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THE ORIGIN OF SPECIES
VOL. I



THE ORIGIN OF SPECIES

BY MEANS OF NATURAL SELECTION



OR THE PRESERVATION OF FAVORED
RACES IN THE STRUGGLE FOR LIFE



By CHARLES DARWIN

M. A., LL. D., F. R. S.



WITH ADDITIONS AND CORRECTIONS
FROM SIXTH AND LAST ENGLISH EDITION



IN TWO VOLUMES
VOL. I



NEW YORK
D. APPLETON AND COMPANY

1898



Authorized Edition.



CONTENTS.



Additions and Corrections, to the Sixth Edition . Page ix
Historical Sketch ^i"



Introduction



1



CHAPTER I.



variation under domestication.



Causes of Variability— Effects of Habit and the use or disuse of
Parts— Correlated Variation— Inheritance— Character of Do-
mestic Varieties— Difficulty of distinguishing between Varieties
and Species — Origin of domestic varieties from one or more
species— Domestic Pigeons, their Differences and Origin-
Principles of Selection, anciently followed, their Effects-
Methodical and Unconscious Selection — Unknown Origin of
our Domestic Productions — Circumstances favourable to Man's
power of Selection . ^

CHAPTER II.
variation under nature.

Variability — Individual differences — Doubtful species — Wide rang-
ing, much diffused, and common species, vary most — Species of
the larger genera in each country vary more frequently than
the species of the smaller genera — Many of the species of the
larger genera resemble varieties in being very closely, but
unequally, related to each other, and in having restricted
ranges ^'■

V



2033577



vi CONTENTS.



CHAPTER III.

STRUGGLE FOB EXISTENCE.

Its bearing on natural selection — The term used in a wide sense —
Geometrical ratio of increase — Rapid increase of naturalised
animals and plants — Nature of the checks to increase — Com-
petition universal — Effects of Climate — Protection from the
number of individuals — Complex relations of all animals and
plants throughout nature — Struggle for life most severe between
individuals and varieties of the same species : often severe
between species of the same genus — The relation of organism
to organism the most important of all relations . . Page 75



CHAPTER IV.

NATURAL SELECTION ; OR THE SURVIVAL OF THE FITTEST.

Natural Selection — its power compared with man's selection — its
power on characters of trifling importance — its power at all
ages and on both sexes — Sexual selection — On the generality
of intercrosses between individuals of the same species — Cir-
cumstances favourable and unfavourable to the results of
Natural Selection, namely, intercrossing, isolation, number of
individuals — Slow action — Extinction caused by Natural Se-
lection — Divergence of Character, related to the diversity of
inhabitants of any small area, and to naturalisation — Action
of Natural Selection, through Divergence of Character and
Extinction, on the descendants from a common parent — Ex-
plains the grouping of all organic beings — Advance in organ-
isation — Low forms preserved — Convergence of Character —
Indefinite multiplication of species — Summary . . .97



CHAPTER V.

LAWS OF VARIATION.

Effects of changed conditions — Use and disuse, combined with
natural selection ; organs of flight and of vision — Acclimatisa-



CONTENTS. vii

tion — Correlatcrl variation — Compensation and economy of
growtli — False correlutions — ^Lultiple, rudimentary, and lowly
organised structures variable — Parts developed in an unusual
manner are higidy variable ; specific characters more variable
than generic : secondary sexual characters variable — Species
of the same genus vary in an analogous manner — Reversions to
long-lost characters — Summary .... Page 164



CHAPTER VI.

DIFFICULTIES OF THE THEORY.

Difficulties of the theory of descent with modification — Absence or
rarity of transitional varieties — Transitions in habits of life —
Diversified habits in the same species — Species with habits
widely different from those of their allies — Organs of extreme
perfection — Modes of transition — Cases of difficulty— Natura
non facit saltum— Organs of small importance— Organs not in
all cases absolutely perfect— The law of Unity of Type and of
the Conditions of Existence embraced by the theory of Natu-
ral Selection 207



CHAPTER VII.

MISCELLANEOUS OBJECTIONS TO THE THEORY OF NATURAL
SELECTION.

Longevity— Modifications not necessarily simultaneous— Modifica-
tions apparently of no direct service— Progressive development
—Characters of small functional importance, the most con-
stant—Supposed incompetence of natural selection to account
for the incipient stages of useful structures— Causes which in-
terfere with the acquisition through natural selection of useful
structures— Gradations of structure with changed functions—
Widely different organs in members of the same class, de-
veloped from one and the same source— Reasons for disbeliev-
ing in great and abrupt modifications .... 263



viii CONTENTS.



