Free bilingual books

On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life
Charles Darwin
(1859)

Downloading books is available only for authorized users


Downloading books is available only for authorized users


Downloading books is available only for authorized users

On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life
An historical sketch of the progress of opinion on the origin of species, previously to the publication of the first edition of this work.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,[1] 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 Vertébres”. 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.[2]

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 problème à réserver entièrement à l’avenir, supposé même 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 “Amaryllidaceæ” (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 geographical 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 palæontologists 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,” &c.(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 Résumé appeared in the “Revue et Mag. de Zoolog.”, Jan., 1851), briefly gives his reason for believing that specific characters “sont fixés, pour chaque espèce, tant qu’elle se perpétue au milieu des mêmes circonstances: ils se modifient, si les circonstances ambiantes viennent à changer. En résumé, l’observation des animaux sauvages démontre deja la variabilité limitée des espèces. Les expériences sur les animaux sauvages devenus domestiques, et sur les animaux domestiques redevenus sauvages, la démontrent plus clairment encore. Ces mêmes expériences prouvent, de plus, que les différences produites peuvent être de valeur générique.” In his “Hist. Nat. Générale” (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 Muséum”, tom. i, p. 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 mystérieuse, indéterminée; fatalité pour les uns; pour les autres volonté providentielle, dont l’action incessante sur les êtres vivantes détermine, à toutes les époques de l’existence du monde, la forme, le volume, et la durée de chacun d’eux, en raison de sa destinée dans l’ordre de choses dont il fait partie. C’est cette puissance qui harmonise chaque membre à l’ensemble, en l’appropriant à la fonction qu’il doit remplir dans l’organisme général de la nature, fonction qui est pour lui sa raison d’être.”[3]

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”, &c.), 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 Géograph.” Bot. tom. i, page 250), “On voit que nos recherches sur la fixité ou la variation de l’espéce, nous conduisent directement aux idées émises par deux hommes justement célèbres, 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.



[1]  Aristotle, in his “Physicæ 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.
[2]  I have taken the date of the first publication of Lamarck from Isidore Geoffroy Saint-Hilaire’s (“Hist. Nat. Générale”, tom. ii. page 405, 1859) excellent history of opinion on this subject. In this work a full account is given of Buffon’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. pages 500-510), published in 1794. According to Isid. Geoffroy there is no doubt that Goethe was an extreme partisan of similar views, as shown in the introduction to a work written in 1794 and 1795, but not published till long afterward; he has pointedly remarked (“Goethe als Naturforscher”, 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 France, came to the same conclusion on the origin of species, in the years 1794-5.
[3]  From references in Bronn’s “Untersuchungen über die Entwickelungs-Gesetze”, it appears that the celebrated botanist and palæontologist 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’Espèce”, 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.

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,[1] 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 Vertébres”. 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.[2]

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 problème à réserver entièrement à l’avenir, supposé même 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 “Amaryllidaceæ” (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 geographical 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 palæontologists 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,” &c.(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 Résumé appeared in the “Revue et Mag. de Zoolog.”, Jan., 1851), briefly gives his reason for believing that specific characters “sont fixés, pour chaque espèce, tant qu’elle se perpétue au milieu des mêmes circonstances: ils se modifient, si les circonstances ambiantes viennent à changer. En résumé, l’observation des animaux sauvages démontre deja la variabilité limitée des espèces. Les expériences sur les animaux sauvages devenus domestiques, et sur les animaux domestiques redevenus sauvages, la démontrent plus clairment encore. Ces mêmes expériences prouvent, de plus, que les différences produites peuvent être de valeur générique.” In his “Hist. Nat. Générale” (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 Muséum”, tom. i, p. 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 mystérieuse, indéterminée; fatalité pour les uns; pour les autres volonté providentielle, dont l’action incessante sur les êtres vivantes détermine, à toutes les époques de l’existence du monde, la forme, le volume, et la durée de chacun d’eux, en raison de sa destinée dans l’ordre de choses dont il fait partie. C’est cette puissance qui harmonise chaque membre à l’ensemble, en l’appropriant à la fonction qu’il doit remplir dans l’organisme général de la nature, fonction qui est pour lui sa raison d’être.”[3]

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”, &c.), 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 Géograph.” Bot. tom. i, page 250), “On voit que nos recherches sur la fixité ou la variation de l’espéce, nous conduisent directement aux idées émises par deux hommes justement célèbres, 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.



