[January 11th, 1844.]

Besides a general interest about the southern lands, I have been now ever since my return engaged in a very presumptuous work, and I know no one individual who would not say a very foolish one. I was so struck with the distribution of the Galapagos organisms, etc. etc., and with the character of the American fossil mammifers, etc. etc., that I determined to collect blindly every sort of fact, which could bear any way on what are species. I have read heaps of agricultural and horticultural books, and have never ceased collecting facts. At last gleams of light have come, and I am almost convinced (quite contrary to the opinion I started with) that species are not (it is like confessing a murder) immutable. Heaven forfend me from Lamarck nonsense of a “tendency to progression,” “adaptations from the slow willing of animals,” etc.! But the conclusions I am led to are not widely different from his; though the means of change are wholly so. I think I have found out (here’s presumption!) the simple way by which species become exquisitely adapted to various ends. You will now groan, and think to yourself, “on what a man have I been wasting my time and writing to.” I should, five years ago, have thought so…

[The following letter written on February 23, 1844, shows that the acquaintanceship with Sir J.D. Hooker was then fast ripening into friendship. The letter is chiefly of interest as showing the sort of problems then occupying my father's mind:]

Dear Hooker,

I hope you will excuse the freedom of my address, but I feel that as co-circum-wanderers and as fellow labourers (though myself a very weak one) we may throw aside some of the old-world formality…I have just finished a little volume on the volcanic islands which we visited. I do not know how far you care for dry simple geology, but I hope you will let me send you a copy. I suppose I can send it from London by common coach conveyance.

…I am going to ask you some more questions, though I daresay, without asking them, I shall see answers in your work, when published, which will be quite time enough for my purposes. First for the Galapagos, you will see in my Journal, that the Birds, though peculiar species, have a most obvious S. American aspect: I have just ascertained the same thing holds good with the sea-shells. It is so with those plants which are peculiar to this archipelago; you state that their numerical proportions are continental (is not this a very curious fact?) but are they related in forms to S. America. Do you know of any other case of an archipelago, with the separate islands possessing distinct representative species? I have always intended (but have not yet done so) to examine Webb and Berthelot on the Canary Islands for this object. Talking with Mr. Bentham, he told me that the separate islands of the Sandwich Archipelago possessed distinct representative species of the same genera of Labiatae: would not this be worth your enquiry? How is it with the Azores; to be sure the heavy western gales would tend to diffuse the same species over that group.

I hope you will (I dare say my hope is quite superfluous) attend to this general kind of affinity in isolated islands, though I suppose it is more difficult to perceive this sort of relation in plants, than in birds or quadrupeds, the groups of which are, I fancy, rather more confined. Can St. Helena be classed, though remotely, either with Africa or S. America?
>From some facts, which I have collected, I have been led to conclude that the fauna of mountains are either remarkably similar (sometimes in the presence of the same species and at other times of same genera), or that they are remarkably dissimilar; and it has occurred to me that possibly part of this peculiarity of the St. Helena and Galapagos floras may be attributed to a great part of these two Floras being mountain Floras. I fear my notes will hardly serve to distinguish much of the habitats of the Galapagos plants, but they may in some cases; most, if not all, of the green, leafy plants come from the summits of the islands, and the thin brown leafless plants come from the lower arid parts: would you be so kind as to bear this remark in mind, when examining my collection.

I will trouble you with only one other question. In discussion with Mr. Gould, I found that in most of the genera of birds which range over the whole or greater part of the world, the individual species have wider ranges, thus the Owl is mundane, and many of the species have very wide ranges. So I believe it is with land and fresh-water shells–and I might adduce other cases. Is it not so with Cryptogamic plants; have not most of the species wide ranges, in those genera which are mundane? I do not suppose that the converse holds, viz.–that when a species has a wide range, its genus also ranges wide. Will you so far oblige me by occasionally thinking over this? It would cost me vast trouble to get a list of mundane phanerogamic genera and then search how far the species of these genera are apt to range wide in their several countries; but you might occasionally, in the course of your pursuits, just bear this in mind, though perhaps the point may long since have occurred to you or other Botanists. Geology is bringing to light interesting facts, concerning the ranges of shells; I think it is pretty well established, that according as the geographical range of a species is wide, so is its persistence and duration in time. I hope you will try to grudge as little as you can the trouble of my letters, and pray believe me very truly yours,

C. Darwin.

P.S. I should feel extremely obliged for your kind offer of the sketch of Humboldt; I venerate him, and after having had the pleasure of conversing with him in London, I shall still more like to have any portrait of him.