CHAPTER VIII.

INSTINCT.

Instincts comparable with habits, but different in their origin-
Instincts graduated— Aphides and ants — Instincts variable-
Domestic instincts, their origin — Natural instincts of the
cuckoo, Molothrus, ostrich, and parasitic bees — Slave-making
lUits — llive-bee, its cell-making instinct — Changes of instinct
and structure not necessarily simultaneous— Difficulties of the
theory of the Natural Selection of instincts— Neuter or sterile
insects — Summary Page 319



ADDITIONS AND COREECTIONS

TO THE SIXTH EDITION.



Numerous small corrections have been made in the
last and present editions on various subjects, according
as the evidence has become somewhat stronger or weaker.
The more important corrections and some additions in
the present volume are tabulated on the following page,
for the convenience of those interested in the subject,
and who possess the fifth edition. The second edition
was little more than a reprint of the first. The third
edition was largely corrected and added to, and the
fourth and fifth still more largely. As copies of the
present work will be sent abroad, it may be of use if I
specify the state of the foreign editions. The third
French and second German editions were from the third
English, with some few of the additions given in the
fourth edition. A new fourth French edition has been
translated by Colonel ]\Ioulinie; of which the first half
is from the fifth English, and the latter half from the
present edition. A third German edition, under the
superintendence of Professor Victor Carus, was from the
fourth English edition; a fifth is now preparing by the
same author from the present volume. The second
American edition was from the English second, with a



X ADDITIONS AND CORRECTIONS.

few of the additions given in the third; and a third
American edition has been printed from the fifth Eng-
lish edition. The Itahan is from the tliird, the Dutch
and three Russian editions from the second EngHsh
edition, and the Swedish from the fifth English edition.



Fifth
Edition.



Page
100

158
220

225
230

231
233

284

248
248
255



Sixth
Edition.



268

270

307
319



Page
vol. i.

10(5

156
221

227
233

234

237

239

254
254
263



333
334

vol. ii.

9
22



Chief Additions and Corrections.



Influence of fortuitous destruction on natural se-
lection.

On the convergence of specific forms.

Account of the Ground-Woodpecker of La Plata
modified.

On the modification of the eye.

Transitions through the acceleration or retarda-
tion of the period of reproduction.

The account of the electric organ of fishes added to.

Analogical resemblance between the eyes of Cepha-
lopods and Vertebrates.

Claparede on the analogical resemblance of the
hair-claspers of the AcaridjB.

The probable use of the rattle to the Rattle-snake.

Helmholtz on the imperfection of the human eye.

The first part of this now chapter consists of por-
tions, in a much modified state, taken from chap,
iv. of the former editions. The latter and larger
part is new, and relates chiefly to the supposed
incompetency of natural selection to account
for the incipient stages of useful structures.
Tliere is also a discussion on the causes which
prevent in many cases the acquisition through
natural selection of useful structures. Lastly,
reasons are given for disbelieving in great and
sudden modifications. Gradations of character,
often accompanied by changes of function, are
likewise here incidentally considered.

The statement with respect to young cuckoos
ejecting their foster-brothers confirmed.

On the cuckoo-like habits of the Molothrus.

On fertile hybrid moths.

The discu.«sion on the fertility of hybrids not

having been acquired tlirough natural selection

condensed and modified.



ADDITIONS AND CORRECTIONS.



XI



Fifth
Edition.


Sixth
Edition.


Page
326


Page
vol. iU

28


377
403
440
463


81
107
148
172


505


218


516


232


518
520
521
541

547


236

237
240
262
262


552


275


568


293


572


297



Chief Additions and Corrections.



On the causes of sterility of hybrids, added to and
corrected.

Pyrgoma found in the chalk.

Extinct forms serving to connect existing groups.

On earth adhering to the feet of migratory birds.

On the wide geographical range of a species of
Galaxias, a fresh-water fish.

Discussion on analogical resemblances, enlarged
and modified.

Homological structure of the feet of certain mar-
supial animals.

On serial homologies, corrected.

Mr. E. Ray Lankester on morphology.

On the asexual reproduction of Chironomus.

On the origin of rudimentary parts, corrected.

