Growth of peat, and preservation of vegetable and animal
remains therem.—The generation of peat, when not com-
pletely under water, is confined to moist situations, where
the temperature is low. It may consist of any of the nu-
merous plants which are capable of growing in such stations ;
but a species of moss (Sphagnum) constitutes a considerable
part of the peat found in marshes of the north of Europe;
this plant having the property of throwing up new shoots in
its upper part, while its lower extremities are decaying.*
Reeds, rushes, and other aquatic plants may usually be traced
in peat; and their organisation is often so entire that there
is no difficulty in discriminating the distinct species.
Analysis of peat.—In general, says Sir H. Davy, one
hundred parts of dry peat contain from sixty to ninety-nine
parts of matter destructible by fire ; and the residuum consists
of earths usually of the same kind as the substratum of
clay, marl, gravel, or rock, on which they are found, together
with oxide of iron. ‘The peat of the chalk counties of
England,’ observes the same writer, ‘ contains much gypsum:
but I have found very little in any specimens from Ireland
or Scotland, and in general these peats contain very little
saline matter.’+ From the researches of Dr. MacCulloch, it
appears that peat is intermediate between simple vegetable
matter and lignite.t
Peat abundant in cold and humid climates.—Peat is some-
times formed on a declivity in mountainous regions, where
there is much moisture; but in such situations it rarely, if
ever, exceeds four feet in thickness. In bogs, and in low
grounds into which alluvial peat is drifted, it is found forty
feet thick, and upwards; but in such cases it generally owes
one half of its volume to the water which it contains. It
has seldom, if ever, been discovered within the tropics ; and
it rarely occurs in the valleys, even in the south of France
and Spain. It abounds more and more, in proportion as we
advance farther from the equator, and becomes not only
more frequent but more inflammable in northern latitudes.§
* For a me of plants which + Irish Bog Reports, p. 209.
form peat, see Rev. Dr. Rennie’s Essays + System of Geology, vol. ii. p. 353.
on Peat, p. 71; and. ee ‘Moctuliagtg § Rey. Dr. Rennie on Peat, p. 260.
Western Isles, vol. i
be traced
hat there
avy, one
n ety-nine
D COnsists
unties of
gypsum:
. Ireland
ery little
loch, it
egetable
ee
Cu. XLIV.] BLOWN SAND, AND VOLCANIC EJECTIONS. 497
The same phenomenon is repeated in the southern hemi-
sphere. No peat is found in Brazil, nor even in the Swampy
parts of the country drained by the La Plata on the east
side of South America, or in the island of Chiloe on the
west; yet when we reach the 45th degree of latitude and
examine the Chonos Archipelago or the Falkland Islands,
and Tierra del Fuego, we meet with an abundant erowth of
this substance. Almost all plants contribute here by their
decay to the production of peat, even the grasses; but it is
a singular fact, says Mr. Darwin, as contrasted with what
occurs in Kurope, that no kind of moss enters into the com-
position of the South American peat, which is formed by
many plants, but chiefly by that called by Brown Astelia
pumila.*
I learnt from the late Dr. Forchhammer, in 1849, that water
charged with vegetable matter in solution does not throw
down a deposit of peat in countries where the mean tempera-
ture of the year is above 43° or 44° Fahrenheit. Frost
causes the precipitation of such peaty matter, but in warm
climates the attraction of the carbon for the oxygen of the
air mechanically mixed with the water increases with the
increasing temperature, and the dissolved vegetable matter
or humic acid (which is organic matter in a progressive state
of decomposition) being converted into carbonic acid, rises
and is absorbed into the atmosphere, and thus disappears.
Extent of surface covered by peat.—There is a vast extent
of surface in Europe covered with peat, which, in Ireland, is
said to spread over a tenth of the whole island. One of the
mosses on the Shannon is described as being fifty miles long,
by two or three broad; and the great marsh of Montoire,
near the mouth of the Loire, is mentioned by Blavier, as
being more than fifty leagues in circumference. According to
Rennie, many of these mosses of the north of Europe occupy
the place of forests of pine and oak, which have, many of
them, disappeared within the historical era. Such changes
are brought about by the fall of trees and the stagnation of
water, caused by their trunks and branches obstructing the
* Darwin’s Journal, p. 349; 2nd ed, Dp: 287
VOL. i,
498 ENCLOSING OF FOSSILS IN PEAT, [Cu. XLIV.
free drainage of the atmospheric waters, and giving rise to
a marsh. In a warm climate, such decayed timber would
immediately be removed by insects, or by putrefaction ; but,
in the cold temperature now prevailing in our latitudes,
many examples are recorded of marshes originating in this
source. Thus, in Mar forest, in Aberdeenshire, large trunks
of Scotch fir, which had fallen from age and decay, are said
to have been soon immured in peat, formed partly out of
their perishing leaves and branches, and in part from the
growth of other plants. We are also told that the overthrow
of a forest by a storm, about the middle of the seventeenth
century, gave rise to a peat-moss near Lochbroom, in Ross-
shire, and that, in less than half a century after the fall of the
trees, the inhabitants dug peat there.* But the rate at which
peat is known to form in places where its growth has been
carefully noted by scientific observers, is so slow that it is
necessary to receive these accounts with caution.
Nothing is more common than the occurrence of buried
trees at the bottom of the Irish peat-mosses, as also in most
of those of England, France, and Holland; and they have
been so often observed with parts of their trunks standing
erect, and with their roots fixed to the subsoil, that no doubt
can be entertained of their having generally grown on the
spot. They consist, for the most part, of the fir, the oak,
and the birch: where the subsoil is clay, the remains of
oak are the most abundant; where sand is the substratum,
fir prevails. In the marsh of Curragh, in the Isle of Man,
vast trees are discovered standing firm on their roots, though
at the depth of eighteen or twenty feet below the surface.
Some naturalists have desired to refer the imbedding of
timber in peat-mosses to aqueous transportation, since rivers
are well known to float wood into lakes; but the facts above
mentioned show that, in numerous instances, such an hy-
pothesis is inadmissible. It has, moreover, been observed,
that in Scotland, as also in many parts of the Continent,
the largest trees are found in those peat-mosses which lie in
the least elevated regions, and that the trees are propor-
* Rennie’s Essays on Peat, p. 69.
C fall of the
te at which
th has been
y that it js
> of buried
Iso in most
they have
s standing
+t no doubt
ywn on the
r, the oak,
emails of
abstratw,
Cu. XLIV.]
BLOWN SAND, AND VOLCANIC EJECTIONS. 499
tionally smaller in those which lie at higher levels; from
which fact De Lue and Walker have both inferred that the
trees grew on the spot, for they would naturally attain a
greater size in lower and warmer levels. The leaves, also,
and fruits of each species, are continually found immersed
in the moss along with the parent trees; as, for example,
the leaves and acorns of the oak, the cones and leaves of the
fir, and the nuts of the hazel.
Supposed recent origin of some peat-mosses.—In Hatfield
moss, in Yorkshire, which appears clearly to have been a
forest eighteen hundred years ago, fir-trees have been found
90 feet long, and sold for masts and keels of ships; oaks have
also been discovered there above 100 feet long. The dimen-
sions of an oak from this moss are given in the Philosophical
Transactions, No. 275, which must have been larger than
any tree now existing in the British dominions.
In the same moss of Hatfield, as well as in that of Kin-
cardine, in Scotland, and several others, Roman roads are
said to have been found covered to the depth of eight feet
by peat, and it thas also been affirmed that all the coins,
axes, arms, and other utensils found in British and French
mosses, are Roman. But the more careful examinations
made of late years of the deposits of peat about 30 feet thick
at Amiens, Abbeville, and other places in the valley of the
Somme, lead me to distrust the inferences formerly drawn as
to the age of a large portion of the European peat, which
has been supposed to be of later date than the time of
Julius Caesar. M. Boucher de Perthes has ascertained that
Gallo-Roman remains occur at Abbeville, in peat nearer the
surface than the more ancient weapons called Celts of the
Stone Period. The same antiquary also. remarks that the
depth at which Roman works of art are met with, is not
always a sure test of age, because in some parts of the
Swamp, especially near the river, the peat is often so fluid
that heavy substances may sink through it.* Recent re-
searches may be said to have demonstrated that no small
part of the European peat is pre-Roman and belongs to the
* See ‘ Antiquity of Man,’ p. 110.
KK 2
500 ENCLOSING OF FOSSILS IN PEAT, [Cu. XLIV.
age of bronze instruments, and even in great part to the
antecedent Neolithic Stone Period, of which more will be
gaid in Chapter XLVII.
According to De Luc, the very site of the aboriginal forests
of Hercinia, Semana, Ardennes, and several others, are now
occupied by mosses and fens. A great part of these changes
have, with much probability, been attributed to the strict
orders given by Severus, and other emperors, to destroy all
the wood in the conquered provinces. So also many of the
British forests, which are now mosses, were cut at different
periods, by order of the English parliament, because they
harboured wolves or outlaws. Thus the Welsh woods were
cut and burnt, in the reign of Edward I.; as were many of
those in Ireland, by Henry II., to prevent the natives from
harbouring in them, and harassing his troops.
Tt is a remarkable fact that in the Danish islands, and in
Jutland as wellas in Holstein, trunks of the Scotch fir, Pinus
sylvestris, are found at the bottom of the peat-mosses, al-
though this species of fir has not been a native of the same
countries in historical times, and, when introduced there, has
not thriven. Higher up in the Danish peat-mosses, prostrate
trunks of the sessile variety of the common oak occur, while
at a still higher level, the pedunculated variety of the same
oak, Quercus robur, Linn., is met with, together with the
alder, birch, and hazel. The oak has now in its turn been
almost supplanted in Denmark by the common beech. There
appears therefore to have been a natural rotation of trees,
whether owing to the exhaustion of the soil, or a change of
climate in Denmark; one set of species, which lived on the
borders of the swamps, having died out and another suc-
ceeded. These changes took place, all of them, before the
historical era; but remains of man have been found even in
the fundamental peat in which the Scotch firs lie buried, and
a flint implement has been taken out, by Steenstrup himself,
from below one of the buried pines. It was a weapon of
the later Stone Period or Neolithic Age—no remains of
Paleolithic Man having as yet been discovered in any part
of Scandinavia.*
* Lubbock, introduction to Nilsson on the Stone Age, 1868.
(Cy, Xu
the
be
Part to
AD wil
latives from
ands, and in
ch fir, Pinus
mosses, al-
of the same
d there, has
ps, prostrate
secur, while
red on
other gu
pefore
nd eve? f
any pe
Cu. XLIV.] BLOWN SAND, AND VOLCANIC EJECTIONS. 501
Sources of bog won-ore.—At the bottom of peat-mosses
there is sometimes found a cake, or ‘ pan,’ as it is termed, of
oxide of iron, and the frequency of bog iron-ore is familiar
to the mineralogist. The oak, which is so often dyed black
in peat, owes its colour to the same metal. From what
source the iron is derived has often been a subject of dis-
cussion, until the discoveries of Ehrenberg seem at length to
have removed the difficulty. He had observed, in the marshes
about Berlin, a substance of a deep ochre yellow passing
into red, which covered the bottom of the ditches, and
which, where it had become dry after the evaporation of the
water, appeared exactly like oxide o
iron. But under the microscope it was
found to consist of slender articulated >
threads or plates, partly siliceous and -XC
partly ferruginous, of a plant of simple
structure, Gallionella ferruginea, of the — Garioner
family called Diatomacee.* There can “
be little doubt, therefore, that bog iron-ore consists of an
aggregate of millions of these organic bodies invisible to the
naked eye.t
Preservation of animal substances in peat.—One interesting
circumstance attending the history of peat-mosses is the
high state of preservation of animal substances buried in
them for periods of many years. In June, 1747, the body of
a woman was found six feet deep, in a peat-moss in the Isle
of Axholm, in Lincolnshire. The antique sandals on her
feet afforded evidence of her having been buried there for
many centuries; yet her nails, hair, and skin are described
as having shown hardly any marks of decay. On the estate
of the Earl of Moira, in the north of Ireland, a human body
was dug up, a foot deep in gravel, covered with eleven feet
of peat; the body was completely clothed and the garments
seemed all to be made of hair. Before the use of wool
was known in that country the clothing of the inhabitants
was made of hair, so that it would appear that this body
had been buried at that early period; yet it was fresh and
Fig. 139,
la ferruginea.
2000 times magnified.
* See above, Vol. I. p. 644.
{ Ehrenberg, Taylor’s Scientific Mem., vol. i. part iii. p. 402.
502 ENCLOSING OF FOSSILS IN PEAT, (Cu. XLIV.
unimpaired.* In the Philosophical Transactions we find an
example recorded of the bodies of two persons having been
buried in moist peat, in Derbyshire, in 1674, about a yard
deep, which were examined twenty-eight years and nine
months afterwards; ‘the colour of their skin was fair and
natural, their flesh soft as that of persons newly dead.’ +
Among other analogous facts we may mention, that in
digging a pit for a well near Dulverton, in Somersetshire,
many pigs were found in various postures, still entire. Their
shape was well preserved, the skin, which retained the hair,
having assumed a dry, membranous appearance. Their
whole substance was converted into a white, friable, lami-
nated, inodorous, and tasteless substance; but which, when
exposed to heat, emitted an odour precisely similar to broiled
bacon.{
Cause of the antiseptre property of peat.——We naturally ask
whence peat derives this antiseptic property? It has been
attributed by some to the carbonic and gallic acids which
issue from decayed wood, as also to the presence of charred
wood in the lowest strata of many peat-mosses, for charcoal
is a powerful antiseptic, and capable of purifying water already
putrid. Vegetable gums and resins also may operate in the
same way.§
The tannin occasionally present in peat is the produce,
says Dr. MacCulloch, of tormentilla, and some other plants ;
but the quantity he thinks too small, and its occurrence too
casual, to give rise to effects of any importance. He hints
that the soft parts of animal bodies, preserved in peat-bogs,
may have been converted into adipocire by the action of
water merely. ||
Miring of quadrupeds.—The manner, however, in which
peat contributes to preserve, for indefinite periods, the harder
parts of terrestrial animals, is a subject of more immediate
interest to the geologist. There are two ways in whicl
animals become occasionally buried in the peat of marshy
erounds; they either sink down into the semifluid mud,
* Dr. Rennie, on Peat, p. 521; where t Dr. Rennie, on Peat, &c., p. 521.
several other instances are referred to. § Ibid. p. 531.
f Phil. Trans, vol. xxxviii. 1734. || Syst. of Geol. vol. ii. pp. 340—346.
hich, When
r to broiled
turally ask
t has been
ids which
of charred
r charcoal
ter already
rate in the
Cu. XLIV.] BLOWN SAND, AND VOLCANIC EJECTIONS, 503
underlying a turfy surface upon which they have rashly
ventured, or, at other times, as we shall see in the sequel,
a bog ‘ bursts,’ and animals may be involved in the peaty
alluvium.
In the extensive bogs of Newfoundland, cattle are some-
times found buried alive with only their heads and necks
above ground ; and after having remained for days in this
situation, they have been drawn out by ropes and saved. In
Scotland, also, cattle venturing on the ‘ quaking moss,’ are
often mired, or ‘ laired,’ as it is termed; and in Ireland, Mr.
King asserts that the number of cattle which are lost in
sloughs is quite incredible.*
Solway moss.—The description given of the Solway moss
will serve to illustrate the general character of these boggy
grounds. That moss, observes Gilpin, is a flat area, about
seven miles in circumference, situated on the western confines
of England and Scotland. Its surface is covered with grass
and rushes, presenting a dry crust and a fair appearance ;
but it shakes under the least pressure, the bottom being
unsound and semifluid. The adventurous passenger, there-
fore, who sometimes in dry seasons traverses this perilous
waste, to save a few miles, picks his cautious way over the
rushy tussocks as they appear before him, for here the
soil is firmest. If his foot slip, or if he venture to desert
this mark of security, it is possible he may never more be
heard of.
‘ At the battle of Solway, in the time of Henry VIII. (1542),
when the Scotch army, commanded by Oliver Sinclair, was
routed, an unfortunate troop of horse, driven by their fears,
plunged into this morass, which instantly closed upon them.
The tale was traditional, but it is now so far authenticated,
that a man and horse, in complete armour, have been
found by peat-diggers, in the place were it was always sup-
posed the affair had happened. The skeleton of each was well
preserved, and the different parts of the armour easily distin-
guished.’
The same moss, on the 16th of December, 1772, having
* Phil. Trans. vol. xv. p. 949
tT Gilpin, Obsery. on Picturesque Beauty, &c., 1772.
504 ENCLOSING OF FOSSILS IN PEAT, [Cu. XLIV,
been filled like a great sponge with water during heavy rains,
swelled to an unusual height above the surrounding country,
and then burst. The turfy covering seemed for a time to act
like the skin of a bladder retaining the fluid within, till it
forced a passage for itself, when a stream of black half-con-
solidated mud began at first to creep over the plain, resemb-
ling, in the rate of its progress, an ordinary lava-current.
No lives were lost, but the deluge totally overwhelmed some
cottages, and covered 400 acres. The highest parts of the
original moss subsided to the depth of about 25 feet; and
the height of the moss, on the lowest parts of the country
which it invaded, was at least 15 feet.
Bursting of peat-mosses.—An inundation in Sligo in Jan-
uary, 1831, affords another example of this phenomenon.
After a sudden thaw of snow, the bog between Bloomfield
and Geevah gave way; and a black deluge, carrying with it
the contents of a hundred acres of bog, took the direction of
a small stream and rolled on with the violence of a torrent,
sweeping along heath, timber, mud, and stones, and over-
whelming many meadows and arable land. On passing
through some boggy land, the flood swept out a wide and
deep ravine, and part of the road leading from Bloomfield
to St. James’s Well was completely carried away from below
the foundation for the breadth of 200 yards.
An ancient log-cabin is recorded as having been found in
1833 at the depth of fourteen feet in the peat of Donegal in
Ireland, The cabin was filled with peat and was surrounded
by other huts, which were not examined. The trunks and
roots of trees preserved in their natural position surrounded
these huts. ‘There can be little doubt that we have here an
example of a village which at some unknown period was
overwhelmed by the bursting of a moss. In such cases the
depth of vegetable matter which may overlie the dwelling
affords no test of antiquity, as the whole thickness may have
accumulated at once when the catastrophe occurred.
From the facts before mentioned, respecting the burst-
ing of mosses and the manner in which they frequently
descend in a fluid state to lower levels, the reader will readily
perceive that lakes and arms of the sea must occasionally
igo in Jan.
2€nOMenop,
Bloomfield
ring with it
direction of
a torrent,
, and over-
In passing
a wide and
Bloomield
from below
SS a, —_ =
Cu. XLIV.] BLOWN SAND, AND VOLCANIC EJECTIONS. 505
become the receptacles of drift peat. Of this, accordingly,
there are numerous examples; and hence the alternations of
clay and sand with different deposits of peat so frequent on
some coasts, as on those of the Baltic and German Ocean.
We are informed by Deguer, that remains of ships, nautical
instruments, and oars, have been found in many of the Dutch
mosses. Gerard has shown by similar proofs that many
mosses on the coast of Picardy, Zealand, and Friesland were
at one period navigable arms of the sea.
Bones of herbivorous quadrupeds in peat.—The antlers of
large and full-grown stags are amongst the most common
and conspicuous remains of animals in peat. They are not
horns which have been shed; for portions of the skull are
found attached, proving that the whole animal perished.
Bones of the ox, hog, horse, sheep, and other herbivorous
animals, also occur. M. Morren has discovered in the peat
of Flanders the bones of otters and beavers,* and M. Boucher
de Perthes has found bones and teeth of the Ursus Arctos,
or the bear which now lives in the Pyrenees, in the peat
of Abbeville. But as a general rule no remains are met
with belonging to extinct quadrupeds, such as the elephant,
rhinoceros, hippopotamus, hyena, and tiger, which are so
common in old Huropean river-gravels.
Bones of the mammoth mentioned by us in the first volume,
pp. 544, 545, as occurring in peat and vegetable matter of
older date than ordinary peat-mosses, are very exceptional.
The great extinct deer also, Cervus Megaceros, has often been
said to have been dug out of peat, but its true position seems
to be in shell-marl underlying peat-mosses. The freshwater
shells of such marl and others occasionally associated with
peat, as well as the landshells met with in the same, are in-
variably of species now living.
Great Dismal Swamp.—lI have described in my ‘Travels in
North America,’ + an extensive swamp or morass, 40 miles
long from north to south, and 25 wide, between the
towns of Norfolk in Virginia, and Weldon in North Caro-
lina. It is called the ‘Great Dismal,’ and has somewhat the
* Bulletin de la Soc. Géol. de France, t Travels, &c., in 1841, 1842, vol. i.
tom. ii. p. 26. p. 143.
506 ENCLOSING OF FOSSILS IN PEAT, [Cu. XLIV.
appearance of an inundated river-plain covered with aquatic
trees and shrubs, the soil being as black as that of a peat-bog.
It is higher on all sides except one than the surrounding
country, towards which it sends forth streams of water to the
north, east, and south, receiving a supply from the west only.
In its centre it rises 12 feet above the flat region which
bounds it. The soil, to the depth of 15 feet, is formed of
vegetable matter without any admixture of earthy particles,
and offers an exception to a general rule before alluded to,
namely, that such peaty accumulations scarcely ever occur so
far south as lat. 36°, or in any region where the summer heat
is so great as in Virginia. In digging canals through the
morass for the purpose of obtaining timber, much of the
black soil has been thrown out from time to time, and
exposed to the sun and air, in which case it soon rots away
so that nothing remains behind, showing clearly that it owes
its preservation to the shade afforded by a luxuriant vegeta-
tion and to the constant evaporation of the spongy soil by
which the air is cooled during the hot months. The surface
of the bog is carpeted with mosses, and densely covered
with ferns and reeds, above which many evergreen shrubs
and trees flourish, especially the White Cedar (Cupressus
thyovdes), which stands firmly supported by its long tap roots
in the softest parts of the quagmire. Over the whole the
deciduous Cypress (Tavodium distichum) is seen to tower with
its spreading top, in full leaf in the season when the sun’s
rays are hottest, and when, if not intercepted by a screen of
foliage, they might soon cause the fallen leaves and dead
plants of the preceding autumn to decompose, instead of
adding their contributions to the peaty mass. On the sur-
face of the whole morass lie innumerable trunks of large
and tall trees blown down by the winds, while thousands of
others are buried at various depths in the black mire below.
They remind the geologist of the prostrate position of large
stems of Sigillaria and Lepidodendron, converted into coal in
ancient carboniferous rocks.
-annunageeeesess ee
VY Now: ot
| Particles
alludag to,
er OCeur 8
timer heat
Tough the
ach of the
time, and
rots away
bat it owes
int vegeta-
gy soil by
he surface
ly covered
en shrubs
Cupressus
+ tap roots
whole the
Cu. XLIV.] BLOWN SAND, AND VOLCANIC EJECTIONS. 507
IMBEDDING OF HUMAN AND OTHER REMAINS, AND WORKS OF
ART, IN BLOWN SAND.
The drifting of sand may next be considered among the
causes capable of preserving organic remains and works of
art on the emerged land.
African sands.—The sands of the African deserts have
been driven by the west winds over part of the arable land
of Egypt, on the western bank of the Nile, in those places
where valleys open into the plain, or where there are gorges
through the Libyan mountains. By similar sand-drifts the
ruins of ancient cities have been buried between the temple
of Jupiter Ammon and Nubia.
We have seen that Sir J. G. Wilkinson is of opinion that,
while the sand-drift is making aggressions at certain points
upon the fertile soil of Egypt, the alluvial deposit of the
Nile is advancing very generally upon the desert; and that,
upon the whole, the balance is greatly in favour of the ferti-
lising mud.*
No mode of interment can be conceived more favourable
to the conservation of monuments for indefinite periods than
that now so common in the region immediately westward of
the plain of the Nile. . The sand which surrounded and filled
the great temple of Ipsambul, first discovered by Burckhardt,
and afterwards partially uncovered by Belzoni and Beechey,
was so fine as to resemble a fluid when put in motion.
Neither the features of the colossal figures, nor the colour of
the stueco with which some were covered, nor the paintings
on the walls, had received any injury from being enveloped
for ages in this dry inpalpable dust.+
At some future period, perhaps when the pyramids shall
have perished, the action of the Sea, or an earthquake, may
lay open to the day some of these buried temples. Or we may
Suppose the desert to remain undisturbed, and changes in the
surrounding sea and land to modify the climate and the
direction of the prevailing winds, so that these may then
* See p. 488. t Stratton, Ed. Phil. Journ., No. v. p. 62.
508 ENCLOSING OF FOSSILS IN PEAT, [Cu. XLIV.
waft away the Libyan sands as gradually as they once brought
them to those regions.
Whole caravans are said to have been overwhelmed by the
Libyan sands ; and Burckhardt informs us that ‘ after pass-
ing the Akaba near the head of the Red Sea, the bones of
dead camels are the only guides of the pilgrim through the
wastes of sands.’—‘ We did not see,’ says Captain Lyon,
speaking of a plain near the Soudah mountains, in Northern
Africa, ‘the least appearance of vegetation; but observed
many skeletons of animals, which had died of fatigue on the
desert, and occasionally the grave of some human being.
All these bodies were so dried by the heat of the sun, that
putrefaction appears not to have taken place after death.
In recently expired animals I could not perceive the slightest
offensive smell; and in those long dead, the skin with the
hair on it remained unbroken and perfect, although so brittle
as to break with a slight blow. The sand-winds never cause
these carcasses to change their places; for, in a short time,
a slight mound is formed round them, and they become
stationary.’*
Towns overwhelmed by sand floods.—The burying of several
towns and villages in England, France, and Jutland, by
blown sand is on record; thus, for example, near St. Pol de
Leon, in Brittany, a whole village was completely buried
beneath drift sand, so that nothing was seen but the spire of
the church.t In Jutland marine shells adhering to sea-
weed are sometimes blown by the violence of the wind to the
height of 100 feet and buried in similar hills of sand.
In Suffolk, in the year 1688, part of Downham was over-
whelmed by sands which had broken loose about 100 years
before, from a warren five miles to the south-west. This
sand had, in the course of a century, travelled five miles, and
covered more than 100 acres of land.t A considerable tract
of cultivated land on the north coast of Cornwall has been
inundated by drift sand, forming hills several hundred feet
above the level of the sea, and composed of comminuted
* Travels in North Africa in the 1772. See also the case of the buried
Years 1818, 1819, and 1820, p. 83. church of Eccles, Vol. I. p. 513.
~ Mém. de l’Acad. des Sci. de Paris, { Phil. Trans. vol. ii. p. 722.
n with the
h so brittle
ever cause
short time,
ey become
of several
atland, by
St. Pol de
ely buried
he spire of
ig to sea
nd to the
nd.
was
100 years
is
ovel-
) st.
niles, oe
ible fra?
peet
inst
Cu. XLIV.] BLOWN SAND, AND VOLCANIC EJECTIONS. 509
marine shells, in which some terrestrial shells are enclosed
entire. By the shifting of these sands the ruins of ancient
buildings have been discovered; and in some cases where
wells have been bored to a great depth, distinct strata, separ-
ated by a vegetable crust, are visible. In some places, as at
New Quay, large masses have become sufficiently indurated
to be used for architectural purposes. The lapidification,
which is still in progress, appears to be due to oxide of
iron held in solution by the water which percolates the
sand.*
IMBEDDING OF ORGANIC AND OTHER REMAINS IN VOLCANIC
FORMATIONS ON THE LAND.
I have in some degree anticipated the subject of this sec-
tion in former chapters, when speaking of the buried cities
around Naples, and those on the flanks of Etna.t From the
facts referred to, it appeared that the preservation of human
remains and works of art is frequently due to the descent of
floods caused by the copious rains which accompany erup-
tions. These aqueous lavas, as they are called in Campania,
flow with great rapidity; and in 1822 surprised and suffo-
cated seven persons in the villages of St. Sebastian and
Massa, on the flanks of Vesuvius.
In the tuffs, moreover, or solidified mud, deposited by
these aqueous lavas, impressions of leaves and of trees have
been observed. Some of those, formed after the eruption
of Vesuvius in 1822, are now preserved in the museum at
Naples.
Lava itself may become indirectly the means of preserving
terrestrial remains, by overflowing beds of ashes, pumice, and
ejected matter, which may have been showered down upon
animals and plants, or upon human remains. Few substances
are better non-conductors of heat than volcanic dust and
scoriz, so that a bed of such materials is rarely melted by a
superimposed lava-current. After consolidation, the lava
affords secure protection to the lighter and more removable
* Boase on Submersion of Part of the of Cornwall, vol. li. p. 140.
Mount’s Bay, &c., Trans. Roy. Geol. Soe, fT Vol. I. p. 640, and Vol. II. p. 22.
510 ENCLOSING OF FOSSILS IN PEAT, ETC. [Cu. XLIV.
mass below, in which the organic relics may be enveloped.
The Herculanean tuffs containing the rolls of papyrus, of
which the characters are still legible, have, as was before
remarked, been for ages covered by lava.
Another mode by which lava may tend to the conservation
of imbedded remains, at least of works of human art, is by its
overflowing them when it is not intensely heated, in which
case they sometimes suffer little or no injury.
Thus when the Htnean lava-current of 1669 covered four-
teen towns and villages, and part of the city of Catania, it did
not melt down a great number of statues and other articles
in the vaults of Catania; and at the depth of 85 feet in
the same current, on the site of Mompiliere, one of the buried
towns, the bell of a church and some statues were found
uninjured (p. 24).
Vered fon,
tania. it diq
her ATticles
99 feet in
f the buried
Were found
CHAPTER XLV.
BURYING OF FOSSILS IN ALLUVIAL DEPOSITS AND IN CAVES.
FOSSILS IN ALLUVIUM—EFFECTS OF SUDDEN INUNDATIONS—TERRESTRIAL ANIMALS
‘MOST ABUNDANTLY PRESERVE
CTS OF LANDSLIPS—ORGANIC RE-
MAINS IN FISSURES AND CAVES—FORM AND DIMENSIONS OF CAVERNS—
THEIR PROBABLE ORIGIN —CLOSED BASINS AND SUBTERRANEAN RIVERS
THE MOREA—1
OF
AVOLTHRA—FORMATION OF BRECCIAS WITH RED CEMENT
——-HUMAN REMAINS IMBEDDED IN MOREA—-SCHMERLING ON INTERMIXTURE OF
HUMAN REMAINS AND BONES OF EXTINCT QUADRUPEDS
FORMER CO-EXISTENCE OF MAN WITH THOSE
FORMED IN OPEN FISSURES AND CAVES.
AS PROVING THE
LOST SPECIES—BONE-BRECCIAS
PossiLs IN ALLUVIUM.—The next subject for our considera-
tion, according to the division before proposed, is the imbed-
ding of organic bodies in alluvium.
The gravel, sand, and mud in the bed of a river does not
often contain any animal or vegetable remains; for the
whole mass is go continually shifting its place, and the
attrition of the various parts is so great, that even the
hardest rocks contained in it are, at length, ground down to
powder. But when sand and sediment are Swept by a flood
over lands bordering a river, such an alluvium may envelop
trees or the remains of animals, which, in this manner, are
often permanently preserved. In the mud and sand pro-
duced by the floods in Scotland, in 1829, the dead and
mutilated bodies of hares, rabbits, moles, mice, partridges,
and even the bodies of men, were found partially buried.*
But in these and similar cases one flood usually effaces
the memorials left by another, and it is only when rivers
are eroding and deepening valleys that portions of old river
channels are left high and dry beyond the reach of floods, in
which case the organic remains may be preserved for ‘ages
* Sir T. D. Lauder, Bart., on Floods in Morayshire, Aug. 1839, p.2177.
512 BURYING OF FOSSILS IN [Cr. XLV.
In districts repeatedly deranged by earthquakes rivers often
shift their channels from one part of a valley to another,
and alluvial accumulations caused by transient floods become
permanent depositaries of organic substances.
Marine alluviwm.—In May, 1787, a dreadful inundation of
the sea was caused at Coringa, Ingeram, and other places,
on the coast of Coromandel, in the East Indies, by a hurri-
cane blowing from the NE., which raised the waters so that
they rolled inland to the distance of about twenty miles from
the shore, swept away many villages, drowned more than
10,000 people, and left the country covered with marine mud,
on which the carcasses of about 100,000 head of cattle were
strewed. An old tradition of the natives of a similar flood,
said to have happened about a century before, was, till this
event, regarded as fabulous by the European settlers.* The
same coast of Coromandel was, so late as May, 1832, the
scene of another catastrophe of the same kind; and when
the inundation subsided, several vessels were seen grounded
in the fields of the low country about Coringa.
Many of the storms termed hurricanes have evidently been
connected with submarine earthquakes, as shown by the
atmospheric phenomena attendant on them, and by the
sounds heard in the ground and the odours emitted.
Houses and works of art in alluvial deposits.—A very ancient
subterranean town, apparently of Hindoo origin, was dis-
covered in India in 1833, in digging the Doab canal. Its
site is north of Saharunpore, near the town of Behat,
and 17 feet below the present surface of the country.
More than 170 coins of silver and copper were found, and
many articles in metal and earthenware. The overlying
deposit consisted of about 5 feet of river sand, with a
substratum, about 12 feet thick, of red alluvial clay. In
the neighbourhood are several rivers and torrents, which
descend from the mountains charged with vast quantities
of mud, sand, and shingle; and within the memory of persons
now living the modern Behat has been threatened by an
inundation, which, after retreating, left the neighbouring
* Dodsley’s Ann. Regist., 1788.
Udation of
the
i Places :
; and when
n grounded
idently been
own by the
ind by the
ery ancient
ALLUVIAL DEPOSITS AND CAVES. 5138
Cu. XLV.]
country strewed over with a superficial covering of sand
several feet thick. In sinking wells in the environs, masses
of shingle and boulders have been reached resembling those
now in the river-channels of the same district, under a
deposit of thirty feet of reddish loam. Captain Cautley,
therefore, who directed the excavations, supposes that the
matter discharged by torrents has gradually raised the whole
country skirting the base of the lower hills; and that the
ancient town, having been originally built in a hollow, was
submerged by floods, and covered over with sediment seven-
teen feet in thickness.*
We are informed, by M. Boblaye, that in the Morea, the
formation termed céramique, consisting of pottery, tiles, and
bricks, intermixed with various works of art, enters go
largely into the alluvium and vegetable soil upon the plains
of Greece, and into hard and crystalline breccias which have
been formed at the foot of declivities, that it constitutes
an important stratum which might, even in the absence of
zoological characters, serve to mark part of the human epoch
in a most indestructible manner.+
Landslips.—The landslip, by suddenly precipitating large
masses of rock and soil into a valley, overwhelms a multitude
of animals, and sometimes buries permanently whole villages,
with their inhabitants and large herds of cattle. Thus three
villages, with their entire population, were covered, when the
mountain of Piz fell in 1772, in the district of Treviso, in
the state of Venice,t and part of Mount Grenier, south of
Chambery, in Savoy, which fell down in the year 1248,
buried five parishes, including the town and church of St.
André, the ruins occupying an extent of about nine square
miles.§
The number of lives lost by the slide of the Rossberg, in
Switzerland, in 1806, was estimated at more than 800, a
great number of the bodies, as well as several villages and
scattered houses, being buried deep under mud and rock.
* Journ. of Asiat. Soe., Nos. xxv. and
Xxi ., 1834.
~ Ann. des Sci. Nat., tom. xxii. p-
117, Feb. 1831,
VOT tL. 1G, 1
{ Malte-Brun’s Geog., vol. i. 5
§ Bakewell, Travels in the Tarentaise,
vol. i. p. 201.
514 BURYING OF FOSSILS IN [Cu. XLV.
In the same country, several hundred cottages, with eighteen
of their inhabitants and a great number of cows, goats, and
sheep, were victims to the sudden fall of a bed of stones,
thirty yards deep, which descended from the summits of the
Diablerets in Vallais. In the year 1618, a portion of Mount
Conto fell, in the county of Chiavenna, in Switzerland, and
buried the town of Pleurs, with all its inhabitants, to the
number of 2,450.
It is unnecessary to multiply examples of similar local
catastrophes, which have been very numerous in mountainous
parts of Europe, within the historical period, more especially
in regions convulsed by earthquakes. It is there that enor-
mous masses of rock and earth, even in comparatively low
and level countries, are detached from the sides of valleys,
and cast down into the river courses, and often so unexpect-
edly that they overwhelm, even in the daytime, every living
thing upon the plains.
PRESERVATION OF ORGANIC REMAINS IN FISSURES AND CAVES.
In the history of earthquakes it was shown that many
hundreds of new fissures and chasms had opened in certain
regions during the last 150 years, some of which are
described as being of unfathomable depth. We also perceive
that mountain masses have been violently fractured and
dislocated, during their rise above the level of the sea; and
thus we may account for the existence of many cavities in
the interior of the earth by the simple agency of earthquakes ;
but there are some caverns, especially in limestone rocks,
which, although usually, if not always, connected with rents,
are nevertheless of such forms, and dimensions, alternately
expanding into spacious chambers, and then contracting
again into narrow passages, that we cannot suppose them to
have owed their origin exclusively to the mere fracturing and
displacement of solid masses.
In the limestone of Kentucky, in the basin of Green River,
one of the tributaries of the Ohio, a line of underground
cavities has been traced in one direction for a distance of
ten miles, without any termination; and one of the chambers,
> a ll
Un
» dn]
to the
ants
* Smiley log
n MOUNtainog
hore PSpee
Paratively Joy
Hes of rally,
D 80 Uherpect.
e, every living
a8 AND CAVES,
m that many
ned in certain
f which ar
also pereeire
|
|
|
|
|
|
|
:
|
Cu, XLV.] ALLUVIAL DEPOSITS AND CAVES. 515
of which there are many, all connected by narrow tunnels,
is no less than ten acres in area, and 150 feet in its greatest
height. Besides the principal series of ‘antres vast,’ there
are a great many lateral embranchments not yet explored.*
The cavernous structure here alluded to, is not altogether
confined to calcareous rocks; for it hag lately been observed
in micaceous and argillaceous schist in the Grecian island
of Thermia (Cythnos of the ancients), one of the Cyclades.
Here also spacious halls, with rounded and irreoular walls,
are connected together by narrow passages or tunnels, and
there are many lateral branches which have no outlet. A
current of water has evidently at some period flowed through
the whole, and left a muddy deposit of bluish clay upon
the floor; but the erosive action of the stream cannot be
supposed to have given rise to the excavations:in the first
instance. M. Virlet suggests that fissures were first caused
by earthquakes, and that these fissures became the chimneys
or vents for the disengagement of gas, generated below by
voleanic heat. Gases, he observes, such as the muriatic,
sulphuric, fluoric, and others, might, if raised to a high
temperature, alter and decompose the rocks which they
traverse. There are signs of the former action of such
vapours in rents of the micaceous schist of Thermia, and
thermal springs now issue from the grottos of that island.
We may suppose that afterwards the elements of the decom-
posed rocks were gradually removed in a state of solution by
mineral waters; a theory which, according to M. Virlet, is
confirmed by the effect of heated gases which escape from
rents in the isthmus of Corinth, and which have greatly
altered and corroded the hard siliceous and jaspideous rocks.+
When we reflect on the quantity of carbonate of lime
annually poured out by mineral waters, we are prepared to
admit that large cavities must, in the course of ages, be
formed at considerable depths below the surface in calcareous
rocks.{ These rocks, it will be remembered, are at once
more soluble, more permeable, and more fragile, than any
* Nahum Ward, Trans. of Antig. Soe.
of Massachusetts. Holmes’s United
States, p. 438.
ft Bull. de la Soe. Géol. de France,
tom. ii. p. 329.
t See above, Vol. I. p. 401.
UL 2
516 BURYING OF FOSSILS IN [Cu. XLY.
others, at least all the compact varieties are very easily
broken by the movements of earthquakes, which would
produce only flexures in argillaceous strata. Fissures once
formed in limestone are not liable, as in many other forma-
tions, to become closed up by impervious clayey matter, and
hence a stream of acidulous water might for ages obtain a
free and unobstructed passage.*
Morea.—Nothing is more common in limestone districts
than the engulfment of rivers, which after holding a sub-
terranean course of many miles escape again by some new
outlet. As they are usually charged with fine sediment, and
often with sand and pebbles where they enter, whereas they
are commonly pure and limpid where they flow out again,
they must deposit much matter in empty spaces in the
interior of the earth. In addition to the materials thus in-
troduced, stalagmite, or carbonate of lime, drops from the
roofs of caverns, and in such mixture the bones of animals
washed in by rivers are often entombed. In this manner we
may account for those bony breccias which we often find in
caves, some of which are of high antiquity while others are
very recent and in daily progress. In no district are engulfed
streams more conspicuous than in the Morea, where the
phenomena attending them have been studied and described
in great detail by M. Boblaye and his fellow-labourers of the
French expedition to Greece.t Their account is peculiarly
interesting to geologists, because it throws light on the red
osseous breccias containing the bones of extinct quadrupeds
which are so common in almost all the countries bordering
the Mediterranean. It appears that the numerous caverns
of the Morea occur in a compact limestone, of the age of
the English chalk, immediately below which are arenaceous
strata referred to the period of our greensand. In the more
elevated districts of that peninsula there are many deep
land-locked valleys, or basins, closed round on all sides by
mountains of fissured and cavernous limestone. The year is
divided almost as distinctly as between the tropics into a
rainy season, which lasts upwards of four months, and a
* See remarks by M. Boble mob Ann. + Ann, des Mines, 3me série, tom. iv.
des Mines, 3me série, tom. iv 1833.
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ALLUVIAL DEPOSITS AND CAVES. 517
Cu. XLV. ]
season of drought of nearly eight months’ duration. When
the torrents are swollen by the rains, they rush from surround-
ing heights into the enclosed basins ; but, instead of giving
rise to lakes, as would be the case in most other countries,
they are received into gulfs or chasms, called by the Greeks
‘Katavothra,’ and which correspond to what are termed
‘gwallow-holes’ in the north of England. The water of
these torrents is charged with pebbles and red ochreous
earth, resembling precisely the well-known cement of the
osseous breccias of the Mediterranean. It dissolves in acids
with effervescence, and leaves a residue of hydrated oxide of
iron, granular iron, impalpable grains of silex, and small
erystals of quartz. Soil of the same description abounds
everywhere on the surface of the decomposing limestone in
Greece, that rock containing in it much siliceous and ferru-
ginous matter.
Many of the Katavothra being insufficient to give passage
to all the water in the rainy season, a temporary lake is
formed round the mouth of the chasm, which then becomes
still further obstructed by pebbles, sand, and red mud, thrown
down from the turbid waters. The lake being thus raised,
its waters generally escape through other openings, at higher
levels, around the borders of the plain, constituting the bottom
of the closed basin.