[What follows is quoted from Sir J. Hooker's notes. "The next act in the drama of our lives opens with personal intercourse. This began with an invitation to breakfast with him at his brother's (Erasmus Darwin's) house in Park Street; which was shortly afterwards followed by an invitation to Down to meet a few brother Naturalists. In the short intervals of good health that followed the long illnesses which oftentimes rendered life a burthen to him, between 1844 and 1847, I had many such invitations, and delightful they were. A more hospitable and more attractive home under every point of view could not be imagined--of Society there were most often Dr. Falconer, Edward Forbes, Professor Bell, and Mr. Waterhouse--there were long walks, romps with the children on hands and knees, music that haunts me still. Darwin's own hearty manner, hollow laugh, and thorough enjoyment of home life with friends; strolls with him all together, and interviews with us one by one in his study, to discuss questions in any branch of biological or physical knowledge that we had followed; and which I at any rate always left with the feeling that I had imparted nothing and carried away more than I could stagger under. Latterly, as his health became more seriously affected, I was for days and weeks the only visitor, bringing my work with me and enjoying his society as opportunity offered. It was an established rule that he every day pumped me, as he called it, for half an hour or so after breakfast in his study, when he first brought out a heap of slips with questions botanical, geographical, etc., for me to answer, and concluded by telling me of the progress he had made in his own work, asking my opinion on various points. I saw no more of him till about noon, when I heard his mellow ringing voice calling my name under my window--this was to join him in his daily forenoon walk round the sand-walk. On joining him I found him in a rough grey shooting-coat in summer, and thick cape over his shoulders in winter, and a stout staff in his hand; away we trudged through the garden, where there was always some experiment to visit, and on to the sand-walk, round which a fixed number of turns were taken, during which our conversation usually ran on foreign lands and seas, old friends, old books, and things far off to both mind and eye.

"In the afternoon there was another such walk, after which he again retired till dinner if well enough to join the family; if not, he generally managed to appear in the drawing-room, where seated in his high chair, with his feet in enormous carpet shoes, supported on a high stool--he enjoyed the music or conversation of his family."

Here follows a series of letters illustrating the growth of my father's views, and the nature of his work during this period.]

Letters, 1843-1856.

[The history of my father's life is told more completely in his correspondence with Sir J.D. Hooker than in any other series of letters; and this is especially true of the history of the growth of the 'Origin of Species.' This, therefore, seems an appropriate place for the following notes, which Sir Joseph Hooker has kindly given me. They give, moreover, an interesting picture of his early friendship with my father:--

"My first meeting with Mr. Darwin was in 1839, in Trafalgar Square. I was walking with an officer who had been his shipmate for a short time in the Beagle seven years before, but who had not, I believe, since met him. I was introduced; the interview was of course brief, and the memory of him that I carried away and still retain was that of a rather tall and rather broad-shouldered man, with a slight stoop, an agreeable and animated expression when talking, beetle brows, and a hollow but mellow voice; and that his greeting of his old acquaintance was sailor-like--that is, delightfully frank and cordial. I observed him well, for I was already aware of his attainments and labours, derived from having read various proof-sheets of his then unpublished 'Journal.' These had been submitted to Mr. (afterwards Sir Charles) Lyell by Mr. Darwin, and by him sent to his father, Ch. Lyell, Esq., of Kinnordy, who (being a very old friend of my father and taking a kind interest in my projected career as a naturalist) had allowed me to peruse them. At this time I was hurrying on my studies, so as to take my degree before volunteering to accompany Sir James Ross in the Antarctic Expedition, which had just been determined on by the Admiralty; and so pressed for time was I, that I used to sleep with the sheets of the 'Journal' under my pillow, that I might read them between waking and rising. They impressed me profoundly, I might say despairingly, with the variety of acquirements, mental and physical, required in a naturalist who should follow in Darwin's footsteps, whilst they stimulated me to enthusiasm in the desire to travel and observe.

"It has been a permanent source of happiness to me that I knew so much of Mr. Darwin's scientific work so many years before that intimacy began which ripened into feelings as near to those of reverence for his life, works, and character as is reasonable and proper. It only remains to add to this little episode that I received a copy of the 'Journal' complete,--a gift from Mr. Lyell,--a few days before leaving England.