Recapitulation on the sterility of hybrids, cor-
rected.

Recapitulation on the absence of fossils beneath
the Cambrian system, corrected.

Natural selection not the exclusive agency in the
modification of species, as always maintained
in this work.

The belief in the separate creation of species gen-
erally held by naturalists, until a recent period.



" But with regard to the material world, we can at least go so far
as this — we can perceive that events ai'e brought about not by
insulated interpositions of Divine power, exerted in each particular
case, but by the establishment of general laws."

Whewell : Bridgewater Treatise.

" The only distinct meaning of the word ' natural ' is stated,
fixed, or settled; since what is natural as much requires and
presupposes an intelligent agent to render it so, i. e., to effect it
continually or at stated times, as what is supernatural or miraculous
does to effect it for once."

Butler : Analogy of Revealed Religion.

" To conclude, therefore, let no man out of a weak conceit of
sobriety, or an ill-applied moderation, think or maintain, that a
man can search too far or be too well studied in the book of God's
word, or in the book of God's works ; divinity or philosophy ; but
rather let men endeavour an endless progress or proficence in both"

Bacon : Advancement of Learning.



Down, Bechenham, Kent,

First Edition, November 2Uh, 1859.
Sixth Edition, Jan. 1873.



AN HISTORICAL SKETCH

OF THE PROGRESS OF OPINION ON THE ORIGIN OF SPECIES,

PREVIOUSLY TO THE PUBLICATIOX OF THE FIRST EDITION
OF THIS WORK.



I WILL here give a brief sketch of the progress of
opinion on the Origin of Species. Until recently the
great majority of naturalists believed that species were
immutable productions, and had been separately created.
This view has been ably maintained by many authors.
Some few naturalists, on the other hand, have believed
that species undergo modification, and that the existing
forms of life are the descendants by true generation of
pre-existing forms. Passing over allusions to the sub-
ject in the classical writers,* the first author who in

* Aristotle, in his ' Pliysic.T? Auscultationes ' (lib. 3, cap. 8, s. 2),
after remarking that rain does not fall in order to make the corn
grow, any more than it falls to spoil the farmer's corn when
threshed out of doors, applies the same argument to organisation;
and adds (as translated by Mr. Clair Grece, who first pointed out
the passage to me), '"So what hinders the different parts [of the
body] from having this merely accidental relation in nature? as the
teeth, for example, grow by necessity, the front ones sharp, adapted
for dividing, and the grinders flat, and serviceable for masticating
the food ; since they wei'e not made for the sake of this, but it was
the result of accident. And in like manner as to the other parts in
which there appears to exist an adaptation to an end. Whereso-
ever, therefore, all things together (that is all the parts of one
whole) happened like as if they were made for the sake of some-
thing, these were preserved, having been appropriately constituted

xiii



XIV HISTORICAL SKETCH.

modern times has treated it in a scientific spirit was
Buft'on. But as his opinions fluctuated greatly at dif-
ferent periods, and as he does not enter on the causes
or means of tlie transformation of species, I need not
here enter on details.

Lamarck was the first man whose conclusions on the
subject excited much attention. This justly-celebrated
naturalist first published his views in 1801; he much
enlarged them in 1809 in his ' Philosophie Zoologique/
and subsequently, in 1815, in the Introduction to his
' Hist. Nat. des Animaux sans Vertebres.' In these
works he upholds the doctrine that all species, including
man, are descended from other species. He first did
the eminent service of arousing attention to the proba-
bility of all change in the organic, as well as in the
inorganic world, being the result of law, and not of
miraculous interposition. I^amarck seems to have been
chiefly led to his conclusion on the gradual change of
species, by the difficulty of distinguishing species and
varieties, by the almost perfect gradation of forms in
certain groups, and by the analogy of domestic produc-
tions. With respect to the means of modification, he
attributed something to the direct action of the physical
conditions of life, something to the crossing of already
existing forms, and much to- use and disuse, that is, to
the effects of habit. To this latter agency he seems to
attribute all the beautiful adaptations in nature; — such
as the long neck of the giraffe for browsing on the



by an internal spontaneity ; and whatsoever thinjrs were not thus
constituted, perished, and still perish." We here sec the princijile
of natural selection shadowed forth, but how little Aristotle fully
comprehended the principle, is shown by his remarks on the
formation of the teeth.



