You will, I presume, give the proportion of the species to the genera, i.e., show on an average how many species each genus contains; though I have done this for myself.
If it would not be too troublesome, do you not think it would be very interesting, and give a very good idea of your Flora, to divide the species into three groups, viz., (a) species common to the old world, stating numbers common to Europe and Asia; (b) indigenous species, but belonging to genera found in the old world; and (c) species belonging to genera confined to America or the New World. To make (according to my ideas) perfection perfect, one ought to be told whether there are other cases, like Erica, of genera common in Europe or in Old World not found in your area. But honestly I feel that it is quite ridiculous my writing to you at such length on the subject; but, as you have asked me, I do it gratefully, and write to you as I should to Hooker, who often laughs at me unmercifully, and I am sure you have better reason to do so.
There is one point on which I am MOST anxious for information, and I mention it with the greatest hesitation, and only in the FULL BELIEF that you will believe me that I have not the folly and presumption to hope for a second that you will give it, without you can with very little trouble. The point can at present interest no one but myself, which makes the case wholly different from geographical distribution. The only way in which, I think, you possibly could do it with little trouble would be to bear in mind, whilst correcting your proof-sheets of the Manual, my question and put a cross or mark to the species, and whenever sending a parcel to Hooker to let me have such old sheets. But this would give you the trouble of remembering my question, and I can hardly hope or expect that you will do it. But I will just mention what I want; it is to have marked the "close species" in a Flora, so as to compare in DIFFERENT Floras whether the same genera have "close species," and for other purposes too vague to enumerate. I have attempted, by Hooker's help, to ascertain in a similar way whether the different species of the same genera in distant quarters of the globe are variable or present varieties. The definition I should give of a "CLOSE SPECIES" was one that YOU thought specifically distinct, but which you could conceive some other GOOD botanist might think only a race or variety; or, again, a species that you had trouble, though having opportunities of knowing it well, in discriminating from some other species. Supposing that you were inclined to be so very kind as to do this, and could (which I do not expect) spare the time, as I have said, a mere cross to each such species in any useless proof-sheets would give me the information desired, which, I may add, I know must be vague.
How can I apologise enough for all my presumption and the extreme length of this letter? The great good nature of your letter to me has been partly the cause, so that, as is too often the case in this world, you are punished for your good deeds. With hearty thanks, believe me,
Yours very truly and gratefully, CH. DARWIN.
CHARLES DARWIN TO J.D. HOOKER. Down, 18th [July, 1855].
...I think I am getting a MILD case about Charlock seed (In the "Gardeners' Chronicle", 1855, page 758, appeared a notice (half a column in length) by my father on the "Vitality of Seeds." The facts related refer to the "Sand-walk"; the wood was planted in 1846 on a piece of pasture land laid down as grass in 1840. In 1855, on the soil being dug in several places, Charlock (Brassica sinapistrum) sprang up freely. The subject continued to interest him, and I find a note dated July 2nd, 1874, in which my father recorded that forty-six plants of Charlock sprang up in that year over a space (14 x 7 feet) which had been dug to a considerable depth.); but just as about salting, ill-luck to it, I cannot remember how many years you would allow that Charlock seed might live in the ground. Next time you write, show a bold face, and say in how many years, you think, Charlock seed would probably all be dead. A man told me the other day of, as I thought, a splendid instance, — and SPLENDID it was, for according to his evidence the seed came up alive out of the LOWER PART of the LONDON CLAY!! I disgusted him by telling him that Palms ought to have come up.
You ask how far I go in attributing organisms to a common descent; I answer I know not; the way in which I intend treating the subject, is to show (AS FAR AS I CAN) the facts and arguments for and against the common descent of the species of the same genus; and then show how far the same arguments tell for or against forms, more and more widely different: and when we come to forms of different orders and classes, there remain only some such arguments as those which can perhaps be deduced from similar rudimentary structures, and very soon not an argument is left.