"Very soon after the return of the Antarctic Expedition my correspondence with Mr. Darwin began (December, 1843) by his sending me a long letter, warmly congratulating me on my return to my family and friends, and expressing a wish to hear more of the results of the expedition, of which he had derived some knowledge from private letters of my own (written to or communicated through Mr. Lyell). Then, plunging at once into scientific matters, he directed my attention to the importance of correlating the Fuegian Flora with that of the Cordillera and of Europe, and invited me to study the botanical collections which he had made in the Galapagos Islands, as well as his Patagonian and Fuegian plants.

"This led to me sending him an outline of the conclusions I had formed regarding the distribution of plants in the southern regions, and the necessity of assuming the destruction of considerable areas of land to account for the relations of the flora of the so-called Antarctic Islands. I do not suppose that any of these ideas were new to him, but they led to an animated and lengthy correspondence full of instruction."

Here follows the letter (1843) to Sir J.D. Hooker above referred to.]

My dear Sir,

I had hoped before this time to have had the pleasure of seeing you and congratulating you on your safe return from your long and glorious voyage. But as I seldom go to London, we may not yet meet for some time–without you are led to attend the Geological Meetings.

I am anxious to know what you intend doing with all your materials–I had so much pleasure in reading parts of some of your letters, that I shall be very sorry if I, as one of the public, have no opportunity of reading a good deal more. I suppose you are very busy now and full of enjoyment: how well I remember the happiness of my first few months of England–it was worth all the discomforts of many a gale! But I have run from the subject, which made me write, of expressing my pleasure that Henslow (as he informed me a few days since by letter) has sent to you my small collection of plants. You cannot think how much pleased I am, as I feared they would have been all lost, and few as they are, they cost me a good deal of trouble. There are a very few notes, which I believe Henslow has got, describing the habitats, etc., of some few of the more remarkable plants. I paid particular attention to the Alpine flowers of Tierra del Fuego, and I am sure I got every plant which was in flower in Patagonia at the seasons when we were there. I have long thought that some general sketch of the Flora of the point of land, stretching so far into the southern seas, would be very curious. Do make comparative remarks on the species allied to the European species, for the advantage of botanical ignoramuses like myself. It has often struck me as a curious point to find out, whether there are many European genera in Tierra del Fuego which are not found along the ridge of the Cordillera; the separation in such case would be so enormous. Do point out in any sketch you draw up, what genera are American and what European, and how great the differences of the species are, when the genera are European, for the sake of the ignoramuses.

I hope Henslow will send you my Galapagos plants (about which Humboldt even expressed to me considerable curiosity)–I took much pains in collecting all I could. A Flora of this archipelago would, I suspect, offer a nearly parallel case to that of St. Helena, which has so long excited interest. Pray excuse this long rambling note, and believe me, my dear sir, yours very sincerely,

C. Darwin.

Will you be so good as to present my respectful compliments to Sir W. Hooker.

[Referring to Sir J.D. Hooker's work on the Galapagos Flora, my father wrote in 1846:

"I cannot tell you how delighted and astonished I am at the results of your examination; how wonderfully they support my assertion on the differences in the animals of the different islands, about which I have always been fearful."

Again he wrote (1849):--

"I received a few weeks ago your Galapagos papers (These papers include the results of Sir J.D. Hooker's examination of my father's Galapagos plants, and were published by the Linnean Society in 1849.), and I have read them since being here. I really cannot express too strongly my admiration of the geographical discussion: to my judgment it is a perfect model of what such a paper should be; it took me four days to read and think over. How interesting the Flora of the Sandwich Islands appears to be, how I wish there were materials for you to treat its flora as you have done the Galapagos. In the Systematic paper I was rather disappointed in not finding general remarks on affinities, structures, etc., such as you often give in conversation, and such as De Candolle and St. Hilaire introduced in almost all their papers, and which make them interesting even to a non-Botanist."

"Very soon afterwards [continues Sir J.D. Hooker] in a letter dated January 1844, the subject of the ‘Origin of Species’ was brought forward by him, and I believe that I was the first to whom he communicated his then new ideas on the subject, and which being of interest as a contribution to the history of Evolution, I here copy from his letter”:–]

Down, July 5, 1844.

I have just finished my sketch of my species theory. If, as I believe, my theory in time be accepted even by one competent judge, it will be a considerable step in science.