In some places, as at Kavaros and Tripolitza, where the
principal discharge is by a gulf in the middle of the plain,
nothing can be seen over the opening in summer, when the
lake dries up, but a deposit of red mud, cracked in all
directions. But the Katavothron is more commonly situated
at the foot of the surrounding escarpment of limestone;
and in that case there is sometimes room enough to allow a
person to enter, in summer, and even to penetrate far into
the interior. Within is seen a suite of chambers, communi-
cating with each other by narrow passages; and M. Virlet
relates, that in one instance he observed, near the entrance,
human bones imbedded in recent red mud, mingled with the
remains of plants and animals of species now inhabiting the
Morea. It is not wonderful, he says, that the bones of man
should be met with in such receptacles; for so murderous
518 BURYING OF FOSSILS IN [Cu. XLV.
have been the late wars in Greece, that skeletons are often
seen lying exposed on the surface of the country.*
In summer, when no water is flowing into the Katavothron,
its mouth, half closed up with red mud, is masked bya vigorous
vegetation, which is cherished by the moisture of the place.
It is then the favourite hiding-place and den of foxes and
jackals ; so that the same cavity serves at one season of the
year for the habitation of carnivorous beasts, and at another
as the channel of an engulfed river. Near the mouth of one
chasm, M. Boblaye and his companions saw the carcass of a
horse, in part devoured, the size of which seemed to have
prevented the jackals from dragging it in: the marks of
their teeth were observed on the bones, and it was evident
that the floods of the ensuing winter would wash in whatso-
ever might remain of the skeleton.
It has been stated that the waters of all these torrents
of the Morea are turbid where they are engulfed; but when
they come out again, often at the distance of many leagues,
they are perfectly clear and limpid, being only charged
occasionally with a slight quantity of calcareous sand. The
points of efflux are usually near the sea-shores of the Morea,
but sometimes they are submarine; and when this is the
case, the sands are seen to boil up for a considerable space,
and the surface of the sea, in calm weather, swells in large
convex waves. It is curious to reflect, that when this
discharge fails in seasons of drought, the pressure of the sea
may force its salt waters into subterraneous caverns, and
_ carry in marine sand and shells, to be mingled with ossiferous
mud, and the remains of terrestrial animals.
In general, however, the efflux of water at these inferior
openings is constant and surprisingly uniform, seeming to
prove that the caverns in the interior serve as reservoirs, and
that the water escapes gradually from them, in consequence
of the smallness of the rents and passages by which they
communicate with the surface.
The phenomena above described are not confined to the
Morea, but occur in Greece generally, and in those parts of
* Bull. de la Soc. Géol. de France, tom. iii. p. 228.
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ALLUVIAL DEPOSITS AND CAVES. 519
Cu. XLV.]
Italy, Spain, Asia Minor, and Syria, where the calcareous
formations of the Morea extend. The Copaic lake in Boeotia
has no outlet, except by underground channels; and hence
we can explain those traditional and historical accounts of
its having gained on the surrounding plains and overflowed
‘owns, as such floods must have happened whenever the
outlet was partially choked up by mud, gravel, or the sub-
sidence of rocks, caused by earthquakes. When speaking
of the numerous fissures in the limestones of Greece, M.
Boblaye reminds us of the famous earthquake of 469 B.c.,
when, as we learn from Cicero, Plutarch, Strabo, and Pliny,
Sparta was laid in ruins, part of the summit of Mount Tay-
getus torn off, and numerous gulfs and fissures caused in the
rocks of Laconia.
During the great earthquake of 1693, in Sicily, several
thousand people were at once entombed in the ruins of
caverns in limestone, at Sortino Vecchio; and, at the same
time, a large stream, which had issued for ages from one of
the grottos below that town, changed suddenly its sub-
terranean course, and came out from the mouth of a cave
lower down the valley, where no water had previously flowed.
To this new point the ancient water-mills were transferred ;
as I learnt when I visited the spot in 1829.
When the courses of engulfed rivers are thus liable to
change, from time to time, by alterations in the levels of a
country, and by the rending and shattering of mountain
masses, we. must suppose that the dens of wild beasts will
sometimes be inundated by subterranean floods, and their
carcasses buried under heaps of alluvium. The bones, more-
over, of individuals which have died in the recesses of caves,
or of animals which have been carried in for prey, may be
drifted along, and mixed up with mud, sand, and fragments
of rocks, so as to form osseous breccias.
In 1833 I had an opportunity of examining the celebrated
caves of Franconia, and among others that of Rabenstein,
then newly discovered. Their general form, and the nature
and arrangement of their contents, appeared to me to agree
perfectly with the notion of their having once served as the
channels of subterranean rivers. This mode of accounting
U
520 BURYING OF FOSSILS IN [Cu. XLV.
for the introduction of transported matter into the Fran-
conian and other caves, filled up as they often are even to
their roofs with osseous breccia, was long ago proposed by
M. C. Prevost,* and seems at length to be very generally
adopted. But I do not doubt that bears inhabited some of
the German caves, or that the cavern of Kirkdale, in York-
shire, was once the den of hywnas. The abundance of bony
dung, associated with hyznas’ bones, has been pointed out
by Dr. Buckland, and with reason, as confirmatory of this
opinion.
The same author observed in every cave examined by him
in Germany, that deposits of mud and sand, with or without
rolled pebbles and angular fragments of rock, were covered
over with a single crust of stalagmite.+ In the English caves
he remarked a similar absence of alternations of alluvium and
stalagmite. But Dr. Schmerling has discovered in a cavern
at Chockier, about two leagues from Liége, three distinct
beds of stalagmite, and between each of them a mass of
breccia, and mud mixed with quartz pebbles, and in the
three deposits the bones of extinct quadrupeds.t
This exception does not invalidate the generality of the
phenomenon pointed out by Dr. Buckland, one cause of
which may perhaps be this, that if several floods pass at
different intervals of time through a subterranean passage,
the last, if it has power to drift along fragments of rock,
will also tear up any alternating stalagmitic and alluvial
beds that may have been previously formed. Another cause
may be, that a particular line of caverns will rarely be so
situated, in relation to the lowest levels of a country, as to
become, at two distinct epochs, the receptacle of engulfed
rivers.
As the same chasms may remain open throughout periods
of indefinite duration, the species inhabiting a country may
in the meantime be greatly changed, and thus the remains
of animals belonging to very different epochs may become
mingled together in a common tomb.
* Mém. de la Soe. d’Hist. Nat. de { Journ. de Géol., tom. i. p. 286.
Paris, tom. iy. ;
t Reliquiz Diluviane, p. 108.
July, 1830
:
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———
521
Cu. XLV.] ALLUVIAL DEPOSITS AND CAVES.
In several caverns on the banks of the Meuse, near Liége,
Dr. Schmerling found human bones in the same mud and
breccia with those of the elephant, rhinoceros, bear, and
other quadrupeds of extinct species. He has observed none
of the dung of any of these animals; and from this circum-
stance, and the appearance of the mud and pebbles, he
concludes that these caverns were never inhabited by wild
beasts, but washed in by a current of water. As the human
skulls and bones were in fragments, and no entire skeleton
had been found, he does not believe that these caves were
places of sepulture, but that the human remains were washed
in at the same time as the bones of extinct quadrupeds, and
that these lost species of mammalia coexisted on the earth
with man.
Bone-breccias formed in open fissures and caves.—Among the
various modes in which the bones of animals become pre-
served independently of the agency of land floods and en-
gulfed rivers, I may mention that open fissures often serve as
natural pitfalls in which herbivorous animals perish. This
may happen the more readily when they are chased by
beasts of prey, or when surprised while carelessly browsing on
the shrubs which so often overgrow and conceal the edges of
fissures.t
During the excavations recently made near Behat in India,
the bones of two deer were found at the bottom of an ancient
well which had been filled up with alluvial loam. Their
horns were broken to pieces, but the jawbones and other
parts of the skeleton remained tolerably perfect. ‘Their
presence,’ says Captain Cautley, ‘is easily accounted for, as
a great number of these and other animals are constantly
lost in galloping over the jungles and among the high grass
by falling into deserted wells.’
Above the village of Selside, near Ingleborough in York-
shire, a chasm of enormous but unknown depth occurs in
* The above was written in 1834,
find there a full account of the Belgian
before the coexistence of man with the
caves which I re-examined in 1860.
' Buckland, Reliquize Diluviane, p.
25
£
Man,’ chap. iv., I have done more justice
to Dr. Schmerling, and the reader will
{ See above, pp. 512, 513.
522 BURYING OF FOSSILS IN [Cu. XLV.
the scar-limestone, a member of the carboniferous series.
‘The chasm,’ says Professor Sedgwick, ‘is surrounded by
grassy shelving banks, and many animals, tempted towards
its brink, have fallen down and perished in it. The approach
of cattle is now prevented by a strong lofty wall; but there
can be no doubt that, during the last two or three thousand
years, great masses of bony breccia must have accumulated
in the lower parts of the great fissure, which probably
descends through the whole thickness of the scar-limestone,
to the depth of perhaps five or six hundred feet.’ ¥
When any of these natural pitfalls happen to communicate
with lines of subterranean caverns, the bones, earth, and
breccia may sink by their own weight, or be washed into the
vaults below.
At the north extremity of the rock of Gibraltar are per-
pendicular fissures, on the ledges of which a number of
hawks nestle and rear their young dn the breeding season.
They throw down from their nests the bones of small birds,
mice, and other animals on which they feed, and these are
gradually united into a breccia of angular fragments of the
decomposing limestone with a cement of red earth.
At the pass of Escrinet in France, on the northern escarp-
ment of the Coiron hills, near Aubenas, I have seen a breccia
in the act of forming. Small pieces of disintegrating lime-
stone are transported, during heavy rains, by a streamlet, to
the foot of the declivity, where landshells are very abundant.
The shells and pieces of stone soon become cemented together
by stalagmite into a compact mass, and the talus thus formed
is in one place 50 feet deep, and 500 yards wide. So firmly
is the lowest portion consolidated, that it is quarried for mill-
stones.
Recent stalagmitic limestone of Cuba.—One of the most
singular examples of the recent growth of stalagmitic lime-
stone in caves and fissures, is that described by Mr. R. C.
Taylor, as observable on the north-east part of the island of
Cuba.t The country there is composed of a white marble,
in which are numerous cavities, partially filled with a cal-
Notes on Geol. of Cuba, 1836,
Phil. Mag., July, 1837.
On the Lake Mountains of North
). 18381.
*
of England, Geol. Soe., Jan. 5.
ey MM UNicatp
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ashed into the
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~
————
|
ALLUVIAL DEPOSITS AND CAVES. 523
Cu. XLV.]
careous deposit ofa brick-red colour. In this red deposit
are shells, or often the hollow casts of shells, chiefly referable
to eight or nine species of land snails, a few scattered bones
of quadrupeds, and, what is still more singular, marine uni-
valve shells, often at the height of many hundred, or even
one thousand feet above the sea. The following explanation
is given of the gradual increase of this deposit. Land snails
of the genera Helix, Cyclostoma, Pupa, and Clausilia, retire
into the caves, the floors of which are strewed with myriads
of their dead and unoccupied shells, at the same time that
water infiltered through the mountain throws down carbonate
of lime, enveloping the shells, together with fragments of the
white limestone which occasionally falls from the roof.
Multitudes of bats resort to the caves; and their dung,
which is of a bright red colour {probably derived from the
berries on which they feed), imparts its red hue to the mass.
Sometimes also the Hutia, or great Indian rat of the island,
dies and leaves its bones in the caves. ‘ At certain seasons
the soldier-crabs resort to the sea-shore, and then return
from their pilgrimage, each carrying with them, or rather
dragging, the shell of some marine univalve for many a
weary mile. They may be traced even at the distance of
eight or ten miles from the shore, on the summit of moun-
tains 1,200 feet high, like the pilgrims of the olden times,
each bearing his shell to denote the character and extent of
his wanderings.’ By this means several species of marine
testacea of the genera Trochus, Turbo, Littorina, and Mono-
donta, are conveyed into inland caverns, and enter into the
composition of the newly formed rock.
CHAPTER XLVI.
IMBEDDING OF ORGANIC REMAINS IN SUBAQUEOUS DEPOSITS.
DIVISION OF THE SUBJECT—IMBEDDING OF TERRESTRIAL ANIMALS AND PLANTS
—INCREASED SPECIFIC GRAVITY OF WOOD SUNK TU GREAT DEPTHS IN THE SEA
LAKE AN
SEA—-FLOATING TREES IN THE MISSISSIPPI—IN. THE GULF-STREAM—ON THE
COAST OF ICELAND, SPITZBERGEN, AND LABRADOR—SUBMARINE FORESTS
EXAMPLES ON COAST OF HAMPSHIRE AND IN BAY OF FUNDY—
MINERALISATION OF PLANTS—IMBEDDING OF INSECTS—OF LES
RIVER FLOODS—SKELETONS IN RECENT SHELL-MARL —IMBEDDING OF MAMMI-
FEROUS REMAINS IN MARINE STRATA,
DIVISION OF THE SUBJECT.—Having treated of the imbedding
of organic remains in deposits formed upon the land, I shall
next consider the including of the same in deposits formed
under water.
It will be convenient to divide this branch of our subject
into three parts; considering, first, the various modes
whereby the relics of terrestrial species may be buried in
subaqueous formations; secondly, the modes whereby
animals and plants inhabiting fresh water may be so entombed;
thirdly, how marine species may become preserved in new
strata.
The phenomena above enumerated demand a fuller share
of attention than those previously examined, since the depo-
sits which originate upon dry land are insignificant in thick-
ness, superficial extent, and durability, when contrasted with
those of subaqueous origin. At the same time, the study of
the latter is beset with greater difficulties; for we are here
concerned with the results of processes much farther removed
from the sphere of ordinary observation. There is, indeed,
no circumstance which so seriously impedes the acquisition
of just views in our science as an habitual disregard of the
important fact, that the reproductive effects of the principal
osits formed
our subject
jous modes
e buried
1g whereby
0 entombed;
Cu. XLVI.] IMBEDDING OF ORGANIC REMAINS. 525
agents of change are confined to another element—to that
larger portion of the globe, from which, by our very organi-
sation, we are almost entirely excluded.*
IMBEDDING OF TERRESTRIAL PLANTS,
When a tree falls into a river from the undermining of the
banks or from being washed in by a torrent or flood, it floats
on the surface, not because the woody portion is specifically
lighter than water, but because it is full of pores containing
air. When soaked for a considerable time, the water makes
its way into these pores, and the wood becomes water-logged
and sinks. The time required for this process varies in
different woods; but several kinds may be drifted to great
distances, sometimes across the ocean, before they lose their
buoyancy.
If wood be sunk to vast depths in the sea, it may be im-
pregnated with water suddenly. Captain Scoresby informs
us, in his Account of the Arctic Regions, that on one occa-
sion a whale, on being harpooned, ran out all the line in the
boat, which it then dragged under water, to the depth of
several thousand feet, the men having just time to escape to
a piece of ice. When the fish returned to the surface ‘ to
blow,’ it was struck a second time, and soon afterwards killed.
The moment it expired it began to sink—an unusual cir-
cumstance, which was found to be caused by the weight of
the sunken boat, which still remained attached to it. By
means of harpoons and ropes the fish was prevented from
sinking, until it was released from the weight by connecting
a rope to the lines of the attached boat, which was no sooner
done than the fish rose again to the surface. The sunken
boat was then hauled up with great labour ; for so heavy was
it, that although before the accident it would have been
buoyant when full of water, yet it now required a boat at
each end to keep it from sinking. ‘When it was hoisted into
the ship, the paint came off the wood in large sheets; and
the planks, which were of wainscot, were as completely
soaked in every pore as if they had lain at the bottom of the —
* See above, Vol. I. p. 99.
526 IMBEDDING OF ORGANIC REMAINS [Cu. XLVI.
sea since the flood! A wooden apparatus that accompanied
the boat in its progress through the deep, consisting chiéfly
of a piece of thick deal, about fifteen inches Square, happened
to fall overboard, and though it originally consisted of the
lightest fir, sank in the water like a stone. The boat was
rendered useless; even the wood of which it was built, on
being offered to the cook for fuel, was tried and rejected as
incombustible.’*
Captain Scoresby found that, by sinking pieces of fir, elm,
ash, &c. to the depth of 4,000 and sometimes 6,000 feet,
they became impregnated with sea-water, and when drawn
up again, after immersion for an hour, would no longer float.
The effect of this impregnation was to increase the dimen-
sions as well as the specific gravity of the wood, every solid
inch having increased one-twentieth in size and twenty-one
twenty-fifths in weight.+
Drift-wood of the Mackenzie River.—When timber is drifted
down by a river, it is often arrested by lakes; and, becoming
water-logged, it may sink and be imbedded in lacustrine
strata, if any be there forming ; sometimes a portion floats
on till it reaches the sea. In the course of the Mackenzie
River in the northwestern part of North America, we have
an example of vast accumulations of vegetable matter now in
progress under both these circumstances.
In Slave Lake in particular, which is 200 miles long, the
quantity of drift-timber brought down annually is enormous.
‘As the trees,’ says Dr. Richardson, ‘retain their roots,
which are often loaded with earth and stones, they readily
sink, especially when water-soaked ; and accumulating in the
eddies, form shoals, which ultimately augment into islands.
A thicket of small willows covers the new-formed island as
soon as it appears above water, and their fibrous roots serve
to bind the whole firmly together. Sections of these islands
are annually made by the river; and it is interesting to study
the diversity of appearances they present, according to their
different ages. The trunks of the trees gradually decay
until they are converted into a blackish-brown substance
* Account of the Arctie Regions, vol. ii. p. 193. tT Tbids pe202:
d t Wenty-0ne
iber is drifted
nd, becoming
in lacustrine
portion floats
e Mackenze
ica, we have
vatter now 12
les long, the
is enormous
their ro0ts
they really
lating inthe
nto shan
IN SUBAQUEOUS DEPOSITS. 527
Cu, XLVI.]
resembling peat, but which still retains more or less of the
fibrous structure of the wood; and layers of this often alter-
nate with layers of clay and sand, the whole being penetrated,
to the depth of four or five yards or more, by the long fibrous
roots of the willows. A deposition of this kind, with the aid
of a little infiltration of bituminous matter, would produce an
excellent imitation of coal, with vegetable impressions of the
willow-roots. What appeared most remarkable was the hori-
zontal slaty structure that the old alluvial banks presented,
or the regu/ar curve that the strata assumed from unequal
subsidence.
‘Tt was in the rivers only that we could observe sections
of these deposits ; but the same operation goes on, on a much
more magnificent scale, in the lakes. A shoal of many miles
in extent is formed on the south side of Athabasca Lake, by
the drift timber and vegetable débris brought down by the
Hilk River; and the Slave Lake itself must in process of
time be filled up by the matters daily conveyed into it from
Slave River. Vast quantities of drift-timber are buried
under the sand at the mouth of the river, and enormous piles
of it are accumulated on the shores of every part of the
lake.’ *
The banks of the Mackenzie display almost everywhere
horizontal beds of wood coal, alternating with bituminous
clay, gravel, sand, and friable sandstone; sections, in short,
of such deposits as are now evidently forming at the bottom
of the lakes which it traverses.
Notwithstanding the vast forests intercepted by the lakes,
a still greater mass of drift-wood is found where the
Mackenzie reaches the sea, in lat. 69° N., where no wood grows
at present except a few stunted willows. At the mouths of
the river the alluvial matter has formed a barrier of islands
and shoals, where we may expect a great formation of coal at
some distant period.
The abundance of floating timber on the Mackenzie is
owing to the direction and to the length of the course of this
river, which runs from south to north, so that the sources of
* Dr. Richardson’s Geognost. Obs. on Capt. Franklin’s Polar Expedition.
528 IMBEDDING OF ORGANIC REMAINS [Cu. XLVI.
the stream lie in much warmer latitudes than its mouths.
In the country, therefore, where the sources are situated, the
frost breaks up at an earlier season, while yet the waters in
the lower part of its course are ice-bound. Hence the
current of water, rushing down northward, reaches a point
where the thaw has not begun, and finding the channel of
the river blocked up with ice, it overflows the banks, sweeping
through forests of pines, and carrying away thousands of up-
rooted trees.
Drift-timber on coasts of Iceland, Spitzbergen, &e.— Although
the Icelander can obtain no timber from the land, he is sup-
plied with it abundantly by the ocean. An immense quantity
of thick trunks of pines, firs, and other trees are thrown
upon the northern coast of the island, especially upon North
Cape and Cape Langaness, and are then carried by the waves
along these two promontories to other parts of the coast,
so as to afford sufficiency of wood for fuel and for construct-
ing boats. Timber is also carried to the shores of Labrador
and Greenland ; and Krantz assures us that the masses of
floating wood thrown by the waves upon the island of John
de Mayen often equal the whole of that island in extent.*
In a similar manner the bays of Spitzbergen are filled with
drift-wood, which accumulates also upon those parts of the
coast of Siberia that are exposed to the east, consisting of
larch, pine, Siberian cedar, fir, and other kinds of trees,
said to come from distant southern latitudes. Some of
the trunks have been deprived of their bark by friction, but
retain their roots and branches and are in such a state of pre-
servation as to form excellent building timber.+ Parts of the
branches and almost all the roots remain fixed to the pines
which have been drifted into the North Sea, into latitudes
too cold for the growth of such timber, but the trunks are
usually barked.
The leaves and lighter portions of plants are seldom car-
ried out to sea, in any part of the globe, except during tropical
hurricanes among islands, and during the agitations of the
* Krantz, Hist. of Greenland, tom.i. ‘ Olafsen, Voyage to Iceland, tom. i.
pp. 63-04.
t Sands oe
lly upon Yori
al by the wares
+ Of the coast,
| for construct.
es of Labrador
the masses of
island of John
| in extent."
, are filled mth
*) parts of the
- consisting of
kinds of OH
IN SUBAQUEOUS
Cx, XLVL] DEPOSITS, 529
atmosphere which sometimes accompany earthquakes
volcanic eruptions.
It will appear from these observations that, although the
remains of terrestrial vegetation, borne down by aqueous
causes from the land, are chiefly deposited at the bottom of
lakes or at the mouths of rivers, yet a considerable quantity
is drifted about in all directions by currents, and may become
imbedded in any marine formation, or may sink down,
when water-logged, to the bottom. of unfathomable abysses,
and there accumulate without intermixture of other sub-
stances.
It may be asked, whether we have any data for inferring
that the remains of a considerable proportion of the existing
species of plants will be permanently preserved, so as to be
hereafter recognisable, supposing the strata now in progress
to be at some future period upraised ?
and
To this enquiry it
_ may be answered, that there are no reasons for Bis pedis
that more than a small number of the plants now flourishing
in the globe will become fossilised ; since the entire ae
tions of a great number of them are remote from lakes and
seas, and even where they grow near to large bodies of water,
the circumstances are quite accidental and partial which
favour the imbedding and conservation of vegetable remains.
Submarine forest on coast of Hants.—Allusion has been
made in the first volume, p. 544, to several localities on the
British shores in which the remains of trees are seen in a
vertical position submerged beneath the mean level of the
sea, often with their roots attached. In many instances it
seems scarcely possible to explain their submergence without
assuming a change to have taken place in the relative level
of land and sea. But such an hypothesis does not seem
necessary in the case about to be described. My friend, Arch-
deacon Harris, discovered, in 1831, evident traces of a fir-
wood beneath the mean level of the sea, at Bournemouth, in
Hampshire, the formation having been laid open during a
low spring tide. It is situated Reteees the beach and a bar
of sand about 200 yards off, and extends 50 yards along the
shore, cropping out from beneath a bed of sand and shingle.
It also lies in the direct line of the Bournemouth Valley, from
VOL. II.
MM
530 IMBEDDING OF ORGANIC REMAINS [Cu. XLVI,
the termination of which it is separated by 200 yards of
shingle and drift-sand. Down the valley flows a large brook,
traversing near its mouth a considerable tract of rough,
boggy, and heathy ground, which produces a few birch trees,
and a great abundance of the bog-myrtle (Myrica gale). In
that part of the submerged peat which was exposed at low
water were seen twenty or more large stumps of fir, from one
to two feet in height, the roots and bases of which still retain
their bark. The sap-wood of these is soft and spongy, but per-
fectly white, and exhibiting its original character. The heart-
wood is exceedingly hard and tough, and in the lar ger stumps,
of a greenish hue like asbestos, saturated with moisture
and exhaling a strong odour of sulphuretted hydrogen.
‘This odour, and the greenish colour, are dependent,’ says
Mr. Harris, ‘ on an incipient formation of iron pyrites, which
is proceeding with some rapidity in the peaty stratum beneath.
The pyrites occurs in small concretions, enclosing both roots
and fibres. In some instances it may be seen filling up the
hollow stems of grasses, in others it has penetrated to the
heart of pieces of fir-wood, two or three inches in diameter,
following the grain of the wood and often ee its place,
so as not to be easily perceivable till broken
Seventy-six rings of annual growth were counted in a
transverse section of one of the trees, which was fourteen
inches in diameter. Besides the stumps and roots of fir,
rushes, and other compressed vegetable matter and pieces
of alder and birch, are found in the peat. In the centre
of the formation the peat was pierced two feet and a half
without being passed through; towards its edges, however,
it is seen resting on a stratum of bluish pebbles, clay and
sand, which crops out also on its seaward side, and is precisely
similar to the sand and pebbles that occur on the adjoining
heaths. The whole formation was shown to exist 40 years
before, in the same situation and presenting the same appear-
ances as in 1831, and I learn from Archdeacon Harris (Feb.
1868) that on several occasions he has since revisited the spot
and again observed the stumps 7 situ.
Now as the sea is encroaching on this shore, we may sup-
pose that at some former period the Bournemouth Valley ex-
On pyrites, whid
stratum beneath,
sing both revi
en filling up the
enetrated to the
hes in diameter,
pplying its place
re counted ma
oh was fourtea
Cu. XLVI.]
IN SUBAQUEOUS DEPOSITS. 531
tended far lower, and that its extremity consisted, as at
present, of rough and boggy ground, partly clothed with fir-
trees. It is also probable that the whole of this rested on
the sand and pebbles already mentioned, and that the sea, in
its progressive encroachments, eventually laid bare, at low
water, the foundations of this marshy ground; in which
case, much of the sand constituting these foundations might
have been washed out by the rapid descent of the fresh water
through them at the fall of the tide. The superstratum of
vegetable matter being matted and bound together by the
roots of trees, would not be washed away, but might be
undermined, and thus sink down below the level of the sea,
until the waves washed sand and shingle over it. This
operation may have also been assisted by the occasional
damming up of the brook by the sand and shingle thrown up
during storms. Mr. Harris informs me that such an obstruc-
tion actually occurred in the years 1818 and 1824, and the
bed of the brook was completely obliterated. On these
occasions an artificial channel was immediately cut; had
this, however, not been done, the lower part of the valley
- would have been flooded ; and by this means the under strata
would have become more saturated with water, and the in-
creased pressure would have augmented the tendency of the
water to escape through them. In confirmation of this
hypothesis we may observe, that small streams of fresh water
often pass under the sands of the sea-beach, so that they
may be crossed dryshod, whilst the water where it issues
again, may be seen to carry out sand and pebbles with great
rapidity.
The Rev. W. B. Clarke, after examining the Bournemouth
submarine peat and several other similar deposits on the
north side of Poole Harbour, came, in 1838, to a conclusion,
like that adopted by Archdeacon Harris and myself, that they
had been sunk and submerged in modern times by the under-
mining of the sandy strata on which they rested, and did not
imply a general subsidence or change of level in that part of
the coast.*
On Peat-bogs and Submarine Forests of Bourne Mouth. Rey. W. B. Clarke,
Proc. of Geol. Soe., p. 599. 1838,
M M 2
532 IMBEDDING OF ORGANIC REMAINS [Cu. XLVI.
Submerged forest in Bay of Fundy.—One of the best au-
thenticated examples of an old upland soil with trees, now
covered by about thirty feet of water at high tide, occurs
at Fort Lawrence in the Bay of Fundy, near the boundary
between Nova Scotia and New Brunswick. Dr. Dawson, an ex-
perienced geologist and most careful observer, has shown that
below layers of marine marsh-alluvium containing shells of
Sanguinolaria fusca, (a bivalve shell probably identical with
Tellina Baltica, Linn.,) there is a bed of tough blue clay,
and beneath it an old peaty soil with erect trunks of trees
and roots. All the stumps observed were those of pine and
beech (Pinus strobus and Fagus ferruginea), trees indicative
rather of dry upland than of swampy ground. The largest
stump of a pine measured two and a half feet in diameter
and exhibited about 200 rings of annual growth. Dr. Dawson
counted thirty stumps in a limited area, and the same forma-
tion occurs at so many points as to lead him to infer that there
has been a very general sinking down of the land in the
same district. The powerful tides of the Bay of Fundy, rising
and falling 40 feet, cause this formation to be peculiarly well
exposed to view at many points, the deposit being laid bare
by the continual encroachments of the sea.*
Mineralisation of plants.—Although the botanist and chemist
have as yet been unable to explain fully the manner in which
wood becomes : petrified, it is nevertheless ascertained that,
under favourable circumstances, the lapidifying process is
now continually going on. A piece of wood was procured by
Mr. Stokes, from an ancient Roman aqueduct in Westphalia,
in which some portions were converted into spindle-shaped
bodies, consisting of carbonate of lime, while the rest of the
wood remained in a comparatively unchanged state.t It
appears that in some cases the most perishable, in others the
most durable, portions of plants are preserved, variations
which doubtless depend on the time when the mineral matter
was supplied. If introduced immediately, on the first com-
mencement of decomposition, then the most destructible
* Dawson, Submerged Forest at Fort tT Geol. Trans., second series, vol. y.
Lawrence, Quart. Geol. Journ., vol. xi. y
p. 119. 1854.
Oue th
t nis gh ep
Tw aks of Urey
08 Of ping and
» trees Indicatis
. — larves
t in diamet
a 7 Dr. Damson
the same form.
0 infer that ther:
he land in th
of Fundy, rismy
p peculiarly wel
being laid bar
oh
snist and ches
manner 12 which
scertainel { a
= afi ss 8
fying proce .
IN SUBAQUEOUS DEPOSITS. 5338
Cx. XLVI.]
parts are lapidified, while the more durable do not waste
away till afterwards, when the supply has failed, and so never
become petrified. The converse of these circumstances gives
rise to exactly opposite results.
Professor Goppert, of Breslau, has instituted a series of
curious experiments, in which he has succeeded in producing
some very remarkable imitations of fossil petrifactions. He
placed recent ferns between soft layers of clay, dried these in
the shade, and then slowly and gradually heated them, till
the clay was red-hot. The result was the production of so
perfect a counterpart of fossil plants as might have deceived
an experienced geologist. According to the different degrees
of heat applied, the plants were obtained in a brown or per-
fectly carbonised condition ; and sometimes, but more rarely,
they were in a black shining state, adhering closely to the
layer of clay. If the red heat was sustained until all the
organic matter was burnt up, only an impression of the plant
remained.
The same chemist steeped plants in a moderately strong
solution of sulphate of iron, and left them immersed in it for
several days, until they were thoroughly soaked in the liquid.
They were then dried, and kept heated until they would no
longer shrink in volume, and until every trace of organic
matter had disappeared. On cooling them he found that the
oxide formed by this process had taken the form of the plants.
A variety of other experiments were made by steeping animal
and vegetable substances in siliceous, calcareous, and metallic
solutions, and all tended to prove that the mineralisation of
organic bodies can be carried much farther in a short time
than had been previously supposed.*
Imbedding of insects —I have observed the elytra and other
parts of beetles in a band of fissile clay, separating two beds
of recent shell-marl, in the Loch of Kinnordy in Forfarshire.
Amongst these, Mr. Curtis recognised Hlator lineatus and
Atopa cervina, species still living in Scotland. These, as well
as other remains which accompanied them, appear to belong
to terrestrial, not aquatic, species, and must have been
* Goppert, Poggendorff's Annalen
der Physik und Chemie, vol. xxxviii,
part iv., Leipsic, 1836. See also Lyell’s
Manual of Geol., p. 49
534, IMBEDDING OF ORGANIC REMAINS [Cu. XLVI,
carried down in muddy water during an inundation. In the
lacustrine peat of the same locality, the elytra of beetles are
not uncommon ; but in the deposits of drained lakes gener-
ally, and in the silt of our estuaries, the relics of this class
of the animal kingdom are rare. In the blue clay of very
modern origin of Lewes levels, Dr. Mantell has found the
Indusia, or cases of the larvee of Phryganea, in abundance,
with minute shells belonging to the genera Planorbis,
Limnea, &c., adhering to them.*
When speaking of the migrations of insects, I pointed out
that an immense number are floated into lakes and seas by
rivers, or blown by winds far from the land; but they are so
buoyant that we can only suppose them, under very peculiar
circumstances, to sink to the bottom before they are either
devoured by insectivorous animals or decomposed.
Of land and freshwater reptiles.—As the bodies of several
crocodiles were found in the mud brought down to the sea
by the river inundation which attended an earthquake in
Java, in the year 1699, we may imagine that extraordinary
floods of mud may stifle many individuals of the shoals of
alligators and other reptiles which frequent lakes and the
deltas of rivers in tropical climates. Thousands of frogs
were found leaping about among the wreck, carried into the
sea by the inundations in Morayshire, in 1829 ;+ and it is
evident that whenever a sea-cliff is undermined, or land is
swept by other violent causes into the sea, land reptiles may
be carried in. ;
Of birds. —We might have anticipated that the imbedding
of the remains of birds in new strata would be of very rare
occurrence, for their powers of flight insure them against
perishing by numerous casualties to which quadrupeds are
exposed during floods; and if they chance to be drowned, or
to die when swimming on the water, it will scarcely ever
happen that they will be submerged so as to become preserved
in sedimentary deposits. In consequence of the hollow
tubular structure of their bones and the quantity of their
feathers they are extremely light in proportion to their
* Trans. Geol. Soe., vol. iii, part i. + Sir T. D. Lauder’s Account, 2nd ed.,
p-. 201, second series. p. 312.
)
:
|
ta :
ces
® nd seas
> they are either
nosed.
Modies of sever]
down to the sa
n earthquake in
at extraordinary
of the shoals of
it Jakes and th
—_ — —
vasands of fogs
f
|
Gu. XLVI]
IN SUBAQUEOUS DEPOSITS. 535
volume; so that when first killed they do not sink to the
bottom like quadrupeds, but float on the surface until the
carcass either rots away or is devoured by predaceous animals.
To these causes we may ascribe the absence of any vestige
of the bones of birds in the recent marl formations of Scotland;
although these lakes, until the moment when they were artifi-
cially drained, were frequented by a great abundance of water-
fowl.
IMBEDDING OF TERRESTRIAL QUADRUPEDS.
River inundations recur in most climates at very irregular
intervals, and expend their fury on those rich alluvial plains,
where herds of herbivorous quadrupeds congregate together.
These animals are often surprised ; and, being unable to stem
the current, are hurried along until they are drowned, when
they sink at first immediately to the bottom. Here their
bodies are drifted along, together with sediment, into lakes or
seas, and may then be covered by a mass of mud, sand, and
pebbles, thrown down upon them. If there be no sediment
superimposed, the gases generated by putrefaction usually
cause the bodies to rise again to the surface about the ninth or
at latest the fourteenth day. The pressure of a thin covering
of mud would not be sufficient to retain them at, the bottom ;
for we see the putrid carcasses of dogs and cats, even in rivers,
floating with considerable weights attached to them, and in
sea-water they would be still more buoyant.
Where the body is so buried in drift-sand, or mud accumu-
lated upon it, as never to rise again, the skeleton may be
preserved entire; but if it comes again to the surface while
in the process of putrefaction, the bones commonly fall
piecemeal from the floating carcass, and may in that case be
scattered at random over the bottom of the lake, estuary, or
sea; so that a jaw may afterwards be found in one place, a
rib in another, a humerus in a third—all included, perhaps,
in a matrix of fine materials, where there may be evidence
of very slight transporting power in the current, or even of
none, but simply of some chemical precipitate.
A large number of the bodies of drowned animals, if they
float into the sea or a lake, especially in hot climates, are
536 IMBEDDING OF ORGANIC REMAINS [Cu. XLVI.
instantly devoured by sharks, alligators, and other carnivo-
rous beasts, which may have power to digest even the bones ;
but during extraordinary floods, when the greatest number
of land animals are destroyed, the waters are commonly so
turbid, especially at the bottom of the channel, that even
aquatic species are compelled to escape into some retreat
where there is clearer water lest they should be stifled. For
this reason, as well as the rapidity of sedimentary deposition
at such seasons, the probability of carcasses becoming per-
manently imbedded is considerable.
In recent shell-marl, Scotland. —In some instances, the
skeletons of quadrupeds are met with abundantly in recent
shell-marls in Scotland, where we cannot suppose them to
have been imbedded by the action of rivers or floods. They
all belong to species which now inhabit, or are known to
have been indigenous in Scotland. The remains of several
hundred skeletons have been procured within the last century
from five or six small lakes in Forfarshire, where shell-marl
has been worked. Those of the stag (Cervus Hlaphus) are
most numerous; and if the others be arranged in the order
of their relative abundance, they will follow nearly thus—
the ox, the boar, the horse, the sheep, the dog, the hare, the
fox, the wolf, and the cat. The beaver seems extremely rare ;
but it has been found in the shell-marl of Loch Marlie, in
Perthshire, and in the parish of Edrom, in Berwickshire.
In the greater part of these lake-deposits there are no
signs of floods; and the expanse of water was originally so
confined, that the smallest of the above-mentioned quadrupeds
could have crossed, by swimming from one shore to the
other. Deer, and such species as take readily to the water,
may often have been mired in trying to land, where the
bottom was soft and quaggy, and in their efforts to escape
may have plunged deeper into the marly bottom. But many
individuals, I suspect, of different species, have fallen in
when crossing the frozen surface in winter; for nothing can
be more treacherous than the ice when covered with snow,
in consequence of the springs, which are numerous, and
which, retaining always an equal temperature, cause the ice,
in certain spots, to be extremely thin, while in every other
—— ==
Mstancas th
idan tly j in rece}
a a igs ty
ru They
T are ty
mains of severa]
) the last centun
where shell-na
rus Elaphus) ar
ged in the order
w nearly thus-
og, the hare, the
extremely nit
Loc th Marl
——-
27
SUBAQUEOUS DEPOSITS.
roar
004
Cu. XLVI.] IN
part of the lake it is strong enough to bear the heaviest
weights.
Flood in the Solway Firth, 1794.—One of the most memor-
able floods of modern date,
visited part of the southern borders of Scotland, on the 24th
of January, 1794, and which spread particular devastation
over the country adjoining the Solway Firth.
We learn from the account of Captain Napier, that the
heavy rains had swollen every stream which entered the
Firth of Solway; so that the inundation not only carried
away a great number of cattle and sheep, but many of the
herdsmen and shepherds, washing down their bodies into the
estuary. After the storm, when the flood subsided, an extra-
ordinary spectacle was seen ona large sand-bank called ‘the
beds of Hsk,’ where there is a meeting of the tidal waters,
and where heavy bodies are usually left stranded after great
floods. On this single bank were found collected together
the bodies of 9 black cattle, 3 horses, 1,840 sheep, 45 dogs,
180 hares, besides a great number of smaller animals, and,
mingled with the rest, the corpses of two men and one
woman.
Floods in Scotland, 1829.—In those more recent floods in
Scotland, in August, 1829, whereby a fertile district on the
east coast became a scene of dreadful desolation, a vast
number of animals and plants were washed from the land,
and found scattered about after the storm, around the mouths
of the principal rivers. An eye-witness thus describes the
scene which presented itself at the mouth of the Spey, in
Morayshire: —‘ For several miles along the beach crowds
were employed in endeavouring to save the wood and other
wreck with which the heavy-rolling tide was loaded; whilst
the margin of the sea was strewed with the carcasses of
domestic animals, and with millions of dead hares and
rabbits.’+
Savannahs of South America.—We are informed by Hum-
boldt, that during the periodical swellings of the large rivers
in South America ereat numbers of quadrupeds are annually
in our island, is that which
and above, Vol. I.
* or? on Practical Store Farm-
ing, p. 2
Y Sir “Tr, D. Lauder’s Floods in
Morayshire, 1829 ;
p. 349.
538 IMBEDDING OF ORGANIC REMAINS [Cu. XLVI.
drowned. Of the wild horses, for example, which graze in
immense troops in the Savannahs, or level grassy plains,
thousands are said to perish when the river Apure, a tributary
of the Orinoco, is swollen, before they have time to reach the
rising ground of the Llanos. The mares, during the season
of high water, may be seen, followed by their colts, swimming
about and feeding on the grass, of which the top alone waves
above the waters. In this state they are pursued by croco-
diles; and their thighs frequently bear the prints of the
teeth of these carnivorous reptiles. « Such is the pliability,’
observes the celebrated traveller, ‘of the organisation of the
animals which man has subjected to his sway, that horses,
cows, and other species of European origin, lead, for a time,
an amphibious life, surrounded by crocodiles, water-serpents,
and manatees. When the rivers return again into their beds,
they roam in the savannah, which is then spread over with a
fine odoriferous grass, and enjoy, as in their native climate,
the renewed vegetation of spring.’*
Floods of the Parana.—The great number of animals which
are drowned in seasons of drought in the tributaries of the
Plata, was before mentioned. Sir W. Parish states, that the
Parana flowing from the mountains of Brazil to the estuary
of the Plata, is liable to great floods, and during one of these,
in the year 1812, vast quantities of cattle were carried away,
‘and when the waters began to subside, and the islands
which they had covered became again visible, the whole
atmosphere for a time was poisoned by the effluvia from the
innumerable carcasses of skunks, capybaras, tigers, and other
wild beasts which had been drowned.’+
Floods of the Ganges.—We find it continually stated, by
those who describe the Ganges and Burrampooter, that these
tivers carry before them, during the flood season, not only
floats of reeds and timber, but dead bodies of men, deer, and
oxen.}
Java, 1699.—I have already referred to the effects of a
flood which attended an earthquake in Java in 1699, when
the turbid waters of the Batavian river destroyed all the
* Humboldt’s Pers. Nar., vol. iv. ft Buenos Ayres and La Plata, p.187.
394. { Malte-Brun, Geog., vol. iii. p. 22.
ray, that horses
lead. for P my |
> aver serpent
1 Into their beds
read over with,
r native climate
of animals which
ributaries of the
1 states, that the
“il to the estuary
ss
559
Cu. XLVI.] IN SUBAQUEOUS DEPOSITS.
fish except the carp; and when drowned buffaloes, tigers,
rhinoceroses, deer, apes, and other wild beasts, were brought
down to the sea-coast by the current, with several crocodiles
which had been stifled in the mud. (See above, p. 159.)
