Preface
AN HISTORICAL SKETCHOF 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 ofSpecies. Until recently the great majority of naturalists believed thatspecies were immutable productions, and had been separately created. Thisview has been ably maintained by many authors. Some few naturalists, onthe other hand, have believed that species undergo modification, and thatthe existing forms of life are the descendants by true generation of preexisting forms. Passing over allusions to the subject in the classicalwriters (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, anymore 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 thedifferent parts (of the body) from having this merely accidental relationin nature? as the teeth, for example, grow by necessity, the front onessharp, adapted for dividing, and the grinders flat, and serviceable formasticating the food; since they were not made for the sake of this, but itwas the result of accident. And in like manner as to other parts in whichthere appears to exist an adaptation to an end. Wheresoever, therefore,all things together (that is all the parts of one whole) happened like asif they were made for the sake of something, these were preserved, havingbeen appropriately constituted by an internal spontaneity; and whatsoeverthings were not thus constituted, perished and still perish." We here seethe principle of natural selection shadowed forth, but how little Aristotlefully comprehended the principle, is shown by his remarks on the formationof the teeth.), the first author who in modern times has treated it in ascientific 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 here enter on details.
Lamarck was the first man whose conclusions on the subject excited muchattention. This justly celebrated naturalist first published his views in1801; he much enlarged them in 1809 in his "Philosophie Zoologique", andsubsequently, 1815, in the Introduction to his "Hist. Nat. des Animaux sansVertebres". In these works he up holds the doctrine that all species,including man, are descended from other species. He first did the eminentservice of arousing attention to the probability of all change in theorganic, as well as in the inorganic world, being the result of law, andnot of miraculous interposition. Lamarck seems to have been chiefly led tohis conclusion on the gradual change of species, by the difficulty ofdistinguishing species and varieties, by the almost perfect gradation offorms in certain groups, and by the analogy of domestic productions. Withrespect to the means of modification, he attributed something to the directaction of the physical conditions of life, something to the crossing ofalready existing forms, and much to use and disuse, that is, to the effectsof habit. To this latter agency he seems to attribute all the beautifuladaptations in nature; such as the long neck of the giraffe for browsing onthe branches of trees. But he likewise believed in a law of progressivedevelopment, and as all the forms of life thus tend to progress, in orderto account for the existence at the present day of simple productions, hemaintains that such forms are now spontaneously generated. (I have takenthe date of the first publication of Lamarck from Isidore Geoffroy Saint-Hilaire's ("Hist. Nat. Generale", tom. ii. page 405, 1859) excellenthistory of opinion on this subject. In this work a full account is givenof Buffon's conclusions on the same subject. It is curious how largely mygrandfather, Dr. Erasmus Darwin, anticipated the views and erroneousgrounds of opinion of Lamarck in his "Zoonomia" (vol. i. pages 500-510),published in 1794. According to Isid. Geoffroy there is no doubt thatGoethe was an extreme partisan of similar views, as shown in theintroduction to a work written in 1794 and 1795, but not published tilllong afterward; he has pointedly remarked ("Goethe als Naturforscher", vonDr. Karl Meding, s. 34) that the future question for naturalists will behow, 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 ariseat about the same time, that Goethe in Germany, Dr. Darwin in England, andGeoffroy Saint-Hilaire (as we shall immediately see) in France, came to thesame conclusion on the origin of species, in the years 1794-5.)
Geoffroy Saint-Hilaire, as is stated in his "Life", written by his son,suspected, as early as 1795, that what we call species are variousdegenerations of the same type. It was not until 1828 that he publishedhis conviction that the same forms have not been perpetuated since theorigin of all things. Geoffroy seems to have relied chiefly on theconditions of life, or the "monde ambiant" as the cause of change. He wascautious in drawing conclusions, and did not believe that existing speciesare now undergoing modification; and, as his son adds, "C'est donc unprobleme a reserver entierement a l'avenir, suppose meme que l'avenir doiveavoir prise sur lui."
