On the Origin of Species, by Charles Darwin potx

The Project Gutenberg EBook of On the Origin of Species, by Charles DarwinThis eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever.. You may cop

The Project Gutenberg EBook of On the Origin of Species, by Charles Darwin

This eBook is for the use of anyone anywhere at no cost and with

almost no restrictions whatsoever You may copy it, give it away or

re-use it under the terms of the Project Gutenberg License included

with this eBook or online at www.gutenberg.org

Title: On the Origin of Species

6th Edition

Author: Charles Darwin

Release Date: November 23, 2009 [EBook

#2009]

Language: English

*** START OF THIS PROJECT GUTENBERG EBOOK

ON THE ORIGIN OF SPECIES ***

Produced by Sue Asscher, and David Widger

THE ORIGIN OF SPECIES BY MEANS OF

NATURAL SELECTION;

OR

By Charles Darwin,

M.A., F.R.S.,

Author of "The Descent of Man," etc.,

etc.

Sixth London Edition, with

all Additions and

Corrections.

can at least go so far as this—we canperceive that events are brought about not

by insulated interpositions of Divinepower, 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 orSETTLED; since what is natural as muchrequires and presupposes an intelligentagent to render it so, i.e., to effect itcontinually or at stated times, as what issupernatural or miraculous does to effect

it for once."—Butler: "Analogy ofRevealed Religion"

"To conclude, therefore, let no man out of

a weak conceit of sobriety, or an applied moderation, think or maintain, that

ill-a mill-an cill-an seill-arch too fill-ar or be too wellstudied in the book of God's word, or inthe book of God's works; divinity orphilosophy; but rather let men endeavour

an endless progress or proficience inboth."—Bacon: "Advancement ofLearning"

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 theprogress of opinion on the Origin ofSpecies Until recently the great majority

of naturalists believed that species wereimmutable productions, and had beenseparately created This view has beenably maintained by many authors Somefew naturalists, on the other hand, havebelieved that species undergomodification, and that the existing forms oflife are the descendants by true generation

of pre existing forms Passing overallusions to the subject in the classicalwriters (Aristotle, in his "PhysicaeAuscultationes" (lib.2, cap.8, s.2), afterremarking that rain does not fall in order

to make the corn grow, any more than itfalls to spoil the farmer's corn whenthreshed out of doors, applies the same

argument to organisation; and adds (astranslated by Mr Clair Grece, who firstpointed out the passage to me), "So whathinders the different parts (of the body)from having this merely accidentalrelation in nature? as the teeth, forexample, grow by necessity, the front onessharp, adapted for dividing, and thegrinders flat, and serviceable formasticating the food; since they were notmade for the sake of this, but it was theresult of accident And in like manner as

to other parts in which there appears toexist 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 thesake of something, these were preserved,having been appropriately constituted by

an internal spontaneity; and whatsoeverthings were not thus constituted, perishedand still perish." We here see theprinciple of natural selection shadowedforth, but how little Aristotle fullycomprehended the principle, is shown byhis remarks on the formation of the teeth.),the first author who in modern times hastreated it in a scientific spirit was Buffon.But as his opinions fluctuated greatly atdifferent periods, and as he does not enter

on the causes or means of thetransformation of species, I need not hereenter on details

Lamarck was the first man whoseconclusions on the subject excited muchattention This justly celebrated naturalistfirst published his views in 1801; he much

enlarged them in 1809 in his "PhilosophieZoologique", and subsequently, 1815, inthe Introduction to his "Hist Nat desAnimaux sans Vertebres" In these works

he up holds the doctrine that all species,including man, are descended from otherspecies He first did the eminent service

of arousing attention to the probability ofall change in the organic, as well as in theinorganic world, being the result of law,and not of miraculous interposition.Lamarck seems to have been chiefly led tohis conclusion on the gradual change ofspecies, by the difficulty of distinguishingspecies and varieties, by the almostperfect gradation of forms in certaingroups, and by the analogy of domesticproductions With respect to the means ofmodification, he attributed something to

the direct action of the physical conditions

of life, something to the crossing ofalready existing forms, and much to useand disuse, that is, to the effects of habit