[The following extract from a letter to Mr. Fox [October, 1855 (In this year he published ('Phil. Mag.' x.) a paper 'On the power of icebergs to make rectilinear uniformly-directed grooves across a submarine undulatory surface.'") gives a brief mention of the last meeting of the British Association which he attended: ] "I really have no news: the only thing we have done for a long time, was to go to Glasgow; but the fatigue was to me more than it was worth, and E. caught a bad cold. On our return we stayed a single day at Shrewsbury, and enjoyed seeing the old place. I saw a little of Sir Philip (Sir P. Egerton was a neighbour of Mr. Fox.) (whom I liked much), and he asked me "why on earth I instigated you to rob his poultry-yard?' The meeting was a good one, and the Duke of Argyll spoke excellently."]
CHAPTER 1.XII. — THE UNFINISHED BOOK
MAY 1856 TO JUNE 1858
[In the Autobiographical chapter (page 69,) my father wrote: — "Early in 1856 Lyell advised me to write out my views pretty fully, and I began at once to do so on a scale three or four times as extensive as that which was afterwards followed in my 'Origin of Species;' yet it was only an abstract of the materials which I had collected." The letters in the present chapter are chiefly concerned with the preparation of this unfinished book.
The work was begun on May 14th, and steadily continued up to June 1858, when it was interrupted by the arrival of Mr. Wallace's MS. During the two years which we are now considering he wrote ten chapters (that is about one-half) of the projected book. He remained for the most part at home, but paid several visits to Dr. Lane's Water-Cure Establishment at Moor Park, during one of which he made a pilgrimage to the shrine of Gilbert White at Selborne.]
LETTERS.
CHARLES DARWIN TO C. LYELL May 3 [1856].
...With respect to your suggestion of a sketch of my views, I hardly know what to think, but will reflect on it, but it goes against my prejudices. To give a fair sketch would be absolutely impossible, for every proposition requires such an array of facts. If I were to do anything, it could only refer to the main agency of change — selection — and perhaps point out a very few of the leading features, which countenance such a view, and some few of the main difficulties. But I do not know what to think; I rather hate the idea of writing for priority, yet I certainly should be vexed if any one were to publish my doctrines before me. Anyhow, I thank you heartily for your sympathy. I shall be in London next week, and I will call on you on Thursday morning for one hour precisely, so as not to lose much of your time and my own; but will you let me this time come as early as 9 o'clock, for I have much which I must do in the morning in my strongest time? Farewell, my dear old patron.
Yours, C. DARWIN.
By the way, THREE plants have come up out of the earth, perfectly enclosed in the roots of the trees. And twenty-nine plants in the table-spoonful of mud, out of the little pond; Hooker was surprised at this, and struck with it, when I showed him how much mud I had scraped off one duck's feet.
If I did publish a short sketch, where on earth should I publish it?
If I do NOT hear, I shall understand that I may come from 9 to 10 on Thursday.
CHARLES DARWIN TO J.D. HOOKER. May 9th, [1856].
...I very much want advice and TRUTHFUL consolation if you can give it. I had a good talk with Lyell about my species work, and he urges me strongly to publish something. I am fixed against any periodical or Journal, as I positively will NOT expose myself to an Editor or a Council, allowing a publication for which they might be abused. If I publish anything it must be a VERY THIN and little volume, giving a sketch of my views and difficulties; but it is really dreadfully unphilosophical to give a resume, without exact references, of an unpublished work. But Lyell seemed to think I might do this, at the suggestion of friends, and on the ground, which I might state, that I had been at work for eighteen (The interval of eighteen years, from 1837 when he began to collect facts, would bring the date of this letter to 1855, not 1856, nevertheless the latter seems the more probable date.) years, and yet could not publish for several years, and especially as I could point out difficulties which seemed to me to require especial investigation. Now what think you? I should be really grateful for advice. I thought of giving up a couple of months and writing such a sketch, and trying to keep my judgment open whether or no to publish it when completed. It will be simply impossible for me to give exact references; anything important I should state on the authority of the author generally; and instead of giving all the facts on which I ground my opinion, I could give by memory only one or two. In the Preface I would state that the work could not be considered strictly scientific, but a mere sketch or outline of a future work in which full references, etc. should be given. Eheu, eheu, I believe I should sneer at any one else doing this, and my only comfort is, that I TRULY never dreamed of it, till Lyell suggested it, and seems deliberately to think it advisable.
I am in a peck of troubles and do pray forgive me for troubling you.