On the western side of the same island, in the territory of
Galongoon, in the Regencies, a more recent volcanic eruption
(that of 1822, before described—see above, p. 57), was attended
by a flood, during which the river Tandoibore down hundreds
of carcasses of rhinoceroses and buffaloes, and swept away »
more than 100 men and women from a multitude assembled
on its banks to celebrate a festival, Whether the bodies
reached the sea, or were deposited, with drift matter, in some
of the large intervening alluvial plains, we are not in-
formed.*
Sumatra.—‘ On the coast of Orissa,’ says Heynes, ‘I have
seen tigers and whole herds of black cattle carried along by
what are called freshes, and trees of immense size.’f
Virginia, 1771.—I might enumerate a great number of
local deluges that have swept through the fertile lands
bordering on large rivers, especially in tropical countries,
but I should surpass the limits assigned to this work. I
may observe, however, that the destruction of the islands,
in rivers, is often attended with great loss of life. Thus
when the principal river in Virginia rose in 1771, to the
height of 25 feet above its ordinary level, it swept entirely
away Elk Island, on which were 700 head of quadru-
peds, — horses, oxen, sheep, and hogs,—and nearly 100
houses. f
The reader will gather, from what was before said re-
specting the deposition of sediment by aqueous causes, that
the greater number of the remains of quadrupeds drifted
away by rivers must be intercepted by lakes before they
reach the sea, or buried in freshwater formations near the
mouths of rivers. If they are carried still farther, the pro-
babilities are increased of their rising to the surface in a
state of putrefaction, and, in that case, of being there devoured
* This accountI had from Mr. Baum-
hauer, Director-General of Finances in
Java.
+ Tracts on India, p. 397.
t Scots Mag., vol. xxxiii.
540 IMBEDDING OF ORGANIC REMAINS. [Cu. XLVI.
by aquatic beasts of prey, or of subsiding into some spots
whither no sediment is conveyed, and, consequently, where
every vestige of them will, in the’ course of time, disappear.
Mammuferous remains in marine strata.—As the bones of
maminalia are often so abundantly preserved in peat, and
such lakes as have just been described, the encroachments of
the sea upon a coast must sometimes throw down the imbedded
Skeletons, so that they may be carried away by tides and
‘currents, and entombed in submarine formations. Some of
the smaller quadrupeds, also, which burrow in the ground,
as well as reptiles and every species of plant, are liable to be
cast down into the waves by this cause, which must not be
overlooked, although probably of comparatively small im-
portance amongst the numerous agents whereby terrestrial
organic remains are included in submarine strata.
During the great earthquake of Conception in 1835, some
cattle, which were standing on the steep sides of the island
of Quiriquina, were rolled by the shock into the sea, while
on a low island at the head of the Bay of Conception seventy
animals were washed off by a great wave and drowned.*
* Darwin’s Journal, p. 372, 2nd ed. 1845, p. 304.
ch Thust not he
vely Smal] ip.
TODY terrestri]
rata,
hin 1835, some
8 of the island
» the sea, while
ception seventy
| drowned.*
CHAPTER XLVII.
IMBEDDING OF THE REMAINS OF MAN AND HIS WORKS IN
SUBAQUEOUS STRATA.
DRIFTING OF HUMAN BODIES TO THE SEA BY RIVER INUNDATIONS—HOW HUMAN
CORPSES MAY BE PRESERVED IN RECENT DEPOSITS—FOSSIL SKELETONS OF MEN
—NUMBER OF WRECKED VESSELS—FOSSIL CANOES, SHIPS, AND WORKS OF ART
—CHEMICAL CHANGES WHICH METALLIC ARTICLES HAVE UNDERGONE AFTER
LONG SUBMERGENCE—IMBEDDING OF CITIES AND FORESTS IN SUBAQUEOUS
STRATA BY SUBSIDENCE—EARTHQUAKE OF CUTCH IN 1819—xsURIED TEMPLES
OF CASHMERE—BERKELEY S ARGUMENTS FOR THE RECENT DATE OF THE CREA-
TION OF MAN—MONUMENTS OF PRE-HISTORIC MAN DISCOVERED IN POST-TERTI-
ARY STRATA.
I SHALL now proceed to enquire in what manner the mortal
remains of man and the works of his hands may be per-
manently preserved in subaqueous strata. Of the many
hundred million human beings which perish in the course of
every century on the land, every vestige is usually destroyed
in the course of a few thousand years; but of the smaller
number that perish in the waters, a certain proportion must
be entombed under circumstances that may enable parts of
them to endure throughout entire geological epochs.
The bodies of men, together with those of the inferior
animals, are occasionally washed down during river inunda-
tions into seas and lakes. Belzoni witnessed a flood on the
Nile in September, 1818, where, although the river rose
only three feet and a half above its ordinary level, several
villages, with some hundreds of men, women, and children,
were swept away.* It was before mentioned that a rise of
six feet of water in the Ganges, in 1763, was attended with
a much greater loss of life. (See above, Vol. I. p. 474.)
In the year 1771, when the inundations in the north of
M“« ieee <7, ® . ¢
* Narrative of Discovery in Egypt, &c., London, 1820.
542 IMBEDDING OF THE REMAINS OF MAN AND [Cu. XLVII.
England appear to have equalled the floods of Morayshire
in 1829, a great number of houses and their inhabitants were
swept away by the rivers Tyne, Can, Wear, Tees, and Greta;
and no less than twenty-one bridges were destroyed in the
courses of these rivers. At the village of Bywell the flood
tore the dead bodies and coffins out of the churchyard, and
bore them away, together with many of the living inhabit-
ants. During the same tempest an immense number of cattle,
horses, and sheep were also transported to the sea, while the
whole coast was covered with the wreck of ships. Four cen-
turies before (in 1338), the same district had been visited by
a similar continuance of heavy rains followed by disastrous
floods, and it is not improbable that these catastrophes
may recur periodically, though after uncertain intervals.
As the population increases, and buildings and bridges are
multiplied, we must expect the loss of lives and property to
augment.*
Preservation of human bodies in the bed of the sea.—If to
the hundreds of human bodies committed to the deep in the
way of ordinary burial we add those of individuals lost by
shipwrecks, we shall find that, in the course of a single
year, a great number of human remains are consigned to
the subaqueous regions. I shall hereafter advert to a calcu-
lation by which it appears that more than 500 British vessels
alone, averaging each a burden of about 120 tons, were
wrecked, and sunk to the bottom, annually between the
years 1793 and 1829. Of these the crews for the most part
escape, although it sometimes happens that all perish. In one
ereat naval action several thousand individuals sometimes
share a watery grave.
Many of these corpses are instantly devoured by predaceous
fish, sometimes before they reach the bottom; still more
frequently when they rise again to the surface, and float in a
state of putrefaction. Many decompose on the floor of the
ocean, where no sediment is thrown down upon them; but
if they fall upon a reef where corals and shells are becoming
agelutinated into a solid rock, or subside where the delta of
* Scots Mag. vol. xxxiii. 1771,
] and bridges are
eS and property ti
of the sea—If ty
to the deep inthe
pdividuals lost by
urse of a single
are consigned ti
advert to a calc
s(n) British ves?
Cu. XLVIL]
HIS WORKS IN SUBAQUEOUS STRATA. 543
a river is advancing, they may be preserved for an incalcu-
lable series of ages.
Often at the distance of a few hundred feet from a coral
reef, where wrecks are often not unfrequent, there are no
soundings at the depth of many hundred fathoms. Canoes,
merchant vessels, and ships of war may have sunk and have
been enveloped, in such situations, in calcareous sand and
breccia, detached by the breakers from the summit of a
submarine mountain. Should a volcanic eruption happen
to cover such remains with ashes and sand, and a current of
lava be afterwards poured over them, the ships and human
skeletons might remain uninjured between the superincum-
bent mass, like the houses and works of art in the sub-
terranean cities of Campania. Already many human remains
may have been thus preserved beneath formations more than
1,000 feet in thickness; for, in some volcanic archipelagos,
a period of thirty or forty centuries might well be supposed
sufficient for such an accumulation. It was stated, that at
the distance of about 40 miles from the base of the delta of
the Ganges, there is an elliptical space about 15 miles in
diameter where soundings of from 100 to 300 fathoms
sometimes fail to reach the bottom. (See above, Vol. I.
p- 475.) As during the flood season the quantity of mud
and sand poured by the great rivers into the Bay of Bengal
is so great that the sea only recovers its transparency at the
distance of 60 miles from the coast, this depression must be
gradually shoaling, especially as during the monsoons, the
sea, loaded with mud and sand, is beaten back in that
direction towards the delta. If therefore a ship or human
body sink down to the bottom in such a spot, it will probably
soon become buried under sediment.
Even on that part of the floor of the ocean to which no
accession of drift matter is carried (a part which probably
constitutes, at any given period, by far the larger proportion
of the whole submarine area), there are circumstances
accompanying a wreck which favour the conservation of
skeletons. For when the vessel fills suddenly with water,
especially in the night, many persons are drowned between
decks and in their cabins, so that their bodies are prevented
544 IMBEDDING OF THE REMAINS OF MAN AND [Cu. XLVII.
from rising again to the surface. The vessel often strikes
upon an uneven bottom, and is overturned; in which case
the ballast, consisting of sand, shingle, and rock, or the
cargo, frequently composed of heavy and durable materials,
may be thrown down upon the carcasses. In the case of
ships of war, cannon, shot, and other warlike stores, may
press down with their weight the timbers of the vessel as
they decay, and beneath these and the metallic substances
the bones of man may be preserved.
Power of human remains to resist decay.—There can be no
doubt that human remains are as capable of resisting decay
as are the harder parts of the inferior animals; and I have
already cited the remark of Cuvier, that ‘in ancient fields of
battle the bones of men have suffered as little decomposition
as those of horses which were buried in the same orave.’
(‘See above, Vol. I. p. 166.) In the delta of the Ganges bones
of men have been found in digging a well at the depth of 90
feet;* but as that river frequently shifts its course and fills
up its ancient channels, we are not called upon to suppose
that these bodies are of extremely high antiquity, or that
they were buried when that part of the surrounding delta
where they occur was first gained from the sea.
Several skeletons of men, more or less mutilated, have
been found in the West Indies, on the northwest coast of
the main land of Guadaloupe, in a kind of rock which is
known to be forming daily, and which consists of minute
fragments of shells and corals, incrusted with a calcareous
cement resembling travertin, by which also the different
erains are bound together. The lens shows that some of the
fragments of coral composing this stone still retain the same
red colour which is seen in the reefs of living coral which
surround the island. The shells belong to species of the
neighbouring sea intermixed with some terrestrial kinds
which now live on the island, and among them is the
Bulimus Guadaloupensis of Férussac. The human skeletons
still retain some of their animal matter, and all their phos-
phate of lime. One of them, of which the head is wanting,
* Von Hoff, vol. i. p. 379.
Whig,
iM wk Cau
‘ it)
rab); si, thy
In the Pies
like gee
SlOrpg
Of the ya.”
the Vesa]
fallin ew 8
“lle Subst.
aN Gg,
The
De Te
- - be My
Tesisting decay
ls; and I bop
ancient fields of
© decompositin
HE Same graye’
he Ganges bone
t ] 1° d epth of 4)
course and ilk
upon tO Suppose
itiquity, or thi!
rrounding delta
mutilated, hare
===
yo
=
HIS WORKS IN SUBAQUEOUS STRATA.
Cu. XLVIL] 548
may now be seen in the British Museum, and another in the
Royal Cabinet at Paris. According to M. Konig, the rock-in
which the former is enclosed is harder under the mason’s saw
and chisel than statuary marble. It is described ag forming
a kind of glacis, probably an indurated beach, which slants
from the steep cliffs of the island to the sea, and is nearly
all submerged at high tide.
Number of wrecked vessels.—When we reflect on the number
‘ of curious monuments consigned to the bed of the ocean
in the course of every naval war from the earliest times, our
conceptions are greatly raised respecting the multiplicity of
lasting memorials which man is leaving of his labours.
During our last great struggle with France, thirty-two of
our ships of the line went to the bottom in the space of
twenty-two years, besides seven 50-gun ships, eighty-six
frigates, and a multitude of smaller vessels. The navies of
the other Huropean powers, France, Holland, Spain, and
Denmark, were almost annihilated during the same period,
so that the aggregate of their losses must have many times
exceeded that of Great Britain. In every one of these ships
were batteries of cannon constructed of iron or brass, whereof
a great number had the dates and places of their manu-
facture inscribed upon them in letters cast in metal. In
each there were coins of copper, silver, and often many
of gold, capable of serving as valuable historical monu-
ments ; in each were an infinite variety of instruments of
the arts of war and peace; many formed of materials, such
as glass and earthenware, capable of lasting for indefinite
ages when once removed from the mechanical action of the
waves, and buried under a mass of matter which may exclude
the corroding action of sea-water. The quantity, moreover,
of timber which is conveyed from the land to the bed of the
sea by the sinking of ships of a large size is enormous ; for
it is computed that 2,000 tons of wood are required for the
building of one 74-gun ship; and reckoning fifty oaks of
100 years’ growth to the acre, it would require forty acres of
oak forest to build one of these vessels.*
* Quart. Journ. of Agricult., No. ix. p. 433.
| NN
VOL. II.
546 IMBEDDING OF THE REMAINS OF MAN AND [Cu. XLVII,
It would be an error to imagine that the fury of war ig
more conducive than the peaceful spirit of commercial enter-
prise to the accumulation of wrecked vessels in the bed of
the sea. From an examination of Lloyd’s lists, from the
year 1793 to the commencement of 1829, the late Admiral
Smyth ascertained that the number of British vessels alone
lost during that period amounted on an average to no less
than one and a half daily; an extent of loss which would
hardly have been anticipated, although we learn from Mo-
reau’s tables that the number of merchant vessels employed
at that time, in the navigation of England and Scotland,
amounted to about 20,000, having one with another a mean
burden of 120 tons.* According to Lloyd’s list for the
years 1820, 1830, and 1831, no less than 1,953 vessels were
lost in those three years, their average tonnage being about
150 tons, or in all nearly 300,000 tons, being at the enormous
rate of 100,000 tons annually of the merchant vessels of one
nation only.
Out of 551 ships of the royal navy lost to the country
during the period above mentioned, only 160 were taken or
destroyed by the enemy, the rest having either stranded or
foundered, or having been burnt by accident: a striking
proof that the dangers of our naval warfare, however great,
may be far exceeded by the storm, the shoal, the lee-shore,
and all the other perils of the deep.t
In the wreck register for 1866, published by the Board of
Trade, the number of shipwrecks and other casualties at sea
is stated at no less than 1,860 on the coast of the United.
Kingdom and in the adjacent seas, and the number of
persons drowned as 896, showing how greatly the loss
increases from increasing activity In commerce.
Buried ships, canoes, and works of art.--When a vessel is
stranded in shallow water, it usually becomes the nucleus of a
sandbank, as has been exemplified in several of our harbours,
and this circumstance tends greatly to its preservation.
Between the years 1780 and 1790 a vessel from Purbeck,
laden with 300 tons of stone, struck on a shoal off the
* Crsar Moreau’s Tables of the Na- + I give these results on the author-
vigation of Great Britain. ity of the late Admiral Smyth, R. N.
ant vessels of on
t to the country
60 were taken or
p, however grit
HIS WORKS IN SUBAQUEOUS STRATA. 547
Cu. XLVIL.]
entrance of Poole harbour and foundered; the crew were
saved, but the vessel and cargo remain to this day at the
bottom. Since that period the shoal at the entrance of the
harbour has so extended itself ina westerly direction towards
Peveril Point in Purbeck, that the navigable channel is thrown
a mile nearer that point.* The cause is obvious: the tidal
current deposits the sediment with which it is charged around
any object which checks its velocity. .Matter also drifted
along the bottom is arrested by any obstacle, and accumulates
round it, just as the African sand-winds, before described,
raise a small hillock over the carcass of every dead camel
exposed on the surface of the desert.
I before alluded to an ancient Dutch vessel, discovered in
the deserted channel of the river Rother, in Sussex, of which
the oak wood was much blackened, but its texture unchanged.
(See above, Vol. I. p. 528.) The interior was filled with fluvia-
tile silt, as was also the case in regard to a vessel discovered
in a former bed of the Mersey, and another disinterred where
the St. Katherine Docks are excavated in the alluvial plain
of the Thames. In like manner many ships have been found
preserved entire in modern strata, formed by the silting up of
estuaries along the southern shores of the Baltic, especially
in Pomerania. Between Bromberg and Nakel, for example,
a vessel and two anchors in a very perfect state were dug up
far from the sea.+
Several vessels have been lately detected half buried in the
delta of the Indus, in the numerous deserted branches of that
river, far from where the stream now flows. One of these,
found near Vikkar in Sinde, was 400 tons in burden, old-
fashioned, and pierced for fourteen guns, and in a region
where it had been matter of dispute whether the Indus had
ever been navigable by large vessels.t
At the mouth of a river in Nova Scotia, a schooner of
32 tons, laden with live stock, was lying with her side to
the tide, when the bore, or tidal wave, which rises there
about 10 feet in perpendicular height, rushed into the estuary,
* This account I received from the
Ha
Honourable and Ven. Chas
+ Von Hoff, vol. i. p. 368.
{ Lieut. Carless, Geograph. Journ.,
vol. viii. p. 388.
NWN 2
548 IMBEDDING OF THE REMAINS OF MAN AND [Cu. XLVII.
and overturned the vessel, so that it instantly disappeared.
After the tide had ebbed, the schooner was so totally buried
in the sand, that the taffrel or upper rail over the stern was
alone visible.* We are informed by Leigh that, on drain-
ing Martin Mere, a lake eighteen miles in circumference, in
Lancashire, a bed of marl was laid dry, wherein no fewer
than eight canoes were found imbedded. In figure and
dimensions they were not unlike those now used in America.
In a morass about nine miles distant from this mere a whet-
stone and an axe of mixed metal were dugup.t In Ayrshire
also, three canoes were found in Loch Doon early in the
present century ; and during the year 1831 four others, each
hewn out of separate oak trees. They were 23 feet in length,
24 in depth, and nearly 4 feet in breadth at the stern. In
the mud which filled one of them was found a war-club of
oak and a stone battle-axe. A canoe of oak was also found
in 1820, in peat overlying the shell-marl of the Loch of Kin-
nordy in Forfarshire.t{
Manner in which ships may be preserved in a deep sea.—It is
extremely possible that the submerged woodwork of ships
which have sunk where the sea is two or three miles deep has
undergone greater chemical changes in an equal space of
time than in the cases above mentioned ; for the experiments
of Scoresby show that wood may at certain depths be impreg-
nated in a single hour with salt water, so that its specific
eravity is entirely altered. (See above, p. 525.) It may often
happen that springs charged with carbonate of lime, silex,
and other mineral ingredients, may issue at great depths, in
which case every pore of the vegetable tissue may be injected
with the lapidifying liquid, whether calcareous or siliceous,
before the smallest decay commences. ‘The conversion, also,
of wood into lignite is probably more rapid under enormous
pressure. But the change of the timber into lignite or coal
would not prevent the original form of a ship from being dis-
tinguished ; for as we find, in strata of the carboniferous era,
* Silliman’s Geol. Lectures, p. 78, ¢ Geol. Trans., second series, vol. ii.
who cites Penn. a) 87. For buri sd enh oee near Glasgow
i ails Lancashire, p. 17, a. D. see ‘ Antiquity of Man,’ p. 4
1700
tat the ster, h
and & war-eh ¢
ak was also foi
[a2
E the Loch of Kin.
ta deep salts
oodwork of ships
ree miles deep hat
in equal space
HIS WORKS IN SUBAQUEOUS STRATA. 549
Cu. XLVIL]
the bark of the hollow reed-lke trees converted into coal, and
the central cavity filled with sandstone, so might we trace
the outline of a ship in coal ; while in the indurated mud,
sandstone, or limestone, filling the interior, we might dis-
cover instruments of human art, ballast consisting of rocks
foreign to the rest of the stratum, and other contents of the
ship.
Submerged metallic substances—Many of the metallic sub-
stances which fall into the waters probably lose, in the course
of ages, the forms artificially imparted to them ; but under
certain circumstances these may be preserved for indefinite
periods. The cannon enclosed in a calcareous rock, drawn
up from the delta of the Rhone, which is now in the museum
at Montpellier, might probably have endured as long as the
calcareous matrix; but even if the metallic matter had been
removed, and had entered into new combinations, still a
mould of its original shape would have been left, correspond-
ing to those impressions of shells which we see in rocks, from
which all the carbonate of lime has been subtracted. About
the year 1776, says Mr. King, some fishermen, sweeping for
anchors in the Gulf-stream (a part of the sea near the Downs),
drew up a very curious old swivel gun, nearly eight feet in
length. The barrel, which was about five feet long, was of
too)
brass; but the handle by which it was traversed was about
three feet in length, and the swivel and pivot on which it
turned were of iron. Around these latter were formed in-
crustations of sand converted into a kind of stone, of ex-
ceedingly strong texture and firmness; whereas round the
barrel of the gun, except where it was near adjoining to the
iron, there were no such incrustations, the greater part of
it being clean, and in good condition, just as if it had still
continued in use. In the incrusting stone, adhering to it on
the outside, were a number of shells and corallines, ‘ just as
they are often found in a fossil state.’ These were all so
strongly attached, that it required as much force to separate
them from the matrix ‘ as to break a fragment off any hard
rock.’*
In the year 1745, continues the same writer, the Fox man-
* Phil. Trans., 1779.
550 IMBEDDING OF THE REMAINS OF MAN AND (Cu. XLVII.
of-war was stranded on the coast of East Lothian, and went
to pieces. About thirty-five years afterwards a violent storm
laid bare a part of the wreck, and threw up near the place
several masses, ‘ consisting of iron, ropes, and balls,’ covered
over with ochreous sand, concreted and hardened into a kind
of stone. The substance of the rope was very little altered.
The consolidated sand retained perfect impressions of parts of
an iron ring, ‘ just as impressions of extraneous fossil bodies
are found in various kinds of strata.’*
After a storm in the year 1824, which occasioned a con-
siderable shifting of the sands near St. Andrew’s, in Scotland, —
a gun-barrel of ancient construction was found, which is con-
jectured to have belonged to one of the wrecked vessels of
the Spanish Armada. It is now in the museum of the Anti-
quarian Society of Scotland, and is incrusted over by a thin
coating of sand, the grains of which are cemented by brown
ferruginous matter. Attached to this coating are fragments
of various shells, as of the common Cardium, Mya, &e.
Many other examples are recorded of iron instruments
taken up from the bed of the sea near the British coast,
incased by a thick coating of conglomerate, consisting of
pebbles and sand, cemented by oxide of iron.
Dr. Davy describes a bronze helmet, of the antique Grecian
form, taken up in 1825, from a shallow part of the sea,
between the citadel of Corfu and the village of Castrades.
Both the interior and exterior of the helmet were partially
incrusted with shells and a deposit of carbonate of lime. The
surface generally, both under the incrustation and where
freed from it, was of a variegated colour, mottled with spots
of green, dirty white, and red. On minute inspection with a
lens, the green and red patches proved to consist of crystals
of the red oxide and carbonate of copper, and the dirty white
chiefly of oxide of tin.
The mineralising process, says Dr. Davy, which has pro-
duced these new combinations, has, in general, penetrated
very little into the substance of the helmet. The incrustation
and rust removed, the metal is found bright beneath; in
* Phil, Trans., vol. lxix. 1779.
Ss a
n instrament:
British coast,
consisting of
itique Grecian
-
551
Cu. XLVI] HIS WORKS IN SUBAQUEOUS STRATA.
some places considerably corroded, in others very slightly.
It proves, on analysis, to be copper alloyed with 18°5 per
cent. of tin. Its colour is that of our common brass, and it
possesses a considerable degree of flexibility.
‘Tt is a curious question,’ he adds, ‘ how the crystals were
formed in the helmet, and on the adhering calcareous deposit.
There being no reason to suppose deposition from solution,
are we not under the necessity of inferring, that the mineral-
ising process depends on a small motion and separation of
the particles of the original compound? This motion may
have been due to the operation of electro-chemical powers
which may have separated the different metals of the alloy.’*
Millions of silver dollars and other coins have been some-
times submerged in a single ship, and on these, when they
happen to be enveloped in a matrix capable of protecting
them from chemical changes, much information of historical
interest will remain inscribed, and endure for periods as inde-
finite as have the delicate markings of zoophytes or lapidified
plants in some of the ancient secondary rocks. In almost
every large ship, moreover, there are some precious stones set
in seals, and other articles of use and ornament composed of
the hardest substances in nature, on which letters and various
images are carved—engravings which they may retain when
included in subaqueous strata, as long as a crystal preserves
its natural form.
It was, therefore, a splendid boast, that the deeds of the
English chivalry at Agincourt made Henry’s chronicle
——as rich with praise
As is the ooze and bottom of the dee
With sunken wreck and sumless treasuries ;
for it is probable that a greater number of monuments of
the skill and industry of man will, in the course of ages, be
collected together in the bed of the ocean, than will exist at
any one time on the surface of the continents.*
* Phil. Trans., 1826, part ii. p. 55.
552 IMBEDDING OF THE REMAINS OF MAN AND [Cu. XLVII.
EFFECTS OF THE SUBSIDENCE OF LAND, IN IMBEDDING CITIES
AND FORESTS IN SUBAQUEOUS STRATA.
We have hitherto considered the transportation of plants
and animals from the land by aqueous agents, and their in-
humation in lacustrine or submarine deposits, and we may
now enquire what tendency the subsidence of tracts of land
may have to produce analogous effects. Severa] examples of
the sinking down of buildings, and portions of towns near
the shore, to various depths beneath the level of the sea
during subterranean movements, were enumerated in the first
volume, Chapter XXIV. The events alluded to were comprised
within a brief portion of the historical period, and confined
to a small number of the regions of active volcanos. Yet
these authentic facts, relating merely to the last century and
a half, gave indications of considerable changes in the phy-
sical geography of the globe, and we are not to suppose that
these were the only spots throughout the surrounding land
and sea which suffered similar depressions.
If, during the short period since South America has been
colonised by Europeans, we have proof of alterations of level
at the three principal ports on the western shores, Callao,
Valparaiso, and Conception,* we cannot for a moment suspect
that these cities, so distant from each other, have been
selected as the peculiar points where the desolating power
of the earthquake has expended its chief fury. On con-
sidering how small is the area occupied by the seaports of
this disturbed region—points where alone each slight change
of the relative level of the sea and land can be recognised,—
and reflecting on the proofs in our possession of the local
revolutions that have happened on the site of each port,
within the last century and a half,—our conceptions must be
greatly exalted respecting the magnitude of the alterations
which the country between the Andes and the sea may
have undergone, even in the course of the last six thousand
years.
Cutch earthquake-—The manner in which a large extent of
surface may be submerged, so that the terrestrial plants and
* See above, pp. 90, 94, 154, 156.
es _mb age
Te compriga i
and Confin al
lleanos, Y,
+ Century anj
$ in the phy-
Suppose that
vunding land
ea bas been
tions of lerel
pores, Callao,
ment suspet
, have been
=
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re
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.
—
Cu. XLVII.] HIS WORKS IN SUBAQUEOUS STRATA. 553
animals may be imbedded in subaqueous strata, cannot be
better illustrated than by the earthquake of Cutch, in 1819,
before alluded to (p. 97). It is stated, that, for some years
after that earthquake, the withered tamarisks and other
shrubs protruded their tops above the waves, in parts of the
lagoon formed by subsidence, on the site of the village of
Sindree and its environs; but, after the flood of 1826, they
were seen no longer. Every geologist will at once perceive
that forests sunk by such subterranean movements may be-
come imbedded in subaqueous deposits, both fluviatile and
marine, and the trees may still remain erect, or sometimes
the roots and part of the trunks may continue in their
original position, while the current may have broken off, or
levelled with the ground, their upper stems and branches.
Buildings how preserved under water.—Some of the buildings
which have at different times subsided beneath the level of
the sea have been immediately covered up toa certain extent
with strata of voleanic matter showered down upon them.
Such was the case at Tomboro in Sumbawa, in the present
century, and at the site of the Temple of Serapis, in the
environs of Puzzuoli, probably about the 12th century. The
entrance of a river charged with sediment in the vicinity
may still more frequently occasion the rapid envelopment of
buildings in regularly stratified formations. But, ifno foreign
matter be introduced, the buildings, when once removed to
a depth where the action of the waves is insensible, and
where no great current happens to flow, may last for indefi-
nite periods, and be as durable as the floor of the ocean itself,
which may often be composed of the very same materials.
There is no reason to doubt the tradition mentioned by the
classic writers, that the submerged Grecian towns of Bura
and Helice were seen under water; and ruins of old sub-
merged towns are mentioned by Captain Spratt as being
visible in the sea off the eastern extremity of Crete or Candia.
It has been already mentioned that different eye-witnesses
have observed the houses of Port Royal, at the bottom ofthe
sea, at intervals of 88, 101, and 143 years after the convul-
sion of 1692 (p. 160).
Ruried temples of Cashmere.—The celebrated valley of
d54 IMBEDDING OF THE REMAINS OF MAN AND [Cu. XLVII.
Cashmere (or Kashmir) in India, situated at the southern foot
of the Himalaya range, is about 60 miles in length, and 20
in breadth, surrounded by mountains which rise abruptly
from the plain to the height of about 5,000 feet. In the
cliffs of the river Jelam and its tributaries, which traverse
this beautiful valley, strata consisting of fine clay, sand, soft
sandstone, pebbles, and conglomerate are exposed to view.
They contain freshwater shells, of the genera Lymneus,
Paludina, and Cyrena, with landshells, all of recent species,
and are precisely such deposits as would be formed if the
whole valley were now converted into a great lake, and if the
numerous rivers and torrents descending from the surround-
ing mountains were allowed sufficient time to fill up the lake-
basin with fine sediment and gravel. Fragments of pottery
met with at the depth of 40 and 50 feet in this lacustrine
formation show that the upper part of it at least has accumu-
lated within the human epoch.
Dr. Thomas Thomson, who visited Cashmere in 1848,
observes that several of the lakes which still exist in the great
valley, such as that near the town of Cashmere, five miles in
diameter, and some others, are deeper than the adjoining
river-channels, and may have been formed by subsidence
during the numerous earthquakes which have convulsed that
region in the course of the last 2,000 years. It is also pro-
bable that the freshwater strata seen to extend far and wide
over the whole of Cashmere originated not in one continuous
sheet of water once occupying the entire valley, but in many
lakes of limited area, formed and filled in succession. Among
other proofs of such lake-basins of moderate dimensions
having once existed and having been converted into land at
different periods, Dr. Thomson mentions that the ruins of
Avantipura, not far from the modern village of that name,
stand on an older freshwater deposit at the base of the
mountains, and terminate abruptly towards the plain in a
straight line, such as admits of no other explanation than by
supposing that the advance of the town in that direction was
arrested by a lake, now drained or represented only by a
marsh. In that neighbourhood, as very generally throughout
Cashmere, the rivers run in channels or alluvial flats, bounded
. — a
1a8 accumu.
© in 1848
in the great
ive miles in
e adjoining
subsidence
rulsed that
|
:
|
Cu. XLVII.] HIS WORKS IN SUBAQUEOUS STRATA. 5Dd5
by cliffs of lacustrine strata, horizontally stratified, and these
strata form low table-lands from 20 to 50 feet high between
the different watercourses. On a table-land of this kind
near Avantipura, portions of two buried temples are seen,
which have been partially explored by Major Cunningham,
who, in 1847, discovered that in one of the buildings a mag-
nificent colonnade of seventy-four pillars is preserved under-
ground. He exposed to view three of the pillars in a cavity
still open. All the architectural decorations below the level
of the soil are as perfect and fresh-looking as when first
executed. The spacious quadrangle must have been silted
up gradually at first, for some unsightly alterations, not in
accordance with the general plan and style of architecture,
were detected, evidently of subsequent date, and such as could
only have been required when the water and sediment had
already gained a certain height in the interior of the temple.
This edifice is supposed to have been erected about the
year 850 of our era, and was certainly submerged before the
year 1416, when the Mahomedan king, Sikandar, called
Butshikan or the idol-breaker, destroyed all the images of
Hindoo temples in Cashmere. Ferishta the historian parti-
cularly alludes to: Sikandar having demolished every Cash-
merian temple save one, dedicated to Mahadéva, which
escaped ‘ in consequence of its foundations being below the
neighbouring water. The unharmed condition of the
human-headed birds and other images in the buried edifice
near Avantipura leave no doubt that they escaped the fury
of the iconoclast by being under water, and perhaps silted up
before the date of his conquest.*
MODERN ORIGIN OF MAN AS INFERRED FROM GEOLOGICAL
EVIDENCE.
Bishop Berkeley on the recent date of the creation of man.—
Bishop Berkeley, in a memorable passage written more than
a century ago, inferred, on grounds which may be termed
strictly geological, the recent date of the creation of man.
* Thomson’s Western Himalaya and ningham, vol. xvii. Journ. Asiat. Soc.
Thibet, p. 292. London, 1852. Cun- Bengal, pp. 241, 277.
556 IMBEDDING OF THE REMAINS OF MAN AND [Cu. XLVII,
‘To anyone,’ says he, ‘ who considers that on digging into
the earth, such quantities of shells, and in some places, bones
and horns of animals, are found sound and entire, after hay-
ing lain there in all probability some thousands of years, it,
should seem probable that guns, medals, and implements in
metal or stone might have lasted entire, buried under ground
forty or fifty thousand years, if the world had been so old.
How comes it then to pass that no remains are found, no
antiquities of those numerous ages preceding the Scripture
accounts of time; that no fragments of buildings, no public
monuments, no intaglios, cameos, statues, basso-relievos,
medals, inscriptions, utensils, or artificial works of any kind,
are ever discovered, which may bear testimony to the exist-
ence of those mighty empires, those successions of monarchs,
heroes, and demi-gods, for so many thousand years? Letus
look forward and suppose ten or twenty thousand years to
come, during which time we will suppose that plagues, famine,
wars, and earthquakes shall have made great havoc in the
world, is it not highly probable that at the end of such a
period, pillars, vases, and statues now in being of granite, or
porphyry, or jasper (stones of such hardness as we know
them to have lasted 2,000 years above ground, without any
considerable alteration), would bear record of these and past
ages? Or that some of our current coins might then be dug
up, or old walls and the foundations of buildings show them-
selves, as well as the shells and stones of the primeval world,
which are preserved down to our times ? *
We may with confidence anticipate, like Berkeley, that if
the duration of the planet is indefinitely protracted, many
edifices and implements of human workmanship and the
skeletons of men will be entombed in freshwater, marine,
and volcanic strata, and will continue to exist even when a
great part of the present mountains, continents, and seas shall
have disappeared. The earth’s crust must be remodelled
more than once before all the memorials of man which are
continually becoming entombed in the rocks now forming will
be destroyed. One complete revolution will be inadequate to
* Alciphron, or the Minute Philosopher, vol. ii. pp. 84, 85. 17382.
gues, famine
havoe in the
nd of sucha
of granite, or
as we know
without any
ese and past
+ then be dug
= show then-
| world,
imerd
ee, : — os
ee
HIS WORKS IN SUBAQUEOUS STRATA. 557
Cu, XLVIL]
efface every monument of our existence ; for many works of art
might enter again and again into the formations of succes-
sive eras, and escape obliteration even though the very rocks
in which they had been for ages imbedded were destroyed,
just as pebbles included in the conglomerates of one epoch
often contain the organised remains of beings which flourished
during a prior era.
Yet it is no less true, as a late distinguished philosopher
has declared, ‘ that none of the works of a mortal being can
be eternal.’ They are in the first place wrested from the
hands of man, and lost as far as regards their subserviency
to his use, by the instrumentality of those very causes which
place them in situations where they are enabled to endure for
indefinite periods. And even when they have been included
in rocky strata, when they have been made to enter ag it
were into the solid framework of the globe itself, they
must nevertheless eventually perish; for every year some
portion of the earth’s crust is shattered by earthquakes, or
melted by volcanic fire, or ground to dust by the moving
waters on the surface. ‘The river of Lethe,’ as Bacon
eloquently remarks, ‘runneth as well above ground as
below.’ *
Monuments of pre-historic man im Europe.—The reader will
see from what was said in the forty-third chapter, that although
we might expect man to become cosmopolitan as soon as he
had acquired such intellectual superiority as belongs even
to the lowest of the human races now inhabiting the globe,
yet so long as he was slightly inferior to these races, he may
have continued for an indefinite time restricted to one limited
area, like the living species of anthropomorphous mammalia.
fiven if he existed as a rational being before the close of the
Pliocene Period, we have no right to assume in the present
state of science that we should have obtained geological evi-
dence of his existence. When treating of the changes of
climate in the first volume, I gave some account (p. 177) of
the results of the joint investigations of the geologist and
_ archeologist in regard to the remains of pre-historic man. It
* Essay on the Vicissitude of Things.
558 IMBEDDING OF THE REMAINS OF MAN AND [Cu. XLVII.
will there be seen that all these remains belong to the latter
part of that modern period in geology which I have called
Post-tertiary, when all the shells, marine and freshwater,
were already of the same species as those now living.
The age of Iron was preceded in Europe by that of Bronze,
when tools of that mixed metal were in use. These bronze
weapons prevailed in Switzerland and Gaul long before the
Roman invasion of those countries. Implements of the same
mixture of copper and tin occur in many of the Swiss lake-
villages and in the peat-mosses of Great Britain, Ireland, and .
Seandinavia. But coins are entirely absent, and no proofs of
the art of writing or of letters having been invented have as
yet been brought to light. Some of the pottery of the Bronze
age is said to show marks of the potter’s wheel, but the
greater part of it was made by hand. Professor Nilsson long
ago observed that the handles of the swords as well as the
bracelets of the Bronze age indicate that the size of the race
which used them was smaller than that of the present inhab-
itants of Northern Europe. Many animals had been domes-
ticated by man in this period, as is shown by the bones pre-
served in certain Swiss lake-dwellings ; several cereals also
and fruits were cultivated. Gold, amber, and glass were in
use for ornamental purposes, but there is no evidence that
silver, zinc, and lead were known. In the Swiss lake-villages
of the antecedent Stone period called Neolithic, as being
newer than a still older age of stone, men were evidently
ignorant of the art of metallurgy. Polished axes commonly
called Celts, chisels, and other tools, were so abundant in
Northern and Western Europe that the Dublin museum con-
tains more than 2,000 of them, that of Copenhagen more
than 10,000, and that of Stockholm not fewer than 15,000.*
The Danish shell-mounds or kitchen-middens, as well as
many of the Swiss lake-dwellings, and a large part of the
Huropean peat, belong to this Neolithic period, but none
of the polished implements of this age occur in the river-
drift gravel-beds, nor in association with extinct mammalia.
Hand-made pottery was in use; the ox, sheep, goat, pig and
Sir J. Lubbock, Introduction to Translation of Nilsson’s ‘Primitive Inhab-
’ .
p. XX1Y.
itants of Scandinavia,
a
— Oe
—_———
Cu. XLVIL] HIS WORKS IN SUBAQUEOUS STRATA. 559
dog were already domesticated, agriculture had commenced,
and flax was cultivated and woven into tissues.
Next in our retrospective survey we come to the monuments
of what M. Lartet has called the Rein-deer period, when that
animal abounded in the South of France.
To this era belong the caves of the Dordogne in central
France, in which MM. Lartet, Christy, and others have ob-
tained thousands of implements made out of stone, bone, and
horn without a trace of any associated pottery, still less of
metallic tools, or polished stone implements. M. Lartet
found in one cave of this period at La Madeleine a fragment
of mammoth tusk on which was rudely carved a representa-
tion of the animal itself; a fact which seems to prove that this
species coexisted with these cave-men. Traces also of the
musk-ox and cave-lion have been met with in the same caves,
but some doubts are still entertained whether these quadrupeds
were contemporary with the men of the Rein-deer period.
This period may be considered as intermediate between the
Neolithic and Paleolithic ages, but it has been classed pro-
visionally by Sir J. Lubbock as Paleolithic. The climate
then prevailing in the south of Europe was evidently much
colder than it is now, but the state of physical geography
has not since undergone any material alteration. :
Lastly we arrive at the still older monuments of the Palzo-
lithic Period properly so called, which consist chiefly of un-
polished stone implements buried in ancient river-gravels and
in the mud and stalagmite of caves. Both the gravel and the
caves are now so situated in their relation to the present
drainage and geography of the countries where they occur as
to imply a great lapse of intervening time during which the
erosive power of rivers has been active in deepening the
valleys. The implements of this age in Western Europe are
chiefly composed of chalk-flint—more rarely of chert from the
greensand. Besides being unpolished they differ in shape
from those of the Neolithic age.* They are associated with
remains of the mammoth, the woolly-haired rhinoceros, the
hippopotamus, the musk-ox, and many other quadrupeds of
ae See Lyell’s ‘ Antiquity of Man,’ pp. 114 and 118, and Lubbock’s ‘Pre-historic
imes,’
560 IMBEDDING OF THE REMAINS OF MAN AND ([Cu. XLVI.
extinct and living species. No pottery has been found strictly
referable to this era, and there is an entire absence of
metallic weapons.
The beds of gravel often called drift, which contain anti-
quities of this age, may be said to have been deposited by the
existing rivers, when these ran in the same direction as at
present, and drained the same areas, but before the valleys
had been scooped out to their present depth. The height
above the present alluvial plains at which the old drift occurs
is often no more than 20 or 30 feet, but sometimes 100 or even
200 feet. Flint flakes having a fine cutting edge, evidently
chipped off by the hand of man, are met with not only in the
old drift, but in formations of the Neolithic and Bronze ages,
for they afford the finest cutting edge that was obtainable
before the invention of steel. In the caves of this early Stone
period implements of the same antique type, with fossil skele-
tons of man, have been detected, agreeing, as before hinted,
(p. 487) in osteological character with some of the existing
races of man. It has been estimated that the number of
flint implements of the Paleolithic type already found in
northern France and southern England, exclusive of flakes, is
not less than 3,000.* No similar tools have been met with
in Denmark, Sweden, or Norway, where Nilsson, Thomsen,
and other antiquaries have collected with so much care the
relics of the Stone age. Hence it is supposed that Paleo-
lithic Man never penetrated into Scandinavia, which may
perhaps have been as much covered with ice and snow as the
ereater part of Greenland is at present.
Paleolithic implements in the drift of the south of Hampshire.
—Flint implements of the normal type of the Palwolithic
period have been lately found in the south of Hampshire,
not in caves nor in old river-gravels within the limits of
existing valleys, but in a tabular mass of drift which caps the
Tertiary strata, and which is intersected both by the Solent
and by the valleys of all the rivers which flow into that channel
of the sea. The position of these implements, to which the
archeologists of Salisbury have called our attention within the
* Sir J. Lubbock, Introduction to Nilsson’s ‘ Primitive Inhabitants of Scandi-
navia, p. Xx.