To this latter agency he seems to attributeall the beautiful adaptations in nature; such

as the long neck of the giraffe forbrowsing on the branches of trees But helikewise believed in a law of progressivedevelopment, and as all the forms of lifethus tend to progress, in order to accountfor the existence at the present day ofsimple productions, he maintains that suchforms are now spontaneously generated (Ihave taken the date of the first publication

of Lamarck from Isidore Geoffroy Hilaire's ("Hist Nat Generale", tom ii.page 405, 1859) excellent history ofopinion on this subject In this work a full

Saint-account is given of Buffon's conclusions

on the same subject It is curious howlargely my grandfather, Dr ErasmusDarwin, anticipated the views anderroneous grounds of opinion of Lamarck

in his "Zoonomia" (vol i pages 500-510),published in 1794 According to Isid.Geoffroy there is no doubt that Goethewas an extreme partisan of similar views,

as shown in the introduction to a workwritten in 1794 and 1795, but notpublished till long afterward; he haspointedly remarked ("Goethe alsNaturforscher", von Dr Karl Meding, s.34) that the future question for naturalistswill be how, for instance, cattle got theirhorns and not for what they are used It israther a singular instance of the manner inwhich 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) inFrance, came to the same conclusion onthe origin of species, in the years 1794-5.)Geoffroy Saint-Hilaire, as is stated in his

"Life", written by his son, suspected, asearly as 1795, that what we call speciesare various degenerations of the sametype It was not until 1828 that hepublished his conviction that the sameforms have not been perpetuated since theorigin of all things Geoffroy seems tohave relied chiefly on the conditions oflife, or the "monde ambiant" as the cause

of change He was cautious in drawingconclusions, and did not believe thatexisting species are now undergoing

modification; and, as his son adds, "C'estdonc un probleme a reserver entierement al'avenir, suppose meme que l'avenir doiveavoir prise sur lui."

In 1813 Dr W.C Wells read before theRoyal Society "An Account of a WhiteFemale, part of whose skin resembles that

of a Negro"; but his paper was notpublished until his famous "Two Essaysupon Dew and Single Vision" appeared in

1818 In this paper he distinctlyrecognises the principle of naturalselection, and this is the first recognitionwhich has been indicated; but he applies itonly to the races of man, and to certaincharacters alone After remarking thatnegroes and mulattoes enjoy an immunityfrom certain tropical diseases, he

observes, firstly, that all animals tend tovary in some degree, and, secondly, thatagriculturists improve their domesticatedanimals 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 theformation of varieties of mankind, fittedfor the country which they inhabit Of theaccidental varieties of man, which wouldoccur among the first few and scatteredinhabitants of the middle regions ofAfrica, some one would be better fittedthan others to bear the diseases of thecountry This race would consequentlymultiply, while the others would decrease;not only from their in ability to sustain theattacks of disease, but from theirincapacity of contending with their more

vigorous neighbours The colour of thisvigorous race I take for granted, fromwhat has been already said, would bedark But the same disposition to formvarieties still existing, a darker and adarker race would in the course of timeoccur: and as the darkest would be thebest fitted for the climate, this would atlength become the most prevalent, if notthe only race, in the particular country inwhich it had originated." He then extendsthese same views to the white inhabitants

of colder climates I am indebted to Mr.Rowley, of the United States, for havingcalled my attention, through Mr Brace, tothe above passage of Dr Wells' work.The Hon and Rev W Herbert, afterwardDean 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 haveestablished, beyond the possibility ofrefutation, that botanical species are only

a higher and more permanent class ofvarieties." He extends the same view toanimals The dean believes that singlespecies of each genus were created in anoriginally highly plastic condition, andthat these have produced, chiefly by inter-crossing, but likewise by variation, all ourexisting species

