Tuesday, 12 March 2019

Darwin's correspondence concerning Hooker's address to the British Association for the Aadvancement of Science (1881)

For some odd reason the correspondence between Darwin and Hooker, which concerns the latter's address for the 51st meeting of the British Association for the Advancement of Science (BAAS), delivered at York on 1 September 1881, has never been published as an ongoing discourse. However, the context usually turns out to be important in historical issues. Stitching together isolated quotes from decades apart and from various sources can easily lead to a patchwork of facts that biases their interpretation.

Therefore, this post is a transcription of the whole Hooker-Darwin correspondence on Hooker's BAAS-address. Both hands are very difficult to read and I had some help by Roland Jackson (@RolandJackson, author of The Ascent of John Tyndall) with some of Hooker's letters. When transcriptions already existed in the form of published collections of either Darwin's or Hooker's letters, I used them. As mentioned above, however, none of the available publications give this BAAS-1881 related correspondence between Darwin and Hooker in full. That is, available transcriptions lack a lot of context. The following transcriptions remain a cloze in places. However, the links to scans of the originals at Cambridge University are given before each transcript, so that readers can confer to them. Suggestions for missing words are welcome and can be sent via Twitter to @jo_dagg.

On 20 August 1881, Hooker asked Darwin about a publication of Karl Ernst von Baer (1859. Ueber Papuas und Alfuren). Translations of the relevant passages of Baer's essay can be found in the previous post. Darwin's reply, on 21 August 1881, also refers to Leopold von Buch (1825. Physicalische Beschreibung der Canarischen Inseln; 1836 in French). Translations of the relevant passages of Buch can be found in an earlier post.

DarwinHooker Correspondence: Feb.–Sept. 1881

Uncertain words in square brackets: []. Illegible words indicated by 6 spaces: _____. [My own comments are in suare brackets and in green.]

Darwin to Hooker, 26 Feb. 1881
Part transcript: More Letters of Darwin.

“My dear Hooker
It was a real pleasure to me to see your hand-writing again, for it is a long time since I have heard of you. What a bore about the [mumps]; but I am very glad that you will soon have complete rest & change, in which [latter] I have [unbounded] faith. I suppose that Lady Hooker goes with you & I hope she may enjoy herself. Pray give her my kindest _____ . I had vaguely thought whether I would pay you a call at Kew, but thought that you would [firstly] be too busy, & it seems that you will be on the road before I could come.
I shd think that you might make a very interesting address on geograph. Distrib. [Could] you give a little history of the subject. I, for one, shd like to read such history in petto; but I can see one very great difficulty, that you yourself ought to figure most prominently in it; & this you would not do, for you are just the man to treat yourself in a dishonourable manner! I shd very much like to see you discuss some of Wallace’s views, especially his ignoring the all powerful effects of the Glacial period with respect to alpine plants. I do not know what you think, but it appears to me that he exaggerates enormously the influence of debacles or [slips] & new surface of soil being exposed for the reception of wind-blown seeds. What kinds of seeds have the plants which are common to the distant mountain-summits in Africa? Wallace lately wrote to me about the mountain-plants of Madagascar being the same with those on mountains in Africa, & seemed to think it proved dispersal by the wind, without apparently having inquired what sort of seeds the plants bore. I suppose it wd be travelling too far (though for geographical section the discussion ought to be far reaching) but I shd like to see the European or Northern element in the C. of Good Hope flora discussed. I cannot swallow Wallace’s view that European plants travelled down the Andes, tenated the hypothetical Antarctic continent (in which I quite believe), & thence spread to S. Australia & the Cape of G. Hope.
Mosley told me not long ago that he proposed to search at Kerguelen Land the coal beds most carefully, and was absolutely forbidden to do so by Sir W. Thomson, who said that he would undertake the work, and he never one visited them. This put me in a passion. I hope that you will keep your intention and make an address on distribution. Though I differ so much from Wallace, his “Island Life” seems to me a wonderful book.
Farewell. I do hope that you may have a most prosperous journey. Give my kindest remembrances to Asa Gray”

Hooker to Darwin, 12 June 1881

“Dear Darwin,
can you [conveniently] send me a few plants of [Oxalis corniculata] – to grow – we are quite out of it & you have plenty near you. I am groaning as usual, – now under the incubus of the Sectional Presidency of the B. A. in York (Geography), which I was ass enough to accept because of Lubbock. Kew is [becoming] [more] [toilsome] than [ever], & I can [rarely] get an [hour] for “Genera plant.m,” which I have been doing the Palms for 16 months at least; the most difficult task I ever undertook. They are evidently a very ancient group & much dislocated structurally and geographically.
     My wife is vastly the better for her Italian trip, though the good of it is [not] likely to [last] long under the hurry & worry of this “[Home/House] of [call] of all natives” - She is [inquiring] about a farm house at Knock-[holt] to take the children to in autumn. Should she fail in her ______ she may ask Mrs Darwin if she knows of any place for them in your neighbourhood.
Ever affectedly, Joseph Hooker”

Darwin to Hooker, 15 June 1881

“My dear Hooker
it was [real] pleasure to me to see once again your well-known hand-writing on the [outside] of your [note]. I do not know how long you have returned from [Italy], but I am very sorry that you are so bothered [always] with work & visits. I cannot but think that you are too kind & civil to visitors, & too conscientious about your official work. But a man cannot cure his virtues anymore than his vices, after early growth, so you must bear your burthen. It is, however, a [great] misfortune for science that you have so very little spare time for the Genera. I can well believe what an awful job the Palms must be.
Even their size must be very inconvenient. You & Bentham must hate the monocotyledons, for what work the [Orchideae] must have been & Graminaceae & Cyperaceae will be.
I am rather despondent about myself & my troubles [are] of an exactly opposite nature to yours, for idleness is downright misery to me, as I find here, as I cannot forget my discomfort for an hour. I have not the heart or [strength] at my age to begin any investigation, lasting years, which is the only thing, which I enjoy; & I have [no] little jobs which I can do. So I must look forward to Down [grave-yard] as the sweetest place on this Earth.
This place is magnificently beautiful & I enjoy the scenery, though weary of it; & the weather has been very cold & almost always hazy. I am so glad that your tour has [answered] for Lady Hooker. I doubt whether Knock-[holt] wd be a pleasant place: it is about [800] ft higher & much [exposed] to all the winds of [Heaven]. We return [home] in the first week of July & shd be truly [glad] to aid Lady Hooker in any [possible] manner which she will suggest.
I have written to my gardener to send you plants of Oxalis corniculata (& seeds if possible): I shd think so [common] a weed was never [asked] for before. & what a poor [return] for the hundreds of plants which I have [received] from Kew!
I hope that I have not bothered for writing so long a [post]; & I did not intend to do so. If Asa Gray has returned with you, [please] give him my kindest [remembrances]. [Frank] is working under De Berg whom he likes very much, [at Strasburg] & [seems pretty happy].
[Your] [old] friend, Charles Darwin”

Hooker to Darwin, 18 June 1881

“Dear Darwin,
Common as you [may] regard Oxalis corniculata, it was not what I intended to ask for, but a commoner, the wood-sorrel! [O. acetosella]. I had no idea you were away from home. I fear I have bothered you in vain by stupidly asking for the wrong plant (it has not [come] yet). However I cannot regret having got so long a letter from you, & with something of yourself in it too. I quite understand your misery at finding yourself when you have “all [play]” offered you, & no work to fall back upon! I should be as bad; but then I know not the condition. When I go away I have work that I can always take with me, official or other: & my misery is the lots accumulating at home. I cannot tell you how I long to throw off the trammels of official [life] & do like Bentham: it is horrid at 63, after 42 years of Public Service too, to have to work [as a pot boiler] over & above official hours. – but then it is my own fault. A man who marries & has a family [late] in life must pay for it.
I hear [that] Grey is dying. Mr & Mrs [Symonds] (my wifes parents) are here, & [insist] on the children going to them in the holidays so that we shall not want [Emma quartered] at Knock[holt]. ______ ______ ______ poor Rolleston is dead. His wife is I hear suffering from acute mania, but some at any rate of her medical attendants regard it as temporary. They have 4 children, & the eldest only 17. We have lost no end of friends this year, & it is difficult to resist the [pessimist] view of creation, when I look back however, & especially my beloved friend to the days I have spent in intercourse with you & yours, that view takes wings to itself & flies away: it is a horrid world [to be sure], but it could have been worse.
I am ______ ______ about my address for York: of which I fear you will [hear] more than you [wish] cure for [doing] incubation.”