8 obtainable
iS early Stone
th fossil skele
defore hinted,
- the existing
he number of
ady found m
ve of flakes, 3
een met with
on, Thomsel,
ach care the
| that Pale
:. which may
j snow as
of Hamp sh ‘
?
—~ ee
|
aamguoeamnet ce ——————
HIS WORKS IN SUBAQUEOUS STRATA. S61
Cx. XLVIL.]
last four years, attests perhaps in a more striking manner the
antiquity of pre-historic man in Europe than any other monu-
ment of the earlier Stone age yet discovered. The great bed
of gravel resting on Hocene Tertiary strata in which these
implements have been found, consists in most places of half-
rolled or semi-angular chalk-flints, mixed with rounded
pebbles washed out of the Tertiary strata. But this drift,
although often continuous over wide areas, is not everywhere
present, nor does it always present the same characters. The
first flint implements found in it were discovered mid-way
between Gosport and Southampton, by Mr. James Brown of
Salisbury, in May 1864, included in gravel from 8 to 12
feet thick, capping a cliff which at its greatest height is 35
feet above high-water mark. I have visited this spot, which
had previously been seen by Messrs. Prestwich and Evans.
The flint-tools exactly resemble those found at Abbeville
and Amiens in France, being some of them of the oval, and
others of the lanceolate form. Many of them exhibit the
same colours and ochreous stain as do the flints in the gravel
in which they lay. A fine series of these implements, from
the Hampshire cliffs, may now be seen in the Blackmore
Museum at Salisbury.
In the gravel capping the cliffs alluded to are blocks of
sandstone of various sizes, some of enormous dimensions,
more than 20 feet in circumference and from 1 to 24 feet
thick. They have probably not travelled far, being a portion
of the wreck of the Eocene strata which have suffered much
denudation. Nevertheless to explain how they and the
stone implements became enveloped in the débris of chalk-
flints, we must have recourse to ice, which may have been
frozen on to them in winter, so as to give them buoyancy
and enable rivers or the sea to transport them to slight
distances from their original site. An extreme climate,
causing a vast accumulation of snow during a cold winter,
and great annual floods when this snow was suddenly melted
in the beginning of the warm season, may best account for
the destruction of large masses of chalk in the upland country,
and the spreading over the ancient surface of the flinty
material originally dispersed in layers through the soft chalk
VOL. II. 00
562 IMBEDDING OF THE REMAINS OF MAN AND ([Cu. XLVI.
The occasional occurrence of unrolled chalk-flints in the
gravel in places where they must have travelled twelve miles
from their nearest source, also implies the aid of ice-action.
The transverse valleys now intersecting the region near the
coast where the flint tools are found, near Gosport, must
have been cut through the Tertiary strata, after the over-
lying gravel had been superimposed, for this lust forms a flat
table-land between the valleys.
On the whole we may infer that not only the valleys of
the smaller streams near Gosport, but those of the Test
(or Southampton river) and of the stream which enters at
Lymington, and those of the rivers Avon and Stour, which
reach the Solent at Christchurch, as well as the Bourne-
mouth valley, have all been excavated since Paleolithic man
inhabited this region; for not only at various points east of
the Southampton estuary, but west of it also on both sides
of the opening at Bournemouth, flint tools of the ancient
type have been met with in the gravel capping the cliffs. The
gravel from which the flint tool was taken at Bournemouth
is about 100 feet above the level of the sea; as I ascertained
after examining the spot in 1867.*
The gravel consists in great part of pebbles derived from
Tertiary strata; and if it was originally spread out by rivers,
the course of the drainage must since have been altered to
such an extent that it is not easy to trace any connection
between the old watercourses and those of the existing
valleys.
Lastly, I learn from Mr. Evans that Mr. Thomas Codrington
has just discovered (Feb. 8, 1868), an oval flint implement in
ervavel at the top of the Foreland cliff on the most eastern
point of the Isle of Wight five miles south-east of Ryde. It
is of the true Paleolithic type, and the gravel in which it is
imbedded at the height of about 80 feet above the level of
the sea, may, as Mr. Evans suggests, have once extended to
the cliffs near Gosport; in which case we should have to infer
* Mr. Alfred Stevens first dug out a soon afterwards obtained two other
hatchet (April, 1866) from this gravel similar implements from gravel wes
at the top of the sea-cliff east of the of the Bournemouth valley.
Bournemouth opening. Dr. Blackmore
id of ite. TWh
‘Rory tio,
points east ¢
> On both sida
of the ancien}
the cliffs, Th
t Bournemouth
is I ascertained
3 derived from
| out by nves,
Cu. XLVII.]
HIS WORKS IN SUBAQUEOUS STRATA. 563
that the channel called the Solent had not yet been scooped
out when this region was inhabited by Paleolithic man. The
gravel found at Freshwater at the west end of the Isle of
Wight, in which the remains of the mammoth have been
detected, is probably of the same date.
If we ascend the Avon from Christchurch to Salisbury
about 30 miles to the north, we find in gravels at various
heights above the river, and in old fluviatile alluvium, flint
tools of the same Paleolithic type. One of these was taken
out by Dr. Blackmore from beneath the remains of a mam-
moth, at Fisherton, near Salisbury. The remains of no less
than 21 species of mammalia have also been detected at the
same place, the greatest number, perhaps, obtained in any one
spot in Great Britain. The associated land and freshwater
shells belong to 31 species, and are all still living in England,
although the quadrupeds imply a colder climate. Among
these are the mammoth and woolly-haired rhinoceros, the
rein-deer, and Norwegian lemming, the Greenland lemming,
and another species of the same family, the Spermophilus,
allied to the marmot. Of this last 13 individuals have
been found, some of the skeletons being perfect, and lying,
as remarked by Dr. Blackmore, in the curved attitude of
hibernation, as may now be seen in the Blackmore Museum.
Besides the bones of quadrupeds, the femur and coracoid
bones of the wild goose (Anser palustris), have been met with,
and some egg-shells corresponding in size with the eges of
the wild goose and wild duck. These shells are in part
covered with superficial incrustations. As the wild 2o00se
now resorts to arctic regions in the breeding season, the
occurrence of its eggs at Fisherton seems to imply a cold
climate such as would have suited the lemming and
marmot.*
To conclude, there are three independent classes of evi-
dence, which in this part of Hampshire point distinctly to
the vast antiquity of Paleolithic man. First, the great
denudation of the Chalk and Tertiary strata, and the im-
portant changes in the shape and depth of the valleys and
the contour of the sea-coast which have since occurred in
* Evans, Geol. Quart. Journ., p. 198, Aug. 1864.
002
564 IMBEDDING OF THE REMAINS OF MAN. [Cu. XLVII.
Hampshire; secondly, a marked change in the fauna, by the
dying out of so many conspicuous species of quadrupeds ;
and thirdly, the change of climate from a colder to a warmer
temperature, implied by the former presence of northern
animals, and by the ice-borne erratics of the drift.
Age of pottery buried in upraised marine strata m Sardinia.
—T have elsewhere called attention * to a marine formation
described by Count Albert de la Marmora as occurring at
Cagliari, on the southern coast of the island of Sardinia, at
the height of more than 300 feet above the level of the
Mediterranean. In this deposit some rude fragments of
pottery were found together with a flattened ball of baked
earthenware, with a hole through the axis, supposed to have
been used for weighting fishing-nets. These works of art
were associated with marine shells all of living species, the
oysters and mussels having both valves united together. i
know of no other instance in Europe of a sea-bottom of the
human period having been lifted up 300 feet above its former
level; but in countries like Sardinia, where the latest vol-
canic cones are of Newer Pliocene, if not of Post-Pliocene
date, such an upheaval may not imply a greater antiquity
than may belong to Neolithic times.t
* ‘Antiquity of Man’ p. 177. Sardinia, I think it most probable that
my ‘Antiquity of Man’ (p.177) the bone-breccias in question may be
I ve that these upraised marine older than the marine strata in which
strata containing pottery were as oldas _ the works of art are imbedded. This
certain bone-breceias near Cagliari, in question has now acquired increased im-
ora’s ac- . 560) has been detected in Paleolithic
count of the geology of that part of deposits in the North of Europe.
ce
pposed wo hare
Works of art
ig species, the
d together, |
bottom of the
bove its former
the latest rol
’ Post-Phiocene
ater antiquity
ble that
ce
4 P my
|
ge
CHAPTER XLVIII.
IMBEDDING OF AQUATIC SPECIES IN SUBAQUEOUS STRATA.
INHUMATION OF FRESHWATER PLANTS AND ANIMALS—SHELL- -MARL—FOSSI-
E
BLENDING OF ORGANIC REMAINS OF DIFFERENT AG
Havine treated of the imbedding of terrestrial plants and
animals, and of human remains, in deposits now forming
beneath the waters, I come next to consider in what manner
aquatic species may be entombed in strata formed in their
own element.
Freshwater plants and animals.—The remains of species
belonging to those genera of the animal and vegetable
kingdoms which are more or less exclusively confined to
fresh water are for the most part preserved in the beds of
lakes or estuaries, but they are oftentimes swept down by
rivers into the sea, and there intermingled with the exuvie
of marineraces. The phenomena attending their inhumation
in lacustrine deposits are sometimes revealed to our observ-
ation by the drainage of small lakes, such as are those in
Scotland, which have been laid dry for the sake of obtain-
ing shell-marl for agricultural uses.
In these modern formations, as seen in Forfarshire, two or
three beds of calcareous marl are sometimes observed separated
from each other by layers of drift peat, sand, or fissile clay.
The marl often consists almost entirely of an aggregate of
shells of the genera Limnea, Planorbis, Valvata, and Cyclas,
of species now existing in Scotland. A considerable proportion
of the Testacea appear to have died very young, and few of
566 IMBEDDING OF AQUATIC SPECIES {[Cu. XLVIII.
the shells are of a size which indicates their having attained
a state of maturity. The shells are sometimes entirely de-
composed, forming a pulverulent marl; sometimes in a state
of good preservation. They are frequently intermixed with
stems of Charee and other aquatic vegetables, the whole being
matted together and compressed, forming laminze often as
thin as paper.
fossilised seed-vessels and stems of Chara.—As the Chara is
an aquatic plant which occurs frequently fossil in formations
of different eras, and is often of much importance to the
geologist in characterising entire groups of strata, I shall
describe the manner in which I have found the recent species
in a petrified state. 'They occur in a marl-lake in Forfarshire,
enclosed in nodules, and sometimes in a continuous stratum
of a kind of travertin.
Fig. 140.
Seed-vessel of Chara hispida.
a. Part of the stem with the seed-vessel attached. Magnified.
6. Natural size of rsa eed-vesse
c. Integument of t he Gy rogonite or petrified seed-vessel of Chara hispida, found in the Scotch
marl lakes. ae fied.
pig ection showing th ithin the integu
Lower end of the integumen nt to which the stem was attached.
7. pper end of the integur na to which the stigmata were attached.
g. One of "the spiral valves
The seed-vessel of these plants is remarkably tough and
hard, and consists of a membranous nut covered by an integu-
ment (d, fig. 140), both of which are spirally striated or
ribbed. The integument is composed of five spiral valves, of
——$— ce em
— ee —
Cu. XLVII.] IN SUBAQUEOUS STRATA. 567
a quadrangular form (g). In Chara hispida, which abounds
in a living state in the lakes of Forfarshire, and which has
become fossil in the Bakie Loch, each of the spiral valves of
the seed-vessel turns rather more than twice round the circum-
ference, the whole together making between ten and eleven
rings. The number of these rings differs greatly in different
species, but in the same appears to be very constant.
The stems of Charz occur fossil in the Scotch marl in
great abundance. In some species, as in Chara hispida, the
plant when living contains so much carbonate of lime in its
vegetable organisation, independently of calcareous in-
crustation, that it effervesces strongly with acids when dry.
Fig. 141.
Stem and branches of Chara hispida.
a. Stem and branches of the natural size.
6. Section of the st ified
c. Showing the central tube surrounded by two rings of smaller tubes.
The longitudinal strize on the stems of Chara hispida have
a tendency to be spiral, and as appears to be the case with
other species of the genus, turn always like the worm of a
screw from right to left, while those of the seed-vessel wind
round in a contrary direction. A cross section of the stem
exhibits a curious structure, for it is composed of a large
568 IMBEDDING OF AQUATIC SPECIES [Cu. XLVIII.
tube surrounded by smaller tubes (fig. 141, b, c), as is seen
in some extinct as well as recent species. In the stems of
several species, however, there is only a single tube.*
The valves of a small animal called Cypris (C. ornata ? Lam.) :
occur completely fossilised, like the stems of Chara, in the
Scotch travertin above mentioned. The same Cypris in-
habits the lakes and ponds of England, where, together with
many other species, it is not uncommon. Although extremely
minute, they are visible to the naked eye, and may be observed
in great numbers, swimming swiftly through the waters of
our stagnant pools and ditches. The antennz, at the end of
which are fine pencils of hair, are the principal organs for
swimming, and are moved with great rapidity. The animal
Fig. 148.
Cypris unrfasciata, a living species, greatly Cypris vidua, a living species,
magnified. greatly magnified.f
a. Upper part. 6. Side view of the same.
resides within two small valves, not unlike those of a bivalve
mollusk, and moults its integuments annually, which the
conchiferous mollusk does not. The cast-off shells, resem-
bling thin scales, and occurring in countless myriads in
many ancient freshwater marls, impart to them a divi-
sional structure, like that so frequently derived from plates of
mica.
The recent strata of lacustrine origin above alluded to are
of very small extent, but analogous deposits on the grandest
scale are forming in the great Canadian lakes, as in Lakes
Superior and Huron, where beds of sand and clay are seen
* On Freshwater Marl, &¢. By C. Bier
Lyell, Geol. Trans., vol. ii., second series, ft See Desmaret’s Crustacea, pl. 55.
a living seis,
pagnibel!
IN SUBAQUEOUS STRATA. 569
Cu. XLVIIL.]
enclosing shells of existing species.* The Chara also plays
the same part in the subaqueous vegetation of North
America as in Europe. I observed along the borders of
several freshwater lakes in the state of New York a luxuriant
crop of this plant in clear water of moderate depth, rendering
the bottom as verdant as a grassy meadow. Here, therefore,
we may expect some of the tough seed-vessels to be preserved
in mud, just as we detect them fossil in the Hocene strata of
Hampshire, or in the neighbourhood of Paris, and many
other countries.
IMBEDDING OF FRESHWATER SPECIES IN ESTUARY AND
MARINE DEPOSITS.
In Lewes levels—We have sometimes an opportunity of
examining the deposits which within the historical period
have silted up some of our estuaries; and excavations made
for wells and other purposes, where the sea has been finally
excluded, enable us to observe the state of the organic remains
in these tracts. The valley of the Ouse between Newhaven
and Lewes is one of several estuaries from which the sea
has retired within the last seven or eight centuries; and
here, as appears from the researches of Dr. Mantell, strata
30 feet and upwards in thickness have accumulated. At
the top, beneath the vegetable soil, is a bed of peat about
5 feet thick, enclosing many trunks of trees. Next below is
a stratum of blue clay containing freshwater shells of about
nine species, such as now inhabit the district. Intermixed
with these was observed the skeleton of adeer. Lower down,
the layers of blue clay contain, with the above-mentioned
freshwater shells, several marine species well known on
our coast. In the lowest beds, often at the depth of 36 feet,
these marine Testacea occur without the slightest inter-
mixture of fluviatile species, and amongst them the skull of
a narwal, or sea-unicorn (Monodon monoceros), has been de-
tected. Underneath all these deposits is a bed of pipe-clay,
derived from the subjacent chalk.t
* Dr. Bigsby, Journ. of Science, &c.,
No. xxxvii. pp. 262, 263.
t+ Mantell, Geol. of Sussex, p. 285;
also Catalogue of Org. Rem., Geol.
Trans, vol. iii. part i. p. 201, 2nd series.
570 IMBEDDING OF AQUATIC SPECIES [Cu. XLVIII.
If we had no historical information respecting the former
existence of an inlet of the sea in this valley and of its
gradual obliteration, the inspection of the section above
described would show, as clearly as a written chronicle,
the following sequence of events. First, there was a sgalt-
water estuary peopled for many years by species of marine
Testacea identical with those now living, and into which
some of the larger Cetacea occasionally entered. Secondly,
the inlet grew shallower, and the water became brackish, or
alternately salt and fresh, so that the remains of freshwater
and marine shells were mingled in the blue argillaceous
sediment of its bottom. Thirdly, the shoaling continued
until the river-water prevailed, so that it was no longer hab-
itable by marine Testacea, but fitted only for the abode of
fluviatile species and aquatic insects. Fourthly, a peaty swamp
or morass was formed, where some trees grew, or perhaps
were drifted during floods, and where terrestrial quadrupeds
were mired. Finally, the soil being flooded by the river only
at distant intervals, became a verdant meadow.
In delta of Ganges and Indus.—It was before stated, that
on the sea-coast, in the delta of the Ganges, there are eight
great openings, each of which has evidently, at some ancient
period, served in its turn as the principal channel of dis-
charge.* As the base of the delta is 200 miles in length, it
must happen that, as often as the great volume of river-
water is thrown into the sea by a new mouth, the sea will at
one point be converted from salt to fresh, and at another
from fresh to salt; for, with the exception of those parts
where the principal discharge takes place, the salt water not
only washes the base of the delta, but enters far into every
creek and lagoon. It is evident, then, that repeated alter-
nations of beds containing freshwater shells, with others
filled with marine exuvize, may here be formed. It has also
been shown by artesian borings at Calcutta (see Vol. I.
p- 478), that the delta once extended much farther than
now into the gulf, and that the river is only recovering from
the sea the ground which had been lost by subsidence at some
former period. Analogous phenomena must sometimes be
MeN Ole lasp fies
, Avillacen,
INE continys
10 longer ba,
the abode ¢f
a peaty swamp
W, OF perhaps
al quadrupeds
the river only
re stated, that
here are eight
some ancieat
annel of dis
——— i ee — —
————
IN SUBAQUEOUS STRATA. ~ 571
Cu. XLVI]
occasioned by such alternate elevation and depression as has
occurred in modern times in the delta of the Indus.* But
the subterranean movements affect but a small number of
the deltas formed at one period on the globe ; whereas the
silting up of some of the arms of great rivers and the opening
of others, and the consequent variation of the points where the
chief volume of their waters is discharged into the sea, are
phenomena common to almost every delta.
The variety of species of Testacea contained in the recent
calcareous marl of Scotland, before mentioned, is very small,
but the abundance of individuals extremely great, a cir-
cumstance very characteristic of freshwater formations in
general, as compared to marine; for in the latter, as is seen
on sea-beaches, coral-reefs, or in the bottom of seas examined
by dredging, wherever the individual shells are exceedingly
numerous, there rarely fails to be a vast variety of species.
IMBEDDING OF THE REMAINS OF MARINE PLANTS AND
; ANIMALS.
Marine plants—The large banks of drift sea-weed which
occur on each side of the equator inthe Atlantic, Pacific, and
Indian oceans, were before alluded to.t These, when they
subside, may often produce considerable beds of vegetable
matter. In Holland, sub-marine peat is derived from Fuci,
and on parts of our own coast from sea-wrack (Zostera maria).
In places where Alge do not generate peat, they may never-
theless leave traces of their form imprinted on argillaceous
and calcareous mud, as they are usually very tough in their
texture.
Sea-weeds are often cast up in such abundance on our shores
during heavy gales, that we cannot doubt that occasionally
vast numbers of them are embedded in littoral deposits now
in progress. We learn from the researches of Dr. Forch-
hammer, that besides supplying in common with land-plants
the materials of coal, the Algze must give rise to important
chemical changes in the composition of strata in which they
are imbedded. These plants always contain sulphuric acid,
* Page 99,
+ Page 392.
572 IMBEDDING OF AQUATIC SPECIES (Cu. XLVIII.
and sometimes in as large a quantity as 8} per cent., combined
with potash: magnesia also and phosphoric acid are constant
ingredients. Whenever large masses of sea-weeds putrefy
in contact with ferruginous clay, sulphuret of iron, or iron
pyrites, is formed by the union of the sulphur of the plants
with the iron of the clay. Many of the mineral character-
istics of ancient rocks, especially the alum slates, and the
pyrites which occur in clay slate, and the fragments of an-
thracite in marine strata, may be explained by the decom-
position of fucoids or sea-weeds.*
Imbedding of cetacea.—It is not uncommon for the larger
Cetacea, which can float only in a considerable depth of
water, to be carried during storms or high tides into
estuaries, or upon low shores, where, upon the retiring of
high water, they are stranded. Thus a narwal (Monodon
monoceros) was found on the beach near Boston in Lincoln-
shire, in the year 1800, the whole of its body buried in the
mud. A fisherman going to his boat saw the horn, and
tried to pull it out, when the animal began to stir itself.+
An individual of the common whale (Balena mysticetus),
which measured 70 feet, came ashore near Peterhead, in
1682. Many individuals of the genus Balznoptera have met
the same fate. It will be sufficient to refer to those cast
on shore in the Firth of Forth near Burntisland, and at
Alloa, recorded by Sibbald and Neill. The other individual
mentioned by Sibbald, as having come ashore at Boyne, in
Banffshire, was probably arazor-back. Of the genus Catodon
(Cachalot), Ray mentions a large one stranded on the west
coast of Holland in 1598, and the fact is also commemorated
in a Dutch engraving of the time of much merit. Sibbald,
too, records that a herd of Cachalots, upwards of 100 in
number, were found stranded at Cairston, in Orkney. The
dead bodies of the larger Cetacea are sometimes found
floating on the surface of the waters, as was the case with
the immense whale exhibited in London in 1831. And the
carcass of a sea-cow or Lamantine (Halicora) was, in 1785,
cast ashore near Leith.
* Forchhammer, Report British As- t Fleming’s Brit. Animals, p. 37; in
soc. 1844. which work other cases are enumerated.
i OS a a
Peterhead, 1
= :
$$ —=—_——— — ——————————eEEr
|
|
|
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IN SUBAQUEOUS STRATA. 573
Cu, XLVIII.]
To some accident of this kind we may refer the position
of the skeleton of a whale, 73 feet long, which was found
at Airthie, on the Forth, near Stirling, imbedded in clay 20
feet higher than the surface of the highest tide of the river
Forth at the present day. From the situation of the Roman
station and causeways at a small distance from the spot, it
is concluded that the whale must have been stranded there
at a period prior to the Christian era.*
Marine reptiles. — Some singular fossils have been dis-
covered in the Island of Ascension in a
stone said to be continually forming on
the beach, where the waves throw up
small rounded fragments of shells and
corals, which, in the course of time,
become firmly agglutinated together,
and constitute a stone used largely for
building and making lime. In a quarry
on the NW. side of the island, about
100 yards from the sea, some fossil eggs Fost cees of turtles foe the
of turtles have been discovered in the
hard rock thus formed. The eggs must have been nearly
hatched at the time when they perished ; for the bones of the
young turtle are seen in the interior, with their shape fully
developed, the interstices between the bones being entirely
filled with grains of sand, which are cemented together, so
that when the egg-shells are removed perfect casts of their
form remain in stone. In the single specimen here figured
(fig. 144), which is only five inches in its longest diameter,
no less than seven eggs are preserved.t
To explain the state in which they occur fossil, it seems
necessary to suppose that after the eggs were almost hatched
in the warm sand, a great wave threw upon them so much
Fig. 144.
* Quart. Journ. of Lit. Sci., &e., No.
xv. p. 172. 1819
pealnis specimen has been presented
Mr. Lonsdale to the Geographical
Society of London
most conspicuous of the bones
represented within the shell in fig. 145,
appear to be the clavicle and coracoid
bone. They are hollow; and for this
reason resemble, at first si ight, the
rof. Owen, in order to ppaae this
point, dissected for me a very young
turtle, and found that ae eae por-
tion only of the bones was ossified, the
interior being still filled with meets
574 IMBEDDING OF AQUATIC SPECIES [Cu. XLVIII.
more sand as to prevent the rays of the sun from penetrating,
so that the yolk was chilled and deprived of vitality. The
shells were perhaps slightly broken at the same time, so that
small grains of sand might gradually be introduced into the
interior by water as it percolated through the beach.
Marine testacea.—The aquatic animals and plants which
inhabit an estuary are liable, like the trees and land animals
Seng
HS
oF
? ~t, (4
meacene
(\" a)
a 3
es
iz O32
OS
=
OS
One of the eggs in fig. 144, of th
of the foetus which had
tur the bones
been nearly hatched.
which people the alluvial plains of a great river, to be swept
from time to time far into the deep; for as a river is per-
petually shifting its course, and undermining a portion of its
banks with the forests which cover them, so the marine
current alters its direction from time to time, and bears away
the banks of sand and mud against which it turns its force.
These banks may consist in great measure of shells peculiar
to shallow and sometimes brackish water, which may have
been accumulating for centuries, until at length they are
carried away and spread out along the bottom of the sea, at
a depth at which they could not have lived and multiplied.
Thus littoral and estuary shells are more frequently liable,
even than freshwater species, to be intermixed with the ex-
uvie of pelagic tribes.
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IN SUBAQUEOUS STRATA. ovo
Cu. XLVIIL]
After the storm of February 4, 1831, when several vessels
were wrecked in the estuary of the Forth, the current was
directed against a bed of oysters with such force, that great
heaps of them were thrown alive upon the beach, and re-
mained above high-water mark. I collected many of these
oysters, as also the common eatable whelks (Buccinwm),
thrown up with them, and observed that, although still living,
their shells were worn by the long attrition of sand which
had passed over them as they lay in their native bed, and
which had evidently not resulted from the mere action of the
tempest by which they were cast ashore.
From these facts we learn that the union of the two parts
of a bivalve shell does not prove that it has not been trans-
ported to a distance; and when we find shells worn, and with
all their prominent parts rubbed off, they may still have been
imbedded where they grew.
Burrowing shells.—It sometimes appears extraordinary,
when we observe the violence of the breakers on our coast,
and see the strength of the current in removing cliffs, and
sweeping out new channels, that many tender and fragile
shells should inhabit the sea in the immediate vicinity
of this turmoil. But a great number of the bivalve Tes-
tacea, and many also of the turbinated univalves, burrow in
sand or mud. The Solen and the Cardium, for example,
which are usually found in shallow water near the shore,
pierce through a soft bottom without injury to their shells;
and the Pholas can drill a cavity through mud of considerable
hardness. The species of these and many other tribes can
sink, when alarmed, with considerable rapidity, often to the
depth of several feet, and can also penetrate upwards again
to the surface, if a mass of matter be heaped upon them.
The hurricane, therefore, may expend its fury in vain, and
may Sweep away even the upper part of banks of sand or
mud, or may roll pebbles over them, and yet these Testacea
may remain below secure and uninjured.
Shells become fossil at considerable depths.—-I have already
stated that, at the depth of 950 fathoms, between Gibraltar
and Ceuta, Captain Smith found a gravelly bottom, with
fragments of broken shells, carried thither probably from the
576 IMBEDDING OF AQUATIC SPECIES [Cu. XLVIII.
comparatively shallow parts of the neighbouring straits,
through which a powerful current flows. Beds of shelly sand
might here, in the course of ages, be accumulated several
thousand feet thick. But without the aid of the drifting power
of a current, shells may accumulate in the spot where they
live and die, at great depths from the surface, if sediment be
thrown down upon them; for even in our own colder latitudes
the depths at which living marine animals abound is very
considerable. Captain Vidal ascertained, by soundings made
off Tory Island, on the north coast of Ireland, that Crustacea,
Starfish, and Testacea occurred at various depths between
50 and 100 fathoms; and he drew up Dentalia from the
mud of Galway Bay, in 230 and 240 fathoms water.
The same hydrographer discovered on the Rockhall Bank
large quantities of shells at depths varying from 45 to 190
fathoms. These shells were evidently recent, as they re-
tained their colours. In the same region a bed of fish-bones
was observed extending for two miles along the bottom of
the sea in 10 and 90 fathoms water. At the eastern ex-
tremity also of Rockhall Bank fish-bones were met with,
mingled with pieces of fresh shell, at the depth of 235
fathoms.
Analogous formations are in progress in the submarine
tracts extending from the Shetland Isles to the north of
Ireland, wherever soundings can be procured. A continuous
deposit of sand and mud, replete with broken and entire
shells, Echini, &c., has been traced for upwards of twenty
miles to the eastward of the Faroe Islands, usually at the
depth of from 40 to 100 fathoms. In one part of this
tract (lat. 61° 50’, long. 6° 30’) fish-bones occur in extra-
ordinary profusion, so that the lead cannot be drawn up
without some vertebree being attached. This ‘ bone bed,’ as
it was called by our surveyors, is three miles and a half in
length, and forty-five fathoms under water, and contains a
few shells intermingled with the bones.
In the British seas, the shells and other organic remains
lie in soft mud or loose sand and gravel; whereas, in the bed
of the Adriatic, Donati found them frequently enclosed in
he eastern ¢r-
sere met wil,
depth of 235
the submane
» the north
eee
IN SUBAQUEOUS STRATA.
Cu, XLVIIL]
stone of recent origin. This is precisely the difference in
character which we might have expected to exist between
the British marine formations now in progress and those of
the Adriatic; for calcareous and other mineral springs
abound in the Mediterranean and lands adjoining, while
they are almost entirely wanting in our own country. I
have already adverted to the eight regions of different depths
in the Hgean Sea, each characterised by a peculiar assem-
blage of shells, which have been described by Professor E.
Forbes, who explored them by dredging. (See above, p. 372.)
But since Edward Forbes fixed the zero of animal life in
the Hgean Sea at 300 fathoms, other observers, Captain
McClintock and Dr. Wallich for example, have found living
starfish at the depth of a thousand fathoms midway between
Greenland and Iceland, and Dr. Hooker in his Antarctic
voyage with Captain Sir J. C. Ross established the fact from
soundings made off Victoria Land between lats. 71° and 78°
south, that the bottom of the ocean was inhabited, at depths
of from 200 to 400 fathoms, by crustacea, mollusca, serpulz,
sponges, and other invertebrata.*
In all these cases, it is only necessary that there should
be some deposition of sedimentary matter, however minute,
such as may be supplied by rivers draining a continent, or
currents preying on a line of cliffs, or melting icebergs loaded
with mud, sand, and boulders, in order that stratified forma-
tions, hundreds of feet in thickness, and replete with organic
remains, should result in the course of ages.
We frequently observe, on the sea-beach, very perfect
specimens of fossil shells, quite detached from their matrix,
which have been washed out of older formations, consti-
tuting the sea-cliffs. They may be all of extinct species,
like the Eocene freshwater and marine shells strewed over
the southern shores of Hampshire, yet when they become
mingled with the shells of the present period, and buried in
the same deposits of mud and sand, they would appear, if
upraised and examined by future geologists, to have been all
* « Antiquity of Man,’ p. 268, and Appendix H., p. 528.
Pee
VOL. II.
578 IMBEDDING OF AQUATIC SPECIES, [Cu. XLVIII,
of the same age. That such intermixture and blending of
organic remains of different ages have actually taken place
in former times, is unquestionable, though the occurrence
appears to be very local and exceptional’ It is, however, a
class of accidents more likely than almost any other to lead
to serious anachronisms in geological chronology.
CHAPTER XLIX.
FORMATION OF CORAL REEFS.
GROWTH OF CORAL CHIEFLY CONFINED TO TROPICAL REGIONS—PRINCIPAL
GENERA OF CORAL-BUILDING ZOOPHYTES—THEIR RATE OF GROWTH—SELDOM
FLOURISH AT GREATER DEPTHS THAN TWENTY FATHOMS—ATOLLS OR ANNU-
LAR REEFS WITH LAGOONS—MALDIVE ISLES—ORIGIN OF THE CIRCULAR FORM
—CORAL REEFS NOT BASED ON SUBMERGED VOLCANIC CRATERS—MR, D
EXP.
TER-
R
WHENCE DERIVED—SUPPOSED INCREASE OF CALCAREOUS MATTER IN MODERN
EPOCHS CONTROVERTED—CONCLUDING REMARKS,
TuE powers of the organic creation in modifying the form and
structure of the earth’s crust are most conspicuously displayed
in the labours of the coral animals. We may compare the
operation of these zoophytes in the ocean to the effects pro-
duced ona smaller scale upon the land by the plants which
generate peat. In the case of the Sphagnum, the upper part
vegetates while the lower portion is entering into a mineral
mass, in which the traces of organisation remain when life
has entirely ceased. In corals, in like manner, the more
durable materials of the generation that has passed away
serve as the foundation on which the living animals continue
to rear a similar structure.
The stony part of the lamelliform zoophyte may be likened
to an internal skeleton; for it is always more or less sur-
rounded by a soft animal substance capable of expanding
itself; yet, when alarmed, it has the power of contracting and
drawing itself almost entirely into the cells and hollows of
the hard coral. Although oftentimes beautifully coloured in
their own element, the soft parts become when taken from
~
580 FORMATION OF CORAL REEFS. (Cu. XLIX.
the sea nothing more in appearance than a brown slime spread
over the stony nucleus.*
The growth of those corals which form reefs of solid stone
is entirely confined to the warmer regions of the globe, rarely
extending beyond the tropics about two or three degrees,
except under peculiar circumstances, as in the Bermuda
Islands, in lat. 32° N., where the Atlantic is warmer by the
Gulf-stream. The Caribbean seas are very coralliferous.
The Pacific Ocean, throughout a space comprehended between
the thirtieth parallels of latitude on each side of the equator,
is extremely productive of coral; as also are the Arabian and
Persian Gulfs. Coral is also abundant in the sea between
the coast of Malabar and the island of Madagascar. Flinders
describes a reef of coral on the east coast of New Holland as
having a length of nearly 1,000 miles, and as being in one
part unbroken for a distance of 350 miles. Some groups of
coral islands in the Pacific are from 1,100 to 1,200 miles in
length, by 300 or 400 in
breadth, as the Dangerous
Archipelago, for example, and
that called Radack by Kot-
zebue ; but the islands within
these spaces are always small
points, and often very thinly
sown.
MM. Duchassaing and Jean
Michelotti have lately written
a concise account of the dis-
tribution of corals in relation
Fig, 146.
: = SLOT
Moandrina labyrinthica, Lam
4
Syn. Celoria labyrinthic
M. Edw. & J. Haimes.
to the depth of the sea.t
A certain number of zoophytes are littoral and are left
uncovered by every low tide—for instance, species of the
genera Zoanthes and Palythoa. In shallow spots where a
certain depth of water always covers the corals, the species
of Porites, Astrea, Madrepora, Solenastrea, and Phyllangia,
flourish. The Meandrine are sometimes left uncovered. All
these may be termed sub-littoral. At a depth of from 6 to
* Ehrenberg, Nat. und Bild. der Coralliaires des Antilles. Mem. della
Coralleninseln, &e., Berlin, 1834. ‘eale Aecad. delle Scienze di Torino,
yY Supplément au Mémoire sur les série 1. tom. xxiii.
Some groups
to 1,200 miks in
300 or 400 n
+ the Danger
, for example, a
Radack by Kot
the islands witht
; are always sal
often very th
hassalDg ani J
ave lately “A
count of OF
a
mie
.Cu, XLIX.]
RATE OF THE GROWTH OF CORAL. 581
10 feet the genera Mussa, Colpophyllia, Lithophylhia, Sym-
phyllia, Millepora, &c., are found, and at the depth of from
10 to 20 feet the species of Dichoccenia, Stephanoceenia,
and Desmophyllum flourish.
The distribution of particular species, in regard to the
depth of water in which they grow, is remarkably uniform.
According to Mr. Darwin, as will appear in the sequel, the
reef-building corals rarely live at a depth exceeding 120 feet,
but M. Duchassaing obtained some species of stony corals
at depths of from 600 to 900 feet in the Caribbean Sea. In
temperate climates such species as the Caryophyllia Smythe,
Stokes, are sub-littoral; but Dr. Duncan reminds me, and
the fact is of no small geological significance, when we are
reasoning on extinct forms, that the closely allied species
(. borealis now lives in deep water off the Shetlands.
Of the numerous zoophytes which are engaged in the
production of coral banks, some of the most common belong
to the Lamarckian genera Astrea, Porites, Madrepora,
Millepora, Pocillopora, and Meeandrina.
Rate of the growth of coral.—Very different opinions have
been entertained in regard to the rate at which coral reefs
increase. In Captain Beechey’s late expedition to the Pacific,
no positive information could be obtained of any channel
having been filled up within a given period; and it seems
established, that several reefs had remained for more than
half a century at about the same depth from the surface.
Ehrenberg also questions the fact of channels and harbours
having been closed up in the Red Sea by the rapid increase
of coral limestone. He supposes the notion to have arisen
from the circumstance of havens having been occasionally
filled up in some places with coral sand, in others with large
quantities of ballast of coral rock thrown down from vessels.
The natives of the Bermuda Islands point out certain corals
now growing in the sea, which, according to tradition, have
been living in the same spots for centuries. It is supposed
that some of them may vie in age with the most ancient trees
of Europe. Ehrenberg also observed single corals of the
genera Meeandrina and Favia, having a globular form, from
6 to 9 feet in diameter, ‘which must (he says) be of
982 FORMATION OF CORAL REEFS. [Cu. XLIX.
Fig. 14
a Genera of Zoophytes most common in coral reefs.
A stroea dipsacea, Ehrenb. sp gyn. Acanthastreea gr andis,
Milne Edw. & J. Haimes.
Fig, 148. Fig. 149,
i eens
Extremity of Sane of Madrepora ye bbc aed theta bei Lam,
murievata, Lin Kus ary si cy tata
“Mine 2 Bay Haimes.
Fig. 150. F a
e
Porites clavaria, Lam. Oculina hirtella, Lam.
Cu. XLIX.] DEPTH AT WHICH CORALS GROW. 583
immense antiquity, probably several thousand years old, so
that Pharaoh may have looked upon these same individuals
in the Red Sea.’* They certainly imply, as he remarks,
that the reef on which they grow has increased at a very
slow rate. After collecting more than 100 species, he found
none of them covered with parasitic zoophytes, nor any
instance of a living coral growing on another living coral.
To this repulsive power which they exert whilst living, against
all others of their own class, we owe the beautiful symmetry
of some large Meeandrinz, and other species which adorn our
museums. Yet Balaniand Serpule can attach themselves to
the dermal tissues of living corals, and holes are excavated
in them by boring mollusks.
At the island called Taaopoto, in the South Pacific, the
anchor of a ship, wrecked about 50 years before, was observed
in seven fathoms’ water, still preserving its original form, but
entirely incrusted by coral.t This fact would seem to imply
a slow rate of augmentation; but to form a correct estimate
of the average rate must be very difficult, since it must vary
not only according to the species of coral, but according to
the circumstances under which each species may be placed ;
such, for example, as the depth from the surface, the quantity
of light, the temperature of the water, its freedom from
sand or mud, or the absence or presence of breakers, which
is favourable to the growth of some kinds and is fatal to that
of others. It should also be observed that the apparent
stationary condition of some coral reefs, which according to
Beechey have remained for centuries at the same depth under
water, may be due to subsidence, the upward growth of the
coral having been just sufficient to keep pace with the sinking
of the solid foundation on which the zoophytes have built.
We shall afterwards see how far this hypothesis is borne out
by other evidence in the regions of annular reefs or atolls.
In one of the Maldive Islands a coral reef, which, within a
few years, existed as an islet bearing cocoa-nut trees, was
found by Lieutenant Prentice, ‘ entirely covered with live coral
and madrepore. The natives stated that the islet had been
* See Ehrenberg’s work above cited, qi aera eathe West of England Jour-
Deol. nal, No. i. p. 4
084 FORMATION OF CORAL REEFS, [Cu. XLIX,
washed away by a change in the currents, and it is clear that
a coating of growing coral had been formed in a short time.*
Experiments, also, of Dr. Allan, on the east coast of Mada-
gascar, prove the possibility of coral growing to a thickness of
three feet in about half a year ; + so that the rate of increase
may, under favourable circumstances, be very far from slow.
It must not be supposed that the caleareous masses termed
coral reefs are exclusively the work of zoophytes: a great
variety of shells, and, among them, some of the largest and
heaviest of known species, contribute to augment the mass.
In the South Pacific, great beds of Serpuls, oysters, mussels,
Pinne marine, Chame (or Tridacne), and other shells,
cover in profusion almost every reef; and on the beach of
coral islands are seen the shells of echini and broken frag-
ments of crustaceous animals. Large shoals of fish are also
discernible through the clear blue water, and their teeth and
hard palates cannot fail to be often preserved although their
soft cartilaginous bones may decay.
It was the opinion of the German naturalist Forster, in
1780, after his voyage round the world with Captain Cook,
that coral animals had the power of building up steep and
almost perpendicular walls from great depths in the sea, a
notion afterwards adopted by Captain Flinders and others;
but it is now very generally believed that most of these zoo-
phytes cannot live in water of great depths.
r. Darwin has come to the conclusion, that those species
which are most effective in the construction of reefs, rarely
flourish at a greater depth than 20 fathoms, or 120 feet. In
some lagoons, however, where the water is but little agitated,
there are, according to Kotzebue, beds of living coral in 25
fathoms’ water, or 150 feet; but these may perhaps have
begun to live in shallower water, and may have been carried
downwards by the subsidence of the reef. There are also
various species of zoophytes, and among them some which
are provided with calcareous as well as horny stems, which
live in much deeper water, even in some cases to a depth of
180 fathoms ; but these do not appear to give origin to stony
reefs.
* Darwin’s Coral Reefs, p. 77. f Ibid. p. 78.
5]
OM the beach i
nd broken frag.
8 Of fish are aly
their teeth ani
Lalthongh thir
list Forster, i
Captain Cock,
y up steep aul
s in the sea
aps and other;
st of these 200
at those specie
Cu. XLIX.] DEPTH AT WHICH CORALS GROW. 585
There is every variety of form in coral reefs, but the most
remarkable and numerous in the Pacific consist of circular
or oval strips of dry land, enclosing a shallow lake or
lagoon of still water, in which zoophytes and mollusca abound.
The annular reefs just raise themselves above the level of the
sea, and are surrounded by a deep and often unfathomable
ocean.
In the annexed cut (fig. 152), one of these circular islands
View of Whitsunday Island. (Capt. Beechey.)*
is represented, just rising above the waves, covered with the
cocoa-nut and other trees, and enclosing within a lagoon of
tranquil water.
The accompanying section will enable the reader to com-
prehend the usual form of such islands. (Fig. 153.)
Fig. 153.
Section of a Coral Island.
a, a. Habitable part of the isl
d, consisting of a strip of coral, enclosing the lagoon.
6, b. The lagoon. J s %
The subjoined cut (fig. 154) exhibits a small part of the
section of a coral island on a larger scale.