I therefore write this in case of my sudden death, as my most solemn and last request, which I am sure you will consider the same as if legally entered in my will, that you will devote 400 pounds to its publication, and further, will yourself, or through Hensleigh (Mr. H. Wedgwood.), take trouble in promoting it. I wish that my sketch be given to some competent person, with this sum to induce him to take trouble in its improvement and enlargement. I give to him all my books on Natural History, which are either scored or have references at the end to the pages, begging him carefully to look over and consider such passages as actually bearing, or by possibility bearing, on this subject. I wish you to make a list of all such books as some temptation to an editor. I also request that you will hand over [to] him all those scraps roughly divided in eight or ten brown paper portfolios. The scraps, with copied quotations from various works, are those which may aid my editor. I also request that you, or some amanuensis, will aid in deciphering any of the scraps which the editor may think possibly of use. I leave to the editor’s judgment whether to interpolate these facts in the text, or as notes, or under appendices. As the looking over the references and scraps will be a long labour, and as the correcting and enlarging and altering my sketch will also take considerable time, I leave this sum of 400 pounds as some remuneration, and any profits from the work. I consider that for this the editor is bound to get the sketch published either at a publisher’s or his own risk. Many of the scrap in the portfolios contains mere rude suggestions and early views, now useless, and many of the facts will probably turn out as having no bearing on my theory.

With respect to editors, Mr. Lyell would be the best if he would undertake it; I believe he would find the work pleasant, and he would learn some facts new to him. As the editor must be a geologist as well as a naturalist, the next best editor would be Professor Forbes of London. The next best (and quite best in many respects) would be Professor Henslow. Dr. Hooker would be very good. The next, Mr. Strickland. (After Mr. Strickland’s name comes the following sentence, which has been erased but remained legible. “Professor Owen would be very good; but I presume he would not undertake such a work.” If none of these would undertake it, I would request you to consult with Mr. Lyell, or some other capable man for some editor, a geologist and naturalist. Should one other hundred pounds make the difference of procuring a good editor, request earnestly that you will raise 500 pounds.

My remaining collections in Natural History may be given to any one or any museum where it would be accepted…

[The following note seems to have formed part of the original letter, but may have been of later date:

"Lyell, especially with the aid of Hooker (and of any good zoological aid), would be best of all. Without an editor will pledge himself to give up time to it, it would be of no use paying such a sum.

"If there should be any difficulty in getting an editor who would go thoroughly into the subject, and think of the bearing of the passages marked in the books and copied out of scraps of paper, then let my sketch be published as it is, stating that it was done several years ago (The words "several years ago and," seem to have been added at a later date.) and from memory without consulting any works, and with no intention of publication in its present form."

The idea that the Sketch of 1844 might remain, in the event of his death, as the only record of his work, seems to have been long in his mind, for in August 1854, when he had finished with the Cirripedes, and was thinking of beginning his "species work," he added on the back of the above letter, "Hooker by far best man to edit my species volume. August 1854."]

Chapter II. “The gradual appearance and disappearance of organic beings.” Corresponds to Chapter X. of the ‘Origin.’

Chapter III. “Geographical Distribution.” Corresponds to Chapters XI. and XII. of the ‘Origin.’

Chapter IV. “Affinities and Classification of Organic beings.”

Chapter V. “Unity of Type,” Morphology, Embryology.

Chapter VI. Rudimentary Organs.

These three chapters correspond to Chapter XII. of the ‘Origin.’

Chapter VII. Recapitulation and Conclusion. The final sentence of the Sketch, which we saw in its first rough form in the Note Book of 1837, closely resembles the final sentence of the ‘Origin,’ much of it being identical. The ‘Origin’ is not divided into two “Parts,” but we see traces of such a division having been present in the writer’s mind, in this resemblance between the second part of the Sketch and the final chapters of the ‘Origin.’ That he should speak (‘Origin,’ Introduction, page 5.) of the chapters on transition, on instinct, on hybridism, and on the geological record, as forming a group, may be due to the division of his early MS. into two parts.

Mr. Huxley, who was good enough to read the Sketch at my request, while remarking that the “main lines of argument,” and the illustrations employed are the same, points out that in the 1844 Essay, “much more weight is attached to the influence of external conditions in producing variation, and to the inheritance of acquired habits than in the Origin.’”

It is extremely interesting to find in the Sketch the first mention of principles familiar to us in the ‘Origin of Species.’ Foremost among these may be mentioned the principle of Sexual Selection, which is clearly enunciated. The important form of selection known as “unconscious,” is also given. Here also occurs a statement of the law that peculiarities tend to appear in the offspring at an age corresponding to that at which they occurred in the parent.

Professor Newton, who was so kind as to look through the 1844 Sketch, tells me that my father’s remarks on the migration of birds, incidentally given in more than one passage, show that he had anticipated the views of some later writers.