Darwin to Hooker, 20 June 1881

“My dear Hooker,
your letter has cheered me, and the world does not look a quarter so black as it did when I wrote before. Your friendly words are worth their weight in gold.
I [daresay] you [have] got Ox. acetosella by the time if not, despatch the enclosed card & you will receive specimens. – I do not believe Ox. acetosella will even grow long except in [the] [dense], shade, – a fact which agrees with [Batelius’] experiments on the movement of the leaflets, given in my last book. – Tear up my [card], if plant not wanted, & do not acknowledge [receipt]. I am very sorry to learn about [Rolleston] & Gray – the former is a horrid case. I liked much the little I ever saw of him. This morning we heard of the death (a blissful release from suffering) of Mc [Lennan], who has left uncompleted a book more valuable, [perhaps], than Primitive [marriage]. Your address must be a horrid bore, the whole subject of Geographical Distribution has been a frightfully big one. – I wish I cd be of any [use] to you; but that’s out of the question, as [the] subject has gone much out of my mind. You ought to keep steadily before your mind, what a splendid [amount] of grand work you have done.
Ever yours affectionately, Charles Darwin”

Hooker to Darwin, 4 August 1881

“Dear Darwin
I am groaning over my address to York after a fashion with which I have more than once bored you awfully. – Now do believe me when I say that it is an unspeakable relief to me to groan towards you; – & I will have done.
I am trying to formulate my ideas on the subject of the several stages of discoveries or ideas by which the Geog. Distrib. (of plants) has been brought up to be a science & to its present level, & showing that these stages have all been erected on ideas first entertained by great voyagers or travellers, thus “hitching” myself on to the sympathies of a geographical audience! Something in this following sort of way:
1. Tournefort’s enunciation of the likeness between the vegetation of successive elevations and degrees of latitude: the true bearings of which have come out only now that we know that said vegetations are affiliated in fact as well as in appearance.
2. Humboldt’s showing that great Natural Orders, Gramineae, Leguminosae, Compsitae, etc., are subject to certain laws of increase or decrease relatively to other plants, in going polewards (in both hemispheres) and skywards. I should also refer parenthetically to his construction of the isothermals as so great an engine towards the advancement of Geog. Bot.
          Now will you give me your idea as to whether I should be right in calling Humboldt the greatest of scientific travellers, or only the most accomplished, – or most prolific? It is the custom to disparage Humboldt now as a shallow man, but when I think of what he did through his own observations during travel, for Geographical distribution of plants, for Meteorology, for Magnetism, for Topography, for Physical Geography and Hydrography, for Ethnology, for political history of Spanish America and for Antiquity of Mexico—besides the truth and picturesqueness of his descriptions of scenery and all else—I am constrained to regard him as the first of scientific travellers; do you? This is however a digression.
3. Lyell’s showing that distribution is not a thing of the present only or of the present condition of climates and present outline and contours of lands, and Forbes’ Essay on the British Flora.
4. The establishment of the permanence since the Silurian period of the present continents and oceans. Were you not the first to insist on this, or at least point this out? Do you not think that Wallace’s summing up of the proof of it is good? (I know I once disputed the doctrine, or rather could not take it in—but let that pass!)
5. The Evolution theory.
6. The discovery of fossil warm plants in high Northern regions, leading to exact ideas as to effect of glacial period as shown by Gray’s Essay.
7. I must wind up with the doctrine of general distribution being primarily from North to south and always along existing continents, with no similar general flow from S to N.—thus supporting the doctrine which has its last expression in Dyer’s Essay read before the Geog. Soc., and referred to in my last R.S. Address (1879, p. 15). Now if this is accepted, we may not too hastily throw overboard Saporta’s doctrine of the boreal origination of the main types of vegetation; and if this again is accepted we cannot altogether neglect Buffon’s argument that vegetation should have commenced where the cooling globe was first cold enough to support it, i.e. at a pole; and lastly, if this is accepted I must bring in Buffon’s speculation in its proper chronological order, and put it as No. 2 of the stages that have led up to our state of knowledge. But I am disposed to regard Saporta’s and Buffon’s views as too speculative for that and to introduce them at the end. What do you think of this point, and of it all?
            It is not even on paper, and how I am to get it all in shape before the end of the month passes my limited powers of prevision.
            I have to take some part in this Congress [the International Medical Congress held in London, 2-9 August 1881], and by request give a Garden Party on Saturday [7 Aug 1881] —it will be a dreadful ordeal I fear (except it rains!).”

Darwin to Hooker, 6 Aug. 1881

“MY DEAR HOOKER,—For Heaven's sake never speak of boring me, as it would be the greatest pleasure to aid you in the slightest degree and your letter has interested me exceedingly. I will go through your points seriatim, but I have never attended much to the history of any subject, and my memory has become atrociously bad. It will therefore be a mere chance whether any of my remarks are of any use.
Your idea, to show what travellers have done, seems to me a brilliant and just one, especially considering your audience.

1. I know nothing about Tournefort’s works.
2. I believe that you are fully right in calling Humboldt the greatest scientific traveller who ever lived. I have lately read two or three volumes again. His Geology is funny stuff; but that merely means that he was not in advance of his age. I should say he was wonderful, more for his near approach to omniscience than for originality. Whether or not his position as a scientific man is as eminent as we think, you might truly call him the parent of a grand progeny of scientific travellers, who, taken together, have done much for science.
3. It seems to me quite just to give Lyell (and secondarily E. Forbes) a very prominent place.
4. Dana was, I believe, the first man who maintained the permanence of continents and the great oceans. … When I read the Challenger’s conclusion that sediment from the land is not deposited at greater distances than 200 to 300 miles from the land, I was much strengthened in my old belief. Wallace seems to me to have argued the case excellently. Nevertheless, I would speak, if I were in your place, rather cautiously; for T. Mellard Reade has argued lately with some force against the view; but I cannot call to mind his arguments. If forced to express a judgment, I should abide by the view of approximate permanence since Cambrian days.
5. The extreme importance of the Arctic fossil plants, is self-evident. Take the opportunity of groaning over [our] ignorance of the Lignite Plants of Kerguelen Land, or any Antarctic land. It might do good.
6. I cannot avoid feeling sceptical about the travelling of plants from the North except during the Tertiary period. It may of course have been so and probably was so from one of the two poles at the earliest period, during Pre-Cambrian ages; but such speculations seem to me hardly scientific, seeing how little we know of the old Floras. I will now jot down without any order a few miscellaneous remarks.

I think you ought to allude to Alph. De Candolle's great book, for though it (like almost everything else) is washed out of my mind, yet I remember most distinctly thinking it a very valuable work. Anyhow, you might allude to his excellent account of the history of all cultivated plants.
How shall you manage to allude to your New Zealand and Tierra del Fuego work? if you do not allude to them you will be scandalously unjust.
The many Angiosperm plants in the Cretacean beds of the United States (and as far as I can judge the age of these beds has been fairly well made out) seems to me a fact of very great importance, so is their relation to the existing flora of the United States under an Evolutionary point of view. Have not some Australian extinct forms been lately found in Australia? or have I dreamed it?
Again, the recent discovery of plants rather low down in our Silurian beds is very important. Nothing is more extraordinary in the history of the Vegetable Kingdom, as it seems to me, than the apparently very sudden or abrupt development of the higher plants. I have sometimes speculated whether there did not exist somewhere during long ages an extremely isolated continent, perhaps near the South Pole.
Hence I was greatly interested by a view which Saporta propounded to me, a few years ago, at great length in MS. and which I fancy he has since published, as I urged him to do—viz., that as soon as flower-frequenting insects were developed, during the latter part of the secondary period, an enormous impulse was given to the development of the higher plants by cross-fertilization being thus suddenly formed.
A few years ago I was much struck with Axel Blytt's* [*See footnote, Vol. iii. p. 215.] Essay showing from observation, on the peat beds in Scandinavia, that there had apparently been long periods with more rain and other with less rain (perhaps connected with Croll's recurrent astronomical periods), and that these periods had largely determined the present distribution of the plants of Norway and Sweden. This seemed to me a very important essay.

I have just read over my remarks and I fear that they will not be of the slightest use to you.
I cannot but think that you have got through the hardest, or at least the most difficult, part of your work in having made so good and striking a sketch of what you intend to say; but I can quite understand how you must groan over the great necessary labour.
I most heartily sympathise with you on the successes of B. and R.: as years advance what happens to oneself becomes of very little consequence, in comparison with the careers of our children.
Keep your spirits up, for I am convinced that you will make an excellent address.
Ever yours affectionately, CHARLES DARWIN”

Hooker to Darwin, 11 Aug. 1881

“My dear Darwin,
Your letter and memos have been unspeakable comforts—for I was beginning to despair of making any Address anything but a budget of snippets of facts and ideas, and you have both helped and encouraged me to give one part of it at any rate a consecutive scientific character.
            Then too the revival of our scientific correspondence and interchange of ideas is extraordinarily pleasing to me, who regard myself as your pupil.
            I am indeed glad that your old appreciation of Humboldt is no more dimmed than is mine. I have been re-reading all his Geog. Bot. Essays, and it is impossible to deny their supreme ability and approach to originality. I wish I had time to write, and space to give to all I think of them—his ‘Distribution Arithmetices’ of the great groups, expressed in definite proportions, is a stroke of originality, if not of genius, and I have called it a sort of parallel (?) (I can’t find a good word!) to his Isothermal lines.
            I cannot find a reference to the permanence of continents in your ‘Coral Reefs’ – a book by the way that shook my confidence in that theory more than all others put together, and the effect of which it has required years of thought to eliminate or rather to overlay. I thought the idea was first published in your ‘Geological Observations,’ of which I cannot find my copy (but shall). Any of Dana’s works must have been long after both. Where does he ‘reclaim,’ and where does J. Mellard Reade publish his vies? I may have long cogitated over the fact that the main water parting Asia is not coincident with the greater elevations of that continent but runs obliquely from S.W. to N.E., and I sometimes determined by huge sedimentary deposits as in Upper India, at others by very low mountains—does this not imply vast oscillations over an already formed land of continental extension?
    I am doubtful about going into the Flora of part ages, beyond the Tertiary. I quite believe in the sudden development of the mass of Phanerogams being due to the introduction of flower-feeding insects, though we must not forget that insects occur in the coal and may have been flower-feeding too.
      I have dealt with Saporta’s view of the polar origin of Floras in my last R.S. Address. I hope we may talk over them and many other such matters when too late for my Address!
     It appears to me that the great Botanical question to settle is, whether the main endemic Southern temperate types originated there and spread Northwards, or whether they originated in the North and have only just reached the South, and have increased and multiplied there (to be turned out in time by the Northern perhaps). The balance of evidence seems to favor the latter view, and if Palaeontologists are to be believed in crediting our tertiaries (even polar ones?) with Proteaceae, it would tend to confirm this view, as do the Cycadeae, not about extinct in the N. Hemisphere and swarming in the South.
      Buffon’s and Saporta’s views of life originating at a pole, because a pole must have first cooled low enough to admit of it, is perhaps more ingenious than true—but is there any reason opposed to it? If conceded, the question arises, did life originate at both Poles or one only? Or if at both was it simultaneously? – but this is the deepest abyss of idle speculation.
Ever yours affectly. J. D. Hooker”