Yours affectionately, C. DARWIN.
CHARLES DARWIN TO J.D. HOOKER. May 11th [1856].
...Now for a MORE IMPORTANT! subject, viz., my own self: I am extremely glad you think well of a separate "Preliminary Essay" (i.e., if anything whatever is published; for Lyell seemed rather to doubt on this head) (The meaning of the sentence in parentheses is obscure.); but I cannot bear the idea of BEGGING some Editor and Council to publish, and then perhaps to have to APOLOGISE humbly for having led them into a scrape. In this one respect I am in the state which, according to a very wise saying of my father's, is the only fit state for asking advice, viz., with my mind firmly made up, and then, as my father used to say, GOOD advice was very comfortable, and it was easy to reject BAD advice. But Heaven knows I am not in this state with respect to publishing at all any preliminary essay. It yet strikes me as quite unphilosophical to publish results without the full details which have lead to such results.
It is a melancholy, and I hope not quite true view of yours that facts will prove anything, and are therefore superfluous! But I have rather exaggerated, I see, your doctrine. I do not fear being tied down to error, i.e., I feel pretty sure I should give up anything false published in the preliminary essay, in my larger work; but I may thus, it is very true, do mischief by spreading error, which as I have often heard you say is much easier spread than corrected. I confess I lean more and more to at least making the attempt and drawing up a sketch and trying to keep my judgment, whether to publish, open. But I always return to my fixed idea that it is dreadfully unphilosophical to publish without full details. I certainly think my future work in full would profit by hearing what my friends or critics (if reviewed) thought of the outline.
To any one but you I should apologise for such long discussion on so personal an affair; but I believe, and indeed you have proved it by the trouble you have taken, that this would be superfluous.
Yours truly obliged, CH. DARWIN.
P.S. What you say (for I have just re-read your letter) that the Essay might supersede and take away all novelty and value from any future larger Book, is very true; and that would grieve me beyond everything. On the other hand (again from Lyell's urgent advice), I published a preliminary sketch of the Coral Theory, and this did neither good nor harm. I begin MOST HEARTILY to wish that Lyell had never put this idea of an Essay into my head.
FROM A LETTER TO SIR C. LYELL [July, 1856].
"I am delighted that I may say (with absolute truth) that my essay is published at your suggestion, but I hope it will not need so much apology as I at first thought; for I have resolved to make it nearly as complete as my present materials allow. I cannot put in all which you suggest, for it would appear too conceited."
FROM A LETTER TO W.D. FOX. Down, June 14th [1856].
"...What you say about my Essay, I dare say is very true; and it gave me another fit of the wibber-gibbers: I hope that I shall succeed in making it modest. One great motive is to get information on the many points on which I want it. But I tremble about it, which I should not do, if I allowed some three or four more years to elapse before publishing anything..."
[The following extracts from letters to Mr. Fox are worth giving, as showing how great was the accumulation of material which now had to be dealt with.
June 14th [1856].
"Very many thanks for the capital information on cats; I see I had blundered greatly, but I know I had somewhere your original notes; but my notes are so numerous during nineteen years' collection, that it would take me at least a year to go over and classify them."
November 1856.
"Sometimes I fear I shall break down, for my subject gets bigger and bigger with each month's work."]
CHARLES DARWIN TO C. LYELL Down, 16th [June, 1856].
My dear Lyell,
I am going to do the most impudent thing in the world. But my blood gets hot with passion and turns cold alternately at the geological strides, which many of your disciples are taking.
Here, poor Forbes made a continent to [i.e., extending to] North America and another (or the same) to the Gulf weed; Hooker makes one from New Zealand to South America and round the World to Kerguelen Land. Here is Wollaston speaking of Madeira and P. Santo "as the sure and certain witnesses of a former continent." Here is Woodward writes to me, if you grant a continent over 200 or 300 miles of ocean depths (as if that was nothing), why not extend a continent to every island in the Pacific and Atlantic Oceans? And all this within the existence of recent species! If you do not stop this, if there be a lower region for the punishment of geologists, I believe, my great master, you will go there. Why, your disciples in a slow and creeping manner beat all the old Catastrophists who ever lived. You will live to be the great chief of the Catastrophists.