With regard to the general style of the Sketch, it is not to be expected that it should have all the characteristics of the ‘Origin,’ and we do not, in fact, find that balance and control, that concentration and grasp, which are so striking in the work of 1859.

In the Autobiography (page 68, volume 1) my father has stated what seemed to him the chief flaw of the 1844 Sketch; he had overlooked “one problem of great importance,” the problem of the divergence of character. This point is discussed in the ‘Origin of Species,’ but, as it may not be familiar to all readers, I will give a short account of the difficulty and its solution. The author begins by stating that varieties differ from each other less than species, and then goes on: “Nevertheless, according to my view, varieties are species in process of formation…How then does the lesser difference between varieties become augmented into the greater difference between species?” (‘Origin,’ 1st edition, page 111.) He shows how an analogous divergence takes place under domestication where an originally uniform stock of horses has been split up into race-horses, dray-horses, etc., and then goes on to explain how the same principle applies to natural species. “From the simple circumstance that the more diversified the descendants from any one species become in structure, constitution, and habits, by so much will they be better enabled to seize on many and widely diversified places in the polity of nature, and so be enabled to increase in numbers.”

The principle is exemplified by the fact that if on one plot of ground a single variety of wheat be sown, and on to another a mixture of varieties, in the latter case the produce is greater. More individuals have been able to exist because they were not all of the same variety. An organism becomes more perfect and more fitted to survive when by division of labour the different functions of life are performed by different organs. In the same way a species becomes more efficient and more able to survive when different sections of the species become differentiated so as to fill different stations.

In reading the Sketch of 1844, I have found it difficult to recognise the absence of any definite statement of the principle of divergence as a flaw in the Essay. Descent with modification implies divergence, and we become so habituated to a belief in descent, and therefore in divergence, that we do not notice the absence of proof that divergence is in itself an advantage. As shown in the Autobiography, my father in 1876 found it hardly credible that he should have overlooked the problem and its solution.

The following letter will be more in place here than its chronological position, since it shows what was my father’s feeling as to the value of the Sketch at the time of its completion.]

When we turn to the Sketch of his theory, written in 1844 (still therefore before the second edition of the ‘Journal’ was completed), we find an enormous advance made on the note-book of 1837. The Sketch is an fact a surprisingly complete presentation of the argument afterwards familiar to us in the ‘Origin of Species.’ There is some obscurity as to the date of the short Sketch which formed the basis of the 1844 Essay. We know from his own words (volume i., page 68), that it was in June 1842 that he first wrote out a short sketch of his views. (This version I cannot find, and it was probably destroyed, like so much of his MS., after it had been enlarged and re-copied in 1844.) This statement is given with so much circumstance that it is almost impossible to suppose that it contains an error of date. It agrees also with the following extract from his Diary.

1842. May 18th. Went to Maer.

“June 15th to Shrewsbury, and on 18th to Capel Curig. During my stay at Maer and Shrewsbury (five years after commencement) wrote pencil-sketch of species theory.”

Again in the introduction to the ‘Origin,’ page 1, he writes, “after an interval of five years’ work” [from 1837, i.e. in 1842], “I allowed myself to speculate on the subject, and drew up some short notes.”

Nevertheless in the letter signed by Sir C. Lyell and Sir J.D. Hooker, which serves as an introduction to the joint paper of Messrs. C. Darwin and A. Wallace on the ‘Tendency of Species to form Varieties,’ (‘Linn. Soc. Journal,’ 1858, page 45.) the essay of 1844 (extracts from which form part of the paper) is said to have been “sketched in 1839, and copied in 1844.” This statement is obviously made on the authority of a note written in my father’s hand across the Table of Contents of the 1844 Essay. It is to the following effect: “This was sketched in 1839, and copied out in full, as here written and read by you in 1844.” I conclude that this note was added in 1858, when the MS. was sent to Sir J.D. Hooker (see Letter of June 29, 1858, page 476). There is also some further evidence on this side of the question. Writing to Mr. Wallace (January 25, 1859) my father says:– “Every one whom I have seen has thought your paper very well written and interesting. It puts my extracts (written in 1839, now just twenty years ago!), which I must say in apology were never for an instant intended for publication; into the shade.” The statement that the earliest sketch was written in 1839 has been frequently made in biographical notices of my father, no doubt on the authority of the ‘Linnean Journal,’ but it must, I think, be considered as erroneous. The error may possibly have arisen in this way. In writing on the Table of Contents of the 1844 MS. that it was sketched in 1839, I think my father may have intended to imply that the framework of the theory was clearly thought out by him at that date. In the Autobiography he speaks of the time, “about 1839, when the theory was clearly conceived,” meaning, no doubt, the end of 1838 and beginning of 1839, when the reading of Malthus had given him the key to the idea of natural selection. But this explanation does not apply to the letter to Mr. Wallace; and with regard to the passage (My father certainly saw the proofs of the paper, for he added a foot-note apologising for the style of the extracts, on the ground that the “work was never intended for publication.”) in the ‘Linnean Journal’ it is difficult to understand how it should have been allowed to remain as it now stands, conveying, as it clearly does, the impression that 1839 was the date of his earliest written sketch.