Darwin to Hooker, 12 August 1881

“My dear Hooker
I can answer hardly any of your questions, but am able to send you by this post Blytt’s first essay, which [please] at [some] [time] return. – My memory [failed] me; I can find nothing about permanence of continents or oceans in my [Coral] Book; but as in [1st edit.] of Origin (p. 309) when I allude to the subject I refer to [Coral] [Reefs], this, I suppose, [deceived] my memory. I am almost sure that Dana’s letter was in Nature, I think in the current year. [Reade’s] article, I believe, was in the Geological Mag., but as I resolved never again to [write] on [such a] difficult subject, I unfortunately kept no record & read the articles merely for amusement.
I think that I must have expressed myself badly about Humboldt. I should have said that he was more remarkable for his astounding knowledge than for originality. I have always looked at him as, in fact, the founder of the geographical distribution of organisms. I thought that I had read that extinct fossil plants belonging to Australian forms had lately been found in Australia, and all such cases seem to me very interesting, as bearing on development.
I have been so astonished at the apparently sudden coming in of the higher phanerogams, that I have sometimes fancied that development might have slowly gone on for an immense period in some isolated continent or large island, perhaps near the South Pole. I poured out my idle thoughts in writing, as if I had been talking with you.
No fact has so interested me for a heap of years as your case of the plants on the equatorial mountains of Africa; and Wallace tells me that some one (Baker?) has described analogous cases on the mountains of Madagascar (398/1. See Letter 397, note.)... I think that you ought to allude to these cases.
I most fully agree that no problem is more interesting than that of the temperate forms in the southern hemisphere, common to the north. I remember writing about this after Wallace’s book appeared, and hoping that you would take it up. The frequency with which the drainage from the land passes through mountain-chains seems to indicate some general law—viz., the successive formation of cracks and lines of elevation between the nearest ocean and the already upraised land; but that is too big a subject for a note.
I doubt whether any insects can be shown with any probability to have been flower feeders before the middle of the Secondary period. Several of the asserted cases have broken down. Your long letter has stirred many pleasant memories of long past days, when we had many a discussion and many a good fight.”

Hooker to Darwin, 20 Aug. 1881
“Dear Darwin
Just a few last words before I commit my vaporings to the public. Of all the followers of Latreille [he probably meant Lamarck], in the mutability of species any one of them use this in explanation of (see end) representative species in very distant locations? Von Baer, as you point out, was convinced by the facts of geog. distribution that all species were descended from one parent form, & I suppose must have been led to this by the phenomena] of representation. Can you tell me if this was so? I d have no time to consult the Zoog. & Anthrop. Untersuch. [He meant the Zoologisch-anthropologische Untersuchungen of Rudoph Wagner (1861, p. 50ff), in which Wagner had excerpted Baer's essay in question. Wagner (1861) was the source that Darwin (1866) had given for Baer (1859) in the Historical Sketch of the 4th edition of his Origin of Species.]
          I find that Dana was the first (of all I have yet found), who broached the doctrine of permanence of position of existing continents. You somewhere do the same for existing oceans, and I read it lately, but for the life of me cannot turn the passage up. Also in the Origin you imply this. But I do not know anyone except Wallace who has summed up all the arguments for it, and marshalled them with convincing force. I know Blytt’s paper & have it, & thought at the time very highly of it, & my opinion is strengthened by reperusal. I gave a sketch of it as the last advance towards a knowledge of the laws of geograph. distributn. I shall return your copy soon with thanks.
          Josph Hooker

P.S. What I want to know if any one ever suggested that the [representative] [for] an instance of an Azorean plant by a Canarian was due to their having in common parents the offspring of which diverged [samely] from the parent type but converged in those [localities], either through both varying in the same direction or by one varying in the direction of the other.”

Darwin to Hooker, 21 Aug. 1881

“My dear Hooker
I cannot aid you much or at all. I shd think that no one could have thought on the modification of species, without thinking of representative species.— But I feel sure that no discussion of any importance had been published on this subject before the Origin; for if I had known of it, I shd assuredly have alluded to it in the Origin, as I wished to gain support from all quarters. I did not then know of Von Buch’s view (alluded to in my Historical Introduction in all the later editions). Von Buch published his “Isles Canaries” in 1836 and he here briefly argues that plants spread over a continent & vary, & the varieties in time come to be species. He also argues that closely allied species have been thus formed in the separate valleys of the Canary Islands, but not on the upper and open parts.
[Vertical writing at the left margin:] I could lend you Von Buch’s Book if you like: I have just consulted the passage. [End of marginal note]
            I have not Baers papers, but as far as I remember the subject is not fully discussed by him.— I quite agree about Wallace’s position on the Ocean & Continent question. — To return to Geograph. Distribution as far as I know no one ever discussed the [meaning of the] relation between representative species, before I did as I suppose Wallace did in his paper before Linn. Soc. Von Buch’s is the nearest approach to such discussion known to me.
Ever yours, Charles Darwin”

Hooker to Darwin, 29 Aug. 1881

“My dear Darwin
I have just seen the announcement of your brother’s death & must send you a few words of heartfelt sympathy. I [have] somehow ______ to think them the happiest, who, like myself, ______ ______ ______ when very young. It seems now as if they [would] then be but ______ ______ , – a blunder no doubt – but we know better what an ______ ______ ______ having lived ______ ______ ______ as you & your brother have.
            It was in your mother’s house near ______ that I first became acquainted with you. & shall never forget his kind face & kinder ______ . That was nearly 40 years ago! - I [will] remember thinking him then quite an ______ man & yet ______ he was then ______ 40.
            Ever my ______ , Joseph Hooker”

Darwin to Hooker, 30 Aug. 1881

“My dear Hooke,
Your note ha pleased me much. The death of Erasmus is a very heavy loss to all of us, for he had a most affectionate disposition. He always appeared to me the most pleasant & [clearest] headed man,  whom I have ever known. ______ will seem a ______ place to me without his presence; but I will not ______ ______ ______ him. I am deeply glad that he died without any great suffering, after a very short illness from mere weakness, & not from any definite disease. He had become quite weary of life! I cannot quite agree with you about the death of the old & ______ . Death in the latter case, when there is a bright future ______ ______ quiet never to be wholly {obliterated].
Farewell my old & dear friend. I remember the little room, where we first met.
            Ever yours, Charles Darwin”

Darwin to Hooker, 3&4 Sept. 1881

3rd Sept.:
“My dear Hooker
I have this minute finished reading your splendid, but too short, address. I cannot doubt that it will have been fully appreciated by the geographers at York: if not they are asses & fools.”

4th Sept.:
“After letting my enthusiasm thus escape, I suddenly felt burst up & had to stop.
I am sorry that I forgot to remind you in relation to A. Blytt that S.B. Skertchly (of the Geolog. Survey) has observed androgen facts in the peat bog of the Cambridgeshire fens; & I Believe that he had come to this conclusion before he knew of Blytt’s views; at least I remember writing to tell him of them. You speak (p. 10) of a glacial period being “inferred” in the S. ______ : surely this is too weak a term considering the enormous number of ______ angular [enatic] [blocks] of ______ [rocks] in the Tertiary plains of Patagonia far from the Andes, & in the ______ ______ of Chiloe, likewise ______ in a Tertiary formation & far for the Andes. That seems to me a capital argument (p. 11) “the several S. temperate ______” an ______ intimately related ______. I shd like to see this argument worked out in detail. But my chief motive for writing in as fullness: a young Patagonian native of ______ ______ in the ______ seems to be an enthusiast about Geograph. Distribution, ______ ______ (& such a man in such a place is a prodigy) & he has published on land mollusca & insects. He wrote to me to ask for hints, so I have told him to attend to ask chance [introductions] & have given him ______, (when ______ is ______) & I sent him Wallace’s big book. Amongst other prints I told him to collect the plants from the highest mountains of the several islands. He ______ that he has made a collection from 2 hills, but these are only 480 & 384 meters high, & offers to send them to anyone whom I might suggest. I have told him that I would mention this to you, but that I thought that the heights were not nearly great enough. Please tell me whether they are worth sending to Kew, or should I tell him to keep them, until he can get other collectings. His name is F. d’Arruda Furtado.
I have no large note-paper with black edges, so have written on this.
Ever yours Ch. Darwin
By the way you pile in your address honours on my old bald head.”