In 1826 Professor Grant, in the concludingparagraph in his well-known paper("Edinburgh Philosophical Journal", vol.XIV, page 283) on the Spongilla, clearly

declares his belief that species aredescended from other species, and thatthey become improved in the course ofmodification This same view was given

in his Fifty-fifth Lecture, published in the

"Lancet" in 1834

In 1831 Mr Patrick Matthew publishedhis work on "Naval Timber andArboriculture", in which he givesprecisely the same view on the origin ofspecies as that (presently to be alluded to)propounded by Mr Wallace and myself inthe "Linnean Journal", and as that enlarged

in the present volume Unfortunately theview was given by Mr Matthew verybriefly in scattered passages in anappendix 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 viewsfrom mine are not of much importance: heseems to consider that the world wasnearly depopulated at successive periods,and then restocked; and he gives as analternative, that new forms may begenerated "without the presence of anymold or germ of former aggregates." I amnot sure that I understand some passages;but it seems that he attributes muchinfluence to the direct action of theconditions of life He clearly saw,however, the full force of the principle ofnatural selection

The celebrated geologist and naturalist,Von Buch, in his excellent "Description

Physique des Isles Canaries" (1836, page147), clearly expresses his belief thatvarieties slowly become changed intopermanent species, which are no longercapable of intercrossing.

Rafinesque, in his "New Flora of NorthAmerica", published in 1836, wrote (page6) as follows: "All species might havebeen varieties once, and many varietiesare gradually becoming species byassuming constant and peculiarcharacters;" but further on (page 18) headds, "except the original types orancestors of the genus."

In 1843-44 Professor Haldeman ("BostonJournal of Nat Hist U States", vol iv,page 468) has ably given the argumentsfor and against the hypothesis of the

development and modification of species:

he seems to lean toward the side ofchange

The "Vestiges of Creation" appeared in

1844 In the tenth and much improvededition (1853) the anonymous author says(page 155): "The proposition determined

on after much consideration is, that theseveral series of animated beings, fromthe simplest and oldest up to the highestand most recent, are, under the providence

of God, the results, FIRST, of an impulsewhich has been imparted to the forms oflife, advancing them, in definite times, bygeneration, through grades of organisationterminating in the highest dicotyledons andvertebrata, these grades being few innumber, and generally marked by intervals

of organic character, which we find to be

a practical difficulty in ascertainingaffinities; SECOND, of another impulseconnected with the vital forces, tending, inthe course of generations, to modifyorganic structures in accordance withexternal circumstances, as food, the nature

of the habitat, and the meteoric agencies,these being the 'adaptations' of the naturaltheologian." The author apparentlybelieves that organisation progresses bysudden leaps, but that the effects produced

by the conditions of life are gradual Heargues with much force on generalgrounds that species are not immutableproductions But I cannot see how the twosupposed "impulses" account in ascientific sense for the numerous andbeautiful coadaptations which we see

throughout nature; I cannot see that we thusgain any insight how, for instance, awoodpecker has become adapted to itspeculiar habits of life The work, from itspowerful and brilliant style, thoughdisplaying in the early editions littleaccurate knowledge and a great want ofscientific caution, immediately had a verywide circulation In my opinion it hasdone excellent service in this country incalling attention to the subject, inremoving prejudice, and in thus preparingthe ground for the reception of analogousviews.