Of thirty-two of these coral islands visited by Beechey in
his voyage to the Pacific, twenty-nine had lagoons in their
* Voyage to the Pacific, &c. in 1825-28.
586 FORMATION OF CORAL REEFS. [Cu. XLIX.
centres. The largest was 30 miles in diameter, and the
smallest less than a mile. All were increasing their dimen-
sions by the active operations of the lithophytes, which ap-
peared to be gradually extending and bringing the immersed
Fig. 154.
(—)
BI a
he
en.
Section of part of a Coral Island.
a,b. Habitable part of the island.
b, b’. Slope of the side A the island, plunging at an angle of forty-five to the depth of
fifteen hundred
c,c. Part of the lagoo
d, d. spa 5 of iris in'te ‘the lagoon, with overhanging masses of coral resembling the
parts of their ae to the surface. The scene presented
by these annular reefs is equally striking for its singularity
and beauty. A strip of land a few hundred yards wide is
covered by lofty cocoa-nut trees, above which is the blue
vault of heaven. This band of verdure is bounded by a beach
of glittering white sand, the outer margin of which is encir-
cled with a ring of snow-white breakers, beyond which are
the dark heaving waters of the ocean. The inner beach en-
closes the still clear water of the lagoon, resting in its greater
part on white sand, and when illuminated by a vertical sun,
of a most vivid green.* Certain species of zoophytes abound
most in the lagoon, others on the exterior margin, where
there is a great surf. ‘ The ocean,’ says Mr. Darwin, ‘ throw-
ing its breakers on these outer shores, appears an invincible
enemy, yet we see it resisted and even conquered by means
which at first seem most weak and inefficient. No periods
of repose are granted, and the long swell caused by the steady
action of the trade wind never ceases. The breakers exceed
in violence those of our temperate regions, and it is impos-
sible to behold them without feeling a conviction that rocks
of granite or quartz would ultimately yield and be demolished
by such irresistible forces. Yet these low insignificant coral
islets stand and are victorious, for here another power, as
antagonist to the former, takes part in the contest. The
organic forces separate the atoms of carbonate of lime one by
* Darwin’s Journal, &c., p. 640, and new edit., of 1845, p. 453.
ta! Pesembin. a
wea the
CeNE present
its singularity
L yards wide j
ch is the bhe
ded by a beach
which is encr.
rond which ar
nner beach e1-
ig in its greater
a vertical sul
yphytes abound
margil, where
"EY throw-
Cu. XLIX.] REEFS CONVERTED INTO ISLANDS. 587
one from the foaming breakers, and unite them into a sym-
metrical structure; myriads of architects are at work night
and day, month after month, and we see their soft and gela-
tinous bodies through the agency of the vital laws conquering
the great mechanical power of the waves of an ocean, which
neither the art of man, nor the inanimate works of nature,
could successfully resist.’ *
As the coral animals require to be continually immersed in
salt water, they cannot raise themselves by their own efforts
above the level of the lowest tides. The manner in which
the reefs are converted into islands above the level of the sea
is thus described by Chamisso, a naturalist who accompanied
Kotzebue in his voyages :—‘ When the reef,’ says he, ‘is of
such a height that it remains almost dry at low water, the
corals leave off building. Above this line a continuous mass
of solid stone is seen composed of the shells of mollusks and
echini, with their broken-off prickles and fragments of coral,
united by calcareous sand, produced by the pulverisation of
shells. The heat of the sun often penetrates the mass of
stone when it is dry, so that it splits in many places, and the
force of the waves is thereby enabled to separate and lift
blocks of coral, frequently six feet long and three or four in
thickness, and throw them upon the reef, by which means
the ridge becomes at length so high that it is covered only
during some seasons of the year by the spring tides. After
this the calcareous sand lies undisturbed, and offers to the
seeds of trees and plants cast upon it by the waves a soil upon
which they rapidly grow, to overshadow its dazzling white
surface. Entire trunks of trees, which are carried by the
rivers from other countries and islands, find here, at length,
a resting-place after their long wanderings: with these come
some small animals, such as insects and lizards, as the first
inhabitants. Even before the trees form a wood, the sea-
birds nestle here ; stray land-birds take refuge in the bushes;
and, at a much later period, when the work has been long
since completed, man appears and builds his hut on the
fruitful soil.’ +
Darwin’s Journal, &., pp. 547, 548, and 2nd edit., of 1845, p. 460.
t Kotzebue’s Voy., 1815-18, vol. iii. pp. 331-333.
988 FORMATION OF CORAL REEFS. [Cu. XLIX.
In the above description the solid stone is stated to consist
of shell and coral, united by sand ; but masses of very compact
limestone are also found even in the uppermost and newest
parts of the reef, such as could only have been produced by
chemical precipitation. Professor Agassiz also informs me
that his observations on the Florida reefs (which confirm
Darwin’s theory of atolls to be mentioned in the sequel)
have convinced him, that large blocks are loosened, not by
shrinkage in the sun’s heat, as Chamisso imagined, but by
innumerable perforations of lithodomi and other boring tes-
tacea.
The carbonate of lime may have been principally derived
from the decomposition of corals and testacea; for when the
animal matter undergoes putrefaction, the calcareous resi-
duum must be set free under circumstances very favourable
to precipitation, especially when there are other calcareous
substances, such as shells and corals, on which it may be
deposited. Thus organic bodies may be enclosed in a solid
cement, and become portions of rocky masses.*
The width of the circular strip of dead coral forming the
islands explored by Captain Beechey, exceeded in no instance
half a mile from the usual wash of the sea to the edge of the
lagoon, and, in general, was only about three or four hundred
yards.+ The depth of the lagoons is various ; in some, entered
by Captain Beechey, it was from 20 to 38 fathoms.
The two other peculiarities which are most characteristic of
the annular reef or atoll is first, that the strip of dead coral
is invariably highest on the windward side, and secondly,
that there is very generally an opening at some point in the
reef affording a narrow passage, often of considerable depth,
from the sea into the lagoon.
Maldive and Laccadive Isles—The chain of reefs and
islets called the Maldives (see fig. 155), situated in the
Indian Ocean, to the south-west of Malabar, forms a chain
470 geographical miles in length, running due north
and south, with an average breadth of about 50 miles. It
* Stutchbury, West of Eng. Journ., Journ. Geol. Soe., Nov. 1864, p. 360.
No. i. p. 50, and P. M. Duncan, Quart. ~ Captain Beechey, part i. p- 188.
Not h
4gined, bat
al boting t
Netpally dering
3 for When the
“aleareons re
very favourahh
ther caleareons
uich it may le
osed in a solid
.
al forming the
1 in no instance
the edge of the
op four hundrel
» some, enterel
pms.
saracteristi 6
» of dead cor
—
the
f
and
e pou
Je spable ann
tu. XLIX.] CIRCULAR FORM OF CORAL ISLANDS. 589
is composed throughout of a series of circular assemblages
of islets, all formed of coral, the larger groups being from
40 to 90 miles in their longest diameter. Captain Hors-
burgh, whose chart of these islands is Pees:
maijeined, states, that outside of each a on
circle or atoll, as it is termed, there a
coral reefs sometimes extending to na
distance of two or three miles, beyond
which there are no soundings at im-
mense depths. But in the centre of
each atoll there is a lagoon from 15
to 49 fathoms deep. In the chan-
nels between the atolls no sound-
ings can usually be obtained at the’
depth of 150 or even 250 fathoms, but
during Captain Moresby’s survey,
soundings were struck at 150 and 200
fathoms, the only instances as yet £
known of the bottom having been
reached, either in the Indian or Pacific
oceans, in a space intervening between
two separate and well characterised ,:
atolls. i
The singularity in the form of the
atolls of this archipelago consists in
their being made up, not of one contin- |
uous circular reef, but of a ring of small ©
coral islets sometimes more than a
hundred in number, each of which is a
miniature atoll in itself; in other words,
a ring-shaped strip of coral surround- *}—-—
ing a lagoon of salt water. To account | Day
€
FE
6
One ag half edie
hanne
~—
©
9A0%e,,
settee ate a:
for the origin of these, Mr. Darwin
supposes the larger annular reef to have
been broken up into a number of frag- o||—
ments, each of which acquired its pecu-
har configurations under the influence cS
of causes similar to those to which the | fe
structure of the parent atoll has been due. Many of the
“Ef no
Ep
|
Equator ial Channel
|
pee es
\
|
590 FORMATION OF CORAL REEFS. [Cu. XLIX,
minor rings are no less than three, and even five miles in
diameter, and some are situated in the midst of the principal
lagoon; but this happens only in cases where the sea can
enter freely through breaches in the outer or marginal reef.
The rocks of the Maldives are composed of sandstone
formed of broken shells and corals, such as may be obtained
in a loose state from the beach, and which is seen when
exposed for a few days to the air to become hardened.
The sandstone is sometimes observed to be an aggregate of
broken shells, corals, pieces of wood, and shells of the cocoa-
nut.*
The Laccadive Islands run in the same line with the
Maldives, on the north, as do the islands of the Chagos
Archipelago, on the south; so that these may be continua-
tions of the same chain of submerged mountains, crested in
a similar manner by coral limestones.
Origin of the circular form—not voleanic.—The circular
and oval shape of so many reefs, each having a lagoon in the
centre, and being surrounded on all sides by a deep ocean,
naturally suggested the idea that they were nothing more
than the crests of submarine volcanic craters overgrown by
coral: and this theory I myself advocated in the earlier
editions of this work. Although I am now about to show
that it must be abandoned, it may still be instructive to point
out the grounds on which it was formerly embraced. In the
first place, it had been remarked that there were many active
volcanos in the coral region of the Pacific, and that in some
places, as in Gambier’s group, rocks composed of porous lava
rise up in a lagoon bordered by a circular reef, just as the
two cones of eruption called the Kaimenis have made their
appearance in the times of history within the circular gulf
of Santorin.t It was also observed that as in 8. Shetland,
Barren Island, and others of volcanic origin, there is one
narrow breach in the walls of the outer cone by which ships
may enter a circular gulf, so in like manner there is often a
single deep passage leading into the lagoon of a coral island,
the lagoon itself seeming to represent the hollow or gulf
* Captain Moresby on the Maldives, ii. p. 400.
Journ. Roy. Geograph. Soc., vol. v. part tT See above, p. 69.
|
:
line With fh
Of the Chao
AY be contin,
als, cresta] m
—The cireuy
a lagoon inthe |
@ deep ocean,
» nothing mor
$ overgrown by
in the earlier
about to show
ructive to pont
Cu, XLIX.] CIRCULAR FORM OF CORAL ISLANDS. 591
just as the ring of dry coral recalls to our minds the rim
of a volcanic crater. More lately, indeed, Mr. Darwin has
shown that the numerous volcanic craters of the Galapagos
Archipelago in the Pacific have all of them their southern
sides the lowest, or in many cases quite broken down, so that
if they were submerged and incrusted with coral, they would
resemble true atolls in shape.*
Another argument which I adduced when formerly de-
fending this doctrine was derived from Khrenberg’s statement,
that some banks of coral in the Red Sea were square, while
many others were ribbon-like strips, with flat tops, and with-
out lagoons. Since, therefore, all the genera and many of
the species of zoophytes in the Red Sea agreed with those
which elsewhere construct lagoon islands, it followed that the
stone-making zoophytes are not guided by their own instinct
in the formation of annular reefs, but that this peculiar shape
and the position of such reefs in the midst of a deep ocean
must depend on the outline of the submarine bottom, which
resembles nothing else in nature but the crater of a lofty sub-
merged volcanic cone. The enormous size, it is true, of some
atolls made it necessary for me to ascribe to the craters of
many submarine volcanos a magnitude which was startling,
and which had often been appealed to as a serious objection
to the voleanic theory. That so many of them were of the
same height, or just level with the water, did not present a
difficulty so long as we remained ignorant of the fact that the
reef-building species do not grow at greater depths than
25 fathoms.
May be explained by subsidence.— Mr. Darwin, after examin-
ning a variety of coral formations in different parts of the
globe, was induced to reject the opinion that their shape
represented the form of the original bottom. Instead of
admitting that the ring of dead coral rested on a circular or
oval ridge of rock, or that the lagoon corresponded to a pre-
existing cavity, he advanced a new opinion, which must, at
first sight, seem paradoxical in the extreme: namely, that
the lagoon is precisely in the place once occupied by the
* Darwin, Volcanic Islands, p. 113.
092 FORMATION OF CORAL REEFS. [Cu. XLIX.
highest part of a mountainous island, or, in other cases, by
the top of a shoal.
The following is a brief sketch of the facts and arguments
in favour of this new view:—Besides those rings of dry
coral which enclose lagoons, there are others having a similar
form and structure which encircle lofty islands. Of the latter
kind is Vanikoro (see Map, fig. 59, p. 586), celebrated on
account of the shipwreck of La Peyrouse, where the coral
reef runs at the distance of two or three miles from the shore,
the channel between it and the land having a general depth
of between 200 and 300 feet. This channel, therefore, is
analogous to a lagoon, but with an island standing in the
middle like a picture in its frame. In like manner in Tahiti
we see a mountainous land, with everywhere round its mar-
gin a lake or zone of smooth salt water, separated from the
ocean by an encircling reef of coral, on which a line of
breakers is always foaming. So also New Caledonia, a long
narrow island east of New Holland, composed partly of
granite and partly of triassic sandstone, is surrounded by a
reef 400 miles long. This reef encompasses not only the
island itself, but a ridge of rocks which is prolonged in the
same direction beneath the sea. No one, therefore, will
contend for a moment that in this case the corals are based
upon the rim of a volcanic crater, in the middle of which
stands a mountain or island of granite and sandstone.
The great barrier reef, already mentioned as running paral-
lel to the north-east coast of Australia for nearly 1,000 miles,
is another most remarkable example of a long strip of coral
running parallel to a coast. Its distance from the main-
land varies from 20 to 70 miles, and the depth of the
great arm of the sea thus enclosed is usually between 10
and 20 fathoms, but towards one end from 40 to 60. This
great reef would extend much farther, according to Mr.
Jukes, if the growth of coral were not prevented off the shores
of New Guinea by a muddy bottom, caused by rivers charged
with sediment which flow from the southern coast of that
ereat island.*
* Quart Journ. Geol. Soe. 4, xciii.
‘aledonia, a long
posed partly
surrounded by a
es not only the
rolonged in the
- therefore, wil
corals are bas
niddle of whit
yndstone.
5 running pal
arly 1,000 i
Te strip of con
ORIGIN OF THEIR FORM. 598
Cu. XLIX.]
Two classes of reefs, therefore, have now been considered ;
first, the atoll, and, secondly, the encircling and barrier reef,
both agreeing perfectly in structure, and the sole difference
lying in the absence in the case of the atoll of all land, and
in the others the presence of land bounded either by an en-
circling or a barrier reef. But there is still a third class of
reefs, called by Mr. Darwin ‘fringing reefs,’ which approach
much nearer the land than those of the encircling and barrier
class, and which indeed so nearly touched the coast as to
leave nothing in the intervening space resembling a lagoon.
‘That these reefs are not attached quite close to the shore
appears to be the result of two causes; first, that the water
immediately adjoining the beach is rendered turbid by the
surf, and therefore injurious to all zoophytes ; and, secondly,
that the larger and efficient kinds only flourish on the outer
edge amidst the breakers of the open sea.”*
It will at once be conceded that there is so much analogy
between the form and position of the strip of coral in the
Fig. 156.
A
Supposed section of an island with ircli f of
A. The island :
b, c. Highest points of the encircling reef between which and the coast is seen a space
occupied by still water.
atoll, and in the encircling and barrier reef, that no explana-
tion can be satisfactory which does not include the whole.
If we turn, in the first place, to the encircling and barrier
reefs, and endeavour to explain how the zoophytes could
have found a bottom on which to begin to build, we are met
at once with a great difficulty. Itis a general fact, long since
remarked by Dampier, that high land and deep seas go
together. In other words, steep mountains coming down
* Darwin’s Journ., p. 557, 2nd edit. chap. 20, and Coral Islands, chapters
VOL. It. QQ
Q
594 FORMATION OF CORAL REEFS. [Cu. XLIX.
abruptly to the sea-shore are generally continued with the
same slope beneath the water. But where the reef, as at
be (fig. 156), is distant several miles from a steep coast, a line
drawn perpendicularly downwards from its outer edges be to
the fundamental rock de, must descend toa depth exceeding
by several thousand feet the limits at which the efficient stone-
building corals can exist, for we have seen that they cease
to grow in water which is more than 120 feet deep. That
the original rock immediately beneath the points b ¢ is ac-
tually as far from the surface de, is not merely inferred from
Dampier’s rule, but confirmed by the fact, that, immediately
outside the reef, soundings are either not met with at all, or
only at enormous depths. In short, the ocean is as deep as
might have been anticipated in the neighbourhood of a bold
coast ; and it is obviously the presence of the coral alone
which has given rise to the anomalous existence of shallow
water on the reef and between it and the land.
After studying in minute detail all the phenomena above
described, Mr. Darwin has offered in explanation a theory
now very generally adopted. The coral-forming polypi, he
states, begin to build in water of a moderate depth, and, while
they are yet at work, the bottom of the sea subsides gradu-
ally, so that the foundation of their edifice is carried down-
wards at the same time that they are raising the superstruc-
ture. If, therefore, the rate of subsidence be not too rapid,
the growing coral will continue to build up to the surface ;
the mass always gaining in height above its original base,
but remaining in other respects in the same position. Not
so with the land: each inch lost is irreclaimably gone; as it
sinks the water gains foot by foot on the shore, till in many
cases the highest peak of the original island disappears.
What was before land is then occupied by the lagoon, the
position of the encircling coral remaining unaltered, with the
exception of a slight contraction of its dimensions.
In this manner are encircling reefs and atolls produced ;
and in confirmation of his views Mr. Darwin has pointed out
examples which illustrate every intermediate state, from that
of lofty islands such as Qtaheite, encircled by coral, to that
of Gambier’s group, where a few peaks only of land rise out
Ps "
Ut
Mtinnes ty
istence of shally
land.
phenomena abr
lanation a thay |
orming polypi,l
2 depth, and, wil
4 subsides grait
» is carried dom
ng the supers”
he not too mp
gure:
a
Cx. XLIX.] ORIGIN OF THEIR FORM. 595
of a lagoon, and, lastly, to the perfect atoll, having a lagoon
several hundred feet deep, surrounded by a reef rising deeply
from an unfathomed ocean.
If we embrace these views, it is clear, that in regions of
growing coral a similar subsidence must give rise to barrier
reefs along the shores of a continent. Thus suppose A
(fig. 157) to represent the north-eas tportion of Australia, and
b c the ancient level of the sea, when the coral reef d was
formed. If the land sink so that it ig submerged more and
more, the sea must at length stand at the level e J, the reef
in the meantime having been enlarged and raised to the
Fig. 157-
point gy. The distance between the shore f, and the barrier
reef g, is now much greater than originally between the
shore ¢ and the reef d, and the longer the subsidence con-
tinues the farther will the coast of the mainland recede.
When the first edition of this work appeared in 1831,
several years before Mr. Darwin had investigated the facts
on which his theory is founded, I had come to the Opinion
that the land was subsiding at the bottom of those parts of
the Pacific where atolls are numerous, although I failed to
perceive that such a subsidence, if conceded, would equally
solve the enigma as to the form both of annular and barrier
reefs.
I shall cite the passage referred to, as published by me in
1831 :—‘It is a remarkable circumstance that there should
be so vast an area in Eastern Oceanica, studded with
minute islands, without one single spot where there is a
wider extent of land than belongs to such islands as Otaheite,
Owhyhee, and a few others, which either have been or are
still the seats of active volcanos.
were maintained between the uy
of earthquakes,
If an equilibrium only
pheaving and depressing force
large islands would very soon be formed in
the Pacific; for, in that case, the growth of limestone, the
QQ2 ;
596 FORMATION OF CORAL REEFS. [Cu. XLIX.
flowing of lava, and the ejection of voleanic ashes, would
combine with the upheaving force to form new land.
‘Suppose a shoal, 600 miles in length, to sink 15 feet,
and then to remain unmoved for a thousand years; during
that interval the growing coral may again approach the
surface. Then let the mass be re-elevated 15 feet, so that
the original reef’ is restored to its former position: in this
ease, the new coral formed. since the first subsidence will
constitute an island 600 miles long. An analogous result
would have occurred if a lava-current 15 feet thick had
overflowed the submerged reef. The absence, therefore, of
more extensive tracts of land in the Pacific, seems to show
that the amount of subsidence by earthquakes exceeds, in
that quarter of the globe, at present, the elevation due to the
same cause.’ *
Another proof also of subsidence derived from the struc-
ture of atolls, was pointed out by me in the following
passage in all former editions. ‘The low coral islands of
the Pacific,’ says Captain Beechey, ‘follow one general rule
in having their windward side higher and more perfect than
the other. At Gambier and Matilda Islands this inequality
is very conspicuous, the weather side of both being wooded,
and of the former inhabited, while the other sides are from
20 to 30 feet under water; where, however, they may be
perceived to be equally narrow and well defined. It is on
the leeward side also that the entrances into the lagoons
occur; and although they may sometimes be situated on a
side that runs in the direction of the wind, as at Bow
Island, yet there are none to windward.’ These observations
of Captain Beechey accord with those which Captain Hors-
burgh and other hydrographers have made in regard to the
coral islands of other seas. From this fortunate circum-
stance ships can enter and sail out with ease; whereas if
the narrow inlets were to windward, vessels which once
entered might not succeed for months in making their way
out again. The well-known security of many of these
harbours depends entirely on this fortunate peculiarity in
their structure.
* See Principles of Geology, Ist. edit., vol. ii. p. 296.
| eds, ip
eration due tp the
ad from the ste.
in the folloviy
® coral islands
“one general rl
more perfect tha
is this inequalty
DUT
Cu. XLIX.] ORIGIN OF THEIR FORM.
‘Tn what manner is this singular conformation to be ac-
counted for? The action of the waves is seen to be the
cause of the superior elevation of some reefs on their wind-
ward sides, where sand and large masses of coral rock are
thrown up by the breakers ; but there is a variety of cases
where this cause alone is inadequate to solve the problem ;
for reefs submerged at considerable depths, where the move-
ments of the sea cannot exert much power, have, neverthe-
less, the same conformation, the leeward being much lower
than the windward side.*
‘T am informed by Captain King, that, on examining the
reefs called Rowley Shoals, which lie off the north-west
coast of Australia, where the east and west monsoons prevail
alternately, he found the open side of one crescent-shaped
reef, the Impérieuse, turned to the east, and of another, the
Mermaid, turned to the west; while a third oval reef, of the
same group, was entirely submerged. This want of con-
formity is exactly what we should expect, where the winds
vary periodically.
‘Tt seems impossible to refer the phenomenon now under
consideration to any original uniformity in the configuration
of submarine volcanos, on the summits of which we may
suppose the coral reefs to grow; for although it is very
common for craters to be broken down on one side only, we
cannot imagine any cause that should breach them all in the
same direction. But the difficulty will, perhaps, be removed,
if we call in another part of the volcanic agency—subsidence
by earthquakes. Suppose the windward barrier to have been
raised by the mechanical action of the waves to the height
of 2 or 3 yards above the wall on the leeward side, and
then the whole island to sink down a few fathoms, the ap-
pearances described would then be presented by the sub-
merged reef. A repetition of such operations, by the alter-
nate elevation and depression of the same mass (an hypothesis
strictly conformable to analogy), might produce still greater
inequality in the two sides, especially as the violent efflux
of the tide has probably a strong tendency to check the
* Voyage to the Pacific, &c., p. 189.
598 FORMATION OF CORAL REEFS, [Cu. XLIX,
accumulation of the more tender corals on the leeward reef :
while the action of the breakers contributes to raise the
windward barrier.’ *
Previously to my adverting to the signs above enumerated
of a downward movement in the bed of the ocean, Dr.
Macculloch, Captain Beechey, and many other writers had
Shown that masses of recent coral had been laid dry at
various heights above the sea-level, both in the Red Sea, the
islands of the Pacific, and in the Hast and West Indies.
After describing thirty-two coral islands in the Pacific,
Captain Beechey mentioned that they were all formed of
living coral except one, which although of coral formation,
was raised about 70 or 80 feet above the level of the sea,
and was encompassed by a reef of living coral. It is called
Elizabeth or Henderson’s Island, and is 5 miles in length
by 1 in breadth. It has a flat surface, and, on all sides,
except the north, is bounded by perpendicular cliffs above
00 feet high, composed entirely of dead coral, more or less
porous, honeycombed at the surface, and hardening into a
compact calcareous mass, which possesses the fracture of
secondary limestone, and has a Species of millepore inter-
Fig. 158.
Elizabeth or Henderson’s Island.
spersed through it. These cliffs are considerably undermined
by the action of the waves, and some of them appear on the
eve of precipitating their superincumbent weight into the
sea. Those which are less injured in this way present no
alternate ridges or indication of the different levels which
the sea might have occupied at different periods; but a
smooth surface, as if the island, which has probably been
raised by volcanic agency, had been forced up by one ereat
subterraneous convulsion.+ At the distance of a few hun-
dred yards from this island, no bottom could be gained with
200 fathoms of line.
Tt will be seen, from the annexed sketch, communicated to
* See Principles of Geol., Ist. edit., 1832, vol. ii. p. 298.
t Beechey’s Voyage to the Pacific, &e., p. 46.
oral, more or ks
hardening into
the fracture of
millepore inte
esa
ably gndernind
" anear on We
Cu. XLIX.] MR. DARWIN'S THEORY OF SUBSIDENCE. 599
me by Lieutenant Smith, of the Blossom, that the trees
came down to the beach towards the centre of the island,
where there is a break in the cliffs resembling at first sight
the openings which usually lead into lagoons; but the trees
stand on a steep slope, and no hollow of an ancient lagoon
was perceived. Beechey also remarks, that the surface of
Henderson’s Island is flat, and that in Queen Charlotte’s
Island, one of the same group, but under water, there was
no lagoon, the coral having grown up everywhere to one
level. The probable cause of this obliteration of the central
basin or lagoon will be considered in the sequel.
That the bed of the Pacific and Indian oceans, where
atolls are frequent, must have been sinking for ages, might
be inferred, says Mr. Darwin, from simply reflecting on two
facts; first, that the efficient coral-building zoophytes do not
flourish in the ocean at a greater depth than 120 feet; and,
secondly, that there are spaces occupying areas of many
hundred thousand square miles, where all the islands consist
of coral, and yet none of which rise to a greater height than
may be accounted for by the action of the winds and waves
on broken and triturated coral. Were we to take for granted
that the floor of the ocean had remained stationary from the
time when the coral began to grow, we should be compelled
to assume that an incredible number of submarine moun-
tains of vast height (for the ocean is always deep, and often
unfathomable between the different atolls,) had all come to
within 120 feet of the surface, and yet no one mountain had
risen above water. But no sooner do we admit the theory of
subsidence than this great difficulty vanishes. However
varied may have been the altitude of different islands, or the
separate peaks of particular mountain-chains, all may have
been reduced to one uniform level by the gradual submer-
gence of the loftiest points and the additions made to the
calcareous cappings of the less elevated summits as they
subsided to great depths.
Openings into the lagoons.—In the general description of
atolls and encircling reefs, it was mentioned that there is
almost always a deep narrow passage opening into the
lagoon, or into the still water between the reef and the
600 FORMATION OF CORAL REEFS. [Cu. XLIX.
shore, which is kept open by the efflux of the sea as the
tide goes down.
The origin of this channel must, according to the theory
of subsidence before explained, be traced back to causes
which were in action during the existence of the encircling
reef, and when an island or mountain top rose within it, for
such a reef precedes the atoll in the order of formation.
Now in those islands in the Pacific, which are large enough
to feed small rivers, there is generally an opening or channel
in the surrounding coral reef at the point where the stream
of fresh water enters the sea. The depth of these channels
rarely exceeds 25 feet; and they may be attributed, says
Captain Beechey, to the aversion of the lithophytes to fresh
water, and to the probable absence of the mineral matter of
which they construct their habitations.*
Mr. Darwin, however, has shown, that mud at the bottom
of river-courses is far more influential than the freshness of
the water in preventing the growth of the polypi, for the
walls which enclose the openings are perpendicular, and do
not slant off gradually, as would be the case, if the nature
of the element presented the only obstacle to the increase of
the coral-building animals.
When a breach has thus been made in the reef, it will be
prevented from closing up by the efflux of the sea at low
tides ; for it is sufficient that a reef should rise a few feet
above low-water mark to cause the waters to collect in the
lagoon at high tide, and when the sea falls, to rush out at
one or more points where the reef happens to be lowest or
weakest. This event is strictly analogous to that witnessed
in our estuaries where a body of salt water accumulated
during the flow issues with great velocity at the ebb of the
tide, and scours out or keeps open a deep passage through
the bar, which is almost always formed at the mouth of a
river, At first there are probably many openings, but the
growth of the coral tends to obstruct all those which do not
Serve as the principal channels of discharge ; so that their
number is gradually reduced to a few, and often finally to
* Voyage to the Pacific, &e., p. 194.
ee ee
Matter of
the botton
reshness of
pi, for the
ar, and do
the nature
merease f
‘itwllk
ea, at lor
Cu. XLIX.] SIZE OF ATOLLS AND BARRIER REEFS. 601
one. The fact observed universally, that the principal opening
fronts a considerable valley in the encircled island, between
the shores of which and the outer reef there is often deep
water, scarcely leaves any doubt as to the real origin of the
channel in all those countless atolls where the nucleus of
land has vanished.
Size of atolls and barrier reefs—In regard to the dimen-
sions of atolls, it was stated that some of the smallest ob-
served by Beechey in the Pacific were only a mile in diameter.
If their external slope under water equals upon an average
an angle of 45°, then would such an atoll at the depth of
half a mile, or 2,640 feet, have a diameter of two miles.
Hence it would appear that there must be a tendency in
every atoll to grow smaller, except in those cases where
oscillations of level Shionae: the base on which the coral
grows by throwing down a talus of detrital matter all round
the original cone of limestone.
Bow Island is described by Captain Beechey as 70 miles in
circumference, and 30 in its greatest diameter, but we have
seen that some of the Maldives are much larger.
As the shore of an island or continent which is subsiding
will recede from a coral reef at a slow or rapid rate according
as the surface of the land has a steep or gentle slope, we
cannot measure the thickness of the coral by its distance
from the coast; yet, as a general rule, those reefs which are
farthest from the land imply the greatest amount of sub-
sidence. We learn from Flinders, that the barrier reef of
north-eastern Australia is in some places 70 miles from the
mainland, and it should seem that a calcareous formation is
there in progress 1,000 miles long from north to south, with
a breadth varying from 20 to 70 miles. It may not, indeed,
be continuous over this vast area, for doubtless innumerable
islands have been submerged one after another between the
reef and mainland, like some which still remain, as, for
example, Murray’s Islands, lat. 9° 54’S. We are told that
some parts of the gulf enclosed within the barrier are 400
feet deep, so that the efficient rock-building corals cannot be
growing there, and in other parts of it islands appear en-
circled by reefs.
602 FORMATION OF CORAL REEFS. [Cu. XLIX,
Tt will follow as one of the consequences of the theory
already explained that, provided the bottom of the sea does
not sink too fast to allow the zoophytes to build upwards
at the.same pace, the thickness of coral will be great in
proportion to the rapidity of subsidence, so that if one area
sinks 2 feet while another sinks 1, the mass of coral in the
first area will be double that in the second. But the down-
ward movement must in general have been very slow and
uniform, or, where intermittent, must have consisted of a
great number of depressions, each of slight amount, other-
wise the bottom of the sea would have been carried down
faster than the corals could build upwards, and the island
or continent would be permanently submerged, having
reached a depth of 120 or 150 feet, at which the effective
reef-constructing zoophytes cease to live. If, then, the sub-
sidence required to account for all the existing atolls must
have amounted to 3,000 or 4,000 feet, or even sometimes
more, we are brought to the conclusion that there has been
a slow and gradual sinking to this enormous extent. Such
an inference is perfectly in harmony with views which the
grand scale of denudation, everywhere observable in the
older rocks, has led geologists to adopt in reference to up-
ward movements. They must also have been eradual and
continuous throughout indefinite ages to allow the waves and
currents of the ocean to operate with adequate power.
The map constructed by Mr. Darwin to display at one
view the geographical position of all the coral reefs through-
out the globe is of the highest geological interest, leading
to splendid generalisations, when we have once embraced
the theory that all atolls and barrier reefs indicate recent
subsidence, while the presence of fringing reefs proves
the land to} be stationary or rising. These two classes of
coral formations are depicted by different colours; and
one of the striking facts brought to light by the same
classification of coral formations is the absence of active
volcanos in areas of subsidence, and their frequent presence
in the areas of elevation. The only supposed exception to
this remarkable coincidence at the time when Mr. Darwin
wrote, in 1842, was the volcano of Torres Strait, at the
Cu. XLIX.] MR. DARWIN’S MAP OF CORAL REEFS. 603
northern point of Australia, placed on the borders of an area
of subsidence ; but it has been since proved that this volcano
has no existence.
We see, therefore, an evident connection, first, bebe the
bursting forth every now and then of volcanic matter through
rents and fissures, and the expansion or forcing outwards of
the earth’s crust, and, secondly, between a dormant and less
energetic development of subterranean heat, and an amount
of subsidence sufficiently great to cause mountains to dis-
appear over the broad face of the ocean, leaving only small
and scattered lagoon islands, or group of atolls, to indicate
the spots where those mountains once stood.
On a review of the differently-coloured reefs on the map
alluded to, it will be seen that there are large spaces in
which upheaval, and others in which depression prevails,
and these are placed alternately, while there are a few
smaller areas where movements of oscillation occur. ‘Thus
if we commence with the western shores of South America,
between the summit of the Andes and the Pacific (a region
of earthquakes and active voleanos), we find signs of recent
elevation, not attested by coral formations, which are want-
ing there, but by upraised banks of marine shells. Then
proceeding westward, we traverse a deep ocean without
islands, until we come to a band of atolls and encircled
islands, including the Dangerous and Society archipelagos,
and constituting an area of subsidence more than 4,000 miles
long and 600 broad. Still farther, in the same direction, we
reach the chain of islands to which the New Hebrides,
Salomon, and New Ireland belong, where fringing reefs and
masses of elevated coral indicate another area of upheaval.
Again, to the westward of the New Hebrides we meet with
the encircling reef of New Caledonia and the great Australian
barrier, implying a second area of subsidence.
he only objection deserving attention which has hitherto
been advanced against the theory of atolls, as before ex-
plained (p. 591), is that proposed by Mr. Maclaren.* ‘ On the
outside,’ he observes, ‘of coral reefs very highly inclined, no
* Scotsman, Noy. 1842, and Jameson’s Edin. Journ. of Science, 1848.
604 FORMATION OF CORAL REEFS. [Cu. XLIX.
bottom is sometimes found with a line of 2,000 or 3,000 feet,
and this is by no means a rare case. Tt follows that the reef
ought to have this thickness; and Mr. Darwin’s diagrams
show that he understood it so. Now, if such masses of coral
exist under the sea, they ought somewhere to be found on
terra firma ; for there is evidence that all the lands yet visited
by geologists have been at one time submerged. But neither
in the great volcanic chain, extending from Sumatra to J apan,
nor in the West Indies, nor in any other region yet explored,
has a bed or formation of coral even 500 feet thick been dis-
covered, so far as we know.’
When considering the objection, it is evident that the
first question we have to deal with is, whether geologists have
not already discovered calcareous masses of the required
thickness and structure, or precisely such as the upheaval of |
atolls might be expected to expose to view? We are called
upon, in short, to make up our minds both as to the internal
composition of the rocks that must result from the growth of
corals, whether in lagoon islands or barrier reefs, and the
external shape which the reefs would retain when upraised
gradually to a vast height,—a task by no means so easy as
some may imagine. If the reader has pictured to himself
large masses of entire corals, piled one upon the other, for a
thickness of several thousand feet, he unquestionably mistakes
altogether the nature of the accumulations now in progress.
In the first place, the strata at present forming very exten-
sively over the bottom of the ocean, within such barrier reefs
as those of Australia and New Caledonia, are known to consist
chiefly of horizontal layers of calcareous sediment, while here
and there an intermixture must occur of the detritus of
granitic and other rocks brought down by rivers from the
adjoining lands, or washed from gsea-cliffs by the waves and
currents. Secondly, in regard to atolls, the stone-making
_ polypifers grow most luxuriantly on the outer edge of the
island, to a thickness of a few feet only. Beyond this margin
broken pieces of coral and calcareous sand are strewed by the
breakers over a steep seaward slope, and as the subsidence
continues the next coating of live coral does not grow ver-
tically over the first layer, but on a narrow annular space
|
De requin
Ga. XLIX.} THE THEORY OF SUBSIDENCE CONSIDERED 605
within it, the reef, as was before stated (p. 593), constantly
contracting its dimensions as it sinks. Thirdly, within the
lagoon the accumulation of calcareous matter is chiefly sedi-
mentary, a kind of chalky mud derived from the decay of the
softer corallines, with a mixture of calcareous sand swept by
the winds and waves from the surrounding circular reef.
Here and there, but only in partial clumps, are found living
corals, which grow in the middle of the lagoon, and mixed
with these and with fine mud and sand, a great variety of
shells, and fragments of testacea and echinoderms.
We owe to Lieutenant Nelson the discovery that in the Ber-
mudas the calcareous mud resulting from the decomposition
of the softer corallines is absolutely undistinguishable when
dried from the ordinary white chalk of Europe,* and this mud
_is carried to great distances by currents, and spread far and
wide over the floor of the ocean. We also have opportunities
of seeing in upraised atolls, such as Elizabeth Island, Tonga,
and Hapai, which rise above the level of the sea to heights
varying from 10 to 80 feet, that the rocks of which they
consist do not differ in structure or in the state of preserva-
tion of their included zoophytes and shells from some of the
oldest limestones known to the geologist. Captain Beechey
remarks that the dead coral in Elizabeth’s Island is ‘ more or
less porous and honeycombed at the surface, and hardening
into a compact rock which has the fracture of secondary lime-
stone. +
The island of Pulo Nias, off Sumatra, which is about 3,000
feet high, is described by Dr. Jack as being overspread by
coral and large shells of the Chama (T'ridacna) gigas, which
rest on quartzose and arenaceous rocks, at various levels from
the sea-coast to the summit of the highest hills.
The cliffs of the island of Timor in the Indian Ocean are
composed, says Mr. Jukes, of a raised coral reef abounding
in Astrea, Meandrina, and Porites, with shells of Strombus,
Conus, Nerita, Arca, Pecten, Venus, and Lucina. Ona ledge
about 150 feet above the sea, a Tridacna (or large clam shell),
two feet across, was found bedded in the rock with closed
* Trans. Geol. Soc. London, 2d serics, + Beechey’s Voyage, vol. i. p. 45.
vol. y.
606 FORMATION OF CORAL REEFS. [Cu. XLIX.
valves, just as they are often seen in barrier reefs. This
formation in the islands of Sandlewood, Sumbawa, Madura,
and Java, where it is exposed in gea cliffs, was found to be
from 200 or 300 feet thick, and it is believed to ascend
to much greater heights in the interior. It has usually the
form of a ‘ chalk-like’ rock, white when broken, but in the
weathered surface turning nearly black.*
It appears, therefore, premature to assert that there are no
recent coral formations uplifted to great heights, for we are
only beginning to be acquainted with the geological struc-
ture of the rocks of equatorial regions. Some of the upraised
islands, such as Elizabeth and Queen Charlotte, in the
Pacific, although placed in regions of atolls, are described by
Captain Beechey and others as flat-topped, and exhibiting
no traces of lagoons. In explanation of the fact, we may :
presume that, after they had been sinking for ages, the
descending movement was relaxed; and while it was in the
course of being converted into an ascending one, the ground
remained for a long season almost stationary, in which case
the corals within the lagoon would build up to the surface,
and reach the level already attained by those on the marein
of the reef. In this manner the lagoon would be effaced, and
the island acquire a flat summit.
It may, however, be thought strange that many examples
have not been noticed of fringing reefs uplifted above the
level of the sea. Mr. Darwin, indeed, cites one instance
where the reef preserved, on dry land in the Mauritius, its
peculiar moat-like structure; but they ought, he says, to be
of rare occurrence, for in the case of atolls or of barrier or
fringing reefs, the characteristic outline must usually be de-
stroyed by denudation as soon as a reef begins to rise; since
it is immediately exposed to the action of the breakers, and
the large and conspicuous corals on the outer rim of the atoll
or barrier are the first to be destroyed and to fall upon the
bottom of vertical and undermined cliffs. After slow and
continued upheaval a wreck alone can remain of the original
reef. If, therefore, says Mr. Darwin, ‘at some period as far
* Paper read to Brit. Assoc. South- that these coral cliffs are now known to
ampton, 1846. Dr. Duncan informsme belong to the Tertiary Period.
a ry a ee at ea ee ee
he margin
Cu. XLIX.] THE THEORY OF SUBSIDENCE CONSIDERED. 607
in faturity as the secondary rocks are in the past, the bed of
the Pacific with its atolls and barrier reefs should be con-
verted into a continent, we may conceive that scarcely any
or none of the existing reefs would be preserved, but only
widely spread strata of calcareous matter derived from their
wear and tear.’*
When it is urged in support of the objection before stated
_(p. 603) that the theory of atolls by subsidence implies the
accumulation of calcareous formations 2,000 or 3,000 feet
thick, it must be conceded that this estimate of the min-
imum density of the deposits is by no means exaggerated.
On the contrary, when we consider that the space over which
atolls are scattered in Polynesia and the Indian oceans may
be compared to the whole continent of Asia, we cannot
but infer from analogy that the differences in level in so
vast an area have amounted, antecedently to subsidence, to
5,000 or evena greater number of feet. Whatever was the
difference in height between the loftiest and lowest of the
original mountains or mountainous islands on which the
different atolls are based, that difference must represent the
thickness of coral which has now reduced all of them to one
level. Flinders, therefore, by no means exaggerated the
volume of the limestone, which he conceived to have been
the work of coral animals; he was merely mistaken as to
the manner in which they were enabled to build reefs in an
unfathomed ocean.
But is it reasonable to expect, after the waste caused by
denudation, that caleareous masses, gradually upheaved in an
open sea, should retain such vast thicknesses? Or may not
limestones of the cretaceous and oolitic epochs, which attain
in the Alps and Pyrenees a density of 3,000 or 4,000 feet, and
are in ereat part made up of coralline and shelly matter,
present us witha true geological counterpart of the recent
coral reefs of equatorial seas? Iam also reminded by Dr.
Duncan that the Miocene coral formations of Jamaica are
enormously thick.
Before we attach serious importance to arguments founded
* Letter to Mr. Maclaren, Scotsman, 1843.