Hooker to Darwin, 7 Sept. 1881

“Dear Darwin
Can you kindly get me some more tubers of ______, for the Centre de Paris, who ______ ______ (______) marvellously ______ ______ tells me that ______ ______ is the only species of the genus that ______ (we ______ ______ ______ ______), all the seeds & most other ______ gradually ______ ______. ______ is a ______, ______ ______ ______, & he tells me that he has at Chateau d’Eau 10,000 plants in flower in May (of terrestrial ______). He has not ______ at all!
______ ______ you sent me ______ ______ ______ ______ ______ & form a beautiful ______, but I ______ not like to disturb it. ______ ______ tells me that ______ ______ formed ______ ______ ______ ______ that he refrained from disturbing it & so has it not in his garden & as he has sent me too ______ of ______ ______ I should like to return ______ him some ______ from you, ______ ______ ______ ______.
            Your criticism ______ Southern ______ ______ is just. My ______ ______ was ______ ______ hasty condensation of matter. What I should have said, was […]

I have heard that Skertchly is a brave observer, but I should much like to know what he has written on peat-bogs. Though I am so overwhelmed with work must I doubt if I could read it. Yet I do hope to live to work out the relations of the southern temperate plants. I do wish I could throw off my official duties here; I am getting so weary of them; & Dyer does them so well; but I could not nearly afford it yet.
There is a tremendously interesting ______ to be worked out in Azores. ______ huge trunks of Cypresses are found there buried in the ground, yet the Cypress is ______ in this island. There must be other preserved plants where these trunks are found. Whether or no, the history of these trunks wants clearing up.
I shall be very glad to see the mountain plants & name them for your friend. I think 3300 is the ______ Azorean altitude.
Lubbock did [capitally] ______ ______ ______.
Joseph Hooker”

Further links

Wednesday, 6 March 2019

Karl Ernst von Baer (1859) independently arrived at species modification and common descent

The very year that Charles Darwin published his book On the Origin of Species, Karl Ernst von Baer published an essay that is remarkable in that it he also arrived at the conclusion that species can transform (though not in a teleological/Lamarckian way) and that common descent explains the patterns of geographic distribution of organisms (Baer 1859. Über Papuas und Alfuren. Ein Commentar zu den beiden ersten Abschnitten der Abhandlung Crania Selecta ex Thesauris Anthropologicis Academiae Imperialis Petropolitanae. Aus den Memoires de l'Académie Impériale des sciences de St.-Pétersbourg, Sixieme série, Sciences naturelles, Tome VIII, besonders abgedruckt).

Rudolph Wagner had quoted excerpts of Baer's essay in one of his own essays in 1861 (Zoologisch-anthroplgische Untersuchunge. Die Forschung über Hirn- und Schädelbildung des Menschen in ihrer Anwendung auf einige Proleme der allgemeinen Natur- und Geschichtswissnschaft. Göttingen: Verlag der Dietrichschen Buchhandlung. (Besonders abgedruckt aus dem neunten Bande der Abhandlungen der Königl. Gesellschaft der Wissenschaften zu Göttingen) and concluded:
"Man sieht, wie hier zwei verschiedene Naturforscher, Darwin und Baer, ohne von einander zu wissen, auf ähnliche Ideen kommen, nur dass dabei dieser [Baer] besonnener, limitierter zu Werke geht." (Wagner 1861, p. 52)

One sees, here, how two different naturalists, Darwin and Baer, arrive at similar ideas without knowing of each other, only that this one [Baer] goes about it more level-headed and restricted. (My translation)
Therefore, Charles Darwin (1866. ) added Baer to the Historical Sketch of the 4th edition of his Origin of Species saying:
"Von Baer, towards 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." (Darwin 1866, p. xxi)
By the way, this Rudolph Wagner was not Moritz Wagner with whom Darwin had a spat about Leopold von Buch. Moritz Wagner, ironically, embraced Buch just like Darwin had done many years before him (see previous post), but tried to champion Buch's as the better theory. In particular, Moritz Wagner insisted on the need of geographic isolation/ separation as a prerequisite to speciation. This later disagreement seems to go back to Darwin's principle of divergence, which allowed Darwin to regard isolation not as a necessary prerequisite but a facilitating factor.
      In the following quote of Baer's (1859) original, the excerpts that Wagner (1861) gave are highlighted. The page numbers are in the 70s for the offprint (Sonderdruck) and in the 300s for the periodical (Memoires de l'Académie). My English translation follows below the German.
"Ich finde für den Begriff von Art keinen andern als: die Summe von Individuen, welche durch Abstammung verbunden sind oder sein könnten. Dass wir diesen Begriff selten erproben können, ist ein schlimmer Umstand, gibt uns aber nicht das Recht zu glauben, wir hätten einen andern, blos weil wir das Wort «Art» häufig anwenden. Will man annehmen, dass zur Anerkennung einer Art irgend ein nie fehlendes Merkmal gehöre, so wird man doch erst zu bestimmen haben, welcher Beschaffenheit das nie fehlende Merkmal sein müsse, und auf den Menschen angewendet, würde dieses Kriterium des Begriffes von Species am wenigsten zu der Aufstellung von verschiedenen Arten führen. Auch bin ich der festen Ueberzeugung, dass unsere zoologischen Systeme viel zu viel Arten aufstellen, eben weil wir kein äusseres Merkmal besitzen, und die Versuche über fruchtbare Fortpflanzung für die Ungeduld, die verzeichnisse zu bervollständigen, nicht anwendbar sind. Es ist auch kein Schade, wenn man die unterscheidbaren Formen aufzählt, nur muss man nicht glauben, dass man die wirklichen Abstammungsreihen registrirt. Ich kann mich aber auch ferner der Ueberzeugung nicht erwehren, dass viele Formen, die jetzt wirklich in der Fortpflanzung sich gesondert erhalten, nur allmälig zu dieser Sonderung gekommen sind und also ursprünglich nur Eine Art bildeten. Die jetzige Verbreitung der Thiere und so viel wir mit Wahrscheinlichkeit auf eine frühere zurückgehen können, scheint mir sehr entschieden dafür zu sprechen. Nahe verwandte und nach unsern gangbaren Ansichten ganz gut begründete Arten finden sich gewöhnlich in derselben Gegend vereint, dass eine ähnliche Form in weit entfernter Gegend vorkommt und dort, wie man zu sagen pflegt, die verwandte Thierform repräsentirt – ist ein viel seltener Eall. Alle gestreiften Pferde der Jetztwelt sind Afrikaner, alle ungestreiften sind Asiaten. Welches Aussehen die fossilen Pferde Amerikas hatten, wissen wir nicht, es ist sogar möglich, dass, wenn noch die Weichtheile erhalten wären, wir sie gar nicht für Pferde halten würden. Dass nahe verwandte Arten auch nahe zusammen wohnen, ist, wie es mir scheint, so sehr Regel, dass es nicht als zufällig betrachtet werden kann. Theilt man z. B. die Antilopen in Gruppen, so leben gewöhnlich die Glieder einer Gruppe nicht sehr fern von einander. Die gabelhörnigen Antilopen (Dicranoceras Wiegm.) leben nur in Amerika und in diesem Welttheile sind keine andern; Tragelaphus-Arten, mit gewundenen Hörnern, nur in Afrika; Hemitragus von der Hoven nur in Asien, und zwar im südöstlichen, Oreotragus Sundeval
[page break: 74/75 (342/344)]
nur in Afrika; Catoblepas eben da, andere Gruppen in Afrika und Arabien oder Syrien zugleich. Beide Länder gränzen nicht nur an Afrika, sondern sind auch ihrer Natur nach Afrikanisch. Von der räumlichen Trennung der Familien der Affen, haben wir schon gesprochen. Es ist aber dieses Verhältniss so häufig, und geht so durch alle Grade der thierischen Classification durch, dass wir unmöglich hier diesen Gegenstand erschöpfen können. Wer weiss nicht, dass die meisten Makis nur in Madagascar leben? Wem ist es unbekannt, dass Neu-Holland durch die vielen Arten von Beutelthieren characterisirt ist, die sonst nur auf benachbarten Inseln, und mit einem Geschlechte freilich auch in Amerika, vorkommen? Wer weiss nicht, dass unter den Fischen, Insecten, Mollusken mancher Gegenden Familien-Aehnlichkeiten vorkommen? Mir scheint, dass diese Gruppirung der Formen einen tiefern Grund haben müsse. Dass dieser aber nicht darin liegt, dass solche Gruppen nur in den Gegenden leben können, in denen wir sie gefunden haben, das ist durch unsre Pferde, Rinder, und Schweine in Süd-Amerika sattsam erwiesen worden. Sie gedeihen dort vortrefflich. Allerdings sind einige Thier-Gruppen über die Erde so vertheilt, dass es aussieht, sie wären ganz gleichmässig ausgestreut, so vorzüglich die grossen Katzen, unter denen die Süd-Amerikanischen von den grössern der alten Welt nur einfach specifisch verschieden sind, auch die Hunde sind kosmopolitisch genug – aber beide reichen als genera, mit einzelnen Arten weit in den Norden. Aber von Säugethier-Formen, die vom Norden weit entfernt bleiben, ist vielleicht nur die Vertheilung zweier Tapir-Arten auf die heissen Gegenden beider Continente merkwürdig, und gerade deswegen, weil sie eine auffallende Ausnahme bildet.
      Die so häufig vorkommende gruppenweise Vertheilung der Thiere nach Verwandtschaften, scheint dafür zu sprechen, dass auch der Grund dieser nicht gleichmässigen Vertheilung ein verwandtschaftlicher ist, d.h., dass die einander sehr ähnlichen Arten wirklich gemeinschaftlichen Ursprungs oder aus einander entstanden sind. Ich meine nicht allein die unnöthig aufgestellten Species, sondern ich meine die Vertheilung der Thiere macht es wahrscheinlich, dass auch viele solcher Arten, die sich jetzt getrennt halten und fortpflanzen, ursprünglich nicht getrennt waren, dass sie also aus Varietäten, nach systematischen Begriffen, zu specifisch verschiedenen Species geworden sind. Ohne diese Ueberzeugung wüsste ich mir durchaus keine Rechenschaft zu geben, warum die Amerikanischen Schweine eine Drüse auf dem Rücken haben, die Schweine der alten Welt nicht, warum in Amerika mehrere Lama-Arten leben, in der alten Welt nicht, in dieser aber mehre Cameele, warum die Amerikanischen Affen einen Backenzahn mehr haben als die der alten Welt, warum keine Paviane und keine ungeschwänzten Affen in der neuen Welt sind. Wenn jede der jetzt bestehenden Arten durch Urzeugung neu beginnen musste, so hätten wir noch besonders Bedingungen aufzusuchen, die den Affen und andern Thieren der alten und der neuen Welt gewisse Familien Charactere aufdrückten. Da Alles in der Natur Bestehende veränderlich ist, theils beweglich im Raume, theils entwickelungsfähig, so ist nicht abzusehen, warum die einzelnen Formen gar keine andere Entwickelung gehabt haben sollten, als jene ganz allgemeine, in der Reihenfolge des Auftretens,
[page break: 75/76 (343/344)]
welche uns die Palaeontologie nachweist*). Wie weit diese Entwickelung der Arten aus einander anzunehmen ist, darüber wage ich mir selbst keine Meinung zu bilden. Ich fühle auch keine Nöthigung dazu. Da sicher nicht alle Formen vom Anfange an auf der noch wenig geformten Erde sein konnten, so kann ich nicht umhin Urzeugungen anzunehmen, wovon ich allerdings den Vorgang mir nicht verständlich zu machen vermag. Wenn ich aber, weil mir die Urzeugung unverständlich ist, die Umwandlung so weit annehmen wollte, dass ich auch den Menschen aus andern Thieren hervorgebildet mir dächte und diese wieder weiter bis zur Monade, so scheint es, dass ich ganze Reihen von nicht erkannten und nicht verstandenen Geheimnissen an einander füge. Wenn ich aber glaube, dass verwandte Thier-Formen erst mit der Zeit zu selbstständigen Arten geworden sind, so werde ich durch die jetzige Vertheilung dahin geführt, und es liesse sich in der Jetzwelt wohl noch manche Analogie finden. Unser nach Europa versetztes Meerschweinchen soll sich nach Rengger nicht mit Cavia Aperea paaren, die man für die Stamm-Rasse hielt. Jezt sucht man nach einem andern Stamme. Wenn sich dieser nicht findet, wird man zugeben müssen, dass noch jetzt neue Arten sich bilden – hier freilich durch der Menschen Theilnahme.
      Haben sich aber mehrere Species aus einer Grundform entwickelt, wie noch jetzt die Rassen sich entwickeln, so darf man auch annehmen, dass früher die Typen überhaupt weniger festgehalten wurden. Ich denke mir, dass erst durch die fortgesetzte Reihe der Generationen der Typus sich immer tiefer einprägt und bin mir sehr wohl bewusst, dass diese Ueberzeugung eine Hypothese ist, aber eine Hypothese, welche nichts enthält, was unsrer Erfahrung widerspräche, aber wohl manche Verhältnisse verständlich macht, namentlich in Bezug auf die Variationen des Menschengeschlechtes. Diejenigen, welche mehrere Arten Menschen annehmen, berufen sich immer darauf, dass die Mohren in Europa nicht weiss werden und die Europäer in Indien und Brasilien nicht schwarz. Aber ganz abgesehen von den kurzen Zeiträumen, in welchen solche Beobachtungen gemacht werden konnten, abgesehen davon, dass die Europäer sich nie so dem Sonnenlichte aussetzen, als die Afrikaner, scheint es mir auch gar nicht widersinnig anzunehmen, dass in der ersten Reihe von Generationen der Typus ein mehr veränderlicher war, also auch stärker von den Einwirkungen der äussern Natur influencirt wurde. Der Generations-Act ist es ja, der den Typus bestimmt, je öfter er gewirkt hat in den Generationen,
     *) Die Botaniker glauben die Unveränderlichkeit der Species am sichersten nachweisen zu können. ,,Der Spross setzt das Individuum fort, aber das Samenkorn, das Product der Befruchtung, den Typus der Species.'' Das ist auch im Allgemeinen gewiss wahr, allein die Natur achtet nun einmal die scharfe Begränzung nicht. Wo kämen denn die ersten edlen Pfropfreiser her, wenn der Typus der Art starr und unveränderlich verharrte? Woher die Varietäten? Und ist es blosses Vorurtheil, dass der Blumist am liebsten die Saat von solchen Blumen säet, die schon einen Schritt in der Veredelung gemacht haben? Auf die Zoologen hat es einen grossen Eindruck gemacht, als Cuvier nach Untersuchung einiger Thier Mumien aus Aegypten versicherte, nicht der kleinste Knochen sei seit der Zeit des Einbalsamirens in diesen Arten verloren oder hinzugekommen. Aber man braucht nicht in der Zeit so weit zurückzugehen, wenn man etwas um sich schaut. Die langschwänzigen Schaafe haben viel mehr Schwanzwirbel als die Schaafe mit Fettpolstern. Kann man sie desshalb für verschiedene Arten halten? Die Schaafe von Baku stehen grade in der Mitte zwischen den Syrischen mit langen Schwänzen und den Krymmischen, bei denen der Schwanz zwischen den Fetthöckern verborgen ist.