There, I have done myself a great deal of good, and have exploded my passion.
So my master, forgive me, and believe me, ever yours, C. DARWIN.
P.S. Don't answer this, I did it to ease myself.
CHARLES DARWIN TO J.D. HOOKER. Down [June] 17th, 1856.
...I have been very deeply interested by Wollaston's book ('The Variation of Species,' 1856.), though I differ GREATLY from many of his doctrines. Did you ever read anything so rich, considering how very far he goes, as his denunciations against those who go further: "Most mischievous," "absurd," "unsound." Theology is at the bottom of some of this. I told him he was like Calvin burning a heretic. It is a very valuable and clever book in my opinion. He has evidently read very little out of his own line. I urged him to read the New Zealand essay. His Geology also is rather eocene, as I told him. In fact I wrote most frankly; he says he is sure that ultra-honesty is my characteristic: I do not know whether he meant it as a sneer; I hope not. Talking of eocene geology, I got so wrath about the Atlantic continent, more especially from a note from Woodward (who has published a capital book on shells), who does not seem to doubt that every island in the Pacific and Atlantic are the remains of continents, submerged within period of existing species, that I fairly exploded, and wrote to Lyell to protest, and summed up all the continents created of late years by Forbes (the head sinner!) YOURSELF, Wollaston, and Woodward, and a pretty nice little extension of land they make altogether! I am fairly rabid on the question and therefore, if not wrong already, am pretty sure to become so...
I have enjoyed your note much. Adios, C. DARWIN.
P.S. [June] 18th. Lyell has written me a CAPITAL letter on your side, which ought to upset me entirely, but I cannot say it does quite.
Though I must try and cease being rabid and try to feel humble, and allow you all to make continents, as easily as a cook does pancakes.
CHARLES DARWIN TO C. LYELL. Down, June 25th [1856].
My dear Lyell,
I will have the following tremendous letter copied to make the reading easier, and as I want to keep a copy.
As you say you would like to hear my reasons for being most unwilling to believe in the continental extensions of late authors, I gladly write them, as, without I am convinced of my error, I shall have to give them condensed in my essay, when I discuss single and multiple creation; I shall therefore be particularly glad to have your general opinion on them. I may QUITE LIKELY have persuaded myself in my wrath that there is more in them than there is. If there was much more reason to admit a continental extension in any one or two instances (as in Madeira) than in other cases, I should feel no difficulty whatever. But if on account of European plants, and littoral sea shells, it is thought necessary to join Madeira to the mainland, Hooker is quite right to join New Holland to New Zealand, and Auckland Island (and Raoul Island to N.E.), and these to S. America and the Falklands, and these to Tristan d'Acunha, and these to Kerguelen Land; thus making, either strictly at the same time, or at different periods, but all within the life of recent beings, an almost circumpolar belt of land. So again Galapagos and Juan Fernandez must be joined to America; and if we trust to littoral see shells, the Galapagos must have been joined to the Pacific Islands (2400 miles distant) as well as to America, and as Woodward seems to think all the islands in the Pacific into a magnificent continent; also the islands in the Southern Indian Ocean into another continent, with Madagascar and Africa, and perhaps India. In the North Atlantic, Europe will stretch half-way across the ocean to the Azores, and further north right across. In short, we must suppose probably, half the present ocean was land within the period of living organisms. The Globe within this period must have had a quite different aspect. Now the only way to test this, that I can see, is to consider whether the continents have undergone within this same period such wonderful permutations. In all North and South and Central America, we have both recent and miocene (or eocene) shells, quite distinct on the opposite sides, and hence I cannot doubt that FUNDAMENTALLY America has held its place since at least, the miocene period. In Africa almost all the living shells are distinct on the opposite sides of the inter-tropical regions, short as the distance is compared to the range of marine mollusca, in uninterrupted seas; hence I infer that Africa has existed since our present species were created. Even the isthmus of Suez and the Aralo-Caspian basin have had a great antiquity. So I imagine, from the tertiary deposits, has India. In Australia the great fauna of extinct marsupials shows that before the present mammals appeared, Australia was a separate continent. I do not for one second doubt that very large portions of all these continents have undergone GREAT changes of level within this period, but yet I conclude that fundamentally they stood as barriers in the sea, where they now stand; and therefore I should require the weightiest evidence to make me believe in such immense changes within the period of living organisms in our oceans, where, moreover, from the great depths, the changes must have been vaster in a vertical sense.