608 FORMATION OF CORAL REEFS. [Cu. XLIX,
on negative evidence, and opposed to a theory which go
admirably explains a great variety of complicated phenomena,
we ought to remember that the upheaval to the height of 4,000
feet of atolls in which the coralline limestone would be 4,000
feet thick, implies, first, a slow subsidence of 4,000 feet, and,
secondly, an elevation of the same amount. Even if the re-
verse or ascending movement began the instant the down-
ward one ceased, we must allow a great lapse of ages for ,
the accomplishment of the whole operation. We must also
assume that at the commencement of the period in question,
the equatorial regions were as fitted as now for the support
of reef-building zoophytes. This postulate would demand
the continuance of a complicated variety of conditions
throughout a much longer period than th y are usually
persistent in one place.
To show the difficulty of speculating on the permanence of
the geographical and climatal circumstances requisite for the
growth of reef-building corals, we have only to state the fact
that there are no reefs in the Atlantic, off the west coast of
Africa, nor among the islands of the Gulf of Guinea, nor at
St. Helena, Ascension, the Cape Verds, or St. Paul’s. With
the exception of Bermuda, there is not a single coral reef in
the central expanse of the Atlantic, although in some parts
the waves, as at Ascension, are charged to excess with cal-
careous matter. The capricious distribution of coral reefs is
probably owing to the absence of fit stations for the reef-
building polypifers, other organic beings in those regions
obtaining in the great strugele for existence a mastery over
them. Their absence, in whatever manner it be accounted
for, should put us on our guard against expecting upraised
reefs at all former geological epochs, similar to those now in
progress.
Inme, whence derived.—Dr. Macculloch, in his System of
Geology, vol. i. p. 219, expressed himself in favour of the
theory of some of the earlier geologists, that all limestones
have originated in organised substances. If we examine, he
says, the quantity of limestone in the primary strata, it will
be found to bear a much smaller proportion to the siliceous
and argillaceous rocks than in the secondary; and this may
TManence of
Usite for th
tate the fac
rest: coast of
nea, nor at
ul’s, With
coral reef i
LIME WHENCE DERIVED.
Cu. XLIX.] 609
have some connection with the rarity of testaceous animals
in the ancient ocean. He further infers, that in consequence
of the operations of animals, ‘the quantity of calcareous
earth deposited in the form of mud or stone ig always in-
creasing; and that as a secondary series far exceeds the pri-
mary in this respect, so a third series may hereafter arise from
the depths of the sea, which may exceed the last in the pro-
portion of its calcareous strata.’
The comparative scarcity of carbonate of lime in the oldest
rocks insisted upon in the passage here cited, was chiefly
deduced from observations on the geology of Scotland, with
which Dr. Macculloch was familiar. Of late years our Cana-
dian surveyors have taught us that the most ancient series
of rocks yet discovered in the earth’s crust, the Laurentian,
may contain vast formations of limestone, and one of these
is characterised by the Hozoon Canadense, a species of fora-
minifera.
If Dr. Macculloch’s propositions went no farther than to
suggest that every particle of lime that now enters into the
crust of the globe may possibly in its turn have been sub-
servient to the purposes of life, by entering into the com-
position of organised bodies, I should not deem the speculation
improbable ; but, when it is hinted that lime may be an
animal product combined by the powers of vitality from some
simple elements, I can discover no sufficient grounds for such
an hypothesis, and many facts militate against it.
If a large pond be made in almost any soil, and filled with
rain water, it will usually become tenanted by testacea ; for
carbonate of lime is almost universally diffused in small quan-
tities. But if no caleareous matter be supplied by waters
flowing from the surrounding high grounds, or by springs, no
tufa or shell-marl is formed. The thin shells of one gen-
eration of mollusks decompose, so that their elements afford
nutriment to the succeeding races; and it is only where a
Stream enters a lake, which may introduce a fresh supply of
calcareous matter, or where the lake is fed by springs, that
shells accumulate and form marl.
All the lakes in Forfarshire which have produced deposits
of shell-marl have been the sites of springs, which still evolve
VOL. II. ; RR
610 FORMATION OF CORAL REEFS. [Cu. XLIX.
much carbonic acid, and a small quantity of carbonate of
lime. But there is no marl in Loch Fithie, near Forfar,
where there are no springs, although that lake is surrounded
by these calcareous deposits, and although, in every other.
respect, the site is favourable to the sastmne late of aquatic
testacea.
We find those Charee which secrete the largest quantity of
calcareous matter in their stems to abound near springs im-
pregnated with carbonate of lime. We know that, if the
common hen be deprived altogether of calcareous nutriment,
the shells of her eggs will become of too slight a consistency
to protect the contents; and some birds eat chalk greedily
during the breeding season.
Tf, on the other hand, we turn to the phenomena of inor-
ganic nature, we observe that, in volcanic countries, there is
an enormous evolution of carbonic acid, either free, in a
gaseous form, or mixed with water; and the springs of such
districts are usually impregnated with carbonate of lime in
great abundance. No one who has travelled in Tuscany,
through the region of extinct volcanos and its confines, or who
has seen the map constructed by Targioni (1827), to show
the principal sites of mineral springs, can doubt, for a mo-
ment, that if this territory was submerged beneath the sea,
it might supply materials for the most extensive coral reefs.
The importance of these springs is not to be estimated by the
magnitude of the rocks which they have thrown down on the
slanting sides of hills, although of these alone large cities
might be built, nor by a coating of travertin that covers the
soil in some districts for miles in length. The greater part
of the calcareous matter passes down in a state of solution
to the sea, and in all countries the rivers which flow from
chalk and other marly and calcareous rocks carry down vast
quantities of lime into the ocean. Lime is also one of the
component parts of augite and other volcanic and hypogene
minerals, and when these decompose it is set free, and may
then find its way in a state of solution to the sea.
The lime, therefore, contained generally in sea-water, and
secreted so plentifully by the testacea and corals of the
Pacific, may have been derived either from springs rising up
Con sist ener
ux greedy
Da of ing.
ngs of such
> of lime in
n Tuscany,
nes, orwho
7), to show
. for a Mo
ith the s¢2,
coral reel
ST Nir Hi Nn
ar“
|
Cu. XLIX.] LIME WHENCE DERIVED. 611
in the bed of the ocean, or from rivers fed by calcareous
springs, or impregnated with lime derived from disintegrated
rocks, both volcanic and hypogene. If this be admitted, the
- greater proportion of limestone in the more modern forma-
tions as compared to the most ancient, will be explained, for
springs in general hold no argillaceous, and but a small
quantity of siliceous matter in solution, but they are con-
tinually subtracting calcareous matter from the inferior
rocks. The constant transfer, therefore, of carbonate of lime
from the lower or older portions of the earth’s crust to the
surface, must cause at all periods, and throughout an inde-
finite succession of geological epochs, a preponderance of
calcareous matter in the newer as contrasted with the older
formations.
CONCLUDING REMARKS.
In the concluding chapters of the First Book, I examined in
detail a great variety of arguments which have been adduced
to prove the distinctness of the state of the earth’s crust at
remote and recent epochs. Among other supposed proofs of
this distinctness, the dearth of calcareous matter, in the
ancient rocks above adverted to, might have been considered.
But it would have been endless to attempt to reply to all
the objections urged against those who would represent the
course of nature at the earliest periods as resembling in all
essential circumstances the state of things now established.
We have seen that a strong desire has been manifested to
discover in the ancient rocks the signs of an epoch when
the planet was uninhabited, and when its surface was in a
chaotic condition and uninhabitable. The opposite opinion,
indeed, that the oldest of the rocks now visible may be the
last monuments of an antecedent era in which living beings
may already have peopled the land and water, has been de-
clared to be equivalent to the assumption that there never
was a beginning to the present order of things.
RR2
612 CONCLUDING REMARKS.
With equal justice might an astronomer be accused of
asserting that the works of creation extended throughout
infinite space, because he refuses to take for granted that the
remotest stars now seen in the heavens are on the utmost
verge of the material universe. Every improvement of the
telescope has brought thousands of new worlds into view ;
and it would, therefore, be rash and unphilosophical to
imagine that we already survey the whole extent of the vast
scheme, or that it will ever be brought within the sphere of
human observation.
But no argument can be drawn from such premises in
favour of the infinity of the space that has been filled with
worlds; and if the material universe has any limits, it then
follows, that it must occupy a minute and infinitesimal point
in infinite space.
So if, in tracing back the earth’s history, we arrive at the
monuments of events which may have happened millions of
ages before our times, and if we still find no decided evidence
of a commencement, yet the arguments from analogy in
support of the probability of a beginning remain unshaken ;
and if the past duration of the earth be finite, then the
ageregate of geological epochs, however numerous, must
constitute a mere moment of the past, a mere infinitesimal
portion of eternity.
It has been argued, that, as the different states of the
earth’s surface, and the different species by which it has been
inhabited have all had their origin, and many of them their
termination, so the entire series may have commenced at a
certain period. It has also been urged, that, as we admit
the creation of man to have occurred at a comparatively
modern epoch—as we concede the astonishing fact of the
first introduction of a moral and intellectual being—so also
we may conceive the first creation of the planet itself.
Tam far from denying the weight of this reasoning from °
analogy; but although it may strengthen our conviction,
that the present system of change has not gone on from
eternity, it cannot warrant us in presuming that we shall be
permitted to behold the signs of the earth’s origin, or the
evidences of the first introduction into it of organic beings.
—, -~ — =_ ee, eS eee PSS be
esimal pout
arrive at the
1 millions ¢f
CONCLUDING REMARKS. 6138
We aspire in vain to assign limits to the works of creation
in space, whether we examine the starry heavens, or that
world of minute animalcules which is revealed to us by the
microscope. We are prepared, therefore, to find that in
time also the confines of the universe lie beyond the reach of
mortal ken. But in whatever direction we pursue our re-
searches, whether in time or space, we discover everywhere
the clear proofs of a Creative Intelligence, and of His fore-
sight, wisdom, and power.
As geologists, we learn that it is not only the present
condition of the globe which has been suited to the accom-
modation of myriads of living creatures, but that many former
states also have been adapted to the organisation and habits
of prior races of beings. The disposition of the seas, con-
tinents, and islands, and the climates, have varied; the
species likewise have been changed ; and yet they have all
been so modelled, on types analogous to those of existing
plants and animals, as to indicate, throughout, a perfect
harmony of design and unity of purpose. To assume that
the evidence of the beginning or end of so vast a scheme lies
within the reach of our philosophical enquiries, or even of our
speculations, appears to be inconsistent with a just estimate
of the relations which subsist between the finite powers of
man and the attributes of an Infinite and Eternal Being.
ABB
BBOT, Pet _ Mississippi, i. 442,
445, 452,
ne on Teeny ian eruptions, i. 629;
24
i. 2
as, Mr., on fossil elephant, i. 184
Adams and Maurie, Messrs., on shells of
Nile delta, 1. 438
Adhémar on recession of glaciers before
48, i. 278
— — attr oe of ocean by ice, 1. 272
Adige, delta of, i. 423
Adria, cena a seaport, 425
Adriatic a of, and deposits in, i.
nie
— pon of, 57
ae an sea, cao Forbes’ dredging
ae S, extreme heat of soil in, i. 277
African sands, eae of, ii. 507
Agassiz on delta eas i. 467
— — Glen Roy ras 1.377
Sa Superior, i. 421
nak laciens, 1. 369, 370
58
— ade oe human races and
ee luis origin of the human race,
li. 475
Air-breathers, scarcity of, in primary
roe
ae. fossil whale ae at, 11. 573
Iry, Professor, cited, i
— — on shiftin
Alaska, voleanos i
Ald] aborough, ee Hf: the sea at, 1.
ng of cart axis, il. 208
Alte ney, Race of,
Dato degli Aetarey his theory,
Aletsch glacier damming up a lake, i.
ee a voleanos of, i. 585
ars von Dr. coral in or ii.
Alluvial plain of amet te 1. 457
— deposits, fos ee te
Alluvium, volean
Alps, height of fossil Sai in, i. 144
GENERAL INDEX.
|
|
|
ANI
ee how much raised during Tertiary
och, 1h, Ws
— two elac “ial Lana ah . aie
renee genera
indslips on the, i. 469
— seener floated down on driftwood
América, North, floods of, i. 351
— — inroads of the sea in, 1. 559
im, isi3l
— probable date of first peopling of, 11.
474
Pee spread of domestic animals
Sells 45 7
deena: ev ae common to Eu-
he sie
Am aoe o ro- Lae:
SAmphitheriom in Oolite of Stoncsfiel,
Anaximander on origin of men from
fis
heak con orem oe ee ii. 312
Andes, chan 132
— height of Pail shells | in, i. 144
slow volcanic ere e 1. 130
voleanos of the,
oe aptitude i A eee of,
is in vibe il. rie 505
oe, of by man, ii. 366
a Le Spade of p ere by, i. ke
— drifted on floating 1 ae 62
— ting on ice- — of, 1 "360
— effects of som fe area
ers, 447
tinct, ound with Paleolithic im-
ae ments,
— ‘extirpated ee man in Great Britain,
. 464
— ‘Sreshwate buried in subaqueous
strata
— hybr recep of, 11. 805
— imbeding of in new strata, 11. 536—
— mid sa of domestic, over Ame-
rie
— six tt a al provinces of, ii. 335
— tameness of unpersecuted, ii. 303
616
ANI
ca age tamed, often will not breed, ii.
Zee a” 11.329
the
ca haa nail of, le a
Aphea its effect o ee : 275
Aphides, mnltiplication of, 11, 439
shower 0 7
Apaides, rev sree of, combined with
74
s and igneous causes contrasted,
“8083 li. 97, 237, 243
~— causes of change considered, i. 327
— — supposed former intensity of, i.
io
f Mediterranean, i
Arehioptory or fossil bird in Oolite,
pie ‘hie ac cited, i. 426
Arctic oe ay Miocene fossil trees in,
1. 208
_ night, counteracting heat in perihe-
lion, i. 281
Arduino, memoirs of, i. 60, 71
Arey, Duke of, his criticisms on theory
ural tae li, 489
Aristotle on deluge of ene: 1. 598
Ss} ntaneons blag on, 1. 34
opinions of, i
rer oa ceca
presi Teed in dae of Ganges, i.
478
— aah at spear i. 890
enice &
— red a Oat 1. 458
Sohal i tuiiiadl i. npiss 391
— — near London, i, 38
— — organic rem mains found in, i. 893
— — increase of internal nen shown
by, ii. 20
Arve, section of sand-bank in channel
of, i. 49
Ascension Island fossil turt] ges from,
DTS
Asis ino, eerie “ coast of, 4380
a dipsacea,
ehhh al yi go Cl each
other’s influence, i. 283
Pe aie tee earlier aoe of, com-
pared to Geolo
eae oo Pacific oceans, mean eee
. 49
GENERAL
INDEX.
BAC
Atlantic, formation of chalk in, i. 307
— mean depth of, i. 265
— absence of coral reefs in Bae 608
— islands, age and origin o 403
— landshel Is of, co ee with
_ British i.
map shoving wine of ocean sur-
© soundings them
— — probably formed 4 in mid-ocean, ii.
— submarine tes of, i li. 63
Atlantis, submersion
Atolls and active a a map of, i.
86
me
—
— Rees pe islands, described, ii.
094, 6
ners dat Cavallo on Vesuvius, chasm
cu . 856
Regesctad ‘of i ice, possible effects of, i.
Aust See Godwin- Austen.
Australia, ber cio of, i. 159, 163
— coral r 92
Australian “Marsupials li. 832
and I theor ry to a
Te ere eer ine line petal
the, 11. 352
e, ll.
egion of mammalia 347
fees. ergne, calcareous springs Ne 1. 899
ee ated springs
=< marest on oo pe “ 72
— a sandstone of, distinct in age from
nglish, i. 114
Ava, fossils of, 1. 43
ee buried temple of in Cash-
354
pCa as coh 1. 602
Avicenna on cause of mountain 27
Axis of pare one ‘rasta in
the m Ra
— changes in obliuity of earth’s, i. 282
— double,
Tas ath : erst ‘omnia change in,
aia eres ese . me 537
Ae
Azores, jeuborga drifted to, 1
oa
— i _ from Eu urope t 1. 865
common to the sditinint il.
pis,
Boars Mr., on Temple of S
n. 165, 167, 172
—— — — expansion of rocks by heat, ii,
935
Bache, aes on width of Gulf-
am,
Hinbpates Dr., cited, i. 209, 210
Bacon, Lord, cited, li. 557
| '
|
|
/
/
ll od ot hee Af od A ae
SUM, thas
® eet oj
isten,
159, 163
. 332
POFY to account
7 line between
ti in we from
le of in Cash-
ntaiDs, i2
pcre
earth's, 1.28
aj change it
: a 5a
7
we
7 sped .
Je of se
; by pet i
pf 4
930
-
;
a SS
BAF
‘affin’s Bay, icebergs in, i. 246
ead flood in the valley of, i. 352
Bagnéres de Luchon, hot springs ot;-t,
Briss, Bay elevation and subsidence
in, il.
— view of See of, Plate VII., 76
Baker, Colonel, on artificial wer in
India, 1
Bakewe alll on Niagara Falls,
Bakie Loch, Charee fossil i in, i. we
ils, 1. 57
Bali an rane of striking contrast of
species
en ait aoe in the S09 of the,
n delta of Mississippi, 1.
Baltic, ice-drifted rocks <8 1; ° 385; li.
— waste of coast on, 1. 656
ee a a lev a ae to the
land, i
gre of ‘Mississippi above plain, i.
Bupa tree, its size and probable age,
Borham am, Dr., on Ictis oe same as
St. Michael’s anngeeap
Barrancos of Som
Barren Island, fla: se of,
ii.
— — view of, ii. 75
Barrier reefs described,
Bartlet t, ey cai fasting five
ay
Basalts, te opinions on, i. 71
at, peculiar, in Palma, ii. 411
Batavia, effects of paiiancke at, il.
Bates, re H. W., on delta of the Ama-
466
zons, i.
ee of the Amazons, i.
_-—— pion pumice, ii. 376
—,-— modern migration of Red
Indian Pr De tropics, ii. ae
_—— ae r of Amazon 276
ec Ol species of tmuttardly linked
by oa li. 388
Aah barriers to migration of ani-
Bath, ther mal waters of, i
Baths, hot, of San n Filippo,
Batrachians, want 0 ger ii. 412
Ba ie, Admiral, on Soahaas boulders,
eae asm i, 421
ae hy Head 4, landati ip a
ear, sup posed entrance ahs ee of
first 7 ar, ii. 448
GENERAL INDEX.
617
BIS
Bears, he of, 11. 857
Beaumont, M. E. de, on change of level
in ene 1. 551
— = hy pothesis of elevation cra-
_ ters, 1638
— on moving sand-dunes of
" MpBasd: 1. 514
—-—mud filling lagunes, i.
—— rents in voleanos, i. 614
—_—— rigi Lato m oe
chains, 1, 121, 128
ee direction of mountain- °
0
———— — on injection of dykes, ii.
45
Beaver, fossil in Perthshire, ii. 536
Beche, Sir H. See De la Beche
Bee, migrations . the, 11. 378
Beechy, Capt. coral salamelig i. 585,
598.
f canoes, ii. 468
Seon upheaval in Conception pay,
i. 1
Beila in apt mud voleanos of, ii. 76
elcher, = award, on polar ichthyo-
saurus
Saco ania in Conception
Bay, 11. 155
spt ts stones thrown up in storms
509
Belzoni i, on oe beings drowned in
Nile flood, i
sala wee Me a and deposits of, i.
Berkeley Bishop, on modern origin of
Bermas, binds of, common to America,
hate pa es! ii. 580, 6
Bew an oe ion be eno in
Eng ve
Bies Boveh i in * Holland formed, 1. 552
Birds, fossil, as oe on theory of
pr sce en yi. 1657
— carried b Atlantic, 11. 365
— conveying jor to ere 11.419, 421
— driven by gales across the ocean, ii.
413
— imbedding of, a rare event, ii. 534
of same ran
— ooh bar of, i
ig of increase deer destruction of,
Bischof sant on carbonic acid in
craters,
= OD) contmtion of granite in so-
-{Malifying ii 236
Biscoe, Captain, on cold of antarctic
regions, 1. 242
618 GENERAL INDEX,
BIS
abe Rigo of, 11. 356
n Niagara limestone, 1. 415
Brranots = rea 1. 414
Blackmore, Dr., on fossil marmot in
drift, in pos stu ure of hibernation, li. 568
we ississippi, pe: 2
Boa constrictor, ations 0 366
Boblage on engulfed. rivers A caves
n Morea, ii. 516,
— M., on céramique in Morea, ii. 513
or
Bolgen, blocks in flysch of
gs Soaring: in open caus am caves,
. 621
hohe: bed’ eee Pe fish-bones now
forming in deep s oe
pine amon. cigad: ih
of migratory Witten
oa tidal wave called the, i
sae os, Artesian. See A: pene te ae
gio and a) sleet i tae fusion of
mmalia in, ii.
Fie hate ae on eek of, i
Botanical geography, i 11. 381, See es
B ap
é, M., cited, i. 39
pet ies ‘drifted by i ice, 1. 885
— stranded by ic 384
Saat ce Sacha forest at, ii.
529
— flint tools in drift at, ii. 5
Boussingault, M., on a aa Om in Andes,
re 582
Bowen, Lieutenant, on boulders in ice,
i.
Boyle on agitation of sea, i. 39
Brace on variation of the hee Ameri-
eee li. 471
raci esuvian eruptions, i
Biskiauootis sediment re ae
48
by, 1.
— delta of the, i. 470-483
Brahminical doctrines pe let feail
Brain, comparison of Negro oe Euro-
pean, 11. 487
ee en of haga with refer-
to
Brander on eos fossils, i. 64
Brayais, M., on upraised sea- high in
Norway, ii. 195
oe caves, extinct animals in, ii. 333
en 8 in caves now fort noe in the
st i, 516
ee in and in injurious, ii.
Bridlington, faaine arctic ‘hells o i.
— eae possible date of, i. 297
BUR
Brieslak on Vesuvius,
Bri megs, Mr., on water- Hel in Egypt,
Bee MaN waste 7 ee of, i. 530
Brine springs, i.
Brine, Co ree on Santorin volcanic
roby ii. 170
Bringier, oe on earthquake of New
Madrid, ii. 108
Bristol Channel, currents in,
British ual ashe islands, dates
426
of, i. 547
oe n long phe ency of negro and
rT types, 1 se
Brose cited, i. , 426
on fossil sonehology 31
ying-out of a species, ii. 268
Broderip, te on opossum of Stones-
field, i
—-—— peas ction of the Dodo, ii. 457
— — — long vitality of mollusca, ii.
374
— -—-— crab covered with oysters, ii.
pee a Adolphe, cited, i. 218
mate of Carbonifen rous period,
— M. Alex., on raised marine strata in
Sweden, ii. 192
Bronze and stone ages, climate of, i.
6
Brown, Dr. R., on ye of Africa,
Guiana, and Brazil, the
—-—on ens me gulf ket il. 392
— Mr. Jame implements in
Hlampshine in il. 5361
Buch. See \ uch.
ee Dr, on ae fossils, 1. 10
nds es near fees th, 1. 538
Buffon, Se theory of. the’ ‘eth a hed
xtinction of speci
— geographical y ponte es ani-
mals, i . 82
_ atural barriers,’ ii. 331
Busia Sir C., on Brazilian plants, il.
385
— — — Miocene flora of Madeira, ii.
4
Bunsen, Prof. pe on mineral springs of
celand, i. 4
—_— — — c Seuaaiie geysers, ii. 216,
219, 221
— hydrogen in volcanic erup-
“ieee li. 224
— — — — mud voleanos, ii. 75
Burchell, Mi, on Gispraeatin of plants,
li. 8 99
Burckhardt on caravans buried in blown
d, ii. 508
san
a=
—
BUR
Burnes, e A., on differ rent colour of
water 1 n Indian rivers, 1
= 6 thquake of Cuteh, 11. 99,
sot on > of the earth, i. 47
Burram See Bre ae ra
Butler, his ieee on Burnet
Butterflies, migration of, ii 3s
_ transitio bal forms of, in valley of
Amazons, l. 338
ae epee, ana effected in
the, 1
ee earth ea Ota 7 Hee 113
— geological structure 0 17,
pipes n earthquake, nin of life
alt
—— -tandslips« — by im 130, 133
— — lakes for b 12
— towns, ant, on hi il -tops, i. 148
Calanna, modern lavas in valley of, ii.
4
31, 3
Calcareous springs, 1. 399
— precipitates, 1. 40
Calcutta, a itesian well at, i. 478
Caldeleu gh, Mr., on ue in
Chili, 0.
Beidées, or r Atr o of Vesuvius, i. 634
Callao, ‘oa nie oyed by sea, ii. 158
aR nges caused by ear rthquakes at,
Sees di Roma, calcareous deposits
of, i
Su era in spite of voleanic
eee, a ipehelle of the, ii. 426
annon in calcareous rock, ii. 549
Canoes Sean in Scotland, i 548
— drifting of, to vast distances, ii. 467
oe palace of Tiberius under water
Catone acid, disengagement of free,
_-— suposed excess in Coal period,
1.
Carnie epoch, plants of, 224
mth of, referred by Mr. Croll
hie stronomical causes, 1. Te
— how far univer rsal, 1.
Beran on ianen shells
Cardium pygmeum, ase appa-
ratus of, i OOT5
Carpenter | on cathe of amputated
extra fingers,
Carraceas, earthquakes in, ii. 106, 112
Carrara mar
Derpopiaiiia: an. a
Cashmere, buried temples on ii. 553
GENERAL INDEX.
CHE
Jaspian Sea, level of, i. 1
Cz taelysmal theory of Stoi
Cat orn tan in part eealee Sra fee lava,
Guta ei or old-world epee il. or
pit eae es, theories respect #8;
, 32
Ca asa his treatise on the Deluge, i. 62
Caterpillars, devastations caused by, il
Catt, Mr., on erratic block in chalk, 1.
2
Cattle decrease in size of half-wild, ii.
| cers supposed intensity of ancient, i.
— supposed sr agit of ancient and
nodern, i.
Guuthass Sir P. on artificial canals in
Rascicn3 i. 47
— fossils of Siwalik Hills, i
~ 901
— —— — bones of deer in well at
Behat: li. 621
— buried Hindoo town, ii.
cara a oP ieee Etna, inclined lava of, ii.
Cave es, fossils buried in, ii. 514, 520,
Cebus, transitional forms of two species
ee. on sinking of Baltic, i. 49;
Central preach not required to account
or volcanic phenomena, il. en , 241
— el the earth discussed, 11. 199,
Dare nal Fr ance, pee eroded in, i. 356
Centres, specific, of aoacvie ii. 336
Ce phalonia, earthquakes i ins adtey el
ks bral, develo dence in so eee.
including man, 1i. 48
Cesalpino on fan ec remains, 1.
Ser: absence of, in secondary ae
>
edding of, ii. 672
Chal, floating ice in sea 0
rm climate indicated fe eile of,
"O13
Chamist 0, M., on coral er ae li. 587
Chamouni, glaciers of, i
Chara hispida, stem and Dae vessels of,
5)
sare “Tessilised | in Scotch marl, ii. 566
saad a-ha on seca bes glaciers, 1. 369
— glacier morain
Chasms left by Calabria earthquake, ii.
26
Chemical action in volcanic eruptions,
li. 232, 242
620 GENERAL INDEX.
CHE
hepstow, rise of tides at, i. 494
Cheshire, waste of coast of, i. 546
Chesil Bank, formation of, i. 534
ve rainless coast regions ‘of, i. 882
voleanos of, i.
= kia of coast in, i, 580; ii. 96
- upheaval of rock, 1899- 36, ie 133
— earthquakes i in, li. 89, 94, 154, 190
— map of, i. 91
Chilian Andes, lakes of lava in, i. 118
Chillesford, marine ces shells ‘of Lior,
Chillingham cattle, ii. 321
, hei
D)
=a
2
B
oO
DM
3
am
[a>]
ial
a
any
risty, Mr., on ae of the
Reindeer period, ii.
n lava in motion
_ .B., on Bournemouth mae
ne et at, 11. 531
acres r slaty structure, i
42
Climate, as affec ye by former ue
phic al chan ge, J
5B
— astronomical causes of change of, i.
268
— causes of change of, i. 233
— concludin remarks on, i. 231
0) 1. 174
— how affected by obliquity of ecliptic,
sof sees kis eet i. 224
ai =
re ge, 1.176
Dev
fol “359
cee Bhropean drift sal cave deposits,
i.
—— Toei strata, 1. 204
— — Lower Mi strata, 1. 202
— — Oolitic and = 1 periods 1, 218
— — Permian perio
— — successive phases. of precession, i.
~- — Glacial epoch, i. 194
— — Interglacial, i. 195
— Pliocene period, i. o
— Miocene period, i. 199
— the Chalk period, i. 213
2a causes affecting, i. 275
— slow cha pe ei owing to great depth
of ocean ca
n Him malayan plants, ii. 319
Climates, oe of distribution of land
which might produce extreme, i. 266
ant caused by excentricity, oe
0
Coal, 2 aie Of 1,229:
bon ifer
Coast-i reg nh: 383
See Car-
COs
Codrington, Mr. T., on flint Ne iii:
In gravel, ae of Wight, ii.
yee &e., 8 in the bed of vf sea,
1. 551
Cold of southern hemisphere, causes of,
re
ke oo T., on crocodiles of
Gang
—-— pee of Ganges, i.
i Bn corees 2 Nae age of Vedas, i.
Collini on igneous ice of Rhi 2 eval
Colonna, F
Bs)
drowned during earth-
quake at, ii. 540
Cone of Vesuvius, vary e of, i. 620
— — Etna truncat ed, i
a,
— growth of volcanic, “ike exogenous
trees, il.
Conglome ee formation of, i
ee 1 extens nsion not appieabl to
Atlantic islands, ii. 406, 4
Continent. antiquity of existing, 1. 258
Conybeare, Rev. W. D., on Lister, i. 40
—— — oe near ieeloeie
Cocde, sie on shingle moved by a
storm, 35
Cook, Captain, on climate of South
Georgia, 40
ite cause of antarctic cold, i.
— drifting of canoes, ii. 467
Coral baie absence of, in Atlantic,
a wnward trea pc a slow and
aniform, 4 i.
— — origin of he circular form of, ii.
9, 590
— rate and mode of growth of, ii. 581,
ates 604
s, formation of, ii. 579
eae of Carbon stron ae i. 228
— West Indian, proving former at
mergence of isthmus of Panama,
25
Cordier og on temperature of earth’s
inter 20
Corneal aia ee Spe in, i. 548, 545
— drift sand in
Jeclad coloused in pa fertilised by
insec 0)
an mandel, inundations of sea on coast,
Ri rage increased brightness
of a star
Correlation of pees i, 314
Coseguina volcano, ise eruption of, 1.
583
a
cos
Semetenny of emereyantsD 1213
— Hindoo
— the Koran ‘ 28
a ee
Gecepalites Lies of shells, ii
374
Cotopaxi volcano, explosive pow er of, 1i.
223
per, the poet, on age of earth, i. 81
i.
evation. See Elevation
Beata, Mr., on prea in Ava, i. 48
— on drifting of caroes
— on earthquake o P eariass, 11.105
Creation, specific centres of, il. 336
Cretaceous reptiles, 1. 214
arg the an nges, i. 4738
Croll, , on causes of nee of =
Re in n geo ee i. 271
of anh s inate
~ excontiity ae ‘ 29
n effect of polar ice-cap, i. 291
— — on submergence of land by at-
action of ice, 1. oo a
on omer, forest bed o 197
Cross- breeds, reversion 7 parent stock
of, i
ee, anon beneficial, ii. 320-322
Cro
tch, Mr, on beetles of Azores, ii. 417
Couikeha , on a reat of sea in
Chilian earthquake, ii. 95
Avena — — formerly more
argely formed, i
— contemporary ee fossiliferous,
i. 210, 2
ube, lagi ae ieee of, ii. 522
Cumming, Rev Cy Devonian
boulder clay 23
ee isin, on buried temples
of Cashmere
Curets estas polar temperature, i.
237
and rivers, comparative transporting
powers of, i Aine
— causes of, i
= destroying noe transporting
of, i. 5
— eet s, how arranged by, i
— effects of, in Saar .
power
—in Straits of Gibraltar, be 562
— greatest velocity of, i
— how affected by Jetta - the earth,
1. 500
— stream and drift, 496
— tidal ee and depositing power
of, i. 565-568
= aseney of, in dispersion of plants, ii.
Ountie, Mr. fossil insects, Ta)
, on
eo) ravages of insects, i i. 439
GENERAL
INDEX
DAR
copa of the Mississippi, i.
rgence
tech, submer by peer fey
9, i. dla
= earthquake Olli: 97, 5538
f, described, iil. 102
Cu uvier, ay Geol logical Works, i. 87
— on fossil snammali, i. 158
a phe 8 of Anaximander, i . 16
iden of Egyptian mummies
reat ving i rai ii. tabisp
ariation in canine race 26
—F, eR om citi Hon Station 11.301
Cy cles of Et how ivided, i. 274
Cypris, fossil in Scotch tr ravertin, ii. 568
Cypris unifasciata and vidua, ii. 568
Dre Mr., on
cones, i. 615
1
— — volcanos of Sandwich Isles, i.
‘cinder’ and ‘tufa’
Daniell Mr., on expansion of platinum,
Danes quoted, i. 76,
oi! y on ees; ear 4g Red River, i.
457
— delta of Mississippi, i. 457
Dawe in, Mr. C., his map of Voleanos
and ‘ Coral Reefs,’ i. 586; 11-603
abser i cod deposits, ene
ee soe shells j in Chili, i
— teriform hills of ielveons
— — — colour of rivers, i. 310
— — — evaporation of snow in Chili,
1. 286
— — — formation of peat, i. 22
— — glacier reaching the sea in
aaa i. 380
— — — migration of species between
Old ca New World, i. 264
led s hingle of South Ame-
rican cons i. 578
e and subsidence of coral
er "950
xuriant eae not re-
esr, a arge Mammalia, i. 190
ones carried by eawdernoae
— — — lux
ae: 217
—_ — — snow line in Tierra del Fuego,
re a
— — — slow voleanic action of Andes,
T1380)
absence of ee and ba-
ete in islands,
— — — Atlantic einnedea volcanos,
aay 64
ae — barriers to migration of ani-
ale ll. 355
ab eines motion of earth-
ake: 11. 1120
622
Darwin, Mr. C., on coral islands,
584, 586, 589
— — — cause of their circular form, ii.
591
— coloured corolla attracting in-
Beis oy
— correlated variability, li. 314
— decrease of bulk in half-wild
tne li. 321
— — — earthquakes, 11. 89
— — — elevated marine sae at Lima,
ll. 158
— — — geographical meee of
ieean to living mamm. eee :
—-8ro
lel lent dooline’
2 tint a to ae = a
cadee il. 3(
one origin of the dog, ii.
2
— — — natural selection, ii. 277-281,
— against theory of
_ relopinent ll.
= ur ignorance of laws of va-
on i
De aaa ates ii. 291
— regrowth of supernumerary
pee in man, il. 477
——-— retreat of sea during earth-
quakes, il. are
‘necessary de-
—— — sion Lae ‘feral’ pigs to
the w iid. ee . 80
= — seeds pire to birds’ feet, ii.
326
— — seeds conveyed in locust dung,
11. 420
— — — seeds uninjured by salt water,
ii. 391
— — — sheep her ae Aas sie Mano L
— — _—— tameness Galapagos birds,
ines
— — unconscious selection, il. 288
— — ‘yariatio n,’ 11.285, 289, 291, 297
— — — wading eke aes of Galapagos, ii.
415
Darwin and Wallace’s essays on spe-
_ cies, ii. 278
Dates in geology, how far determinable
by variations of exce1 tricity, 1. 295
Daubeny, Dr., on Vesuvius, i. 630
— — volcanos, i. 592 3
— — springs, i a 3g
— — gases in ota s, il. 76
— hy irogan ¢ and nitrogen in vol-
canic eruptions, ii. 224, 226
Javis, Mr., on Chines o deluge, 10
Javy, Dr., on Graham a ibe tah Es)
— — — helmet taken from sea neat
Corfu, ii. 550
GENERAL INDEX,
DEL
Davy, Rev. C.,
Liebe, i.
ee Sir H., on formation of travertin,
on vessel engulfed at
pa —-— progressive development,
1. 146
— — lake of the sonar . 404
— — — his analysis of pea 496
— i 7 2: ;
nos, li. 224,
anid aa rac
Dawson, Dr.,
flora, i. 149,
s of man, ii. 465
on heat TIC apenas
230
submerged forest of Bay of
Fun nay, il. 56382
Dead Sea, level of, i. 112
Dease and Simpson on strata com-
nee sse cas by ice, 1. 382
eau See Beaumont
= Candolle Alphonse on agin of
see is il.
oy oti regions, ii. 382
—— — of plants by
man, li. se "399
ee of species, ii. 435
n hybrid ae il. 325
——on ou tloneean of tre . 45
— er — South ‘Amievialiny cert plants,
nese Baron V)
n Der, on snow-capped
. 248
submarine forest, i. 548
—— — cubeteaee of Port Royal,
61
Delta of the Amazons, i. 466
— Ganges and Brahmapootra, ip
-— mp es. River, antiquity of,
i. 457,
ns Be ke
— ey poe 42
— marine, of the “Rhi ne, 1. 427
- of Ganges ee Indus, es fresh-
rine beds i the, 11. 570
in lakes, i. 416, 42
-— = ni howe deposited in, i. 809
eluding remarks on, i. 484
ays his treatise on Geo ee 1. 82,8
on conversion of forests into peat-
mosses, ii. 500
Deluge, nae shell s refer red - 1eoly oo
sed causes of, 1. 110
593
— — 0
n Chih, ii
|
|
4 Rhone
inet i. 3
Port Boa,
poo, i
gato
fe
iii)
f
DEN
nmark, inroads of the sea halal, {asf
Denudation and depositio 107
Deposition aa denu dation, Fats of the
same process, i.
Deposits stony, of he Rhone delta, i
De Saussure 0 on motion of glaciers, i. 369
Descloizeaux 0 n Icelan die gey sers, ii, 220
=O!) ees of Auvergne, i. 72
Désor, M., on fish found in 8
we ls, i 393 7 a
= ee motion, 1. 371
ropical as spect of, oe beds
Be iated with ae sch,
Deucalion’s deluge a, "503.
Deville, St. Claire, on contraction of
granite i bE
— hydrogen in volcanic eruptions,
a 224 ae
a a ae of granite in so-
~ lidifying, ii i
Devonian Sd. supposed ice-action of,
i 0
= Ob, 1. rae
Devonshire, v oe ast in, 1. 53
Dezertas, a sels “of, common to
Madeira, ii.
— Monizia is, a plant peculiar to
Dis aoe mace in voleanic tuff, i. 644
Dikes in Vesuvius, ali formed, ie 627
n Val del ae anes 5 ane
= ae of, far from Sie centres,
17
Dilwvial theories, i. 88, 44
Diodorus Siculv us on Samothracian de-
a Wee, te
—on St. Michael’s Mount, Cornwall,
1. 539
Dion Cassius on Herculaneum and Pom-
peil,
Disco Islan d, in Greenland, Miocene
fossil trees near, il. 208
Dodo, extinction of the, ii. 456
Dog, different races, ae far varying,
li. 263
— Lamarck on origin of, ii. 250
294
— introduced in Juan " Fernander, de-
Stroyed the goats, ii. 45
Dogger Bank, heaping up of the, i. 669
Dolla rt, how formed, 1. 555
Dolon mi re a asa of aD 1 73
sie ty Ufa
229, ue
mestic races breed tog ar. i 284.
eae becoming ‘ feral,’ . 304
GENERAL INDEX. 6238
EAR
Domest ae ge aptitude of some animals
for, 11. 301
rek on effects of, ii. 250
Dome sticity eliminating deere eae
eae on deposits in Adriatic, i. 4 126
seas of Adriatic, i. 57
Donny, at, on ee heating of water
freed from alr,
D’Orbigny. See Ox
Dorsets| hire, eS ia a waste of cliffs
in, i. 536
Dove, Professor, on mean annual iso-
therm: als, i. 239
— — — on heat i pane of the earth
n aphelion, i.
Dee formation ey Straits of, i. 516
— waste of cliffs of, 515
Downham, town overwhelmed by sand
flood, ii. 508
Dranse, River, flood of, i, 354
Drift, climate of European, i. 192
Drift sand, fossils in, 508
Driftwood of Mississippi, 1. 646
Mackenzie River oe
Drinkw ater on ‘Life of Galileo’ (note),
83
ieee their theory of the universe,
25
Duchassaing, M., on oe of coral
growth in the sea, ii. 58
DE aa on Piast of Monte
Nuovy
— if ieee of elevation craters,
Dujardin, M., on shells and seeds rising
n Artesian wells, i. 393
Dans an, Dr., on West Indian corals,
als
— — ae reefs, ii. he
— — — wth of cora
Dune ree s of blown ane 514
Du fe destruction of, 1 oe sea, 1.
51
—
=
=
on
CO
ra
Dwarf’s Tower, near Viesch, i. 342
«Setar ve eels ne 32
the, i i 202
— ioe of se ae outer crust,
212
— se oidal figure of, a not prove
original fluidity, ii. 199, 240
— supposed central fluic vie Hid 99
BeOS cy s of original formation of the,
. 200
Fanh. pillars formed 1 by rain, i. 335
1 vais ritzerland
=e
ee
Oo
oS
aa ra
Eart arthquake at Visp veer eee
pillars, i. 341
— focus, depth of, ii. 139
624 GENERAL INDEX.
EAR
capil, rd of ae 1783) 18118
— Lis 1755 147
mee "Zealand i . 82
— waye, rate of seaha o of, ii. 149,
— waves, complicated action of, ii. 139
— — focus of how determined, 11. 136,
138
Ber and mode of action of, i,
185, 40
pee caused by, il :
— chronology esenibed, li, 82 et
ai
— deficient accounts of ancient, ii.
— deficiency of historical records = il.
— elevation of land during, ii. 82, 94
effects of in in 19th sel Ho 11. 110
— excavation of valley nu. 129
eA ntmatey ey ar matador
at ee sshd 58
century, il. ae 111
ie
-— ey oe pig a deep- -seated cen-
t 19;
— and Volnnos recapitulation of causes
Obra
Earths axis = Aerie hypothesis of
change in,
— primitive ae gradual diminution
of, i. 303
— cooling from a state of fusion, ii.
226
shifting of axis of, 11. 208, 241
ace es of the crust of, ii. 203, 206
flexibility of the crust of, 11. 22 7
a church buried in blown sand, i.