In 1846 the veteran geologist M.J.d'Omalius d'Halloy published in anexcellent though short paper ("Bulletins del'Acad Roy Bruxelles", tom xiii, page

581) his opinion that it is more probablethat new species have been produced bydescent with modification than that theyhave been separately created: the authorfirst promulgated this opinion in 1831.Professor Owen, in 1849 ("Nature ofLimbs", page 86), wrote as follows: "Thearchetypal idea was manifested in theflesh under diverse such modifications,upon this planet, long prior to theexistence of those animal species thatactually exemplify it To what naturallaws or secondary causes the orderlysuccession and progression of suchorganic phenomena may have beencommitted, we, as yet, are ignorant." In hisaddress to the British Association, in

1858, he speaks (page li) of "the axiom of

the continuous operation of creativepower, or of the ordained becoming ofliving things." Further on (page xc), afterreferring to geographical distribution, headds, "These phenomena shake ourconfidence in the conclusion that theApteryx of New Zealand and the RedGrouse of England were distinct creations

in and for those islands respectively.Always, also, it may be well to bear inmind that by the word 'creation' thezoologist means 'a process he knows notwhat.'" He amplifies this idea by addingthat when such cases as that of the RedGrouse are "enumerated by the zoologist

as evidence of distinct creation of the bird

in and for such islands, he chieflyexpresses that he knows not how the RedGrouse came to be there, and there

exclusively; signifying also, by this mode

of expressing such ignorance, his beliefthat both the bird and the islands owedtheir origin to a great first CreativeCause." If we interpret these sentencesgiven in the same address, one by theother, it appears that this eminentphilosopher felt in 1858 his confidenceshaken that the Apteryx and the RedGrouse first appeared in their respectivehomes "he knew not how," or by someprocess "he knew not what."

This address was delivered after thepapers by Mr Wallace and myself on theOrigin of Species, presently to be referred

to, had been read before the LinneanSociety When the first edition of thiswork was published, I was so completely

deceived, as were many others, by suchexpressions as "the continuous operation

of creative power," that I includedProfessor Owen with otherpalaeontologists as being firmlyconvinced of the immutability of species;but it appears ("Anat of Vertebrates", vol.iii, page 796) that this was on my part apreposterous error In the last edition ofthis work I inferred, and the inference stillseems to me perfectly just, from a passagebeginning with the words "no doubt thetype-form," etc.(Ibid., vol i, page xxxv),that Professor Owen admitted that naturalselection may have done something in theformation of a new species; but this itappears (Ibid., vol iii page 798) isinaccurate and without evidence I alsogave some extracts from a correspondence

between Professor Owen and the editor ofthe "London Review", from which itappeared manifest to the editor as well as

to myself, that Professor Owen claimed tohave promulgated the theory of naturalselection before I had done so; and Iexpressed my surprise and satisfaction atthis announcement; but as far as it ispossible to understand certain recentlypublished passages (Ibid., vol iii page798) I have either partially or whollyagain fallen into error It is consolatory to

me that others find Professor Owen'scontroversial writings as difficult tounderstand and to reconcile with eachother, as I do As far as the mereenunciation of the principle of naturalselection is concerned, it is quiteimmaterial whether or not Professor

Owen preceded me, for both of us, asshown in this historical sketch, were longago preceded by Dr Wells and Mr.Matthews.

M Isidore Geoffroy Saint-Hilaire, in hislectures delivered in 1850 (of which aResume appeared in the "Revue et Mag

de Zoolog.", Jan., 1851), briefly gives hisreason for believing that specificcharacters "sont fixes, pour chaqueespece, tant qu'elle se perpetue au milieudes memes circonstances: ils se modifient,

si les circonstances ambiantes viennent achanger En resume, L'OBSERVATIONdes animaux sauvages demontre deja lavariabilite LIMITEE des especes LesEXPERIENCES sur les animaux sauvagesdevenus domestiques, et sur les animaux

domestiques redevenus sauvages, lademontrent plus clairment encore Cesmemes experiences prouvent, de plus, queles differences produites peuvent etre deVALEUR GENERIQUE." In his "Hist.Nat Generale" (tom ii, page 430, 1859)

