Charles Darwin On the Origin of Species

On the Origin of Species, 6th Edition
Darwin, Charles

---

An Historical Sketch Of The Progress Of Opinion On The Origin Of
Species, Previously To The Publication 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
subject in the classical writers (Aristotle, in his "Physicae Auscultationes" (lib.2,
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 were not made for
the sake of this, but it was the result of accident. And in like manner as to other parts
in which there appears to exist an adaptation to an end. Wheresoever, therefore, all
things together (that is all the parts of one whole) happened like as if they were
made for the sake of something, these were preserved, having been appropriately
constituted by an internal spontaneity; and whatsoever things were not thus
constituted, perished and still perish." We here see the principle of natural selection
shadowed forth, but how little Aristotle fully comprehended the principle, is shown
by his remarks on the formation of the teeth.), the first author who in modern times
has treated it in a scientific spirit was Buffon. But as his opinions fluctuated greatly
at different periods, and as he does not enter on the causes or means of the
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, 1815, in
the Introduction to his "Hist. Nat. des Animaux sans Vertebres". In these works he
up holds the doctrine that all species, including man, are descended from other
species. He first did the eminent service of arousing attention to the probability of all
change in the organic, as well as in the inorganic world, being the result of law, and
not of miraculous interposition. Lamarck 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 productions. 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 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 existence at the present day of simple productions, he maintains that such
forms are now spontaneously generated. (I have taken the date of the first
publication of Lamarck from Isidore Geoffroy Saint-Hilaire's ("Hist. Nat. Generale",

---

Geoffroy 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 1828 that he published his conviction that the same forms have not
been perpetuated since the origin of all things. Geoffroy seems to have relied chiefly
on the conditions of life, or the "monde ambiant" 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 donc un probleme a reserver
entierement a l'avenir, suppose meme que l'avenir doive avoir prise sur lui."

---

In 1813 Dr. W.C. Wells read before the Royal 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 Essays 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
indicated; but he applies it only to the races of man, and to certain characters alone. After
remarking that negroes and mulattoes enjoy an immunity from certain tropical diseases, he
observes, firstly, that all animals tend to vary in some degree, and, secondly, that
agriculturists improve their domesticated animals by selection; 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 inhabitants
of the middle regions of Africa, some one would be better fitted than others to bear the
diseases of the country. This race would consequently multiply, while the others would
decrease; not only from their in ability to sustain the attacks of disease, but from their
incapacity of contending with their more vigorous neighbours. 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 occur:
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 climates. I am indebted to Mr.
Rowley, of the United States, for having called my attention, through Mr. Brace, to the above
passage of Dr. Wells' work.
The Hon. and Rev. W. Herbert, afterward Dean of Manchester, in the fourth
volume of the "Horticultural Transactions", 1822, and in his work on the
"Amaryllidaceae" (1837, pages 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
inter-crossing, but likewise by variation, all our existing species.
In 1826 Professor Grant, in the concluding paragraph in his well-known paper
("Edinburgh Philosophical Journal", vol. XIV, page 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
Fifty-fifth 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
enlarged 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 different subject, so that it
remained unnoticed until Mr. Matthew himself drew attention to it in the "Gardeners'
Chronicle", on April 7, 1860. The differences of Mr. Matthew's views from mine are not of
much importance: he seems to consider that the world was nearly depopulated at
successive periods, and then restocked; and he gives as an alternative, that new forms
may be generated "without the presence of any mold 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, page 147), clearly expresses his belief that
varieties slowly become changed into permanent species, which are no longer
capable of intercrossing.
Rafinesque, in his "New Flora of North America", published in 1836, wrote (page 6)
as follows: "All species might have been varieties once, and many varieties are
gradually becoming species by assuming constant and peculiar characters;" but
further on (page 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,
page 468) has ably given the arguments for and against the hypothesis of the
development and modification of species: he seems to lean toward the side of
change.
The "Vestiges of Creation" appeared in 1844. In the tenth and much improved
edition (1853) the anonymous author says (page 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 providence of
God, the results, FIRST, of an impulse which has been imparted to the forms of life,
advancing them, in definite times, by generation, through grades of organisation
terminating in the highest dicotyledons and vertebrata, these grades being few in
number, and generally marked by intervals of organic character, which we find to be
a practical difficulty in ascertaining affinities; 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 believes 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 cannot see how the two supposed "impulses" account in a
scientific sense for the numerous and beautiful coadaptations 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 early editions little accurate
knowledge and a great want of scientific caution, immediately had a very wide
circulation. In my opinion it has done excellent service in this country in calling
attention 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'Halloy published in an excellent
though short paper ("Bulletins de l'Acad. Roy. Bruxelles", tom. xiii, page 581) 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 1849 ("Nature of Limbs", page 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
progression of such organic phenomena may have been committed, we, as yet, are
ignorant." In his address to the British Association, in 1858, he speaks (page li) of
"the axiom of the continuous operation of creative power, or of the ordained
becoming of living things." Further on (page xc), after referring to geo-graphical
distribution, he adds, "These phenomena shake our confidence in the conclusion
that the Apteryx of New Zealand and the Red Grouse of England were distinct
creations in and for those islands respectively. Always, also, it may be well to bear
in mind that by the word 'creation' the zoologist means 'a process he knows not
what.'" He amplifies this idea by adding that when such cases as that of the Red
Grouse are "enumerated by the zoologist as evidence of distinct creation of the bird
in and for such islands, he chiefly expresses that he knows not how the Red Grouse
came to be there, and there exclusively; signifying also, by this mode of expressing
such ignorance, his belief that both the bird and the islands owed their origin to a
great first Creative Cause." If we interpret these sentences given in the same
address, one by the other, it appears that this eminent philosopher felt in 1858 his
confidence shaken that the Apteryx and the Red Grouse first appeared in their
respective homes "he knew not how," or by some process "he knew not what."