5
— — views of, taken in 1839, 1862, i.
Palit lation porn ity of, affect-
clin
E Pals rt Sanna; 1. 476
a BEE Rev. W. H., on Indian fossils,
1. 213
Pas of age attached to floating
ood, i
Egypt , towns “ee a ean) in, il. 507
Hegyptian cosmogony, 1
_ mummies ential mae
species, il. 26 ;
} hrenbeng ¢ on infusria in tuff, 1. 645
g Pompeii, i. 644
— a n “of ee iron- ore, 11. 601
— — growth of corals, ii. 580, 581,
C
living
59
Kifel, hot springs of the, i. 396
K eae a source of Flint heat, i.
ETN
Elephant, covering of fur 184
— Sy otic: required for food of the,
== possible rate of increase of the, ii.
317
—_remains of extinct, in Sicily and
Malta, ii. 342
Ele ephants carcasses of, when imbedded
in ice, Ba
== 10 ing group, li. 337
Blevation & ‘alters, en of, 1. 638 ;
13
cage pe chr: of land, causes of, ii.
234,
— areas a and of subsidence in Pacidle,
Elizabeth or ere Island, upraised
atoll of, ii.
Elsa, R. qenreie: eae by the, i. 400
Embankment of Po and Adige, i. 423
England, waste oe west coast of, 1. 546
sony Sees, and oe climate Ofet
— parol, ice-action in
——ma aes wing aerate changes
the, .2
Pyeehs, ological, comparative dura-
tion
ne fee Min: in Ischia, i. 601
Equatorial current, course ‘of, 1. 498
Equinoxes, precession of, i. 274 ; ii. 203,
Equivocal generation, theory o
Erdmann, eee Axel, on rise x indi in
Sweden 186
Erie, currents s of Ta ke,
Erraties, ie nee of, in eee - re-
gions, i. 109
— and ice-action
E ae oe of Monte Nuovo i. 608-615
Ese on der we on seca in the
Val wh Steer itt
— Ha bern Dee rd iy)
— — — — — glacier motion, i. 370
Eschricht on ieee on of Gracia
whales
Essex, pada of sea on coast of, i
Estuary deposits, pbb gee of ae
er species in
Eat! a “. ea 1. ie
— formati of %
E at chet af some N, African
ae
a of the, ii. 348
Et tn nee mi: naa in cone of, 1. 578
glacier under he on, li. 38
— ancient bee 2 ie sae
— antiquity of cone o of, i
— double axis a exaption ii. 9
— fossils in lavas of, ii. 510
— greenstone dikes in, li. 9
EIN
aes historical ne aire Of, 11, ey
eral cones, obliteration of, i
= “sve Piivoarie formations ie ae
of, i. 5
— recent fossil plants in tuffs ee
pas section showing a axis of, 11. ve
Salabrian one
Sle
34
— ubterranean caverns on, ll. 24, 31
Eupho Shin feedin e beetles of aa
islands, il.
it delta of, advancing rapidly,
Ee, Southern, voleanic system of, i.
— small change of se el which would
unite it with an 1. 34!
as a n and — "amount of differ-
etwee PLT
© ia, Mr. on sa “ef axis of earth’s
oe in Isle of
Wight grave ie 56:
Evaporation, eerie caused by, ii. 496
Everest, Rev. R., on climate of fossil
_slephant, 1. 180
ae phase brought down
by Gan,
Fe atatton yall , 1. 856; ii. 133, 562
ty, ae anions of v, ariations
292
i the earth’s orbit:
P ceision of rocks a heat, Hi. 177,222
oo ss species, i
onstant ee “it nature, ii.
ices,
— — the sede i. 456°
— species by man, ii. 451
Die: formation of the, a accounted for
by natural selection, ii. 491
Eyre ey glacier of, i. 208
oN rock off Porto Santo, ii. 405,
425
oa Dr., on peat near Calcutta,
| 1,475
— — — range of elephant,
— — — mammalia of siwalik Hills, 1.
Pak Islands, fauna of, i. 220
Falloppio on fossil concretions, i. 33
ia of Niagara, i. 35
Faluns of Tiaraine e, 1. 200
oe ay, Mr., on water of Geysers, i.
409
tert Terolabioni ti. 375
piOle. LT. | 8
GENERAL INDEX.
8
625
FLO
Farquharson, Rev. J., on formation of
ground-ice, i. 367
— — — — Seo
tch floods, i. 35¢
es caused by Cals astee eligi
22
.
So
— — — New Zealand earthquake, ii.
Fa ats gradual formation of, i. Pt
Faunas and Floras of islands
+ AOS
Feather stonhaugh on Red shade sain;
Felspa st ship oe Olas
ral’ v les never atiealt revert
1. 304
oe old f
Fergusson, Me, on ‘the Swatch of no
Lgeeten mation of jheels, 478
ce - eponderance of, in Goal period,
. 609
Fir, upright stumps of, in Bournemouth
_peat, il.
-trunks in Danish peat mosses, ii.
Fish, fluviatile fossil, of Vicksburg, i
— oes
sion, i. 1
— muon of British species in Devo-
nian
— fownd pits in Artesian wells, i. 393
ration and distribution of, ii. 3
Pisheaton, near Salisbury, fossils of drift
their bearing on progres-
or
io}
Fis Coates of known species of, ii.
Fishing -hut buried in marine strata, ii.
cues: caused by Calabrian earth-
quake, ii. 12
mar reservation of organic remains in,
Fitton, Dr., on English Geology,
Fi see Capt., on earthquakes 4 in ‘Ohili,
Finmboron ugh Head, waste of, i. 509
Flem g; Dr. ,on fossil ¢ ee i. 187
ange of animals as proofs of
welsinate, iy deff
supposed sai of former
_ tropical climate, i
— On pa oh of species by
man, ii. acs
a tion of ae i. 365
aitentin ie of Cetac 1, 572
loses, animals drow
3g
— ne alae of eri: 1. 454
— of Scotland, i
eer i Tey Beye
626 GENERAL INDEX,
FLO
Floods of N. America, a a
oe agnes ree
— voli, 1. 354
Flora er Faunas of ee be 402
Piysch blocks enclosed in, i. 209
Folkestone, encroachments ‘of sea at, 1.
Forbes, J.D., on motion of glaciers, i.
— — — rainfall in Norway, i.
— — — thickness of lava in mee
i. 64
— — —snow-line in northern hemi-
sphere, 7 24
— heat of ae setae 1. 245
— fluid lava, 6
— — — temple of San ii. 173
—_— Hee: belay on climate of the drift, i.
tion exceptional, i. 150
_-—— ~~ nsion of arctic fauna, i. 297
— present distribu tion of animals
rani ake ae a Glacial period,
8
iel9
— — — former aoa oF Atlantic
_ islands _ Europe,
n of sai il.
——— Eaton of mollusca, i ony
aie 5
— shells at great depths in the
sea, il, 576
— a pig’s power of swimming, ii.
356
— shells of White Island, San-
torin, 1. 6
Forebhamnes, Aas ., on boulder drifted
by ice
~~ — = chemical changes in fossil
aleve, il.
—_——— eecden of peat, il. 497
pane submerged, i. 462-544
whether by attraction of ice, 1. 290
aaehey Mr., on curves of J “Mississippi, ;,
443
— — — area of Mississippi delta, 1. 458
-— —mud-island of Mississippi, i. 450
Forster, on on coral reefs, li. 684
itmeg in pigeon’s craw, ii.
395
Howkis on Italian geology, 1. -
und Testa on fossil fish, 1.
Fossiliferous series, causes of ae in,
i.
— strata, table of,
Fossil shells, height of in Alps, Andes,
and Himala
— early ae intone concerning, 34-
Fossil s, in alluvial deposits and cayes,
ll. aa: See ene: Remains.
GEF
Fouqué, M., on chemical action in vol-
canos, 11. 233
—_—— hedneotas in voleanic eruptions,
li, 224
Px, Vian on a a currents in earth’s
ee 230
in Cornwall mine, ii.
a ware of, 1. 31
Fa of coast re he 547
a
klin, Dr., o bec in Mary-
shee li. 889
water plants biter re li. 565
cous school o
ries on minute ae of a fungus,
joe reefs of coral, i heer
Fuchsel, Fibs opinions of ai
Fundy, Bay of, wave called ne ‘bore,’
Bie 125
— — rain-prints in, i. 334
— — — submerged forest in, i. 532
as rae OS Archipelago, nar ee
. 22
a ete species of land-birds in, ii.
leas oe: Ferruginea, forming bog iron-
5
Geieecar eruption o
Gambier, volcanic island oie by
coral, 11. 574, 590
Ganges, Artesian borings in delta of, i.
478
and B eS ~ bs sPea[ll
—_ — antiquity of ser
— delta of the 470
— deposits in EHS Olyate reas
— islands formed by, i.
— sediment ershal doy by 1. 481
— animals drowned in the, ii. 538
— bones of men ee in dele Ofaalle
544
oo causes of, in fossiliferous strata,
— in the records of creation, ii
pes on crossed varieties of oe
292
— ae brid plans’ . 808
Gases, expansive ne er of liquid, 11. 222
Gastaldi pe Miocene blocks of the Su-
perga, 1.
Ganda on gre between fossil
and | x ing mammalia, il. 481
—484
— pei at relat tionship of fossil and
living quad rumana, 1
Gay- -Lussac, XN
nic eruptions, "92
Gefle, rise of aes near, li, 188-190
ayhrogen in yolea-
Spe
He <
)
ae?
nm)
Mts
ns ii
Leginn-
deed by
ta of
idl
GEIL
eikie, A., on second advance of gla-
ciers, 1. |
asenee on Etna er uption, 1. 887
__ — glacier under lava, ii. 38
— ae eruptions of Etna, 11. 28—
__ — double axis of aes li. 9
ics, alternate, 11. 827
Generelli’s i of Lazzaro
Moro’s views, 1. 62— a
Geneva, Lake, delta of Rhone in, i.
sediment deposited in, i. 308
Geogr Paaic causes of pp of climate
more influential than astronomical,
eee - predominant in affecting climate,
P caghation of fossil mammalia, ii.
333
— — — animals, 11. 329. See Regions.
= man, ll. 464
— — — plants, ii. 381
— provinces of animals, ii. 335
Gesgraphy, ches Se - pg copay
and Primary periods,
— ‘aa changes of, ete bate cli-
— changes os revealed by geology, i.
— — — since the anaes ee 1. 250
—-—— Eocene period, i. 251
a epochs, ies ant ape
f, 1. 800
Bech iety a London eee i 1. 86
Geology, ee ern progress of, rae 89
— distinct from Cosmogony, i.
ae an ato of | J crn i.
_ Esalstire tendency of early, i. 324
— defined, i
= ~ compared to pet: 2 1, 2, 4, 92
school of,
— ia ttaihes which has retarded, i. 90
Georgia, U.S., new ravines formed in,
i. 844
— South. Sze ae eax
Gerbanites, theory of.
German Ocean, shoals aa valleys in, i.
568
Gesner on petrifications, i. a
Geysers of Iceland, i. 409; ii. 1
— cause of their intammithent action, ii.
=e OE Teel andic, ii. 216, 217
Gibrata Straits of, i. 562
birds’ bones i es likaien at, 1. 522
Glacial epoch, i
GENERAL INDEX
— changes of level since, i. 194
— period, temperature of, i. 288
— — possible a Of ch, 291- 296
627
ah aaa period, comparative duration of,
300
~ species living before and after,
dential: ig
— — enduring the ough all phases of
precession, i. 281
ccmee. by] pothesis of greater mean warmth
in,
— Periods le not recurred periodi-
call
Glacier, moraines of, i
— supposed, at ey of Amazons,
Agassiz on, i. 468
— view of, with moraines, 1. he
— -lake of Switzerland, i wie
— near the sea in New Zealand, i Teena le
224
— os hs receding before 10th century,
— ‘amying and scoring power of, i. 374,
37i
Glen Tilt, granite veins o 1. 75,
Gmelin o te Sindee of Sch, i Seal
5 atc, ie Cane, Mr., on ae driven
et 68) Mlle 113°
— migrations of reindeer, ii.
Godwin. ours Mr., on stones drifted
by ice, 1. 2
— is aie deposits, i. 572
— — — on valley of Declish Channel,
1, 535
— — —— Porlock Bay submerged forest,
. O46
Gold. ne ee of, brought about by
Chine . 296
ones ae ee of, whence derived,
ye 3)
ood Sands, i. 525
ee wild, fossil eggs of, near Salis-
bury, 1. 563
Goppert, Prof., on mineralisation of
plants, 11. 53
Gould, Captain, eUrey of Mississippi
d elta, 1764, i. 461
oe Capt., on sinking of west coast
of Gre enland, i
vance ae ommed i in 18381, ii. 58
_ airs, on Fier ebee aka in Chili, ii. 94,
Granite citateamation of, i
med at differ see ao
— veins observed thes Moan in Glen
ilt, i
— of the
Har tz, Werner
a cons
1. 70
on aCe. of Cutch,
£88 2
628 -GENERAL INDEX.
GRA
Graves oe on extirpation of species
by man, ii. 456
Great Britain, pica animals ex-
tirpated in, il. 454
Great igen Sith mp, Virginia, 11. 505
er tradition te sre iges in, 1. 594
arthqua akes i
Greek hae ee of the, i
Orodks a of, i. 14-28,
ie a oF neighbouring
ap rie
Green, Cole, on eae fish of Vicks-
burg, i
Greenland Chee of land in, i, 131
older than Se ie 237
subs idences car
é earthquake, i Realy te
Groins d deer be d, i
— effects 1. 566
Grotto del "Cano carbonic acid in, i. 411
bla a .3
— — transporting rocks in Son: 1. 385
Gr ce repeat tion of, li.
Guadaloupe, £ fossil man skeletons from,
teen: active Mer ae 1m, 583
Guidotti, Professor, ¢ ted, i. 19
Guilding on meen of ene i.
Guinea, current of gulf of, i.
res i ae on stony ait of Som-
as ere
Gulf-stream, causes and velocity of, i.
—501
— — course and warming effects of, i.
4
Gulholmen, rise of land near, ii. 188
Ginther, Dr., on range of reptiles, i.
229
— -- — tropical character of snakes,
ii.
arine fish of Pacific and Ca-
a sea,
—on tia rot mth of fish, ii. 271
iat Me ler motion, 1. 371
Gyrog¢ onites ner il. 566
ey land gained from lake of
Hiatitanon of plants described, ii. 38
Habkeren blocks, disputed origin i i.
Hal, Pig bea B., on flood of Bagnes, i.
3538
— — — — trade winds, i. 497
-— — — waste of Mississippi banks,
1. 444
HEE
ae eee B., on snags of Mississippiy
— temple of Serapis, ii. 170
— say amnee: experiments on rocks, iz
rf
— far . rie on geology of New York,
Hae be Bi J., on voleanos in
Smyrna,
— Sir C., on eee of Port Royal,
pt
on formation of Monte Nuovo,
— — — — Herculaneum, i. 646
== Vestvianieruption lose
622
pee Calabrian earth 41.125
— temple of Sempis il. 167
Ham aipehineiee waste of co . 5380
— ae: Paleolithic implicate Tilers
— su oe ine forest on coast of, ii.
Harris, Archdeacon, on Hampshire ne
marine ieee 52
unk ae near Poole, ii.
Hartt, Abe on ge onian Beis 1. 15
Hartun ng, , on ice-borne rocks in
Azores, 11 42
— — — eruption of Lancerote, 1 11,109
Hartz Mountains, nse ie ie 70
Harwich, waste
errs sate ee of. ane near,
529
Hatfield Moss, trees found in, ii.
Head, ie Edmund, on temple a om
pis, 11. 166
Heat, eause of diffusion over the globe,
Ae
— measurement of in space, i. 278
aes el gradual decline of, on globe,
se of Bere of level of temple
of piste ile(7)
— increasing w with depth, ii. 204, 241
— theory of central, ii. 205 , 241
my Sore loss uf, in solar sys-
tem
Heath, Me, D D., on effect of polar ice-
Heel, ‘emupt ions of,
r, Wr: on sudden Oe ses of New
ee snow = ite
Heer, Professor, on fonsal zamia, 1. 218
— a pee. of Gkninghen flora, 1.
418
ae iokon. ne flora of Madeira, i i. 406
— Hes fossils of Melville Islands, i.
225
— Interglacial period, i, 196
— ninghe n flora, i. 200
a
GENERAL INDEX. 629
HEE
Heer, Lee on Surturbrand of Ice-
land, i
—wW vie: east of
~ plants, ie
—on Jae s and animals of Swiss
~ Jak ke-dwellings, i. 28
ee and Sandy Island, view of, i.
cry ptogamous
sea on, 1. 554
let incrustations on a submerged,
Hender son on eruption of Skaptar Jokul,
i. 49, .
andic Geysers, li. 216
mein aid Kalm on Rika Falls,
3
1
“eee on changes in the earth’s fi-
gure, 1
Herbert, iis , on re hybrids, ii. 824
sd
Vem yy cliffs in, 1. 52
Herodotus on marine fossils of Nile
if
Herschel, Sir J., on nee snhehete by
Dbrioniical causes 7
————hi ai rawing Se set earth-
pillars, i. 33
—_——— spo effect of land under
sunshine, i. 27
— light and heat received by
the earth, : 270
———-—t temperature of space, 1.
1 difference
+h 7
mate een a south of the pis
i. 277
— variation of obliquity of
_ edliptig, 1. 282
hei of Etna, ii. 1
orm of the
— germination of boiled seeds,
is hypothesis of the cause of
i. ii. 229
——-—on magnetic storm 1859, ii.
231
— — — flexibility of earth’s crust,
ii. 229
— Sir ue on motion of earth through
Space, 1. 802
— — — — original fluidity of the earth,
Hsien Captain, on channel oe by
shifting ue su banks, 1. 6
Hib “sap (i 1D blocks ate out of
etland ile, i. 508, 505
Bilas Be offroy St., on ddiensary
organs, i O73
HOP
pas ae oy oe ., on transmutation
spec
Hilger on Cont Pliocene’ of Missis-
ie ar 448,
is ae it New Orleans
well, i
Himalsye: height sae fossil shells in, i.
Hindoo cosmogony, i
Hindostan, metas * le li. 146
ag a otamus, teeth of fossil, in banks
Nile n Nubia, i ey
Hoff Von, fg el of Caspian, i
Hoffmann on lava of
Holbach against alluvial foe i.
pee seo a sea in, 1. 552-557
sul ne peat in
Hallwds. oer fee.
earthquake, 11. 128
ee head, submer ‘ged peat-bed at, i.
d71
formed by
Hooke on duration of ssh i. 41, 42
— his diluvial theor
— on fobell turtles Lau high tem-
perature, 1. 174
Hooker, vs on blocks carried by ice-
bergs, i. 382
‘fi a Lee retaining traces
of cultivation, i.
—_—— a of Ganges i. 470-477
rain in Indi 330-332
——— ae Pawcletig radiation of
heat, 1
cies, ll.
a ne , li. 886, 3
— cause of see a oo aaa
ious in aoe islands,
hich are w er by
man tee eee in St. Helena, i.
453, jae
Mees
"apparent immutability of spe-
cea, Ae pak ing at great
Maspitia in rere sea, ll.
aie seaweed, li. 393
ma an pant i. 319
417
mber of ites of plants, ii.
2
— — — useful native Australian plants,
li, 286
— — — variation ie selection in the
Vv oe world, 11. 282
ae Ws; a fox “drifted to an island
ff Icelan ea
lane on change of cree from geo-
So he causes, i. a
Sirota 372
eceived i earth in passing
~ tough sea .3
an vam ss of earth’s crust, i. 129;
il, 208,
630 GENERAL INDEX,
HOP
Hopkins on action of earthquake wave,
i.
ee Mr., on thickness of Nile mud,
i
— Icelandic geysers, i
Horsburgh on icebergs in tow rita
Horge-tbo gradational extinct forms
Hiss: now a waning group, il. 337
wii Dr., on Hi ia in Java,
s of Java, 1
Houses | baeed in alluvial canes ie
Hubbard on floods of North America, i,
Hue, M., on yaks frozen in ice in Tibet,
thy 1G,
Huggins on spectrum analysis of a va-
riable star, 1. 803
Human remains, . durability, 1. ie
— — in caves co 5 ary with e
tinct int quadrats, ae
— ce adaoupo, u. 544
— pea moss
Hawbee « ane of ‘the, i . 570
eu ae on average rainfall 1. 329
asses frozen in mud, i, 189
na earthqua
Tete eel .
— his deftaition of Laren action, i.
5
— on diffusion of heat over the globe,
i
— — loss of heat in southern hemi-
Pesan He
— migration of animals, i. 179
— — thickness of snow on re i. 287
— Botanical se ii.
— — earthquake of Lisbon, ii. om
— — eruption of Jorullo,
insects hci - to sitet heights by
the wind, i
- mniggmation of animals from specific
Scfliies, ll. 886
— — migration of American waterfowl,
ii. 364
— — origin of gulf-weed
— Pr: ini pe “domestic ens in the
Pam
Hhiiphvove, pears on Mississippi, i.
eels and ae, ge , report on
siss aye
——— ca Fawites down by
SiSs anes 1. 453-458
Hunt ‘Vr T. Sterry, on ee 1.413
Hunter, John, on hybrids,
a= multiple origin of aN dog, ii.
€
Hurst Castle shingle bank, i. 531
ICE
Hutchinson, John, his Moses’s Principia,
Hutton satiety Geology from Cos-
— “bois of, 73 73, 74-77, 88
— on original formation of the earth, ii.
2
ee on origin of Ancon sheep, ii.
—— aft ‘Natural Selection,’ ii. sie
— — six-fingered variety of man, ii.
Hybrid wild plants,
Hybridisation of eine a plants, 1i.
Hybridity will a account for special
ate 8,11. 326
8 of canine species, i, 306
i bide horse and ass, ii. 306
— powerless in the struggle for exist-
ence, ii. 310
Hydrogen present in volcanic eruptions,
pr Ae rocks, i, 144
CE, es imhedded in, i. 296
oating in sea of white chalk, i.
— solid matter ee by, i. 363
— aera and e of polar, i. 285
1. 205
— — supposed, in Poanen eee
222
n Devonian period, i
— — transportation of rocks by, i in alte,
Teeberg, seen off Cape of Good Hope, i.
— carrying a mass of rocks, i. 381
Icebergs, a hans of conveying seeds to
islands, sh
j 0) 1. 379
— floating s oth a cause of cold, i. 245
lee ears probabl e thickness of polar, ‘
oe’ ae ey level of the
ocean, 1. 272, 2
Ice- cody at bak es in the Glacial
period, 1
Bea Soct of on dip level of the ocean,
i. 289,
Tee-flo oes, ancind of animals on, li. 160
Ice-streams in Ba ffin’s Bay, 1. 288
Tesla, gees stranded on, i
of reindeer supa 0 :
il. 46 50
— geysers of, 1. 409; ii. 215
— Miocene strate of, i. 201
or est.
"Upto,
ICE
goes new island near, i
ar turbrand and fossil es OL 1.
SS sapp posed effects of first polar bear
entering ST, = ‘
— voleanic eruptions in,
Tehthyosaus ‘a lias, lat. re *y W219,
Ictis of Diodorus Siculus, i. 542
avee action. See Vc oleanie. ve
conser rvative power of, 1. 288,
— ad aqueous forces, counterbalancing
and antagonistic effects of, 11, 97, 937,
43
—_ Se supposed former intensity of,
s, nature of subterranean, meray
Inbaldingo of Sete ed insects, and birds,
li. 589, 0
— Pcl quadrupeds, ii. 535
r. buried houses and cities in, 11.
Indian region of mammailia, rise of land
which would unite all the islands of
the, 11. 346
pea of level in delta of the,
_ 98
_ ae er ake of 77
Infusorial tuff of Pompeii, i. 644
Tnland seas, iis Of, 1 ses ron 421
rganic causes a chang
effect of, in SS ating the
intellectual pei of a nation, il.
Insect-destroying animals in Paraguay,
ii.
Insects in Devonian strata, i
— agency of, in re salar
Sole
mber of British insects known
~ (1838), i i*271
a a Atlant islands chiefly indigenous,
“dist ee and a ge i 377
— ertisation of pla eS s by, 1
mbedding of, i
of Chili some of he species, li.
hire gorges will not account for
_— fers "1 of oh ii. 294
of migration, ii. 357
“Insular climates g, 1. 239
— Faunas and hain ii. 402
Inter- one ial periods, i. 195
Ir oe end of peat mosses in, li.
at with buried hut in, ii. 504
as acting point of, il. 207
GENERAL INDEX.
JON
ron-ore, sources of bog, ii
Ischia, view of yoleanie i 4 i. 601
Poa “P rings of, i. 409
— voleanic eruption 8 of, i. ise 605
ae of 1828 in, 93
yoy new, in Misdtveretn past, e707 16
- sane of peopling with landshells, ii.
429
eae! Leesa tae: of, in eas i. 554
of Se 6 ad i
— for be ra Gan “72
2 aoa of pee eel il. 361
— floras and faunas of, ii. 402
of Atlantic, age and origin of, ii.
a
— some originally uninhabited by man,
— "the peopling of, accords with theory
of variation and natural selection, ii.
oat Wight, waste of its shores, i.
Isothermal ee ya curves in Europe
nd A , 239
Tsothermals, mae an ‘mean annual, i,
WO retetien of, in Glacial period, i.
a alteration . Acaniga mean between
nd, 1.
Ivery, vast stores of, in ‘Siberia, i. 185
ACK, Dr., on coral of Pulo Nias, ii.
5
Jamaica, earthquake in, 1692, ii. 160
— thickness of Miocene coral bay Sake
a pe Sir Henry, on Dead Sea level, i.
— block of oh dredged up in
"Belinduith harbour,
Jamieson, bs - Elion, on glacier-lake
theory, i
oe Tidion is of snakes in, ii.
Bits Salle of poison in, i. 589
voleanos in, 1. 589; 11. 56
— eathquakes Ma Fs 105, 113, 146,
16
— river floods in 538
and Sum nay foc connection
a he etween
mae i lic res on English landshells,
toral ee under marine
BL alte in idee: 1.
Jones, Sir W., on Moni s institutes,
632 GENERAL INDEX,
JOR
Jorullo, saa gebdie of, 1. ot ii. 53
—nor ruptions of, ii. 56
Juan Pomaden santlhiedktcat at, i. 154
Jukes, ny Bey voleanie islands near
Java,
= a reef, ii. 605
ee eine on eruptions of Java, ii. 11,
— — Papandayang volcanic eruption,
ii.
Jutland, inroads of sea in, i. 556
AMTSCHATKA, eon in, i. 588
Kaschnitz, Herr Von _ struc-
tion of earth-pillars by rain . 839
ari on eeailiion of land et sea,
29
Kaiavothra of Greece, ii. 517
Kau up, gibbon, or long-armed
ree C J., on Indian fossils, i. 213
pore Prot, on rise of land i in Nor-
Keill’s on Whiston and Burnet, i. 49
Kent, inroads of sea on coast of, 1. 5622
Kentue wet caves in limestone, ii. 514
so a Count, map of Russia, 1.
King, Capt., on coral reefs, 1. 597
ee on submerged cannon, ii. 54
— Rev. S. W., on Eccles Church, i.
13
rs Loch of, insects in marl of, ii.
canoe in peat of, i
Kirby a nd Spence on dees instinets, ii.
—— — ects pt Re balance
species, ii. 437, 4 , 441
Kin ‘wan, his geo ley oy 1. 82
Kélreuter on hybrid plan 307
nig, Mr., on ab ca Sipe skele-
arte Suis - é
Koran, sisi eer ie of the, : 28
Kotzebue n drifted canoe, ii. 1. 467
Kurile Talags active isha in, i. 588
cere rocks drifted by ice on,
Laceadive ana coral reefs of, ii. 588
La cép ede o mmies from Egypt, ii.
Gaspeti of coral islands, ii. 599
Lagrange on limits of excentricity of
earth’s orbit, i. 269
Lake, dammed u up by a glacier, i. 376
— delta bas, 1,417, 421
— ee plants and animals of, ii.
285, 287°
LAN
et: new, formed sys earthquakes
n New Ma drid, ii.
— — — durin
ii, 12
— formed in Louisiana, i. 454
Ferma his theory of progression, i,
oeCalnnen earthquake,
— on Egyptian mummies, ii. 265
— — rudimentary organs, ii. 274
— — slowness of geological change, ii.
266
es conversion of orang into man, ii.
5
— his definition of nb i. 246
— sketch of his theory of eae aaa
one 260
ii, bt) nde aie heat, i.
— effect of, in warming the atmosphere,
i, 237, 241
—_ eight of, compared to depth of sea,
i.
_ oe ee peeps 258
now abnormal n quantity at the
~ pales, i
1. 247
—proportion of, to sea in tropics, i.
— poston of, which would favour warm
ate, 1. 248
_ nie of, in n Sweden, i, 121, 133
— rise and depression of, i 24
— and pes present a distribution
of, i. 257
— causes of elevation and subsidence
of, 1. 284, 242
— balance of dry, how preserved, ii. 237
— permanent upheaval Sen sabe
of, in New Zealand, i
— elevation and ssidence of, without
eta on 2 il.
ris ee il.
AP age of fossil, i prec 1S-
sshanie au 42
of Aidan islands nearly all in-
_ Aigenous, . 421
— odes i ph _ beg may reach
oceanic ‘alandaed
— of Great Britain and Atlantic is-
_ lands compared, ii. 42
Landslip in Dotsichal ire, 1. 5386
Landslips on the oe i. 469
— floods caused by, 1. 850
— during Calabrian earthquake, i. 1380-
— Breas of organic remains by, ii.
Tanguages, plurality of, among rude
tribes,
— origin of compared to that of species,
il. 470
LAP
Laplace on non-contraction of globe, i.
— — density of the earth, ii.
Lariviére, M., on ice- eaneeeel poe,
1.3
La co, M., on hha of the Rein-
deer perio
ee his euiarit of Nile mud, i.
Lanes Sir T. D., on Moray floods, i.
Se == —— fioodsin scotland, 11. 51 1
law streams, ieee volume of, in
any eruption
of Iceland ae central France, il.
Lavas of Somma, slope of, i. 632, 638,
— Red-brick, of Madeira, ii. 404
— want of parallelism se on Etna, ii. 14
azzaro Moro. See Mor
Leaves, fossil, in tuffs of oe
Casa ee Acqua on ae side
f Somma, i.
Lehman, eeae ai 1756, i. 59
7A bnitz on origin of pratitite masses,
leay on reptiles of the Chalk, i.
— fossil horses of United fhe li.
Lemming, migrations of the, ii
ess i ord genera of, in Mada-
gasca
aes fossil oe on banks of, i. 181,
lane do da Vinci 7 fossil shells, i. 31
Leslie, Sir J., on heat received by poles
8
temperature of hottest
nth in London,
Teval. of aN Sea ad oa.
= meee of, in Calabrian owe
Leronia’ computation of excentricity
rth’s orbit, i. 270
Aa een, arine strata containing
freshwater species at, ii. 569
oat Prof., on tebe Geysers, ii.
Li ft t, influence of, on plants,
ite, layer of, in San Jorge, Madeira,
Lima, ae ated marine ci at, ii. 158
Lime, whence — oe wa
Sse w:
Lindley, Dr., on en ea of Melville
“Island, i. 225
— number of species of plants, ii.
270
Linnzus on dispersion of plants, ii. 886,
393
GENERAL INDEX.
MAC
Linnzus on Me hybrids and protean
Piet: ll. 32¢
ee of s species, He O00
— -— number of species of insects, ii.
71
— — plants spend by man, li. 398
— mis Siar
— strv oe man and ape, il. ie
Lippi on ‘Mereulaneum and Pompeii
643,
Liquid gases, expansive power of, ii:
ove
Lisbon, earthquakes at, i. 596
— earthquake of 1755, ii. 147
— subsidence of quay of, 7 147
Lister _ ee shells, i
ene: ne on natives ae erass-
oh . 286
Lo ti dovastations caused by, 1. 440
— mi gration 0
— seeds ca riod bs
Loess Mississippi Valley, 1. 463
Loge cali aes in eke of Donegal, ii.
ae ae Fy sais contrast of
sp ae
London sian a ne 389
eee ee stem of, Pe lame, 1.
oe formation of lakes in, 1.
ee and Fries, Profs., cited, 11. sat
— Prof., on rise of lend i in Seviedeor:
Lowe, Rev. R. T., on Madeiran land-
shells, i li. 421
pense Mui Suffolk, how formed, i.
Labbe, Si J., on deposition of Nile
—-—— ees Neolithic, i. 176
— — — — absence of poteat among
savages, 11. 479
ie ig
man, ii. 558-560
of pre-historic
ACACUS ae doubtful
authenticity of, i
MacClelland, rae on Se line in
. 590
Bay of B
McChntock, Capa, on oolitice fossils
near the 218
— — — lifei
rng Dr.,
ag ae seas, 11. 577
on rol of peat, ii.
eS GS ele of peat, 11. 496
of limestone, li. 608
Mackenzie en floods . 188
— driftwood of the, ii. in
634 GENERAL INDEX,
MAC
Maclaren, hay remarks on theory of
atolls, i
“ endo, Cuereth, on delta of Indus,
M:Nab, Mr. J., his sketch of an iceberg,
Metieasrar a sub- Bee of Ethio-
pian zoological region, i 7
— number of peculiar sfedtos in, ll,
Mair birds of, common to Europe,
— ea Porto Santo, proportion of ex-
tinct and living landshells of, il. 422-
426
hespme Archi ipelago, sos of, ii. 405
drepora muricata, i
eof y rleanie ner li. 230, 242
a cosmog: 1. 28
eres siadidisations roeedaees in the,
Majoli on voleanic ejection of shells,
Malay ees ee,
'y in the,
— ae arked aie races in the,
gr eat zoological
Maldive Islands, coral reefs of, ii. 58
ae ape, on Trinidad silent
Mal ilet * Mr Tiago ee earth-
quake, i. 118, 137,
— — — —ea ede vorticose move-
ment, ii. 120
———— cone tuakes, li. 82
—_—— de cee the
earthquake fork i.
epth of sede ane focus,
ii. 139
oe es during earth-
pees
Malt ae le Fe s gpapelaiion applied
mals, ii.
Pes Resse shsoie cS how far affecting
reptile lif 220
— fossil, as hed on progression, it
— of Mississippi loess, i. 465
— successive appearance of higher, i.
163
— aes of, in Atlantic islands, ii,
ee regions of, ii. 335, 340, 341,
343, 346,
— fossil of Pikermi, il. 482
MAP
Mammalia, Pe rs, relation of fos-
sil to livin
—_—— diststhubion of fossil, ii. 333
— of the Nearctic region, ii.
— Imbedding o
Mammifer fossil of trias, 1. 158
Mammifers, number of shai of, ii, 271
Mammoth, climate of the, i. 178
— Siberian, i. ce
on Yenesei, 1866, i. 185
able foe of, i. 18
Man, introduction of, and its effects, i.
— durability of bones of, i. 166; 11. 544
a ae agency in dispersing ie il.
_ agency of, in dispersion of animals,
2 Ol d-World type, i 474
— ue deeb) doveloreaa of, li, 485, 487
— ae erged from one starting point, ii.
= pe teeta of species by, ii, 451
— his origin and distribution, ii. 464
— and horse found in So olway moss, ii.
503
— Rea soes of his remains and works
n subaqueous gt ii. 641
— peer origin of, ii. 55
_ sonnel in Hae of pre-historic,
li. 5657
— only | - many exterminating
agents, li.
~~ question Pry siulticl oer of, i. 475
mains of, in the bed of the sea, ii.
~ 549
— remains of, in lowest Danish peat, ii.
— barbarism of Paleolithie, ii. 493
— subject to animal laws, ii. 49
— whether his bodily Kae varies, ii.
471-47
— six-fingered variety of, ii. 47
— whether a from a higher or
risen mare wer type, li. 479
Man pe
Mantel ‘De. on imbedding of insects,
_ ie Walter, on New Zealand earth-
quake,
eect nA shail on the coast of Holland,
— alice i the Baltic, i. 557
— Ganges a d Brabmapootr, 1.471
a — Hhothaemen line
ae sree deta i. ate
— Si beria
—_ trict of Naples, i. 559-
579
— voleanos from Philippine Islands
~ to Bengal, i. 586
|
|
|
‘
é
t Svas Nig. co hee f eek. %
\\ FS FEU Va ee wey
MAP
sw vies aay of mud-lumps of
Tississip
— — changes i geography since the
Eocene Benedck 25%
— — present unequal distribution of
land and sea, i.
— ideal, of normal distribution of land
sea, 1.
= Or: Sea i. 114
ili, ii. 91
Chi
a Cutel ie
—— depth of ocean between Atlantic
islands and the mainland,
li. 40
— Indian oy Australian zoological
‘goes
— Ma inn Archipelago, ii. 405
and, 1
Mops, ideal, showing position oi
and sea, which might ea ex-
tremes of heat and cold, Bea
Marine fossils, Greek Fisiae as to, 1.
— alluvium burying fossils, ii. 572
yaad Loney species imbed-
aaa in .
— pla sas naa ing of, ii. 571
— aes imbedding of, ii. 573
— strata, mammalia imbedded ry le
540
— testacea, ape! of, 1. 574
— upraised s ister ii. 192
Ma len Se, or eed er-lake, 7
Marks ¢ is ee water et in Swe-
en, i
Marl ies ee spend) ii.
armora, nt de la, on ra
oe
Ss
=|
2
oe
ko)
°o
ct
ot
>)
lop)
artius on animals poate on : oting
islands, ii.
Mattioli on fossil organic shapes,
Mauritius, scr ie fted above fe ter
ee labyrinth, i. 580
Mivemanean, reer of, at Nile delta,
_ pth temperature, and currents of,
— ove of, compared to Red Sea, i.
— sec oe of basins of, 1. 562
ea of tides in, 11. 168
, metamorphoses of the 327
Meech ¢ on increase of heat by Hise
of signe asibee 273
— on solar pakenion.
Megna River, arm of ee ditties i.
470
GENERAL INDEX.
MIS
ars a Dyr., on extinction of the Dodo,
Melville pies carboniferous fossils
Tol. 22
— — migr nati ion of musk-ox to, ii
Memphis, computation of erowth of Nile
mud at, 1. 485
eed 8 as m7 8
r de Glac oj Sith of, i. 370
— of
Metallic substances changed fie sub-
mersion, ii. 54
Metamorphic rocks, texture and origin
of, 1.
Metzger on modifications effected in
maize,
Macs lates of, i
, H. Von, on area of Tris, A.
“oe
Meyer, Dr., on earthquake in Seay li, 95
ent fa ev. J., on earthquakes, i. 61
— retreat of sea during sndthenieicons
"150, 52
Michelotti, 'M Jean, on growth of corals,
580
Microests, discovery of,1n Upper Trias,
Middendorf, M., . en by,
near pag hs of Lena, i
n Siberian naminothy i, 184-188
Migration _ ce . 364
— nai "31 7
uadr rel ii. 855-3638
_—— Geet , ll. 865
—— Tastabed el 2
Migratory in iain dia.ak 357
Milford Haven, rise of fides at, 1. 494
Millennium, i. 32
Miller socet W. A., on spectrum analysis
f a variable star, i. 808
Mineral Oe of strata variations
— pane ingredients of, DF O07,
— veins, contraction of, explained, ii.
12
Minerals of Vesuvius, i. a p
MitbraTsati on of plant 532
Mines, heat measured be pera in, ii.
Miocene fossil trees in arctic latitudes,
— Lower, strata of, i. 202
— se cdi warm climate of, i. 199
ice-action in, i.
— age of Atlantic ‘islands,
_ Bit of plants in aici nee
Mississippi basin and delta of, i, 440
636 GENERAL INDEX.
MIS
ee ‘ bluffs’ of the, i
colou caused by cai i, 310
— iugaan ‘e banks of, i. 448
— cuts-off of the
coe cae alia plain of, i. 457
— gro
— dni bbe ee . be 464
— Valley, loess of, i.
mud-lumps at mouths of, i. 447
‘ryfaen, recent marine shells on,
Mollusks, nthe oy eee: on theory of
progression
— egos of attacked to floating wood, ii.
— distribution and mare ta “is li. 872
372
node
Moluceas ee <es in, 1693, ii. 160
— volcanos of the, i. 585
Monads, SL iiaitnak’s th ry of, i
Mongibello (Etna), axis of tah, a
Mon nkeys eee of Eocene and Mio-
Monte oie, apn fish of, i
and ish inelaieva
ae of, i. 616
— San ail: mammoths of i. 186
— Somma, small rai ikes in, 1. 636
sap ve ae on ihe races of man, il.
Monti le size ahi
rmatio
Montlosice on Sey - Auvergne, i.
Moore, J. C., calculations of climatal
__ effects ss exeentrie ity, 1. 29
— — on West Indian corals, 1 Bb4:
—— — — effect of polar ice-cap, i.
4
Morai s of glaciers olsen 374
Mor: ayshire, effects of fl oe in, U1. 511
Morea, Lccaniie of the, j 513
osseous breccias now tavininion in the,
4
516
— Seay remains imbedded in, ii. 3
Morlot, J M., on subsidence of bed
Adriatic, i. 425
two glacial periods, i. 196
NEL
oe gpa: his geological views, i:
Mori on, » De on unity of type in Red-
Tndig an, ae
Moths flyin 80
Mount St. ‘elias, Santieht a ae ii.
Mountain-chaing, doctrine of sudden rise
of, 121-1
— — upheaval and subsidence of, 131-
138
Moya, or ee mud, from voleano in
Quito, ii
Micaatiiaa t, course of, i. 498
rmi ing effec es i. 24
Mud: change of the Missdesippi delta, i.
447
— — views of, i 451
— currents 3 of 3 in Celgbaian earthquake,
ii. 133
voleanos, ii. 75
Males. See Hybrids.
Mummies Tayo identical with living
species,
oe cho ‘Sir R. I., on Hartz Moun-
iv7
—— — of Russia, i. 251
— ——on oh Babee Mocks . 209
—_—— — ies ts ae
— — — on extension re inh ee 1. 188
— — — — marine de of Devonian,
sip g)
tin of Tivoli, i. 407
Mure: ee ,on nfs shells of Nile, 1. 438
Murray Mr. n Silver Pits and Dogger
569
i, i
Musk-ox, migration of, to Melville Is-
land, i 31
My yas meliceps confined to high moun-
sell.