he amplifies analogous conclusions

From a circular lately issued it appearsthat Dr Freke, in 1851 ("Dublin MedicalPress", page 322), propounded thedoctrine that all organic beings havedescended from one primordial form Hisgrounds of belief and treatment of thesubject are wholly different from mine;but as Dr Freke has now (1861)published his Essay on the "Origin ofSpecies by means of Organic Affinity", thedifficult 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 thetheories of the Creation and theDevelopment of organic beings withremarkable skill and force He arguesfrom the analogy of domestic productions,from the changes which the embryos ofmany species undergo, from the difficulty

of distinguishing species and varieties,and from the principle of generalgradation, that species have beenmodified; and he attributes themodification to the change ofcircumstances The author (1855) has alsotreated Psychology on the principle of the

necessary acquirement of each mentalpower and capacity by gradation.

In 1852 M Naudin, a distinguishedbotanist, expressly stated, in an admirablepaper on the Origin of Species ("RevueHorticole", page 102; since partlyrepublished in the "Nouvelles Archives duMuseum", tom i, page 171), his belief thatspecies are formed in an analogousmanner as varieties are under cultivation;and the latter process he attributes toman's power of selection But he does notshow how selection acts under nature Hebelieves, like Dean Herbert, that species,when nascent, were more plastic than atpresent He lays weight on what he callsthe principle of finality, "puissancemysterieuse, indeterminee; fatalite pour

les uns; pour les autres volonteprovidentielle, dont l'action incessante surles etres vivantes determine, a toutes lesepoques de l'existence du monde, laforme, le volume, et la duree de chacund'eux, en raison de sa destinee dansl'ordre de choses dont il fait partie C'estcette puissance qui harmonise chaquemembre a l'ensemble, en l'appropriant a lafonction qu'il doit remplir dansl'organisme general de la nature, fonctionqui est pour lui sa raison d'etre." (Fromreferences in Bronn's "Untersuchungenuber die Entwickelungs-Gesetze", itappears that the celebrated botanist andpalaeontologist Unger published, in 1852,his belief that species undergodevelopment and modification Dalton,likewise, in Pander and Dalton's work on

Fossil Sloths, expressed, in 1821, asimilar belief Similar views have, as iswell known, been maintained by Oken inhis mystical "Natur-Philosophie" Fromother references in Godron's work "Surl'Espece", it seems that Bory St Vincent,Burdach, Poiret and Fries, have alladmitted that new species are continuallybeing produced I may add, that of thethirty-four authors named in this HistoricalSketch, who believe in the modification ofspecies, or at least disbelieve in separateacts of creation, twenty-seven havewritten on special branches of naturalhistory or geology.)

In 1853 a celebrated geologist, CountKeyserling ("Bulletin de la Soc Geolog.",2nd Ser., tom x, page 357), suggested that

as new diseases, supposed to have beencaused by some miasma have arisen andspread over the world, so at certainperiods the germs of existing species mayhave been chemically affected bycircumambient molecules of a particularnature, and thus have given rise to newforms.

In this same year, 1853, Dr Schaaffhausenpublished an excellent pamphlet("Verhand des Naturhist Vereins derPreuss Rheinlands", etc.), in which hemaintains the development of organicforms on the earth He infers that manyspecies have kept true for long periods,whereas a few have become modified.The distinction of species he explains bythe destruction of intermediate graduated

forms "Thus living plants and animals arenot separated from the extinct by newcreations, but are to be regarded as theirdescendants through continuedreproduction."

A well-known French botanist, M Lecoq,writes in 1854 ("Etudes sur Geograph."Bot tom i, page 250), "On voit que nosrecherches sur la fixite ou la variation del'espece, nous conduisent directement auxidees emises par deux hommes justementcelebres, Geoffroy Saint-Hilaire etGoethe." Some other passages scatteredthrough M Lecoq's large work make it alittle doubtful how far he extends hisviews on the modification of species.The "Philosophy of Creation" has beentreated in a masterly manner by the Rev