SECONDLY.
Submerge our present continents, leaving a few mountain peaks as islands, and what will the character of the islands be, — Consider that the Pyrenees, Sierra Nevada, Apennines, Alps, Carpathians, are non-volcanic, Etna and Caucasus, volcanic. In Asia, Altai and Himalaya, I believe non-volcanic. In North Africa the non-volcanic, as I imagine, Alps of Abyssinia and of the Atlas. In South Africa, the Snow Mountains. In Australia, the non-volcanic Alps. In North America, the White Mountains, Alleghanies and Rocky Mountains — some of the latter alone, I believe, volcanic. In South America to the east, the non-volcanic [Silla?] of Caracas, and Itacolumi of Brazil, further south the Sierra Ventanas, and in the Cordilleras, many volcanic but not all. Now compare these peaks with the oceanic islands; as far as known all are volcanic, except St. Paul's (a strange bedevilled rock), and the Seychelles, if this latter can be called oceanic, in the line of Madagascar; the Falklands, only 500 miles off, are only a shallow bank; New Caledonia, hardly oceanic, is another exception. This argument has to me great weight. Compare on a Geographical map, islands which, we have SEVERAL reasons to suppose, were connected with mainland, as Sardinia, and how different it appears. Believing, as I am inclined, that continents as continents, and oceans as oceans, are of immense antiquity — I should say that if any of the existing oceanic islands have any relation of any kind to continents, they are forming continents; and that by the time they could form a continent, the volcanoes would be denuded to their cores, leaving peaks of syenite, diorite, or porphyry. But have we nowhere any last wreck of a continent, in the midst of the ocean? St. Paul's Rock, and such old battered volcanic islands, as St. Helena, may be; but I think we can see some reason why we should have less evidence of sinking than of rising continents (if my view in my Coral volume has any truth in it, viz.: that volcanic outbursts accompany rising areas), for during subsidence there will be no compensating agent at work, in rising areas there will be the ADDITIONAL element of outpoured volcanic matter.
THIRDLY.
Considering the depth of the ocean, I was, before I got your letter, inclined vehemently to dispute the vast amount of subsidence, but I must strike my colours. With respect to coral reefs, I carefully guarded against its being supposed that a continent was indicated by the groups of atolls. It is difficult to guess, as it seems to me, the amount of subsidence indicated by coral reefs; but in such large areas as the Lowe Archipelago, the Marshall Archipelago, and Laccadive group, it would, judging, from the heights of existing oceanic archipelagoes, be odd, if some peaks of from 8000 to 10,000 feet had not been buried. Even after your letter a suspicion crossed me whether it would be fair to argue from subsidences in the middle of the greatest oceans to continents; but refreshing my memory by talking with Ramsay in regard to the probable thickness in one vertical line of the Silurian and carboniferous formation, it seems there must have been AT LEAST 10,000 feet of subsidence during these formations in Europe and North America, and therefore during the continuance of nearly the same set of organic beings. But even 12,000 feet would not be enough for the Azores, or for Hooker's continent; I believe Hooker does not infer a continuous continent, but approximate groups of islands, with, if we may judge from existing continents, not PROFOUNDLY deep sea between them; but the argument from the volcanic nature of nearly every existing oceanic island tell against such supposed groups of islands, — for I presume he does not suppose a mere chain of volcanic islands belting the southern hemisphere.
FOURTHLY.
The supposed continental extensions do not seem to me, perfectly to account for all the phenomena of distribution on islands; as the absence of mammals and Batrachians; the absence of certain great groups of insects on Madeira, and of Acaciae and Banksias, etc., in New Zealand; the paucity of plants in some cases, etc. Not that those who believe in various accidental means of dispersal, can explain most of these cases; but they may at least say that these facts seem hardly compatible with former continuous land.
FINALLY.