In 1813 Dr. W.C. Wells read before the Royal Society "An Account of a WhiteFemale, part of whose skin resembles that of a Negro"; but his paper wasnot published until his famous "Two Essays upon Dew and Single Vision"appeared in 1818. In this paper he distinctly recognises the principle ofnatural selection, and this is the first recognition which has beenindicated; but he applies it only to the races of man, and to certaincharacters alone. After remarking that negroes and mulattoes enjoy animmunity from certain tropical diseases, he observes, firstly, that allanimals tend to vary in some degree, and, secondly, that agriculturistsimprove their domesticated animals by selection; and then, he adds, butwhat is done in this latter case "by art, seems to be done with equalefficacy, though more slowly, by nature, in the formation of varieties ofmankind, fitted for the country which they inhabit. Of the accidentalvarieties of man, which would occur among the first few and scatteredinhabitants of the middle regions of Africa, some one would be betterfitted than others to bear the diseases of the country. This race wouldconsequently multiply, while the others would decrease; not only from theirin ability to sustain the attacks of disease, but from their incapacity ofcontending with their more vigorous neighbours. The colour of thisvigorous race I take for granted, from what has been already said, would bedark. But the same disposition to form varieties still existing, a darkerand a darker race would in the course of time occur: and as the darkestwould be the best fitted for the climate, this would at length become themost prevalent, if not the only race, in the particular country in which ithad originated." He then extends these same views to the white inhabitantsof colder climates. I am indebted to Mr. Rowley, of the United States, forhaving 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 fourthvolume of the "Horticultural Transactions", 1822, and in his work on the"Amaryllidaceae" (1837, pages 19, 339), declares that "horticulturalexperiments have established, beyond the possibility of refutation, thatbotanical species are only a higher and more permanent class of varieties." He extends the same view to animals. The dean believes that single speciesof each genus were created in an originally highly plastic condition, andthat these have produced, chiefly by inter-crossing, but likewise byvariation, all our existing species.
In 1826 Professor Grant, in the concluding paragraph in his well-knownpaper ("Edinburgh Philosophical Journal", vol. XIV, page 283) on theSpongilla, clearly declares his belief that species are descended fromother 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 andArboriculture", in which he gives precisely the same view on the origin ofspecies as that (presently to be alluded to) propounded by Mr. Wallace andmyself in the "Linnean Journal", and as that enlarged in the presentvolume. Unfortunately the view was given by Mr. Matthew very briefly inscattered passages in an appendix to a work on a different subject, so thatit remained unnoticed until Mr. Matthew himself drew attention to it in the"Gardeners' Chronicle", on April 7, 1860. The differences of Mr. Matthew'sviews from mine are not of much importance: he seems to consider that theworld was nearly depopulated at successive periods, and then restocked; andhe gives as an alternative, that new forms may be generated "without thepresence of any mold or germ of former aggregates." I am not sure that Iunderstand some passages; but it seems that he attributes much influence tothe direct action of the conditions of life. He clearly saw, however, thefull 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), clearlyexpresses his belief that varieties slowly become changed into permanentspecies, 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 manyvarieties are gradually becoming species by assuming constant and peculiarcharacters;" but further on (page 18) he adds, "except the original typesor 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 thehypothesis of the development and modification of species: he seems tolean toward the side of change.
The "Vestiges of Creation" appeared in 1844. In the tenth and muchimproved edition (1853) the anonymous author says (page 155): "Theproposition determined on after much consideration is, that the severalseries of animated beings, from the simplest and oldest up to the highestand most recent, are, under the providence of God, the results, FIRST, ofan impulse which has been imparted to the forms of life, advancing them, indefinite times, by generation, through grades of organisation terminatingin the highest dicotyledons and vertebrata, these grades being few innumber, and generally marked by intervals of organic character, which wefind to be a practical difficulty in ascertaining affinities; SECOND, ofanother impulse connected with the vital forces, tending, in the course ofgenerations, to modify organic structures in accordance with externalcircumstances, as food, the nature of the habitat, and the meteoricagencies, these being the 'adaptations' of the natural theologian." Theauthor apparently believes that organisation progresses by sudden leaps,but that the effects produced by the conditions of life are gradual. Heargues with much force on general grounds that species are not immutableproductions. But I cannot see how the two supposed "impulses" account in ascientific sense for the numerous and beautiful coadaptations which we seethroughout nature; I cannot see that we thus gain any insight how, forinstance, a woodpecker has become adapted to its peculiar habits of life. The work, from its powerful and brilliant style, though displaying in theearly editions little accurate knowledge and a great want of scientificcaution, immediately had a very wide circulation. In my opinion it hasdone excellent service in this country in calling attention to the subject,in removing prejudice, and in thus preparing the ground for the receptionof analogous views.