[1]  Aristotle, in his “Physicæ 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.
[2]  I have taken the date of the first publication of Lamarck from Isidore Geoffroy Saint-Hilaire’s (“Hist. Nat. Générale”, tom. ii. page 405, 1859) excellent history of opinion on this subject. In this work a full account is given of Buffon’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. pages 500-510), published in 1794. According to Isid. Geoffroy there is no doubt that Goethe was an extreme partisan of similar views, as shown in the introduction to a work written in 1794 and 1795, but not published till long afterward; he has pointedly remarked (“Goethe als Naturforscher”, 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 France, came to the same conclusion on the origin of species, in the years 1794-5.
[3]  From references in Bronn’s “Untersuchungen über die Entwickelungs-Gesetze”, it appears that the celebrated botanist and palæontologist 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’Espèce”, 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.

  • attack: To attack is to try to fight or to hurt.
  • middle: The middle of something is the center or halfway point.
  • trick: A trick is something you do to fool another person.
  • well: You use well to say that something was done in a good way.
  • chemical: A chemical is something that scientists use in chemistry.
  • create: To create means to make something new.
  • experiment: An experiment is a test that you do to see what will happen.
  • kill: To kill someone or something is to make them die.
  • among: If you are among certain things, they are all around you.
  • comprehend: To comprehend something is to understand it.
  • ever: Ever means at any time.
  • grade: A grade is a score or mark given to someone’s work.
  • planet: A planet is a large round thing in space.
  • several: Several is more than two but not many.
  • suppose: To suppose is to guess.
  • view: To view is to look at something.
  • concern: Concern is a feeling of worry.
  • habit: A habit is a thing that you do often.
  • issue: An issue is an important topic.
  • shake: To shake is to move back and forth or up and down quickly.
  • spread: To spread is to move quickly to more places.
  • continue: To continue something is to keep doing it.
  • error: An error is something you do wrong.
  • result: A result is something that happens because of something else.
  • since: Since is used to talk about a past event still happening now.
  • cause: To cause is to make something happen.
  • face: If you face a problem, you deal with it.
  • follow: To follow means to go behind someone and go where they go.
  • pet: A pet is an animal that lives with people.
  • wise: To be wise is to use experience and intelligence to make good choices.
  • announce: To announce something is to make it known.
  • claim: To claim means to say that something is true.
  • condition: The condition of someone or something is the state that they are in.
  • difference: A difference is a way that something is not like other things.
  • famous: If someone or something is famous, they are known to many people.
  • force: Force is a person’s strength or power.
  • harm: Harm is hurt or problems caused to someone or something.
  • lay: To lay means to put or place in a horizontal or flat position.
  • sense: To sense something is to know about it without being told.
  • sudden: When something is sudden, it happens very quickly.
  • contrast: A contrast is the sharp difference between two things.
  • hang: To hang something is to keep it above the ground.
  • necessary: If something is necessary, you must do it.
  • single: If something is single, then there is only one.
  • success: Success is doing something well that you choose to do.
  • theory: A theory is an idea about how something works.
  • against: To be against something is to be touching it or opposed to it.
  • damage: To damage something is to break it.
  • fix: To fix something is to make it work.
  • island: An island is land in the middle of water.
  • still: Still is used when you say that a situation keeps going on.
  • certain: If you are certain about something, you know it is true.
  • effect: An effect is a change made by something else.
  • far: If something is far, it is not close.
  • immediate: If something is immediate, it happens quickly.
  • remain: To remain somewhere is to stay there.
  • rest: To rest is to stop being active while the body gets back its strength.
  • separate: If two things are separate, they are not together.
  • tail: A tail is a part of an animal’s body, sticking out from its rear or back.
  • collect: To collect things is to group them together all in one place.
  • either: Either is used with or to say there are two or more possibilities.
  • ground: The ground is the top part of the Earth that we walk on.
  • truth: The truth is a fact or something that is right.
  • alone: If someone is alone, they are not with another person.
  • material: A material is what is used to make something.
  • thin: If someone or something is thin, they are not fat.
  • cell: A cell is a small room where a person is locked in.
  • contain: To contain something is to have it inside.
  • equal: To be equal is to be the same.
  • hole: A hole is an opening in something.
  • owe: To owe is to have to pay or give back something received from another.
  • position: A position is the way something is placed.
  • sight: A sight is something interesting to see.
  • structure: A structure is a building.
  • whole: Whole means all of something.
  • direct: If something is direct, it goes straight between two places.
  • limit: A limit is the largest or smallest amount of something that you allow.
  • suffer: To suffer is to feel pain.
  • excite: To excite someone means to make them happy and interested.
  • fortunate: If you are fortunate, you are lucky.