The sketch of 1844 is written in a clerk’s hand, in two hundred and thirty-one pages folio, blank leaves being alternated with the MS. with a view to amplification. The text has been revised and corrected, criticisms being pencilled by himself on the margin. It is divided into two parts: I. “On the variation of Organic Beings under Domestication and in their Natural State.” II. “On the Evidence favourable and opposed to the view that Species are naturally formed races descended from common Stocks.” The first part contains the main argument of the ‘Origin of Species.’ It is founded, as is the argument of that work, on the study of domestic animals, and both the Sketch and the ‘Origin’ open with a chapter on variation under domestication and on artificial selection. This is followed, in both essays, by discussions on variation under nature, on natural selection, and on the struggle for life. Here, any close resemblance between the two essays with regard to arrangement ceases. Chapter III. of the Sketch, which concludes the first part, treats of the variations which occur in the instincts and habits of animals, and thus corresponds to some extent with Chapter VII. of the ‘Origin’ (1st edition). It thus forms a complement to the chapters which deal with variation in structure. It seems to have been placed thus early in the Essay to prevent the hasty rejection of the whole theory by a reader to whom the idea of natural selection acting on instincts might seem impossible. This is the more probable, as the Chapter on Instinct in the ‘Origin’ is specially mentioned (Introduction, page 5) as one of the “most apparent and gravest difficulties on the theory.” Moreover the chapter in the Sketch ends with a discussion, “whether any particular corporeal structures…are so wonderful as to justify the rejection prima facie of our theory.” Under this heading comes the discussion of the eye, which in the ‘Origin’ finds its place in Chapter VI. under “Difficulties of the Theory.” The second part seems to have been planned in accordance with his favourite point of view with regard to his theory. This is briefly given in a letter to Dr. Asa Gray, November 11th, 1859: “I cannot possibly believe that a false theory would explain so many classes of facts, as I think it certainly does explain. On these grounds I drop my anchor, and believe that the difficulties will slowly disappear.” On this principle, having stated the theory in the first part, he proceeds to show to what extent various wide series of facts can be explained by its means.

Thus the second part of the Sketch corresponds roughly to the nine concluding Chapters of the First Edition of the ‘Origin.’ But we must exclude Chapter VII. (‘Origin’) on Instinct, which forms a chapter in the first part of the Sketch, and Chapter VIII. (‘Origin’) on Hybridism, a subject treated in the Sketch with ‘Variation under Nature’ in the first part.

The following list of the chapters of the second part of the Sketch will illustrate their correspondence with the final chapters of the ‘Origin.’

Chapter I. “On the kind of intermediateness necessary, and the number of such intermediate forms.” This includes a geological discussion, and corresponds to parts of Chapters VI. and IX. of the ‘Origin.’

Chapter II. “The gradual appearance and disappearance of organic beings.” Corresponds to Chapter X. of the ‘Origin.’

Chapter III. “Geographical Distribution.” Corresponds to Chapters XI. and XII. of the ‘Origin.’

Chapter IV. “Affinities and Classification of Organic beings.”

Chapter V. “Unity of Type,” Morphology, Embryology.

Chapter VI. Rudimentary Organs.

These three chapters correspond to Chapter XII. of the ‘Origin.’

Chapter VII. Recapitulation and Conclusion. The final sentence of the Sketch, which we saw in its first rough form in the Note Book of 1837, closely resembles the final sentence of the ‘Origin,’ much of it being identical. The ‘Origin’ is not divided into two “Parts,” but we see traces of such a division having been present in the writer’s mind, in this resemblance between the second part of the Sketch and the final chapters of the ‘Origin.’ That he should speak (‘Origin,’ Introduction, page 5.) of the chapters on transition, on instinct, on hybridism, and on the geological record, as forming a group, may be due to the division of his early MS. into two parts.