HISTOraCAL SKETCH. XV

branches of trees. But he likewise believed in a law of
progressive development; and as all the forms of life
thus tend to progress, in order to account for the ex-
istence at the present day of simple productions, he
maintains that such forms are now spontaneously gen-
erated*

Geofiroy Saint-Hilaire, as is stated in his ' Life,'
written by his son, suspected, as early as 1795, that
what we call species are various degenerations of the
same type. It was not until 1838 that he published
his conviction that the same forms have not been per-
petuated since the origin of all things. Geoffroy seems
to have relied chiefly on the conditions of life, or the
" monde amhiant " as the cause of change. He was
cautious in drawing conclusions, and did not believe
that existing species are now undergoing modification;
and, as his son adds, " C'est done un probleme a reserver
entierement a I'avenir, suppose meme que Tavenir doive
avoir prise sur lui."

In 1813, Dr. W. V. Wells read before the Eoyal

* I have taken the date of the first publication of Lamarck from
Isicl. Geoffroy Saint-Hilaire's ('Hist. Nat. Generale.' torn. ii. p.
405. 1859) excellent history of opinion on this subject. In this
work a full account is given of Bullon's conclusions on the same
subject. It is curious how largely my grandfather, Dr. Erasmus
Darwin, anticipated the views and erroneous grounds of opinion of
Lamarck in his 'Zoonomia' (vol. i. pp. 500-510). pubHshed in
1794. According to Isid. Geoffroy there is no doubt that Goethe
was an extreme partisan of similar views, as shown in the Intro-
duction to a work written in 1794 and 1795, but not published till
long afterwards : he has pointedly remarked ('Goethe als Natnr-
forscher,' von Dr. Karl Meding, s. 34) that the future question for
naturalists will be how, for instance, cattle got their horns, and not
for what they are used. It is rather a singular instance of the
manner in which similar views arise at about the same time, that
Goethe in Germany, Dr. Darwin in England, and Geoffroy Saint-
Hilaire (as we shall immediately see) in Prance, came to the samo
conclusion on the origin of species, in the years 1794-5.



xvi HISTORICAL SKETCH.

Society ' An Account of a White female, part of whose
skin resembles that of a Negro '; but his paper was not
published until his famous ' Two Essa3^s upon Dew and
Single Vision ' appeared in 1818. In this paper he
distinctly recognises the principle of natural selection,
and this is the first recognition which has been indi-
cated; but he applies it only to the races of man, and
to certain characters alone. After remarking that ne-
groes and mulattoes enjoy an immunity from certain
tropical diseases, he observes, firstly, that all animals
tend to vary in some degree, and, secondly, that agri-
culturists improve their domesticated animals by selec-
tion; and then, he adds, but what is done in this latter
case " by art, seems to be done with equal efficacy,
though more slowly, by nature, in the formation of
varieties of mankind, fitted for the country which they
inhabit. Of the accidental varieties of man, which
would occur among the first few and scattered inhabi-
tants of the middle regions of Africa, some one would
be better fitted than the others to bear the diseases of
the country. This race would consequently multiply,
while the others would decrease; not only from their
inability to sustain the attacks of disease, but from their
incapacity of contending with their more vigorous neigh-
bours. The colour of this vigorous race I take for
granted, from what has been already said, would be
dark. But the same disposition to form varieties still
existing, a darker and a darker race would in the course
of time occvn": and as the darkest would be the best
fitted for the climate, this would at length become the
most prevalent, if not the only race, in the particular
country in which it had originated." He then extends
these same views to the white inhabitants of colder



HISTORICAL SKETCH. xvii

climates. I am indebted to Mr. Kowloy, of tlic United
States, for having called my attention, through Mr.
Brace, to the above passage in Dr. Well's work.

The Hon. and Rev. W. Herbert, afterwards Dean of
Manchester, in the fourth volume of the ' Horticultural
Transactions,' 1832, and in his work on the ' Amaryl-
lidacege ' (1837, pp. 19, 339), declares that " horticultural
experiments have established, beyond the possibility of
refutation, that botanical species are only a higher and
more permanent class of varieties." He extends the
same view to animals. The Dean believes that single
species of each genus were created in an originally
highly plastic condition, and that these have produced,
chiefly by intercrossing, but likewise by variation, all
our existing species.

In 1826 Professor Grant, in the concluding para-
graph in his well-known paper C" Edinburgh Philosophi-
cal Journal,' vol. xiv. p. 283) on the Spongilla, clearly
declares his belief that species are descended from other
species, and that they become improved in the course of
modification. This same view was given in his 5oth
Lecture, published in the ' Lancet ' in 1834.