  • length: The length of something is how long it is from one end to the other.
  • observe: To observe something is to watch it.
  • race: A race is a contest to see who is the fastest.
  • respond: To respond is to give an answer to what someone else said.
  • yet: Yet is used to say something has not happened up to now.
  • exist: To exist is to be real.
  • original: If something is original, it is the first one of that thing.
  • pound: To pound something is to hit it many times with a lot of force.
  • process: A process is the steps to take to do something.
  • publish: To publish a book is to get it printed and ready to sell.
  • celebrate: To celebrate is to do something to show that an event is special.
  • determine: To determine means to choose or make a decision.
  • lone: If someone or something is lone, they are the only one of that kind.
  • whether: You use whether when you must choose between two things.
  • argue: To argue is to angrily speak to someone because you do not agree.
  • indicate: To indicate means to show, point or make something clear.
  • product: A product is something that is made.
  • select: To select something is to choose it.
  • treat: To treat is to act in a certain way toward someone.
  • conclusion: The conclusion of something is the final part of it.
  • doubt: Doubt is a feeling of not being sure.
  • however: However means despite or not being influenced by something.
  • toward: If you go toward something, you go closer to it.
  • wood: Wood is the thing that trees are made of.
  • already: If something happens already, it happens before a certain time.
  • bit: A bit is a small amount of something.
  • consider: To consider something means to think about it.
  • extra: If something is extra, it is more than what is needed.
  • lie: To lie is to say or write something untrue to deceive someone.
  • opinion: An opinion is a thought about a person or a thing.
  • regard: To regard someone or something is to think of them in a certain way.
  • serve: To serve someone is to give them food or drinks.
  • war: A war is a big fight between two groups of people.
  • appear: To appear is to seem.
  • enter: To enter a place is to go into it.
  • excellent: When something is excellent, it is very good.
  • operation: An operation is when a doctor replaces or removes something in the body.
  • though: Though is used when the second idea makes the first seem surprising.
  • various: If something is various, there are many types of it.
  • actual: Actual means that something is real or true.
  • deliver: To deliver something is to take it from one place to another.
  • earn: To earn means to get money for the work you do.
  • gate: A gate is a type of door. Gates are usually made of metal or wood.
  • include: To include something means to have it as part of a group.
  • occur: To occur means to happen.
  • course: A course is a class in school.
  • mental: If something is mental, it has to do with your mind.
  • fit: If something fits, it is small enough orthe right size to go there.
  • passage: A passage is a long area with walls that goes from one place to another.
  • probable: If something is probable, it is likely to happen.
  • support: To support something is to like it and help it be successful.
  • term: A term is a word for something.
  • instance: An instance is an example of something.
  • period: A period is an amount of time when something happens.
  • populate: If people populate an area, they live there.
  • produce: To produce something is to make or grow it.
  • regular: If something is regular, it happens often and in equal amounts of time.
  • sign: A sign is a notice giving information, directions, a warning, etc.
  • tip: A tip is a pointed end of something.
  • tradition: A tradition is something people have been doing for a long time.
  • wide: If something is wide, it is large from side to side.
  • attention: Attention is the notice, thought, or consideration of someone.
  • final: If something is final, it is the last part.
  • further: Further is used to say something is from a distance or time.
  • maintain: To maintain means to make something stay the same.
  • physical: If something is physical, it is related to your body and not your mind.
  • prove: To prove something is to show that it is true.
  • suggest: To suggest something means to give an idea or plan about it.
  • actually: Actually means in fact or really.
  • quite: Quite is used to say that something is complete or very much.
  • specific: If something is specific, it is precise or exact.
  • list: A list is a record of information printed with an item on each line.
  • notice: To notice something is to see it for the first time.
  • own: To own something means to have it. That thing belongs to you.
  • gain: If you gain something, you get more of it.
  • importance: Importance means the quality or condition of being needed or valued.
  • knowledge: Knowledge is information that you have about something.
  • major: If something is major, it is big or important.
  • mean: Mean describes someone who is unkind or cruel.
  • progress: Progress is the act of getting closer to doing or finishing something.
  • respect: Respect is a good opinion of someone because they are good.
  • skill: A skill is the knowledge and ability that allows you to do something well.
  • above: If something is above, it is at a higher level than something else.
  • amount: An amount is how much there is of something.
  • belief: A belief is a strong feeling that something is correct or true.
  • different: Different describes someone or something that is not the same as others.
  • evidence: Evidence is a fact or thing that you use to prove something.
  • master: A master is a person who is very good at something.
  • surface: The surface of something is the top part or outside of it.