[page break: 76/77 (344/345))]
desto unveränderlicher, scheint es mir, wird der Typus. So werden wir uns mit einer geringern Zahl von Urzeugungen begnügen lassen, denn wir können dann wohl für alle Katzen-Arten, oder für die meisten wenigstens, einen gemeinschaftlichen Ursprung uns denken – und die Entstehung von Mongolen und Negern u.s.w. wäre auf diese Hypothese leicht zurückzuführen. So wie wir jetzt im Kleinen Familien-Aehnlichkeit sich fortpflanzen sehen, oder Krankheits-Anlagen, die zuweilen nach Generationen wieder hervortreten, oder Anlage für Haar-Reichthum u.s.w. so wären jene Stamm-Verschiedenheiten frühzeitige Familien-Eigenthümlichkeiten.
     Man verstehe mich nicht unrecht. Ich sehe mich nur ausser Stande, specifische Unterschiede unter den Menschen zu erkennen, so lange man mir nicht geschwänzte Menschen oder ähnliche Unterschiede nachweist, und wenn die jetzigen Stämme der Menschen sich fruchtbar verbinden, so erlaube man mir wenigstens zu fragen, was denn eigentlich selbstständige Art ist? ob etwas, das der Naturforscher nach Gutdünken sondert, oder eine in der Natur begründete Sonderung, und worin diese denn besteht? – Ein Bedürfniss, alle Menschen von Einem Paare abzuleiten, beherrscht mich durchaus nicht. Vielmehr scheint es mir, dass, wenn irgendwo die Bedingungen zur Erzeugung von Menschen da waren, wie sie auch gekommen sein mögen, es viel natürlicher wäre, dass sie ergiebiger wirkten, als nur auf Ein Paar. Es ist uns dieser Vorgang auch viel zu wenig verständlich, als dass wir ein Recht hätten, es zu bezweifeln, dass Menschen an sehr verschiedenen Orten und vielleicht zu verschiedenen Zeiten als Autochthonen ohne Voreltern auftreten konnten. Dann wären die geringen Verschiedenheiten noch weniger auffallend. Allein eben weil uns der Vorgang ganz unverständlich ist, dürfen wir nur nach Erfahrungen und Analogien urtheilen und diese sprechen, da alle Säugthier-Arten nur Einen Verbreitungsbezirk nachweisen, nicht für den Ausgang des Menschengeschlechts von vielen Ursitzen, so lange wir den Menschen nur als Thier betrachten. – Möglich, dass es mit dem Menschen anders war, dann müssen wir aber auch zugeben, dass der Mensch nicht nach der Regel der Thiere wurde. Vielleicht lag das sogar – ich will nicht sagen in den Zwecken der Schöpfung, denn in dem Entwickelungs-Gange der Natur ist ja Nothwendigkeit und Zweckmässigkeit innig verbunden, wirklich nur Eins; also besser: in den Entwickelungs-Bedingungen der Natur. Dann hätte man aber Unrecht, im Menschen nur das zweibeinige Thier zu erkennen, das zufällig mehr Vernunft davon getragen und eine Sprache sich erwischt hat. Ist er nur das Thier, so muss er den Regeln und Gesetzen der Thiere unterwürfig sein. Ist er mehr, etwa Ziel der Entwickelung auf der Erde, – wozu der ganze Species-Streit?" (Baer 1859, p. 74 (342) - 77 (345))
My translation follows:
"I find no other concept for species than: the sum of individuals that are connected through descent/reproduction or could be connected thus. That we can hardly ever test this concept is a severe circumstance; it does not legitimate us to believe, however, that we have another just because we use the term «species» frequently. To assume a trait that is never absent from any individual of a species, one would first have to determine of what properties such a never absent trait would need to be; and applied to humans, such a criterion for the species concept would be the least to lead to the erection of different [human] species. I am also convinced that our zoological systems erect far too many species, exactly because we have no such trait, and experiments about fertile propagation are inapplicable for the impatience to complete the registers. And it is no harm to enumerate the distinguishable forms, but one must not believe that this registers the true lineages of descent.
Furthermore, I cannot defy the conviction that many forms, which do now really stay separate of each other in their reproduction, have come only gradually to this separation and originally formed only one species. The current distribution of animals, and as much as we can infer about a likely previous one, seems to strongly support this. Closely related and, according to our practical views, well established species usually occur together in the same region. It is a far rarer case that a similar form occurs in a faraway region and represents, as it is customary to say, the related animal form there. All striped horses are African, all non-striped ones are Asian.
We do not know what the fossil horses of America looked like; it is even possible, that we would not regard them as horses if the soft body parts were also preserved. To me, the fact that closely related species also live close to each other seems to be the rule, to such an extent, that it cannot be regarded as a coincidence.
[... Examples of the last statement omitted. Page break 74/75 ...]
The grouped distribution of related animals that is so common seems to indicate that the reason for this uneven distribution is also relational, that is, the closely related species truly have a common origin or developed from each other. I do not merely mean gratuitously erected species, but I think that the distribution of animals renders it likely that many of those species, which now live and reproduce separately, were originally not separated. By systematic categories, they developed from varieties into uniquely different species. Without this conviction I would not know how to account for the fact that American swines have a gland on their back but not swines of the old world, why several lama species live in America but not in the old world, in the latter however several camels, why American monkeys have one more molar that those of the old world, why no baboon and tailless monkeys [apes] are in the new world. If each of the presently existing species had to emerge from spontaneous generation [Urzeugung], we would still need special conditions that impressed these animals of the old and new world with their peculiar family characters. As everything existing in nature is changeable, partly mobile in space, partly able to develop, it is not comprehensible why these forms should have no other development that their general sequence of occurrence revealed to us by paleontology.*) I do not dare to venture a guess on how far this development of species from each other is to bee assumed. And I do not feel a need to do so either. It seems impossible that all forms existed from the beginning on the hardly formed Earth, I am forced to assume some spontaneous generation, though I cannot comprehend the process. If, however, because spontaneous generation is incomprehensible to me, I assumed the transformation to such an extent that I even imagined humans as developed from other animals, and this up to the first monad, whole sequences of unrecognized and not understood secrets seem to get concatenated. If, however, I believe that related animal forms have become independent species only with time, then their currnt distribution will lead there, and several other analogies from the present world could also be found. The guinea-pig, transferred to Europe, doe not pair with Cavia Aperae, which has been taken to be its stem-race, according to Rengger. Now they search for another stem. If this should remain elusive, one will have to admit that new species still develop even now. – here, of course, only through human participation.
       If several species developed from a basic form, as races still to today, then one is permitted to assume that previous types have been less fastened. I think that the type got engrained ever more deeply only through the perpetual sequence of generations, and I am conscious of the fact that this is a hypothesis, a hypothesis, however, that does not contradict any of our experiences, but renders comprehensible some affairs, especially in relation to variations of the humankind. Those who assume several species of humans always appeal to the fact that the Moors do not become white in Europe and the Europeans in India and Brazil not black. Except for the short time-spans, however, in which these observations have been made. except for the fact that Europeans never expose themselves to the sunlight as much as the Africans, it seems plausible to me to assume that the type was more variable in the first row of generations, and therefore also more influenced by conditions than today. The act of generation determined the type, the more often it recurred,
     *) The botanists believe to be able to prove the fixity of species the best. "While the shoot/scion continues the individual, the seed, the product of fertilization, continues the type of the species." That is surely true in general, however, nature does not heed sharp boundaries. Where would the first refined grafting scion come from, if the type of the specs was fixed and unchangeable? Wherefrom the varieties? Is it mere prejudice that the flower breeder prefers to sow seeds of flowers that have already taken the first step of refinement? The zoologists have been very impressed by Cuvier, who assured them, after the inspection of some mummies from Egypt, that not the smallest bone has been lost or added to these species since their embalmment. But one does not need to travel back that far and just look around a little. The long tailed sheep have many more tail vertebrae than the sheep with fat pads. Can they, therefore, be considered distinct species? The sheep of Baku are intermediate between the Syrian ones with long tails and the Krymmian ones, whose tail is hidden between the fat humps.