In 1831 Mr. Patrick Matthew published his work on
' Naval Timber and Arboriculture,' in which he gives
precisely the same view on the origin of species as that
(presently to be alluded to) propounded by Mr. Wallace
and myself in the ' Linnean Journal,' and as that en-
larged in the present volume. Unfortunately the view
was given by Mr. Matthew very briefly in scattered
passages in an Appendix to a work on a difEerent sub-
ject, so that it remained unnoticed until Mr. Matthew
himself drew attention to it in the ' Gardener's
Chronicle,' on April Tth, 18C0. The differences of Mr.



xviii HISTORICAL SKETCH.

Matthew's view from mine are not of much importance:
he seems to consider that the world was nearly de-
populated at successive periods, and then re-stocked;
and he gives as an alternative, that new forms may he
generated '" without the presence of any mould or germ
of former aggregates." I am not sure that I understand
some passages; but it seems that he attributes much
influence to the direct action of the conditions of life.
He clearly saw, however, the full force of the principle
of natural selection.

The celebrated geologist and naturalist. Von Buch,
in his excellent ' Description Physique des Isles
Canaries ' (1836, p. 147), clearly expresses his belief
that varieties slowly become changed into permanent
species, which are no longer capable of intercrossing.

Eafinesque, in his ' New Flora of North America,'
published in 1836, wrote (p. 6) as follows: — "All
species might have been varieties once, and many va-
rieties are gradually becoming species by assuming con-
stant and peculiar characters; " but farther on (p. 18)
he adds, " except the original types or ancestors of the
genus."

In 1843-44 Professor Haldeman ('Boston Journal of
Nat. Hist. U. States,' vol. iv. p. 468) has ably given the
arguments for and against the hypothesis of the develop-
ment and modification of species: he seems to lean
towards the side of change.

The ' Vestiges of Creation ' appeared in 1844. In
the tenth and much improved edition (1853) the
anonymous author says (p. 155): — "The proposition
determined on after much consideration is, that the
several series of animated beings, from the simplest and
oldest up to the highest and most recent, are, under the



HISTORICAL SKETCH. xix

providence of God, the results, first, of an impulse which
has been imparted to the forms of life, advancing them,
in defini-te times, by generation, through grades of or-
ganisation terminating in the highest dicotyledons and
vertebrata, these grades being few in number, and gen-
erally marked by intervals of organic character, which
we find to be a practical difficulty in ascertaining affini-
ties; second, of another impulse connected with the
vital forces, tending, in the course of generations, to
modify organic structures in accordance with external
circumstances, as food, the nature of the habitat, and
the meteoric agencies, these being the ' adaptations ' of
the natural theologian." The author apparently be-
lieves that organisation progresses by sudden leaps, but
that the effects produced by the conditions of life are
gradual. He argues with much force on general grounds
that species are not immutable productions. But I can-
not see how the two supposed '' impulses " account in a
scientific sense for the numerous and beautiful co-
adaptations which we see throughout nature; I cannot
see that we thus gain any insight how, for instance, a
woodpecker has become adapted to its peculiar habits
of life. The work, from its powerful and brilliant style,
though displaying in the earlier editions little accurate
knowledge and a great want of scientific caution, imme-
diately had a very wide circulation. In my opinion it
has done excellent service in this country in calling at-
tention to the subject, in removing prejudice, and in
thus preparing the ground for the reception of analogous
views.

In 1846 the veteran geologist M. J. d'Omalius d'Hal-
loy published in an excellent though short paper (' Bul-
letins de I'Acad. Eoy. Bruxelles,' tom. xiii. p. 581)



XX HISTORICAL SKETCH.

his opinion that it is more probable that new species
have been produced by descent with modification than
that they have been separately created: the author first
promulgated this opinion in 1831.

Professor Owen, in 18-19 (' Nature of Limbs/ p. 86),
wrote as follows: — " The archetypal idea was manifested
in the flesh under diverse such modifications, upon this
planet, long prior to the existence of those animal
species that actually exemplify it. To what natural
laws or secondary causes the orderly succession and



Online LibraryCharles DarwinThe origin of species by means of natural selection : or the preservation of favored races in the struggle for life (Volume 1) → online text (page 1 of 28)