  • attack: To attack is to try to fight or to hurt.
  • middle: The middle of something is the center or halfway point.
  • trick: A trick is something you do to fool another person.
  • well: You use well to say that something was done in a good way.
  • chemical: A chemical is something that scientists use in chemistry.
  • create: To create means to make something new.
  • experiment: An experiment is a test that you do to see what will happen.
  • kill: To kill someone or something is to make them die.
  • among: If you are among certain things, they are all around you.
  • comprehend: To comprehend something is to understand it.
  • ever: Ever means at any time.
  • grade: A grade is a score or mark given to someone’s work.
  • planet: A planet is a large round thing in space.
  • several: Several is more than two but not many.
  • suppose: To suppose is to guess.
  • view: To view is to look at something.
  • concern: Concern is a feeling of worry.
  • habit: A habit is a thing that you do often.
  • issue: An issue is an important topic.
  • shake: To shake is to move back and forth or up and down quickly.
  • spread: To spread is to move quickly to more places.
  • continue: To continue something is to keep doing it.
  • error: An error is something you do wrong.
  • result: A result is something that happens because of something else.
  • since: Since is used to talk about a past event still happening now.
  • cause: To cause is to make something happen.
  • face: If you face a problem, you deal with it.
  • follow: To follow means to go behind someone and go where they go.
  • pet: A pet is an animal that lives with people.
  • wise: To be wise is to use experience and intelligence to make good choices.
  • announce: To announce something is to make it known.
  • claim: To claim means to say that something is true.
  • condition: The condition of someone or something is the state that they are in.
  • difference: A difference is a way that something is not like other things.
  • famous: If someone or something is famous, they are known to many people.
  • force: Force is a person’s strength or power.
  • harm: Harm is hurt or problems caused to someone or something.
  • lay: To lay means to put or place in a horizontal or flat position.
  • sense: To sense something is to know about it without being told.
  • sudden: When something is sudden, it happens very quickly.
  • contrast: A contrast is the sharp difference between two things.
  • hang: To hang something is to keep it above the ground.
  • necessary: If something is necessary, you must do it.
  • single: If something is single, then there is only one.
  • success: Success is doing something well that you choose to do.
  • theory: A theory is an idea about how something works.
  • against: To be against something is to be touching it or opposed to it.
  • damage: To damage something is to break it.
  • fix: To fix something is to make it work.
  • island: An island is land in the middle of water.
  • still: Still is used when you say that a situation keeps going on.
  • certain: If you are certain about something, you know it is true.
  • effect: An effect is a change made by something else.
  • far: If something is far, it is not close.
  • immediate: If something is immediate, it happens quickly.
  • remain: To remain somewhere is to stay there.
  • rest: To rest is to stop being active while the body gets back its strength.
  • separate: If two things are separate, they are not together.
  • tail: A tail is a part of an animal’s body, sticking out from its rear or back.
  • collect: To collect things is to group them together all in one place.
  • either: Either is used with or to say there are two or more possibilities.
  • ground: The ground is the top part of the Earth that we walk on.
  • truth: The truth is a fact or something that is right.
  • alone: If someone is alone, they are not with another person.
  • material: A material is what is used to make something.
  • thin: If someone or something is thin, they are not fat.
  • cell: A cell is a small room where a person is locked in.
  • contain: To contain something is to have it inside.
  • equal: To be equal is to be the same.
  • hole: A hole is an opening in something.
  • owe: To owe is to have to pay or give back something received from another.
  • position: A position is the way something is placed.
  • sight: A sight is something interesting to see.
  • structure: A structure is a building.
  • whole: Whole means all of something.
  • direct: If something is direct, it goes straight between two places.
  • limit: A limit is the largest or smallest amount of something that you allow.
  • suffer: To suffer is to feel pain.
  • excite: To excite someone means to make them happy and interested.
  • fortunate: If you are fortunate, you are lucky.
  • length: The length of something is how long it is from one end to the other.
  • observe: To observe something is to watch it.
  • race: A race is a contest to see who is the fastest.
  • respond: To respond is to give an answer to what someone else said.
  • yet: Yet is used to say something has not happened up to now.
  • exist: To exist is to be real.
  • original: If something is original, it is the first one of that thing.
  • pound: To pound something is to hit it many times with a lot of force.