For these several reasons, and especially considering it certain (in which you will agree) that we are extremely ignorant of means of dispersal, I cannot avoid thinking that Forbes' 'Atlantis,' was an ill-service to science, as checking a close study of means of dissemination. I shall be really grateful to hear, as briefly as you like, whether these arguments have any weight with you, putting yourself in the position of an honest judge. I told Hooker that I was going to write to you on this subject; and I should like him to read this; but whether he or you will think it worth time and postage remains to be proved.
Yours most truly, CHARLES DARWIN.
[On July 8th he wrote to Sir Charles Lyell.
"I am sorry you cannot give any verdict on Continental extensions; and I infer that you think my argument of not much weight against such extensions. I know I wish I could believe so."]
CHARLES DARWIN TO ASA GRAY. Down, July 20th [1856].
...It is not a little egotistical, but I should like to tell you (and I do not THINK I have) how I view my work. Nineteen years (!) ago it occurred to me that whilst otherwise employed on Natural History, I might perhaps do good if I noted any sort of facts bearing on the question of the origin of species, and this I have since been doing. Either species have been independently created, or they have descended from other species, like varieties from one species. I think it can be shown to be probable that man gets his most distinct varieties by preserving such as arise best worth keeping and destroying the others, but I should fill a quire if I were to go on. To be brief, I ASSUME that species arise like our domestic varieties with MUCH extinction; and then test this hypothesis by comparison with as many general and pretty well-established propositions as I can find made out, — in geographical distribution, geological history, affinities, etc., etc. And it seems to me that, SUPPOSING that such hypothesis were to explain such general propositions, we ought, in accordance with the common way of following all sciences, to admit it till some better hypothesis be found out. For to my mind to say that species were created so and so is no scientific explanation, only a reverent way of saying it is so and so. But it is nonsensical trying to show how I try to proceed in the compass of a note. But as an honest man, I must tell you that I have come to the heterodox conclusion that there are no such things as independently created species — that species are only strongly defined varieties. I know that this will make you despise me. I do not much underrate the many HUGE difficulties on this view, but yet it seems to me to explain too much, otherwise inexplicable, to be false. Just to allude to one point in your last note, viz., about species of the same genus GENERALLY having a common or continuous area; if they are actual lineal descendants of one species, this of course would be the case; and the sadly too many exceptions (for me) have to be explained by climatal and geological changes. A fortiori on this view (but on exactly same grounds), all the individuals of the same species should have a continuous distribution. On this latter branch of the subject I have put a chapter together, and Hooker kindly read it over. I thought the exceptions and difficulties were so great that on the whole the balance weighed against my notions, but I was much pleased to find that it seemed to have considerable weight with Hooker, who said he had never been so much staggered about the permanence of species.
I must say one word more in justification (for I feel sure that your tendency will be to despise me and my crotchets), that all my notions about HOW species change are derived from long continued study of the works of (and converse with) agriculturists and horticulturists; and I believe I see my way pretty clearly on the means used by nature to change her species and ADAPT them to the wondrous and exquisitely beautiful contingencies to which every living being is exposed...
CHARLES DARWIN TO J.D. HOOKER. Down, July 30th 1856.
My dear Hooker,
Your letter is of MUCH value to me. I was not able to get a definite answer from Lyell (On the continental extensions of Forbes and others.), as you will see in the enclosed letters, though I inferred that he thought nothing of my arguments. Had it not been for this correspondence, I should have written sadly too strongly. You may rely on it I shall put my doubts moderately. There never was such a predicament as mine: here you continental extensionists would remove enormous difficulties opposed to me, and yet I cannot honestly admit the doctrine, and must therefore say so. I cannot get over the fact that not a fragment of secondary or palaeozoic rock has been found on any island above 500 or 600 miles from a mainland. You rather misunderstand me when you think I doubt the POSSIBILITY of subsidence of 20,000 or 30,000 feet; it is only probability, considering such evidence as we have independently of distribution. I have not yet worked out in full detail the distribution of mammalia, both IDENTICAL and allied, with respect to the ONE ELEMENT OF DEPTH OF THE SEA; but as far as I have gone, the results are to me surprisingly accordant with my very most troublesome belief in not such great geographical changes as you believe; and in mammalia we certainly know more of MEANS of distribution than in any other class. Nothing is so vexatious to me, as so constantly finding myself drawing different conclusions from better judges than myself, from the same facts.