---

This address was delivered after the papers by Mr. Wallace and myself on the
Origin of Species, presently to be referred to, had been read before the Linnean
Society. When the first edition of this work was published, I was so completely
deceived, as were many others, by such expressions as "the continuous operation
of creative power," that I included Professor Owen with other palaeontologists as
being firmly convinced of the immutability of species; but it appears ("Anat. of
Vertebrates", vol. iii, page 796) that this was on my part a preposterous error. In the
last edition of this work I inferred, and the inference still seems to me perfectly just,
from a passage beginning with the words "no doubt the type-form," etc.(Ibid., vol. i,
page xxxv), that Professor Owen admitted that natural selection may have done
something in the formation of a new species; but this it appears (Ibid., vol. iii. page
798) is inaccurate and without evidence. I also gave some extracts from a
correspondence between Professor Owen and the editor of the "London Review",
from which it appeared manifest to the editor as well as to myself, that Professor
Owen claimed to have promulgated the theory of natural selection before I had
done so; and I expressed my surprise and satisfaction at this announcement; but as
far as it is possible to understand certain recently published passages (Ibid., vol. iii.
page 798) I have either partially or wholly again fallen into error. It is consolatory to
me that others find Professor Owen's controversial writings as difficult to
understand and to reconcile with each other, as I do. As far as the mere enunciation
of the principle of natural selection is concerned, it is quite immaterial whether or not
Professor Owen preceded me, for both of us, as shown in this historical sketch,
were long ago preceded by Dr. Wells and Mr. Matthews.
M. Isidore Geoffroy Saint-Hilaire, in his lectures delivered in 1850 (of which a
Resume appeared in the "Revue et Mag. de Zoolog.", Jan., 1851), briefly gives his
reason for believing that specific characters "sont fixes, pour chaque espece, tant
qu'elle se perpetue au milieu des memes circonstances: ils se modifient, si les
circonstances ambiantes viennent a changer. En resume, L'OBSERVATION des
animaux sauvages demontre deja la variabilite LIMITEE des especes. Les
EXPERIENCES sur les animaux sauvages devenus domestiques, et sur les
animaux domestiques redevenus sauvages, la demontrent plus clairment encore.
Ces memes experiences prouvent, de plus, que les differences produites peuvent
etre de VALEUR GENERIQUE." In his "Hist. Nat. Generale" (tom. ii, page 430,
1859) he amplifies analogous conclusions.