In 1846 the veteran geologist M.J. d'Omalius d'Halloy published in anexcellent though short paper ("Bulletins de l'Acad. Roy. Bruxelles", tom.xiii, page 581) his opinion that it is more probable that new species havebeen produced by descent with modification than that they have beenseparately 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 suchmodifications, upon this planet, long prior to the existence of thoseanimal species that actually exemplify it. To what natural laws orsecondary causes the orderly succession and progression of such organicphenomena may have been committed, we, as yet, are ignorant." In hisaddress to the British Association, in 1858, he speaks (page li) of "theaxiom of the continuous operation of creative power, or of the ordainedbecoming of living things." Further on (page xc), after referring togeographical distribution, he adds, "These phenomena shake our confidencein the conclusion that the Apteryx of New Zealand and the Red Grouse ofEngland 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 ideaby adding that when such cases as that of the Red Grouse are "enumerated bythe zoologist as evidence of distinct creation of the bird in and for suchislands, he chiefly expresses that he knows not how the Red Grouse came tobe there, and there exclusively; signifying also, by this mode ofexpressing such ignorance, his belief that both the bird and the islandsowed their origin to a great first Creative Cause." If we interpret thesesentences given in the same address, one by the other, it appears that thiseminent philosopher felt in 1858 his confidence shaken that the Apteryx andthe 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 onthe Origin of Species, presently to be referred to, had been read beforethe Linnean Society. When the first edition of this work was published, Iwas so completely deceived, as were many others, by such expressions as"the continuous operation of creative power," that I included ProfessorOwen with other palaeontologists as being firmly convinced of theimmutability of species; but it appears ("Anat. of Vertebrates", vol. iii,page 796) that this was on my part a preposterous error. In the lastedition of this work I inferred, and the inference still seems to meperfectly just, from a passage beginning with the words "no doubt the type-form," etc.(Ibid., vol. i, page xxxv), that Professor Owen admitted thatnatural selection may have done something in the formation of a newspecies; but this it appears (Ibid., vol. iii. page 798) is inaccurate andwithout evidence. I also gave some extracts from a correspondence betweenProfessor Owen and the editor of the "London Review", from which itappeared manifest to the editor as well as to myself, that Professor Owenclaimed to have promulgated the theory of natural selection before I haddone so; and I expressed my surprise and satisfaction at this announcement;but as far as it is possible to understand certain recently publishedpassages (Ibid., vol. iii. page 798) I have either partially or whollyagain fallen into error. It is consolatory to me that others findProfessor Owen's controversial writings as difficult to understand and toreconcile with each other, as I do. As far as the mere enunciation of theprinciple of natural selection is concerned, it is quite immaterial whetheror not Professor Owen preceded me, for both of us, as shown in thishistorical sketch, were long ago preceded by Dr. Wells and Mr. Matthews.
M. Isidore Geoffroy Saint-Hilaire, in his lectures delivered in 1850 (ofwhich a Resume appeared in the "Revue et Mag. de Zoolog.", Jan., 1851),briefly gives his reason for believing that specific characters "sontfixes, pour chaque espece, tant qu'elle se perpetue au milieu des memescirconstances: ils se modifient, si les circonstances ambiantes viennent achanger. En resume, L'OBSERVATION des animaux sauvages demontre deja lavariabilite LIMITEE des especes. Les EXPERIENCES sur les animaux sauvagesdevenus domestiques, et sur les animaux domestiques redevenus sauvages, lademontrent 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 analogousconclusions.
>From a circular lately issued it appears that Dr. Freke, in 1851 ("DublinMedical Press", page 322), propounded the doctrine that all organic beingshave descended from one primordial form. His grounds of belief andtreatment of the subject are wholly different from mine; but as Dr. Frekehas now (1861) published his Essay on the "Origin of Species by means ofOrganic Affinity", the difficult attempt to give any idea of his viewswould 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 the Development of organic beings withremarkable skill and force. He argues from the analogy of domesticproductions, from the changes which the embryos of many species undergo,from the difficulty of distinguishing species and varieties, and from theprinciple of general gradation, that species have been modified; and heattributes the modification to the change of circumstances. The author(1855) has also treated Psychology on the principle of the necessaryacquirement of each mental power and capacity by gradation.