[Page break: 76/77 (344/345)]
the more fixed, me thinks, the type becomes. Hence, we should be content with a limited number of spontaneous generations, and we can assume a common origin for all cats, or at least for most of them – and the origin of mongoles, negroes, etc. could easily be deduced from this hypothesis. In the same way as we now do see family-resemblances propagate in the small, or predispositions for disease that sometimes recur after generations, or dispositions for luxuriance of hair etc., so the differences in phyla would have been former family-peculiarities."

Tuesday, 5 March 2019

Leopod von Buch's Description of the Canary Islands impressed the young Charles Darwin

Darwin's Notebook B (1837-38), on the transmutation of species, states:
"Von Buch. — Canary Islands, French Edit. Flora of Islds very poor. (p. 145) 25 plants. St. Helena without ferns, analogous to nearest continent: poorness in exact proportion to distance (?) & similarity of type (?)" (Darwin 1837-38, p. 156)

"I can understand in one small island species would not be manufactured. but why they should be manu Does it not present analogy to what takes place from time? Von Buch distinctly states that permanent varieties become species p. 147, p. 150, not being crossed with others. — Compares it to languages. But how do plants cross? — — admirable discussion." (Darwin 1837-38, p. 158)
Leopold von Buch, Wikimedia commons, public domain

Leopold von Buch is undoubtedly a very important predecessor of Charles Darwin. It is, therefore, interesting to take a closer look at Buch's statements that influenced Darwin. Darwin's notes in his Notebook B (see quotes above) relate to Physicalische Beschreibung der Canarischen Inseln (Leopold von Buch 1825, p. 130 and 133f), which Darwin read in its French translation by C. Boulanger, Description Physique des Iles Canaries (Léopold de Buch 1836, p. 144f + 147ff). As German is my mother-tongue, I will depart from the original German passages and translate them into English.
"Der bekannte französische Naturforscher Du Petit Thouars fand auf der Insel Tristan d'Acunha in 37°21' südlicher Breite, und deren Spitzen sich in die Wolken verlieren, von phänerogamen Pflanzen nicht mehr als 25 verschiedene Arten, von denen einige an das Cap, andere an das beinahe gleich weit entfernt gelegene Amerika erinnern, und in St. Helena steigt ihre Anzahl, nach Roxburgh's (sic) Catalog, ebenfalls auf nicht mehr als 36 Arten." (von Buch 1825, 130)

The famous French naturalist Du Petit Thouars discovered no more than 25 species of phanerogamous plants on the island Tristan d'Acunha in 37°21' southern latitude, whose peaks trail off into the clouds, some of them are redolent of the Cap and others of the almost equally distant America. And on St. Helena their number rises to no more than 36 species according to Roxburgh's catalogue. (My translation)
The next passage from Buch (1825, 133f or 1836, 147ff) seems odd in that Buch first describes a process of species transformation on continents and thereafter seems to describe the identical process in closer detail for islands, yet he separates the two descriptions by the sentence "Nicht so auf Inseln" (Not so on islands), as if he was about to propose a very different process for islands. The only difference, however, is that the varieties on continents need to depart from each other spatially to vast distances, whereas the same isolation is supposed to be possible on much smaller spatial scales on islands.
"Die Individuen der Gattungen auf Continenten breiten sich aus, entfernen sich weit, bilden durch Verschiedenheit der Standörter (sic), Nahrung und Boden Varietäten, welche, in ihrer Entfernung nie von anderen Varietäten gekreuzt und dadurch zum Haupttypus zurückgebracht, endlich constant und zur eigenen Art werden. Dann erreichen sie vielleicht auf anderen Wegen auf das Neue die ebenfalls veränderte vorige Varietät, beide nun als sehr verschieden und sich nicht wieder miteinander vermischende Arten. Nicht so auf Inseln. Gewöhnlich in enge Thäler oder in den Bezirk schmaler Zonen gebannt, können sich die Individuen erreichen und jede gesuchte Fixirung einer Varietät wieder zerstören. Es ist dies ungefähr so, wie Sonderbarkeiten oder Fehler der Sprache zuerst durch das Haupt einer Familie, dann durch Verbreitung dieser selbst, über einen ganzen District einheimisch werden. Ist dieser abgesondert und isolirt, und bringt nicht die stete Verbindung mit andern die Sprache auf ihre vorige Reinheit zurück, so wird aus dieser Abweichung ein Dialekt. Verbinden natürliche Hindernisse, Wälder, Verfassung, Regierung, die Bewohner des abweichenden Districts noch enger, und trennen sie sie noch schärfer von den Nachbarn, so fixirt sich der Dialekt, und es wird eine völlig verschiedene Sprache. —
     Deswegen eben, ist es so wichtig, den Standort genau anzugeben, und zu bezeichnen, an welchem die Pflanzen auf den Inseln sich finden. Er hat fast jederzeit etwas Eigenthümliches. Ist er durch natürliche Hindernisse, durch Bergreihen, welche mehr scheiden, als bedeutende Entfernungen über dem Meer, von andern Orten sehr getrennt, so kann man immer dort ganz neue, in anderen Theilen der Insel nicht vorkommende Pflanzenarten erwarten. Vielleicht hat ein glücklicher Zufall, durch eine besondere Verbindung von Umständen den Saamen über die Berge gebracht. Sich selbst an der abgeschlossenen Stelle überlassen, wird dann auch hier im Laufe der Zeiten die aus den neuen Bedingungen des Wachstums entstandene Varietät zur eigenen Art, welche sich immer mehr von ihrer ersten ursprünglichen Form entfernt, je länger sie ungestört in dieser eingeschlossenen Gegend erhalten wird." (von Buch 1825, p. 133)