Pisce ee ‘foansaiel i, 159
Nee ne: — of, raised by an erup-
i canic sTaivieb of, i. 599
stranded near Boston, i . O72
Niwa
Natural barriers, the Pcie) of, 11. 331
selection, ii. oe —3
— — objections ho theory of, 11. 489
ae ot
— — ultim Baie secures the prevalence
of gi he tae Hs
— Dar Meat bit ee
Nea retie oii, mam ino he 11.340
Nea-Kaimeni, fowinatir ion of, 1
Needles of the Isle of Wig a ue
ro, constancy of character ie 4, ‘000
Biot ig Baopean, amount of difference
between
Nelson, Liege. on iptv reefs, ii. 605
NEO
agen era, climate of, 177
nie Boeri date of, 1. 295
implem of the, 11. 548
ons of animale, ll. 385
Neptunists ae: Vuleanists, i.
Nero, Francesco del, on eruption of
M uo
0 vO,
New Madrid, ve country of, 1. 456
= Noe me coral reef surrounding,
— ‘Mary US., foie ie S 106
— — — sunk country o
— Zeal, apc: mee of i hes -cress
in, i.
—_—— earthquake of ae he 82
— glaciers of, *
= aoe aye
— map of ae 7 of earthquake, ii.
—— ee of indigenous mammalia
in
Teak Deakins. various ages of, 1. 114
ie Lieutenant, on mud of Nile,
Nina, recession of pra 1. 559
of the Falls
Nile a ‘borings ate Insets » 485
— delta
Nilsson, Prof, on sinking of land south
of Stock holm, i:
———mi igration se eels, 11. 371
— — — weapons of Pre- histotio man,
i. 558
Nomenclature geological, defects of, 1.
116
a , ae on rise of land in
weden 87
Novi ake of coast of, i. 511
North Cape of land at, i. aoe
land now rising a 95
Novem Revistas former Te of,
ae
me climates of the, i. 276
Ne otistrand, destruction of, by the sea,
Riiwey, xi e of land in, ii. 195
4 wic : once situated on an arm of the
16
a Sota, ie deposits of red
marl
of . idos { in, i. 560
Nommulis ee ee ae of, i. 209
0, Monte, internal talus of, i.
te bow island formed in 1788, i
0” , River, fossils on shores of, i. 181
obi iquity of ecliptic, Eee in,
dechec: oo by Calabrian earth-
quake,
GENERAL INDEX.
OWE
ne valley of i tm freshwater
ve jee Me 1.467
of, a cause of slow
geographical change, i. 265
ae ne al, Tatuarck’s belief in, ii.
Ss
rae hirtella, ii. 582
‘ual on tabtinley strata of Italy, i
GEninghen Upper Miocene flora of, i.
cue on electro-magnetism, ii. 230
Ogygian deluge, i. 59
les _ sandstone, pice of fossils of,
otivio Ws » deposits in Gh ie, 1. 426
uf, "of the Sen’ 1. 28
Oolite feast “alii Ate’ 0
Ox rane ntane, Pt
char e of to man, ii. 257
Orbigny, M. A. de, on Pampean mud, i.
ee of
Gace of the pal how far excentric,
and why, i
Organic life, ae development
— remains, controversy as to origin of,
1. 3:
——im one of, in subaqueous de-
posits, 11. 52
—_—— imbedded in volcanic formations,
11. 509
— world-changes in the,
Onguaams eventual success oe higher,
Oriental cosmogony, i
‘ Origin of Species, by Daxwn, effect of
its publication, ii. 28
Orkney Islands, waste a i. 507
Otaheite. See Tahiti
we sketch of ae doctrines,
oven, sae nEee on ae fossil mam-
malia and birds,
— — — theory of ce ession, i. 155
— Polar ichthyosaurus, i. ‘219
ye ub- oye oe mammalia,i.165
raat
——on qe0th ae mmo 187
— — — Parthenogenesis, ii. 201
—-—— eects opterygia, 478
— rank of Dryo ical, li. 483
— is eee structure of man
and ape, 1
— — — cer are classification of verte-
aiphende ii. 4
— — — bones - forge il 573
— — — extinction of the Dodo
-— peapeanhieed aut %
ig to living mammalia, i1. 334
638 GENERAL INDEX.
PAC
Pate coral islands of the, ii. 596
etic region, mammalia of
the, 11. 841
Paleolithic, or older stone age, climate
of, 1. 17-7,;:193
— plate possible ee of, i. 296
— man, barbar 1. 479, 493
iod, imploments of the, in Hamp-
Bee re anit | ’
age, probable climate of the, i. 568
Piledine aries by ae aire i. 5696
paey on animal origin of fossils, i.
Pallas on eri! Sea, 1. 66
— fos nes of Siberia, i. 181-183
= okies s of Siberia, 1. 66
dom mesticity Belbsas ta sterility,
Palen Mr., on shingle beaches, i. 531
pcos oe submergence of isthmus
_ acs ay
—_ Hearne ‘heets ae eee of
isthmus of, 11. 446
ey of fish and ae ead
oth sides sch sire of, 11. 370
lea Darwin’s theory of, il. 291
Pa apal ndayang, a RS of cone of, 11.
Papyrus rolls in Pompeii, i. ig:
Paradise, ee on seat of, i. 48
— a R., animals aed in the, ii.
538
Paris, Artesian well near,
as te eae on ao earth-
seb Bae drowned in Parana
538
Paro ama ah - ancient causes
controverted, i
Sir , on Polar bears
360
Peat-bed, efi containing £.
45
Peat in delta of Ganges, i. 478
— al eee in cold ee climates, ii.
— animal substances preserved in, ii.
— fossil animals buried in 06
—- fossilised objects raat fe in, ii. 499,
505
— growth and ayes ns 496, 502
— mosses, burst: — of, i
— — extent o
— — recent origin ot some, ii. nas
Penco, in ‘Chili, elevation near, il.
Peng elly , Mr. te of rea
perm £ 538
adh ie of St. Michael’s Mount,
ies 5
PLA
Pennant on migration of eer: 1.179
Penzance, loss of land near, i.
Percy, Dr, on no os of heat, ii.
Perihelion, its effect on climate, i ae
Permian fossils imply warm climate,
22
Pa" “Ep ice-action in, i. 222
Perrey, exis, on earthquakes, il.
82, st
volcanic Pied 1. 588
Pa. voeans in, 1
earthquake of 1746, . 156
Peruvian ane of : food, ae
roleum springs, i.
Phaser Tatton
Phea cies of hie oh breed
net
Philippi, De. re on oe change ot
species in Sicily i
ossil foe of Etna, ii. 6
Phillips, Profeson, on waste of York-
shire coast, i. 510
_ . peo below earth’s
sae)
Phle epreean oielde volcanos of, i. 608,
Pietra Mala, inflammable gas o 8
ah 150 races of domesticated, i.
— reat changes made by man in the,
— reversion of to Columba Livia when
crossed, il.
— a doméatie races of interbreed, 1i.
one powers of swimming of, i
EA e mi, a ar Athens, fossil mee
Pimpernel sterility of crossed varieties
Ping ‘ol, D . ON ae of west coast of
Melee’ il.
Pint on height ae size of Monte Nuovo,
Pitch- lake of Trinidad, i. 414
Plants, ene hei bearing on theory of
progre
—— of Ca shonin period, i. 224
agency of man in dispersing, ii. 397
—- — ae in distribution of, ii.
394
— absence of boreal, on Madeiran
mountains, ii. 41
— eosmopolite character of cryptoga-
wit th win sa oS Me 388
— eo diage rsion of, i
— i he piplbct ety of; 11. 38
—of Atlantic islands seep to
British, 11. 421
PLA
ii Plants of Australia and Europe com-
pared, ii.
_— different parte of altered by man, ii.
_— effects of increase = Sie species in
exterminating others, 11. 447
oiler ‘buried in marine de-
ad
Tile a insects have coloured
rolla, ii
—hermaphiait, often not self-ferti-
| ak
on flowering li. 319
as — hybridisation of, 11. 30
—im bedding of in ents deposits,
ue
— mineralisation of, ii. 532
— number of known ceric of, ii. 270
number of species known to ancients,
1. 38
— Bes of birds applicable to, ii.
— stable and unstable ipa of, ii. 282
— fossil in tuffs of Etna, ii.
— imbedding of marine, ii. re 1
— provinces vot eee and dispersion
of, ii. 386, 3
_ reationship of Madeiran to Europe,
d hybrid, i
“Pinati virtue’ of a theory of, i. 20,
Platyrrhine, or New-world monkeys, ii.
ao s illustrations of Hutton, i. 78,
Pyfin we formation of Lake of Ge-
oe es of level of Baltic, ii. 183
Pliny on new islands in Mediterranean,
— ‘he Elder, killed on hosing i. 603
unger, on Vesuv . 603
_ ciactitie nature we our sented ii.
234
Pliocene strata, climate of, i. 198
Plo a mains, i. 40
ge, i.
1 eta on doctrines of Anaximander,
Plutonic rocks, texture and origin of, i.
“s Eyer, frequently shifts its course,
i ie
jaan of the, i. 423
ye of, i
‘Poisson, ae zaoaied ma, earth in
_Passing through space,
nsolidation of ae oe rite
Polar or now abnormal, i. 247
GENERAL INDEX,
PRO
ane of Pati Rt cinta of natural
> foreign, ii.
Pompei infasoval beds covering, i. 644
veloping, i. 64
— parhis eat the mass enveloping, i.
7
objects preserved in, i. bre 647
— ee heletans buried ir 48
ne oe daleatonee pes ings near, i.
Ponzi, Pr je on ase mammoths of
Monte Saero, ae
Porites clavari “id,
Port Hudso 2 Blu nas forest in, i.
— Roy ee hee aaah NL ae ii. 160
ried hous
Pontand, fossil ammonites % "4 42
— Is of, wasting away
Porto ‘Santo, ao pe ieee of
rocks of,
a sees Ae idhashans peculiar to,
Pathovte Grantonit, monocotyledon in
the coal, i. 149
Pobteie, phucriess of, in caves of Reindeer
L abdaibe 11. 559
n upraised marine strata, Sardinia,
eet Archdeacon, on effect of polar ice-
cap, 1. 29
Precession, four cycles of, how divided,
274
1
— nee of successive Hea of, i. 280
— of the Equinoxes, i.
— as Rs thickness of aan s crust,
ee
Proj of man as an inhabitant of
lax 9
Pasatiee: Lieut., on coral reef of Mal-
dives, ii.
Prestwich, Mr., on Artesian wells, i.
— on climate of drift, i. 192
Prévost, M. Constant, on rents formed
ain heaval, i. 613
— Thylacotherium, i. 159
— Graham Island, ii. 60
— — his division of geological
causes, be 495
ossils in caves, ii. 520
Teicha, pe on absence of mammalia
in islands, tila
— — — Egyptian cosmogony, i
pe ae Bit of, bearing “i fossil
nimals o
pe A Rk, Se ae i ants on, 1. 148
sa enna ya El pe mollusca On; VAL
ee nm ae fish on
640 *GENERAL INDEX.
PRO
ide Sk cheer sig of, bearing of fossil
Pron essive pderalupinet of organic life,
46-17
—_—— hold by Lamarck, i
— -— in man chiefly pecan li. 485,
48
Treo or polymorphous genera, ii.
baie of animals coincident with
marked human races, 11. seas
—Z Seacvon See Regio
Pumice, eggs of Mo repay ‘transported
ie
Seen strata of White Island, ii. 68
ca peninsula of, wasting away, i
ea tic mammalia of, i. 161
eri marine upraised deposit at, ii.
— ‘ie of Serapis near, ti. 165
section of marine stra ge near, li. 167
By eicroten system of, i.
UADRUMANA, fossil, 164
~~ pradational extinct forms of, ii.
483
Quadrupeds. See Mammalia.
Quaggas, migrations of, ii. 358
paroe on varieties of silkworms,
tes ravine of Niagara near, i.
359, 361
Quirini on sas He seein 1 ree OA,
Quito, volea
ne takes i Vi97, i. 112, 159
he eee Feral, modified in Porto
S
ti
‘ Races,’ tidal currents so called, i. 572
ty of some artificially formed,
== antiqui
li. 282
— of man, es i ae adele i. 464
— distribut nan, oe
with BSP Bee ia .4
fer tilit, ty when crossed of haere
i. 305
— Saeed to herd apart of domestic,
peeled.
metation’t impeded by snow,
ar as, s, Sir S., on cate" in eebs
Rafts of the Mississippi, i. 444
— floating, carrying animals, ii. 361
a ke of, 1. 329
in England, Norway, and
ares 1 " 329,
—_—— — asi n ee Ganges, i 1. 330
— — — — Eastern Bengal, 1. 350
REIL
Raised ie 129
amsay, rofessor, on Miocene ice-
action, rt
20
— — foreign matter in Bath springs,
1, 398
— — — ice-action in Permian times,
1, 222
Devonian times, i. 230
Raspe on on new ser i. 19, 62
alt, 1
Rat, j earrice iy man into America,
Rats, peo nie of, 11. 357
avine excavated in Gee orgia,
ir tae Colonel, on delta of “Tiers,
Ray, 1 his physico-theological theory, &c.,
ls
eras on multiplication of insects,
Recapitulation causes of earthquakes
4
aaa nae aoe of sea on,
— ee views of in 1781 Seal 1834, ve
Reenpero on flood in Val del Bove, ii.
Red ina supposed universality of, i.
— Riv er, new lakes ae by, i. 454
— drift wood in
_—— — junetare of, her Mississippi, i
oa — Sea level of, i. 496
— Ehre enberg on corals of, ii. 583-
oa pean = pe of type throughout
1erica
Ream an on ae of English coast, i.
5s
Redmann, Dr., on snow-capped moun-
tain on the equator i, 24
Refriger n, Leibnitz’s theory of, i. 40
ei Rae mle of, applied to dct
Meus botanical, ii. 382
— of mammal and birds, ii. 335
— — neotropical of baer ii. 335
mammé sealiae a
BEreren of mammalia, ii. 847
‘Reign Bihesee Bi Duke edie: ll, eriti-
n Darwin in the, 489
Reindeer pets “poset ae of}: 1s
REI
Reindeer, increase of, imported into Ice-
land, ii. 450
— migrations of the, ii. 357
Reinhardt. on ahignation of Greenland
Ne ales, 1. 286
nnell on oceanic currents, 1. 495,
_— — Ganges, i. 471, 473 3
_— — the recipient of the gulf-water, 1.
2!
— velocity of Plate oh ne 1. 497
Rennie on peat-mosses
aed oe ane re ated by absence
| naples aoe ey in n tompemte _
yada hemisphere,
= ‘aun of, implying warm "ai
mat
— as as he on ae 1.155
— of the Chalk, 1
pe Coal, i 229°
——— Miocene Epes i. 200
— migration
ae, oh i. ey
573
Rescobie, “swelling up of a mound in
och of,
Rev ersion “ cross-breeds to the parent
stock, ii. 290
— to as cha Sonne ray by crossing
distinct varieties, ii.
ata on inate re by excen-
tricity, i. 270
a Paced of sea at mouths of the, i.
548
— changes in en arms of the, 1. 549
— its delta, i
Rhinoceros, fs eae 1. 183
— gradatio nal extinct “ag = ii. 483
Rhone, ep of, a with
Ary
Ten of in ore 7 ae i. 417
— marine delta co ea
—a a 2 nin oes rock in delta
cate Captain, cited, i
Seta , Sir : ., ON anima Bats buried
aes i snow, eS
— — iso icra lines, i. 236
— — — — distribution of animals, li.
340
— — — — distribution of fish, i
— — — — drift timber in Save as
ni. 526
aa Sapa of musk-ox, ii. 361
— — —sheep of Rocky Monuntaing, i.
304
Riddell on sediment of Mississippi, i.
458
Rink on fossil trees in arctic latitudes,
1. 203
WOK, 11.
GENERAL INDEX, 64]
RUN
Rink on ny of snow in Green-
a o he
S arradtis in Baffin’s Bay, i.
Ritter, ae on doctrines of reins
der, i. 16
Ene -ice, carrying power of, i. 363
— and current bs; comparative transport-
ing power of, i. 57
— courses, fae anged i Calabrian earth-
quake, i. 129
Rivers, oo. of, 1. 34
— colour of, caused by sediment, i.
309
— floods hee eae 1. 349
2 thn doa
velocity of be es
agency of in ¢ : ne - te if
386
rapa tee gr f the Morea, ii. 517
Roberts, Mr. z. ,on New Zeal: ei earth-
qué ee il.
Robertson, Ont, on mud voleanos, il.
Roches moutonnées, i. 375
— near earth- tae in the Ritten,
Rockall oe Bae shells at great
epth
Rocks, ae Of sae on, 1. 367, 3
— older r, why most solid ey Pian
— ena by lightning, i 1 oa
OE sy of texture in veh an rd
ewe
Sinton ean gained from sea, i. 528
Roses, number of Species in Britai nay
326
Ross, dees Sir J., on floating ice-
berg
et GS Sb eee high antarctic land, a
source of cold, i. 242
—— — — — grounded icebergs in
Baffin’s Bay, i. 245
a thickness of antarctic
— — — — — erratic blocks in Victoria
Land, i. 28
Ros ossberg, landslip of the, ii. 513
Rotatio a the earth, currents caused
by, i.
Barker a vessel found in bed of, ii.
ara a on Mexican hunting-dogs,
Round “Tower of Terranuova, fault in,
Mee ntary bain ad bearing on
transmutatio ay)
7
Runn of Kutehy on apes in, i. 228
— described, i
uy
642 GENERAL INDEX,
RUT
Rutimeyer on monkey in Middle Kocene,
1.
— — Habkeren blocks, i. 210
ABINA and Graham’s Island erup-
tions, li.
sre General, on marine currents, i.
497
— — — Artesian well, i
— — — casks carried a ae i.
499
— solar magnetic period, i. 303
Sabrina, new as island of, ii. 58
Seemann, Louis, on chemical affinity, il.
234
eet former submergence of, dividing
African and Ethiopian faunas, ii.
344
Be ten beds, marine fauna of, 1,
St. ape tides at, 1
— —ch anges Wr te by man among
species in 453
aiet ewan of goats in, ii. 412
St. Larsen yee view of rocks drifted
b in the, i. 864
e Michael Mownt. three views of, 1.
——-- ‘eae during many cen-
ee 1. 53
St. Andrew’s, Meena eun-barrel near, il.
550
St. Domingo, earthquake of, 1770, ii.
— — hot oe bursting forth during
ear hens,
ware fossil. ege of wild goose near,
Salt springs, 3
ater, access ce to voleanic foci, ii.
wetto della Pisce Etna, lava cas-
ades in,
Salvages, Fae an flora of the, ii. 410
Samoa, submarine volcanic eruption
ne 9
Boe aan deluge, i
Sand-bars on coast of oie 1. 424
Sand-dunes, 1. 516
— cones mane up during earthquakes,
128
Sandfloods overwhelming towns, ii. 508
Sands, hacia gees g of human remains,
&e.
Sandwich ak voleanos of, i. 590;
San ‘Filippo, baths of, 40
Santa Maria, isle of, uprais od 93
Santorin, geological forms ition of, i. 72
~ absence of dikes Le
an a date of old volcanic formations,
— pvite in ee ash of, ii. 68
66,
sing islands Pre 71
a volean nic pinch
— map and sectio of, i
sie Vignone, pyre ite by springs
1. 40
Sardinic peat in upraised marine
strata of, ii,
ee ie ea ae question of origin of,
Sau sdect, ee
and sea, 1.
Saussure, de, on Take e of Geneva, i. 418
— — — Alps and Jura, i. 6
Savannahs,
grazing he ii.
eee Professor A., on formation of
Monte Nuovo, i. ie
— — — cited, 1. 28
on rate - subsidence of Temple
eS Serapis, il.
ers | 1a, pe rise of land in,
on Pe iit: of land
257-2
drowned while
— Sweden
ES ae in SS cals Bt of, ii. 191
Scheuchzer on fossil fi
Se Py erling, Dr., on fail in caves, ii.
seh MS! ete on Santorin vol-
eruption
Scilla, ¢ on Cale eee
— fall of sea-cliffs nea ook ob i all!
Sclater, ae - geo, oountinel Sadie of
birds,
Stonenby 4 on efi of Gulf-stream
in sie eee i. 246
unk ne a whale, i = Ai
Seo seta of Vesuvius, 1.
Sette i action of rie sea on Nee Of 1.
508
— river-floods in, i. 349
— animals ie away in floods of, ii.
537
soe Mr., on basalts of Vesuvius, i.
— — — Vesuvian eruption, i. 6
— — — formation of voleaniec cones, 1.
29
Beh ies? ve Ischia by, i. 601
— — cited, i
—on eins f Etna, 1
Hee rt of Matgele ane Jo-
an ah
Scudder, Mr, on Devonian insects, 1157
Sea, its influences on climate, 1. yr
nib ny
— — change of leve fei ie
se of land, i. 24 il. 179
¢
Siig
4
jl
i
ling
" ei
Ue :
Q of ling
“hLag
at Vi
Mtn
af Teapl
ot lad
AS
GENERAL INDEX. 643
EA
Sea, depth of, compared to height of land,
i. 260
— extent of open, at north pole, 1.
ee he on coasts, 1. 502,
548, 552, 556,
— beaches, es movement of,
Te
Sehnihc caused by attraction of
F icegeap, i
_ preservation of human remains in
the, 1.
— proofs of permanence of level of, ii.
— retreat of during Lisbon earthquake,
i. 15 ii
— weed, distribution of species, 11. 391
Sedgwick, Professor, on Devonian strata,
1, 32
— — — on organic remains in fissures,
ii.
Sediment of the Mississippi, i. 458
rate of subsidence of some kinds of,
5
—area over which it er be tran-
sported by currents, i.
Bis governing deposition * ‘ ante
— brought down by Ganges
— transfer of i rivers and wine iste
Sedimentary deposition, causes which
occasion a shifting of the areas of, i.
30
niformity of change in, i. 307
Soeds cated feet and in stomachs of
birds, ii. , 421
— collected sh savages for food, 11. 286
— conveyed to islands by icebergs, ii.
Selection, natural, compared to artificial,
li. 316
— by man ‘ unconscious ’ and ‘ methodi-
sli ad, on rise of land in Sweden,
i uence of formations explained, i. 324
Serapis, ae f Jupiter, at its period
of greatest iegation ion, li.
— — elevation and subsidence of,
un. 171
— —— — ground plan of environs of,
1. 165
— -~ — history of, ii. 168 .
_—-—— Ene ii. 170
— — — date of modern subsidence, ii.
Serra del pe. on Etna, dip and curve
of lava: Va cael
oalare. Lage cing ana li. 327
Seven Sleepers, legend o i. 97
Severn, tides in estuary a 494
SIL
3 Cliff,
ood Mr. i on ae of Nile
vir i. 48
ea ae ake at Lisbon, ii. ves
Sheep, "Norfolk. herding apart, 1
Shell- ia animal remains imibedded in,
il. eae
, 565, 571
Shells ri Gailante period, i. 228
— — the drift as proofs of climate, is
192
— marine, in New Orleans Artesian
well, i. 459
— supposed fossil, of oe i. 637
— upraised, of the Baltic, i. 314
— fossil, of delta of a Amazons, i.
467
— — importance of, i
— gece of recent, in ce Tertiary
perio 1. 312
= aces ng, 11. 675
— fossil, oreat depths, ii 575
— in upra sed marine sania in Swe-
den, i. 193
— wide range of some, ii. 373. See
Mollusks.
Sheppeys Isle of, waste of coasts in, i.
Shetland Isles, action of the sea on, i.
alge masses, drifted by the sea
1. 503
— a effects of lightning on rocks in,
1, 503
isa? oe now in progress
near, 1
Shingle beeslliy a 531-634
Ships, fossil, ii. 546-548
mber of w reeked ii. 46
Shoals ie gle ne palleey in Ger-
n Oce "568
Siberia, map of : a
— lowlanc
— peut a iowiana he i. 188
Siberian mammot -191
-— rhinoceros ng in ee soil of
Siberia, i. 183
ichet, Dr:,.0 n deafness in cats, il. 314
Sicily, ceriival: in, 1. 594; ii, 1118,
159, 5
Bae | testacea in limestone Ole
mud voleanos of, ii. 76
Sidell, oie: on oer -lumps of Mis-
nies: ; , 462
Silex deposi a by ee ade 1. a
Siliceous pms of Azo
1 ee orms, improved me man’s selec-
a
Silliman, Piet, on Ta schooner in
Nova Séotia, 4 D48
644 GENERAL INDEX.
SIL
Silting up of pert 1. 557
of, 1. 569
Simeto, River, excavation, of lava by, i.
35
See aoe of, SEE by earth-
ms teh, i
aa ae pare ee
Siwélik ii, Nee sis of ae i. 201
Six-fingered variety of man, ii. 476
Skaptar Taal, eruption of, 11. 49
ieee human, in rock of Guada-
loupe,
Slesw wick, ge of coast in, i. 557
ie burstin ng of a peat-moss in, 11. 504
Slo r H., on dispersion of plants,
William, Ray tabular view of
British strata,
Sm Mr., of Jordanhill, on rate of
subsidence of Temple of Serapis, ii.
ames volcanic country round, i. 592
Smyth, Admiral, on depth and. cur-
oats ie: te raaae i, 561-564
temperature of Mediterranean,
eon a.
— pele of Mediterranean, i. 4
hells at great depth at Gi-
~ braltar, ii. 575
— — floating ean ii. i
— — — height of sai i
Gieaia h wn 1 win indy i ii. ay
—_——— ae 1 of ate ee 8
— — — number of wrecked aah i.
546
Snags of the Mississippi River, i. 446
Snakes of Japan of Indian origin, ii.
pe Ww, evaporation of, in dry air, i. 286
—i mpeding radiation of heat, i. 284
ore
|
ee
E
oO
367
Eeierielles in oe head fishing hut
near, 18
eee ti ide, comparatively eal i. 110
Solar magnetic periods, i
Bree iar Se pie loss of heat
in, ii.
Soldani on nmiersopi shells of the Me-
an, i. 65
diterr.
on s bas . 65
Shout. iene when haps li. 568
Solfatara, Lake of t fo
olcano oft i.
8, description ee the, 11. 508
Si cee oe submarine forest on coast
of, i. 546
Somma, er supposed recent fossil
gholis of, i. 637
— slope of escarpment of, i. 631
SPI
Semma, formed like Vesuvius, i. 637
Sorbonne, College of the, i. 58
uth Carolina, earthquake my ll. 106
te orgia, climate
Southern hemis oe Cold Ok due to
geographica conditions, eoee
sre apie! 8
a on origin of marine fossils, i
Species, fhencias on eras of creation ee
22
oa sal de of, in successive ‘stra-
se ange in, he in geolo-
logical chronology, i
_— fet. buried in nbn strata,
565
Broe on the dying out of, ii. 268
— causes Yee e survives and another
dies out, ii.
— how an equiibeium is preserved be-
tween, 1. 435, 4
— definition of an rm, il. 245
— have they a real ae e@, li. 245
— Pe out and coming in of, il. 267,
272
ension a one alters range of
ie hi 449
f, by ma
— evol ae ion of done ade pear e crea~
tiv 492
— exti bie of H. 483-463
— how affected we sheet in physical
eography, li.
ae. Tamarek's pass n of term, il. 246
t of t emt eo of, 13. 246
coming in of another, ii. 4
— new cannot be produced by man, ll.
— power of exten no preroga-
tive of ma 46
her ented vapid i increase, li. 317
eiprocal effect of aquaticand terres-
mR li.
— two era could not coexist on
the Bien ec
— ‘Ves oo Creation’ on, i. 274
— be Wallace on nature of, 1. 276,
— gts ther indefinitely aie a 300
Specific centres, doctrine
Spencer, Herbert, on ety io the
iple of inheritance, ii. 291
ae eton s of, in attitude
pri
gle mophilus
f hi
on Paes se: of
Spix an artins
eae by man,
anima on pee on floating is-
inns i. 362
pe,
GENERAL INDEX
SPO
gaimconas generation, theory of, i. 34
belie ved by author of ‘ Vestiges,’
Seats epinin, on a ee fe aie
ture of Mediterranean,
Springbok, migratior 2 the, i on
Springs, ferr uginous, 1.
— brine, 1.
— carbonated, eee i. 411
“eli ha ous, of Azores, 1. 408
sh
= pessoeun, 413
— ra ature a raised by earth-
guns :
—hot, abundant in voleanic regions,
— calcareous, 1
— | eee ae Dee i. 408
— ther 7 Bath, 1.
— se ear rngakes, ii. 128, 146
Squirrels, migrations of, il. 857
Stabiee, buried city of, 1. 65
ae a La alternating with alluvium
i. 520
Stalagmitio deotegtone of Cub 522
Stanley, Hon. W., ey of enn
in sunk ae ed, 1
Stars, as are our ae
— a f the, pared to ohh ag the
279
Stations z plants described, ii. 383
onditions which affect the,
i. 443
icsren, formation of Straits of, i. 553
oe agency et ha voleanic eruptions,
i, 214, i
Steno, adva pes of, 1. 36
Stephenson on ae in Teeland, i1. 49
as jaw of, from Stonesfield,
Sterility opt of domesticity to
eli ee ii
A. ie, _ Bournemouth
flint implements,
oa, Mr., on ee of Aaa 1. 646
Stockholm, ike . near, 1. 18
e, E. T., 2 exeotriities of
th - ea aith’s ee
Stone Age, clim ef 106 198; 11. 563
Stonesficld, fossils
Storm, magnetic, of Ss
Storms, effects of,
Strabo Mesa: TAD (4
— theory of, i.
— on mud raising the bed of Euxine, i.
ae 1850, i. 231
Se ch, 1. 585
anomek Colonel, on delta of Ganges,
Strata contorted ae ice, i. 883
— consolidation 140
— table of Peaitcots, 1, 189
645
SUT
Strata, rene of curved and hori-
zontal, i. 315, 316
— anci€ ent, submerged, and therefore
sible, 1
Stratification in aula causes of, 1.
_ of débris deposited by currents, 1
Strick] and, yl
odo, il.
Stromboli, st es during Calabrian
ea “eee ke, 11.
Stufas, jets sof ik ees regions,
1. 3894
Styx rock off Porto Santo, ii. 405, 426
Sisepennine strata, climate of, i. 199
nei jueous eae aap of fos-
sin, ll. 624
anal forest on Hampshire coast,
li. 529
on extinction of the
— volcanos, ii. 58, 6
pre en of, in Secondary
f land, i1. 165, 234, 552
Subterranean changes unseen by us, i.
— movements, gradual development of,
it
—— ee ett of, i
Suffolk ¢ aa stifed, 1. 519
gs, 1.
ulphurie acid, lake of, in Java, i. 589
Sumatra, Bereiey arrangements of yol-
canos 1
— an imal aeeasan in river-floods in,
Sitar: great eruption in island of,
sites
— ee as li. 553
Summer’s heat in Sais coantor
rer | - eter of snow,
== cold i in a phelion of ee excentri-
> de
Sun, spots in the, 11. 230
Sunda, Isles ae clad region of, i.
Core aw low part of delta of
Gan
‘Sunk coun wre of New ade in
valley of Mississippi, i. 456; 11. 108
Superga, Miocene erratic bloc ka of, i
sag dae ee deltas of, 1. 421
— fossil cypris and eee in, 11. 568
Bis Sans of Iceland, 1. 202
‘Survival of a panne Pols
t, secon for pro-
ss of ifbinn ee il.
ack: waste of coast ha ie
Sutlej, ‘River, fossils near, 1.
646 GENERAL INDEX.
SWA
Swanage Bay cay shag by sea, i. 531
‘Swatch’ in the of Bengal, i. 475
site ys rise of a vbobert le 314: li. 180—
— ma “~ of, 1
— in ee of ack in south of, ii, 190
Swinburn, Capt., on Graham Teland, ik.
6
Switzerland, towns destroyed by land-
slips in, i.
Sykes, Colonel, on rainfall in India, i.
Syria, earthquakes in, i. 594; ii. 89
ABLE gt capagaie pebiapey 1. 189
yin ricities of
seta ane
Tahiti, coral ee Olen: ae
Talus of Monte Nuovo, i
Tamed animals often will ie breed, ii.
3138
boars on geology of. Tuscany, i. 59
orm a of limestone in Tus-
Oe ae Dis stichum, ii. 506
Tay, estuary of, sacra ieee of sea in,
i. 508
teal: on bisa of Norfolk coast, i. 513
— Revd. R., on New Zealand. earth-
quake, li. so.
— Mr. en - on stalagmitic limestone
of Cuba, ii. 522
Teatro Geni, on Etna, ancient lava
current of, ii. 1
Temperature, nee for computing,
— how far pias by extinct orders and
eae as
— lowered . foe and melting of snow,
i. 271 :
— erie of currents in equalising, i.
—_ aye: Glacial one i. 288
— ees 3
—_ 2, Sea variations in, i. 801
See Climate and Heat.
Tem eaten buried i in Cashmere, ii. 558
Terraces of Lake Superior, i. 421
Ter ee a, Subsidence — ite he
Terres 7 changes, the system of, ie 325
—~ one r he sat, su seen diminution
; a)
Tertiary form ations, Be bedi dct:
voll
— — fossil mammals ai pcb ;
60
_ rae eb climate “ or warmer
n at present, i.
Paste on Monte Beles bake 1. 65
TRA
yale _ See beri piee and Shells.
— bu
urrowing, i
Pecan. ores of ro 1.141
Thames, valley of, Hie ona: Petre In, a:
— Sin vessels in alluvial plain of,
Thanet, Isle of, loss of -_ ina. ~
Theophrastus, opinions of, i, 19,
Thera in te er eruption and eae
of, 1650, i
There ha rile in voleanic re-
gion wk
Thomson, Dr, on buried temples of
Kaiten li. 653
a a de, on Artesian wells, i.
93
Thy gee Prevost Ren . Fei
wild ox of, i
Tide ee ss ren
Tides, differen
height to Shee they rise, i.
witha destroyin ng and transporting
power, 1. 565
— absence of inter anes a proof against
central fluidity, ii. 208,
gi tie Fuego, temperate climate of,
. 24
Tigris ae Euphrates, their union a mo-
dern event, 1. 48
— - delta of ey i. 484
n date of nape upraised
strata in Seok: 1, 193
se ries d forest of, i.
el Greco ov aa ll pie
1, 344,
Totten, Col. oe expansion of stone by
heat,
Towns pork 2 by sandfloods, ii.
508
i.
Torrents, action of, in widening valleys,
34
ee eee ini Be oe moths flying far
eter
Tr. te inds, 197
Traditions of ieges, ‘adit ii, 154
Transition texture, i.
Teena forms fata species, ii.
icine A Wie urged against
the os cos a
Trap ro ny man 117
Travers, Me Loe hp on nie aan of
European plants in New Zealand, ii.
Travertin of the Elsa, i. 400
— San Vignone, i. 400
GENERAL INDEX.
Travertin of San Filippo, i.
by caleareous oo i. 401
6
Trias, fossil mammalia of, i. 161
Trifoglietto, ancient axis of Bina, rhe Hah
Trinidad, pitch lake of, i
Tristram, Mr, on aang Lae of
Red Sea
Truncation of eceesig cones, ii. 20, 145
Tufa. See Tra
Turtles, eggs of fossil, u. 573
oo, ey ° of, 1. 59
on of ‘imestone of, ii. 610
Ty fio on motion of oe 1. 373
rel, earth- ‘eins of, i
DDEVALLA, change of level at,
since Glacial period, ii. 192
Ullah ans ct ation of the, ii. 100
Ulloa on ead of wild ass in 8.
America, id 459
Uneonfomabe ae inferences de-
ved fr
i omnity ¢ of eal changes, i. 305-
le ‘cea theory of, i. 112
ory of, i
Upheaval, pros of slow, i
— signs n Atlantic vinnds, i
Upsala, nae brackish wa ater orth
posits near, li, 194
AL DEL BOVE, on Etna, changes
in, by modern eruptions, ii, 25-38
dikes in, ii
ty)
iow — views and description of the,
Weds excavation of, in Central France,
— newly formed, i. 344
— on Etna, ii.
— excavation of, assisted by earth-
nendes
— envated since Paleolithic man
“oe!
Baltioncri on natural causes of change,
ii
— on origin of springs, i. 50
Valparaiso, coast raised at, i. 94, 95
Variation. accumulated by man in any
required direction, 1i. 997
— Are a definite limits to? ii. 300
— of a species, number of causes pro-
ducing, ii. 818
647
VOL
Variation of races under domestication,
il.
— our ignorance of the laws producing,
490
atin nefited by slight crossing,
li. 820,
— often Pee into common stock, ii.
Vedas, sacred hymns of, i
Venetz on recession eg au before
the tenth century, i
Verneuil, pe a te 1, 251
ocks: alt of renee 114
Vessels, wr rocked, re Ship
ste
stiges ‘is Creation on nature of
species, 1
iia ian miner a
Vesuvius, ancient Lines of, i. 602
— renewal of oo of, i. 60
eae. of, i
Fe of, aes 1138, i. 606
oe oe of, 1. 618
ropy, 1. 625
= struct of cone of, 1. 620
— and Somma, ideal rae Of wGs
— fossil leaves es in liga roe Me ie
— valleys o side of i
Aer ee on eet at ee neat
nthe sea, 11. 576
Virgina, pecs drowned in river floods
vere NL. on agglomerate of Santorin,
ii.
— — on Samothracian deluge, i. 593
— — — corrosion of rocks by gases, il.
515
— human remains in breccia of
the Morea, ii. 517
Vi ov earthquake at, in 1855, i
Vistula, River, its course div oe by
packed sil . 864
Vivarais, counter-current of lava in, ii. 51
Pavenic action poke - wih
— ov et t of isa oge :
eae yee Andes, ee
— regio aie
— regions, ane rate ete of,
i. 579-59
— vents, linear arrangement of, i
— accumulations, ee of, in Madeira
and Grand Can
See: nee ares present in, ii.
or
on =
— fe access of air and fresh water to,
1, 225
enuption mre possibly disperse land-
aes
a eruptions, agency of steam in, ii, 214
— dikes.
— foci, access Sof = water to, il. 223
648 GENERAL INDEX,
Ss ald ar imbedded in,
— he ae ao and electricity
pena ges 23
most consistent with par-
Be fluidity. of earth’s tele il. ie
eo eruptions n 1800, i 408
Voleanos, a cause of thot phate i,
— and atolls, map of active, i. 586
— how he distinguish active from ex-
tinct,
-— of Phie Mes Fields, i.
— Sandwich Islands, i. ms
aa — safety valves, according to Strabo,
na ee earthquakes, common origin of,
ii. 198, 240
— — — recapitulation of causes of, ii.
0
— limited areas of, at any one period,
ible
— mud cones, il. 75
— submarine, ii. 58
— why equ cone at junction of sea and
229
land, i
Voltain's s attacks n Geology, i. 79
n Baer, on ice- “drifted rocks, i. 3885
Weis Buch cit ted, 1. 225
——on felspathie voleanie rocks, i.
580
— — — formation of Monte Nuovo, i.
610
— — hypothesis of elevation craters, i.
633
——— On glacier i in Norway, i 1. 3880
— — — rents in volcanos, i. 614
—_—— — role of Greece, : Pas
—— ruption of Lance
— — a marine pine in Sw aa
il. 191
e of land in Sweden, ii. 185
ne Hoff 0 on ie of Caspian, i. 28
Von Liebig on Barren Island, ii. 74
se Schrenck on migrations of animals,
. 180
iat. and Neptunists, i. 71
sarap Vs on pitch lake of Trinidad,
Wallac Aan fred, on ae connection
of I f Malay Islands, i. 250
eposition of Nile mud, i. 437
——— fe aie li. 276,
— ind of Ze
of | his is body, i.
sth Lae of Japan
oan. se 3
278, 280
varying instead
ical aoe in Malay
Penang 1. 3
WHI
Wallace, aan on peculiar species of
ustral and Ind dian regions, ii.
49
— — — cnt ian species identical with
European, ii. 3
— — — limits to variability of a spe-
cies, ii. 800
—— — — barriers to migration of ani-
mals, ii. 855
— mammals of Java and Borneo,
ll. 846
—Indo-Malayan and Papuan
races, ll. Pll
—_——— eur og and destruec-
tion of Tife |
tees theory of volition,
ii. 281
ao mestic animals becoming
ag era al, . B04
Wallariad! ‘heony of
Wallich, Dr, n Ava Pac) Sls 4
+ = poh ain peat near One
i. 478
— George, Rae in seg ae seas, 11. 577
Waltershausen, V 1, 2, 20
‘ Warping,’ land uiiteal me ie 569
bi of coasts by action of sea, i. 493-
Water figs! See hes of, i. 347}
of running, i.
— cal and Sa agency of in voleanos,
223,
Waterton Mr., on species of mar-
supia se ile
334
n New Z onland earth-
ke, ii. 87
Wells, Artesian. See Artesian Wells
Wener, eee horizontal Silurian strata
of, i.
Werner, i oe i. 68-7
on texture of ae i. 141
Weat Indies, pete volcanos in, 1. 584
Upper Miocene strata of, i fe
West. pats: earthquakes, ii. 146,
me ted to Azores by Gulf.
ety 419
Whales, caieeetiane of, to north pole, i.
Wheat in ripe di Peypt identical
with living species
ae Dee nge mapa bg 86
n Si 11, long ng voleanic dike, i. 57
Whisks Ee during serene in
mbav
Whiston his ‘dba of the earth, i. 48
White Mountains, | s inthe, 1.351
ee peipacne pense Obes
siden of Li ie uote ii. 148
Whitsunday ie view of, 11. 585
GENERAL INDEX. 649
WIL
Wilkinson, Sir Z. G., on sand-drifts of
Africa, ii. 507
s of Nile 33
ge his ces to stron, te 81
Wilson, on Hindoo hgh 6
Wind, nae drifted by, 11. 507
Winds, currents cau aie the, i. 499
Winter in aphelion, rae : of, i ie “O71
Winter, long ey cold, in southern
P eapliars . 248
one ore
, 61
on Graham Island,
Wolt ‘etitpaton of, in Great Britain by
Wo ollas sto an Je ay on beetles of
Atlantic islands, i ll.
——— — — lands hells of Atlantic
islands, ii . 423
Wood, impregnated with ri water,
when sunk to ereat depth, 0. 625
Woodcock, seeds adhering i a on
foot of, 11. 421
Woo eR theory 0 of, i. 46, 106
Wrangel on upheaval of arctic land, i.
187
ZUY
Wreck register of lost ships, ii. 546
bm eae the Lydian, his theory, i
23
Xenophanes on marine fossils, i. 19
AK, wild ox of Tibet, frozen in ice,
a‘ armouth, seine silted up at, 1. 516
Yarrell on varieties of an fish, il. 296
Yorkshire, wa gate of ¢ oast,
Young, Dr. 5 On compression pe matter
at the earth’s centre, ii. 208
U fame me faek NEW. See New Ze: eee
Zoological Provinces, ii. 329. ¢
Regions.
Zoophytes, which form coral reefs, ii
Zu oe Zee, formation of, 1
— great mosses on the is ee 1, 561
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