In 1852 M. Naudin, a distinguished botanist, expressly stated, in anadmirable 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 asvarieties are under cultivation; and the latter process he attributes toman's power of selection. But he does not show how selection acts undernature. He believes, like Dean Herbert, that species, when nascent, weremore plastic than at present. He lays weight on what he calls theprinciple of finality, "puissance mysterieuse, indeterminee; fatalite pour les uns; pour les autres volonte providentielle, dont l'action incessantesur les etres vivantes determine, a toutes les epoques de l'existence dumonde, la forme, le volume, et la duree de chacun d'eux, en raison de sadestinee dans l'ordre de choses dont il fait partie. C'est cette puissancequi harmonise chaque membre a l'ensemble, en l'appropriant a la fonctionqu'il doit remplir dans l'organisme general de la nature, fonction qui estpour lui sa raison d'etre." (From references in Bronn's "Untersuchungenuber die Entwickelungs-Gesetze", it appears that the celebrated botanistand palaeontologist Unger published, in 1852, his belief that speciesundergo development and modification. Dalton, likewise, in Pander andDalton's work on Fossil Sloths, expressed, in 1821, a similar belief. Similar views have, as is well known, been maintained by Oken in hismystical "Natur-Philosophie". From other references in Godron's work "Surl'Espece", it seems that Bory St. Vincent, Burdach, Poiret and Fries, haveall admitted that new species are continually being produced. I may add,that of the thirty-four authors named in this Historical Sketch, whobelieve in the modification of species, or at least disbelieve in separateacts of creation, twenty-seven have written on special branches of naturalhistory 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 theworld, so at certain periods the germs of existing species may have beenchemically affected by circumambient molecules of a particular nature, andthus 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 whichhe maintains the development of organic forms on the earth. He infers thatmany species have kept true for long periods, whereas a few have becomemodified. The distinction of species he explains by the destruction ofintermediate graduated forms. "Thus living plants and animals are notseparated from the extinct by new creations, but are to be regarded astheir descendants through continued reproduction."
A well-known French botanist, M. Lecoq, writes in 1854 ("Etudes surGeograph. Bot. tom. i, page 250), "On voit que nos recherches sur la fixiteou la variation de l'espece, nous conduisent directement aux idees emisespar deux hommes justement celebres, Geoffroy Saint-Hilaire et Goethe." Some other passages scattered through M. Lecoq's large work make it alittle doubtful how far he extends his views on the modification ofspecies.
The "Philosophy of Creation" has been treated in a masterly manner by theRev. Baden Powell, in his "Essays on the Unity of Worlds", 1855. Nothingcan be more striking than the manner in which he shows that theintroduction of new species is "a regular, not a casual phenomenon," or, asSir John Herschel expresses it, "a natural in contradistinction to amiraculous 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 theintroductory remarks to this volume, the theory of Natural Selection ispromulgated by Mr. Wallace with admirable force and clearness.
Von Baer, toward whom all zoologists feel so profound a respect, expressedabout the year 1859 (see Prof. Rudolph Wagner, "Zoologisch-AnthropologischeUntersuchungen", 1861, s. 51) his conviction, chiefly grounded on the lawsof geographical distribution, that forms now perfectly distinct havedescended from a single parent-form.
In June, 1859, Professor Huxley gave a lecture before the Royal Institutionon the "Persistent Types of Animal Life". Referring to such cases, heremarks, "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 oforganisation, was formed and placed upon the surface of the globe at longintervals by a distinct act of creative power; and it is well to recollectthat such an assumption is as unsupported by tradition or revelation as itis opposed to the general analogy of nature. If, on the other hand, weview "Persistent Types" in relation to that hypothesis which supposes thespecies living at any time to be the result of the gradual modification ofpre-existing species, a hypothesis which, though unproven, and sadlydamaged by some of its supporters, is yet the only one to which physiologylends any countenance; their existence would seem to show that the amountof modification which living beings have undergone during geological timeis but very small in relation to the whole series of changes which theyhave suffered."
In December, 1859, Dr. Hooker published his "Introduction to the AustralianFlora". In the first part of this great work he admits the truth of thedescent and modification of species, and supports this doctrine by manyoriginal observations.
The first edition of this work was published on November 24, 1859, and thesecond edition on January 7, 1860.