On continents, the individuals of a genus spread, depart far from each other, develop through the differences in the location, nutrition and soil varieties which, in their distance, never cross with other varieties and thus never get drawn back to the main type, eventually get constant and become their own species. They may then reach on another route, again, the also altered previous variety, both now as very different species that do no longer mix with each other. Not so on islands. Usually banished in steep valleys or narrow zones, the individuals can reach each other and destroy each sought fixation of a variety. This is similar to the oddities or mistakes in language that are first propagated by the head of a family and then, spread with the family itself, become native to a whole district. If the latter is separated and isolated, and if the first contact with others does not bring the language back to its previous purity, then the deviation will become a dialect. If natural barriers, forests, constitution, government connect the inhabitants of the deviant district and separate them even sharper from the neighbors, then the dialect will get fixed and it will become a completely different language. —
     Therefore, it is important to indicate the location/site/habitat exactly and to specify on which ones the plants on the islands can be found. It [the location] almost always has something peculiar. If it is isolated from other locations by natural barriers, mountain ranges, which separate more than considerable distances over the sea, then one can expect to find new plant species that do not occur in other parts of the island. Maybe a lucky coincidence has brought the seeds over the mountain range by some special combination of conditions. Left to their own in the isolated location, the variety that develops because of the new conditions of growth will, in the course of time, become an own species which departs the farther from its first original form the longer it remains undisturbed in this isolated area. (My translation)
The next passage from Buch (1825, 134 or 1836, 149) is significant because it shows that Buch subscribed to the old doctrine that the conditions of life (e.g., soil, climate) cause variation (though it remains open whether Buch thought of it as a teleological/Lamarckian process or not), and it illustrates the lack of natural selection from Buch's scheme. This is important, because claims of Darwin's plagiarism or dishonesty tend to mix up the different parts of evolutionary theory. 
[...] welche Verschiedenheit in dem Pyrethrum, und dabei solche Aehnlichkeit, dass man sehr leicht geneigt wird, alle Arten dieser Gattung aus einem gemeinschaftlichen Stamme entsprungen zu glauben! Diese verschiedenen Arten finden sich fast nirgends vereinigt, sondern fast jede ist an ihr eigenes Thal, oder an ihren eigenen District gefesselt. Auch die Verschiedenheit der Cinerarien ist nicht so groß, dass man sie nicht für Erzeugnisse der Insel selbst halten könnte, welche durch Verschiedenheit des Standortes, Bodens und des Clima bewirkt worden sind." (Buch 1825, 134)

[...] what difference in the Pyrethrum, and what similarity at the same time, that one is easily inclined to believe that all these species arose from one stem! These different species were almost nowhere found together, but each is bound to its own valley or its own district. The difference between Cinerarien is also not too big to regard them as products of the island itself, which were caused through differences in the location, soil and climate. (My translation)
The realization that mutation and recombination are (mostly) independent of conditions of existence is a much later insight and Darwin also subscribed to this doctrine. However, he thought of this variation as non-teleological (non-Lamarckian). He even began The Origin of Species by stating the central tente of this doctrine: "WHEN we look to the individuals of the same variety or sub-variety of our older cultivated plants and animals, one of the first points which strikes us, is, that they generally differ much more from each other, than do the individuals of any one species or variety in a state of nature. When we reflect on the vast diversity of the plants and animals which have been cultivated, and which have varied during all ages under the most different climates and treatment, I think we are driven to conclude that this greater variability is simply due to our domestic productions having been raised under conditions of life not so uniform as, and somewhat different from, those to which the parent-species have been exposed under nature." (Darwin 1859, p. 7)

The last section of Buch (1820 134f or 1836, 149f) was significant for Darwin (1837-38), because Buch related the rarity or abundance of certain plant species on islands to the facilility with which their seeds can be transported.
"In solchen Gründen mag wohl die Ursache liegen, warum die ,,Compositae" einen so besonders hervorstechenden Theil der canarischen Flora bilden. Es ist mehr als der siebente Theil der ganzen Zahl ursprünglicher Pflanzen. In Nordafrica ist es nur der neun und zwanzigste Theil. Der durch den Pappus geflügelte Saamc kann wohl leichter weiter geführt werden, als der weniger bewegliche Saame anderer Arten. — An der Schwierigkeit dieser Fortführung mag es liegen, warum an den Küsten der canarischen Inseln noch nie ein Eryngium gesehen worden ist, da doch die atlantische Flora davon acht verschiedene Arten aufführt, und selbst noch auf den nächsten maroccanischen Küsten von dieser Gattung vier verschiedene Arten wachsen. — In dieser Schwierigkeit mag ebenfalls der Grund liegen, warum die Leguminosen in der canarischen Flora so weit in dem Verhältnifs zurückbleiben, welches ihnen die Natur in diesen Glimaten bestimmt zu haben scheint. Sie bilden wenig über den dreifsigsten Theil der ganzen Masse, in Nordafrica hingegen den neunten Theil. — 
      Dagegen scheint den Semperviven auf diesen Inseln ein besonders günstiges Vaterland geworden zu seyn. Fast jedes Thal kann von ihnen eine neue Art aufweisen, und wahrscheinlich hat man sie noch lange nicht alle entdeckt. Von allen Arten der Semperviven enthalten die canarischen Inseln 4/7, und zu den dreizehn, die man vorher schon kannte, hat Christian Smith noch acht ganz neue Arten hinzufügen können. —" (Buch 1820, 134f)

In such reasons my lie the cause why the "Compositae" form such a prominent part of the canarian Flora. It is more than the seventh part of the total number of aboriginal plants. In Northafrica it is only the twenty ninth part. The seed, which is winged through the pappus, can be more easily taken afar than the less mobile seeds of other species. — This difficulty of dispersal may be the reason why no Erygium has evver been seen at the beaches of the Canary islands, despite the fact that the Atlantic flora features eight different species of it, and even on the next Maroccan beaches four of them can be found. — This difficulty may also be the reason, why the leguminoses lag behind so strongly in their proportion of the canary flora, which nature seems to have destined for them in similar climates. The form less than a thirteenth of the whole mass, in comparison with a ninth in Northafrica. —
      Conversely, the Sempervivens seem to have found a particularly favourable fatherland. Almost every valley has an own new species of them, and they are probably not all discovered yet. Of all Sempervivens, the Canary islands contain 4/7, and Christian Smith added another eight ne species to the thirteen that were already known. —" (My translation) 

Friday, 1 February 2019

My Brontosaur Theory on Counterfactual Histories of Science

Good evening. To get the THRUST of this post, please watch the clip first.

So called counterfactual histories are scenarios of what could have come to pass, if some contingent event of the past had turned out differently. It is controversial whether exploring such counterfactual alternative paths to the actual history has any merit for academic historiography. This is even more true for the history of science, because science is often assumed to approach one reality. Alternative paths in a counterfactual history must inevitably reach the same or a very similar state of knowledge, so the assumption.  

Therefore, historians of science usually claim that counterfactual narratives usually result in an alternative state of science that is pretty close or even identical to the actual state of science. This claim is supported by the assumption that a plausibility constraint prevents counterfactual histories from becoming incompatible with the actual science. That is, if a counterfactual history would end in a state of science that was incompatible with the actual science, then it would turn into science fiction and cease to belong to academic historiography. In other words: Counterfactual histories of science cannot be incompatible with the current state of science and be plausible at the same time!

Plausible counterfactual narratives that do end in identical or closely similar states of science are variously referred to as being contingent in a benign or weak sense (e.g., Soler 2008; Hesketh 2016; Tambolo 2018). One could think of this as two potential paths that departed at a contingent point of the past, but only one path got realized. If both had been realized, the gap between them would have remained rather thin and they would eventually have converged again. Think of the outline of a worm rather than a brontosaur

A popular example of a counterfactual narrative that has been taken to be benign or weak in this sense is Peter Bowler's Darwin Deleted (2013). It ends in an alternative state of science that is identical in its scientific content and only differs in its social context. In Darwin Deleted, Charles Darwin dies prematurely but, in the end, the resulting evolutionary theory is identical to the current one. The difference between the counterfactual and the actual science is that some social discontents (like social Darwinism, Nazi eugenics) got associated with alternatives to natural selection (e.g, Lamarckism, Spencerian ideas, orthogenesis) and sunk together with them. That is, they did not get associated with natural selection, which came in later. Therefore, natural selection came out clean in Bowler's counterfactual and Bowler's aim of his counterfactual was, in fact, to prove that there is no necessary association between natural selection and its social discontents.

I am not interested, here, in these social issues or Bowler's beef with the Intelligent Design proponent Weikart, who apparently wants to burden Darwin with some responsibility for the holocaust etc. Instead, I want to refute the above claimed necessary association between the plausibility of counterfactual histories of science and their compatibility with the actual science.

If this association was necessary, then any history of science (even one about actual not counterfactual research) would appear to be outlandishly improbable to us, because it went through states that are utterly incompatible with the current state of knowledge. Take Bowler's Darwin Deleted, for example. It is completely incompatible with the current state of evolutionary biology somewhere in the middle, because alternatives to natural selection like Lamarckism, use-inheritance, blending inheritance etc. rule there. At the same time, this intermediate state of science is not only plausible but grounded in what many actual scientists and philosophers did indeed believe for a long time after Darwin and before the Modern Synthesis. That is, even actual history confronts us with states of science that are incompatible with the current state and yet plausible to the highest possible degree.

In other words, the gap between the path of Bowler's counterfactual and the actual history of evolutionary biology is not worm shaped!

Hence my theory, which is mine, ahem ahem: The gaps between most counterfactual and actual histories of science are thin at the beginning, much, !much! thicker in the middle, and then thin again in the end. That is my Brontosaur Theory of counterfactual histories of science. It is mine and belongs to me and I own it and what it is too.