---

From a circular lately issued it appears that Dr. Freke, in 1851 ("Dublin Medical
Press", page 322), propounded the doctrine that all organic beings have descended
from one primordial form. His grounds of belief and treatment of the subject are wholly
different from mine; but as Dr. Freke has now (1861) published his Essay on the
"Origin of Species by means of Organic Affinity", the difficult attempt to give any idea of
his views would be superfluous on my part.
Mr. Herbert Spencer, in an Essay (originally published in the "Leader", March,
1852, and republished in his "Essays", in 1858), has contrasted the theories of the
Creation and the Development of organic beings with remarkable skill and force. He
argues from the analogy of domestic productions, from the changes which the
embryos of many species undergo, from the difficulty of distinguishing species and
varieties, and from the principle of general gradation, that species have been
modified; and he attributes the modification to the change of circumstances. The
author (1855) has also treated Psychology on the principle of the necessary
acquirement of each mental power and capacity by gradation.
In 1852 M. Naudin, a distinguished botanist, expressly stated, in an admirable
paper on the Origin of Species ("Revue Horticole", page 102; since partly
republished in the "Nouvelles Archives du Museum", tom. i, page 171), his belief
that species are formed in an analogous manner as varieties are under cultivation;
and the latter process he attributes to man's power of selection. But he does not
show how selection acts under nature. He believes, like Dean Herbert, that species,
when nascent, were more plastic than at present. He lays weight on what he calls
the principle of finality, "puissance mysterieuse, indeterminee; fatalite pour les uns;
pour les autres volonte providentielle, dont l'action incessante sur les etres vivantes
determine, a toutes les epoques de l'existence du monde, la forme, le volume, et la
duree de chacun d'eux, en raison de sa destinee dans l'ordre de choses dont il fait
partie. C'est cette puissance qui harmonise chaque membre a l'ensemble, en
l'appropriant a la fonction qu'il doit remplir dans l'organisme general de la nature,
fonction qui est pour lui sa raison d'etre." (From references in Bronn's
"Untersuchungen uber die Entwickelungs-Gesetze", it appears that the celebrated
botanist and palaeontologist Unger published, in 1852, his belief that species
undergo development and modification. Dalton, likewise, in Pander and Dalton's
work on Fossil Sloths, expressed, in 1821, a similar belief. Similar views have, as is
well known, been maintained by Oken in his mystical "Natur-Philosophie". From
other references in Godron's work "Sur l'Espece", it seems that Bory St. Vincent,
Burdach, Poiret and Fries, have all admitted that new species are continually being
produced. I may add, that of the thirty-four authors named in this Historical Sketch,
who believe in the modification of species, or at least disbelieve in separate acts of
creation, twenty-seven have written on special branches of natural history or
geology.)

---

In 1853 a celebrated geologist, Count Keyserling ("Bulletin de la Soc. Geolog.", 2nd
Ser., tom. x, page 357), suggested that as new diseases, supposed to have been caused
by some miasma have arisen and spread over the world, so at certain periods the germs
of existing species may have been chemically affected by circumambient molecules of a
particular nature, and thus have given rise to new forms.
In this same year, 1853, Dr. Schaaffhausen published an excellent pamphlet ("Verhand.
des Naturhist. Vereins der Preuss. Rheinlands", etc.), in which he maintains the
development of organic forms on the earth. He infers that many species have kept true for
long periods, whereas a few have become modified. The distinction of species he explains
by the destruction of intermediate graduated forms. "Thus living plants and animals are
not separated from the extinct by new creations, but are to be regarded as their
descendants through continued reproduction."
A well-known French botanist, M. Lecoq, writes in 1854 ("Etudes sur Geograph. Bot.
tom. i, page 250), "On voit que nos recherches sur la fixite ou la variation de l'espece,
nous conduisent directement aux idees emises par deux hommes justement celebres,
Geoffroy Saint-Hilaire et Goethe." Some other passages scattered through M. Lecoq's
large work make it a little doubtful how far he extends his views on the modification of
species.
The "Philosophy of Creation" has been treated in a masterly manner by the Rev.
Baden Powell, in his "Essays on the Unity of Worlds", 1855. Nothing can be more
striking than the manner in which he shows that the introduction of new species is "a
regular, not a casual phenomenon," or, as Sir John Herschel expresses it, "a natural
in contradistinction to a miraculous process."

---

The third volume of the "Journal of the Linnean Society" contains papers, read
July 1, 1858, by Mr. Wallace and myself, in which, as stated in the introductory
remarks to this volume, the theory of Natural Selection is promulgated by Mr.
Wallace with admirable force and clearness.
Von Baer, toward whom all zoologists feel so profound a respect, expressed about the
year 1859 (see Prof. Rudolph Wagner, "Zoologisch-Anthropologische Untersuchungen",
1861, s. 51) his conviction, chiefly grounded on the laws of geographical distribution, that
forms now perfectly distinct have descended from a single parent-form.
In June, 1859, Professor Huxley gave a lecture before the Royal Institution on the
"Persistent Types of Animal Life". Referring to such cases, he remarks, "It is difficult to
comprehend the meaning of such facts as these, if we suppose that each species of
animal and plant, or each great type of organisation, was formed and placed upon the
surface of the globe at long intervals by a distinct act of creative power; and it is well to
recollect that such an assumption is as unsupported by tradition or revelation as it is
opposed to the general analogy of nature. If, on the other hand, we view "Persistent
Types" in relation to that hypothesis which supposes the species living at any time to be
the result of the gradual modification of pre-existing species, a hypothesis which, though
unproven, and sadly damaged by some of its supporters, is yet the only one to which
physiology lends any countenance; their existence would seem to show that the amount of
modification which living beings have undergone during geological time is but very small in
relation to the whole series of changes which they have suffered."
In December, 1859, Dr. Hooker published his "Introduction to the Australian
Flora". In the first part of this great work he admits the truth of the descent and
modification of species, and supports this doctrine by many original observations.
The first edition of this work was published on November 24, 1859, and the
second edition on January 7, 1860.

---