  • process: A process is the steps to take to do something.
  • publish: To publish a book is to get it printed and ready to sell.
  • celebrate: To celebrate is to do something to show that an event is special.
  • determine: To determine means to choose or make a decision.
  • lone: If someone or something is lone, they are the only one of that kind.
  • whether: You use whether when you must choose between two things.
  • argue: To argue is to angrily speak to someone because you do not agree.
  • indicate: To indicate means to show, point or make something clear.
  • product: A product is something that is made.
  • select: To select something is to choose it.
  • treat: To treat is to act in a certain way toward someone.
  • conclusion: The conclusion of something is the final part of it.
  • doubt: Doubt is a feeling of not being sure.
  • however: However means despite or not being influenced by something.
  • toward: If you go toward something, you go closer to it.
  • wood: Wood is the thing that trees are made of.
  • already: If something happens already, it happens before a certain time.
  • bit: A bit is a small amount of something.
  • consider: To consider something means to think about it.
  • extra: If something is extra, it is more than what is needed.
  • lie: To lie is to say or write something untrue to deceive someone.
  • opinion: An opinion is a thought about a person or a thing.
  • regard: To regard someone or something is to think of them in a certain way.
  • serve: To serve someone is to give them food or drinks.
  • war: A war is a big fight between two groups of people.
  • appear: To appear is to seem.
  • enter: To enter a place is to go into it.
  • excellent: When something is excellent, it is very good.
  • operation: An operation is when a doctor replaces or removes something in the body.
  • though: Though is used when the second idea makes the first seem surprising.
  • various: If something is various, there are many types of it.
  • actual: Actual means that something is real or true.
  • deliver: To deliver something is to take it from one place to another.
  • earn: To earn means to get money for the work you do.
  • gate: A gate is a type of door. Gates are usually made of metal or wood.
  • include: To include something means to have it as part of a group.
  • occur: To occur means to happen.
  • course: A course is a class in school.
  • mental: If something is mental, it has to do with your mind.
  • fit: If something fits, it is small enough orthe right size to go there.
  • passage: A passage is a long area with walls that goes from one place to another.
  • probable: If something is probable, it is likely to happen.
  • support: To support something is to like it and help it be successful.
  • term: A term is a word for something.
  • instance: An instance is an example of something.
  • period: A period is an amount of time when something happens.
  • populate: If people populate an area, they live there.
  • produce: To produce something is to make or grow it.
  • regular: If something is regular, it happens often and in equal amounts of time.
  • sign: A sign is a notice giving information, directions, a warning, etc.
  • tip: A tip is a pointed end of something.
  • tradition: A tradition is something people have been doing for a long time.
  • wide: If something is wide, it is large from side to side.
  • attention: Attention is the notice, thought, or consideration of someone.
  • final: If something is final, it is the last part.
  • further: Further is used to say something is from a distance or time.
  • maintain: To maintain means to make something stay the same.
  • physical: If something is physical, it is related to your body and not your mind.
  • prove: To prove something is to show that it is true.
  • suggest: To suggest something means to give an idea or plan about it.
  • actually: Actually means in fact or really.
  • quite: Quite is used to say that something is complete or very much.
  • specific: If something is specific, it is precise or exact.
  • list: A list is a record of information printed with an item on each line.
  • notice: To notice something is to see it for the first time.
  • own: To own something means to have it. That thing belongs to you.
  • gain: If you gain something, you get more of it.
  • importance: Importance means the quality or condition of being needed or valued.
  • knowledge: Knowledge is information that you have about something.
  • major: If something is major, it is big or important.
  • mean: Mean describes someone who is unkind or cruel.
  • progress: Progress is the act of getting closer to doing or finishing something.
  • respect: Respect is a good opinion of someone because they are good.
  • skill: A skill is the knowledge and ability that allows you to do something well.
  • above: If something is above, it is at a higher level than something else.
  • amount: An amount is how much there is of something.
  • belief: A belief is a strong feeling that something is correct or true.
  • different: Different describes someone or something that is not the same as others.
  • evidence: Evidence is a fact or thing that you use to prove something.
  • master: A master is a person who is very good at something.
  • surface: The surface of something is the top part or outside of it.

  •  
    Next chapter