I have a second theory, which is the second part of my first theory and it is also mine. This is it: AHEM!!! By chopping brontosaur counterfactuals in half and truncating them, the gap between the counterfactual and the actual history will become cone shaped. That is, the gap will gape and never close again. I call this my Hyolith Theory on Counterfactual Histories of Science.

Reconstruction of Haplophrentis, a hyolith. From Wikipedia (CC BY-SA 3.0)

1. Bowler, P.J. 2013. Darwin deleted. Imagining a world without Darwin. The University of Chicago Press.
2. Hesketh, I. (2016). Counterfactuals and history: Contingency and convergence in histories of science and life. Studies in History and Philosophy of Biological and Biomedical Sciences, 58, 41-48.
3. Soler, L. (2008). Revealing the analytical structure and some intrinsic major difficulties of the contingentist/inevitabilist issue. Studies in History and Philosophy of Science, 39,
4. Tambolo, L. 2018. So close no matter how far: counterfactuals in history of science and the inevitability/contingency controversy. Synthese, https://doi.org/10.1007/s11229-018-1787-7.

Tuesday, 8 January 2019

How the theories of Matthew, Darwin, and Wallace came to be seen as identical

The following blog post tries to explain how it came about that Patrick Matthew, Charles Darwin, and Alfred Wallace all thought about their evolutionary theories (first published in 1831 by Matthew and in 1858 jointly by Darwin and Wallace)  as essentially identical, when closer analysis reveals significant differences (e.g., Dagg 2018). How could they, and many people ever since, have overlooked the differences?

Huxley's review of Darwin's Origin of Species
Thomas H. Huxley anonymously reviewed Charles Darwin's On the Origin of Species (1859). His review was first published in the Times (26 December 1859, pp. 8-9). The Gardeners’ Chronicle and Agricultural Gazette (3 March 1860, pp.192-193) reproduced it. Therein, Huxley gave examples of breeds (pigeons, swine, cattle) that grossly deviated from their wild ancestors and explained the process of artificial selection employed by the breeders before stating: 
"But in all these cases we have human interference. Without the breeder there would be no selection, and without the selection no race. Before admitting the possibility of natural species having originated in any similar way, it must be proved that there is in nature some power which takes the place of man, and performs a selection sua sponte. It is the claim of Mr. Darwin that he professes to have discovered the existence and the modus operandi of this natural selection, as he terms it; and, if he be right, the process is perfectly simple and comprehensible, and irresistibly deducible from very familiar but well nigh forgotten facts." (Huxley 1860, 193, col. 3)
He then continued with the over-reproduction of all organisms, the struggle of survival and the survival of the fittest resulting from it. That is, Huxley's review was a simplification and popularization of Darwin's theory that every lay-reader of the time could comprehend. Most strikingly, Huxley's review completely lacked the principle of divergence by which Darwin laid so much stock, but which is now largely forgotten or, if not, causes much perplexity among biologists. 

Darwin mentioned it in a letter to Asa Gray, 5 September 1857, (Darwin Correspondence Project, Letter no. 2136, accessed on 8 Jan. 2019, http://www.darwinproject.ac.uk/DCP-LETT-2136) stating: "One other principle, which may be called the principle of divergence plays, I believe, an important part in the origin of species." In a later letter to Joseph D. Hooker, 8 June 1958, (Darwin Correspondence Project, Letter no. 2282, accessed on 8 Jan. 2019, http://www.darwinproject.ac.uk/DCP-LETT-2282), he stated that the principle of divergence and natural selection will together form the key-stone of his book to come (On the Origin of Species). And in his Autobiography, edited by Nora Barlow (1958, 120), Darwin recounted an eureka moment, when he came across this principle while in a carriage on a road and he likened his solution to the one of Columbus and his egg. 

Why was the principle of divergence important to Darwin? 
Biologists, today, see island biogeographies everywhere. A hilltop in a flat country can be an island just as an isolated valley in the mountains. Rivers and other geographic barriers can create one island biogeographic setting for some species and a totally different setting for others depending on their ecological niches. Biologists see island biogeographies where Darwin saw none. Furthermore, they know about genetic drift as a mechanisms that accelerates evolutionary change in small populations in these settings. 

Darwin, however, had found from taxonomic studies that taxa on continents were not only larger than on islands but also that their members (e.g., genera, species) were more divergent from each other than on smaller islands. He also believed that the smallness of the populations on islands would retard the process of evolution there simply by making favorable variants a rare occurrence. Therefore, he needed a principle that would explain this pattern. In other words, he needed something that would drive lineages apart on continents and in the absence of catastrophes or islands. 

What was the principle of divergence?
His principle of divergence achieved this by proposing that the internal competition between varying individuals within species was disruptive enough to allow lineage splitting. Advantageous sports dodged being swamped somehow and, instead, managed to exterminate the intermediate (parental) form. If more than one such variant occurred simultaneously, and the variants could no longer interbreed after the extinction of the parental form, lineage splitting (speciation) had occurred without geographic isolation of the variants (in sympatry). Geographic isolation could facilitate this lineage splitting, but is was not a necessary prerequisite.

In this principle of divergence, Darwin's theory differed not only from Wallace's (who had an island biogeographic setting for lineage splitting) and Matthew's (who had catastrophes doing the lineage splitting), but also from Huxley's simplified review and from current evolutionary theory. The latter is, in my humble opinion, closer to Wallace's island biogeographic scheme than to Darwin's original scheme from 1859.   

Matthew's priority claim
Matthew had read Huxley's review in the Gardeners' Chronicle from 3 March 1860 and sent his priority claim to that periodical at 7 March 1860. This is evident from the date and signature given by Matthew at the end of his letter to the journal. (It took the editors until 7 April 1860 to publish Matthew's claim.) It is unlikely that Matthew had consulted Darwin's book at length or in any detail within those four days. It seems far more likely that he had simply taken what he could gather from Huxley's review and written his priority claim on the spot, collating passages from his book that fit the simplified account given by Huxley. 

Darwin's reply to Matthew's claim
Darwin's response was equally hasty (within 6 days). It got published on 21 April 1860 in the Gardeners' Chronicle (pp. 362-363). However, Darwin had sent his response to Joseph D. Hooker for approval on 13 April 1860 (Darwin Correspondence Project, Letter no. 2758, accessed on 8 January 2019, http://www.darwinproject.ac.uk/DCP-LETT-2758). Basically, Darwin had ordered Matthew's book (see letter to Charles Lyell, 10 April 1860, Darwin Correspondence Project, Let. 2754, accessed 8 Jan. 2019, http://www.darwinproject.ac.uk/DCP-LETT-2754), in order to make sure that the passages given by Matthew in his priority claim were scattered passages in a book on an otherwise different subject. This he made sure, in order to excuse himself for having overlooked Matthew's book in his long pondering on the subject. His response read:
"I have been much interested by Mr. Patrick Matthew’s communication in the Number of your Paper, dated April 7th. I freely acknowledge that Mr. Matthew has anticipated by many years the explanation which I have offered of the origin of species, under the name of natural selection. I think that no one will feel surprised that neither I, nor apparently any other naturalist, had heard of Mr. Matthew’s views, considering how briefly they are given, and that they appeared in the appendix to a work on Naval Timber and Arboriculture. I can do no more than offer my apologies to Mr. Matthew for my entire ignorance of his publication. If another edition of my work is called for, I will insert a notice to the foregoing effect."
Wallace's review of Butler's Evolution Old and New
Alfred Wallace only returned from the Malay Archipelago in 1862. Consequently, he remained largely ignorant about Matthew's ideas until Samuel Butler sent him a complimentary copy of his book Evolution, Old and New (1879). Butler (1879) claimed that Darwin's theory was nothing but Lamarckism redux and that Matthew's theory was worlds apart in this. However, Butler mistook Matthew's catastrophism as necessarily putting him in one camp with Cuvier and opposite to Lamarck. Matthew had in fact married Cuvier's catastrophism to transmutationism (Lamarckian or otherwise). Apart from this nonsense, Butler also re-quoted the passages that Matthew had already re-quoted in his priority claim against Darwin in 1860 (except for one paragraph about spontaneous generation). Apparently, Wallace read these passages from Matthew only now for the fist time. He replied in a letter to Butler:
"To my mind, your quotations from Mr. Patrick Matthew are the most remarkable things in your whole book, because he appears to have completely anticipated the main ideas both of the Origin of Species and of Life and Habit." (Wallace to Butler, 9 May 1879
Wallace published a review of Butler's book in the journal Nature (12 June 1879, Vol. 20: 141-144), in which he had the following to say about Matthew: 
"We come next to Mr. Patrick Matthew, who in 1831 put forth his views on the development theory in a work on arboriculture; and we think that most naturalists will be amazed at the range and accuracy of his system, and will give him the highest credit as the first to see the important principles of human and “natural selection,” conformity to conditions, and reversion to ancestral types; and also the unity of life, the varying degrees of individuality, and the continuity of ideas or habits forming an abiding memory, thus combining all the best essential features of the theories put forth by Lamarck, Darwin, and Mr. Butler himself."
Wallace continued with re-quoting yet again, some of the re-quotes by Butler of Matthew. 

Thus, a persistent historical pattern had been firmly established. From now on, every other decade, someone would stumble over Matthew (1831), be very surprised about his prescience and re-quote the same old passages once over, in order to emphasize how very identical these were to Darwin's and Wallace's theories. This would reiterate itself for the next century and a half without any proper historiography of the Patrick Matthew case ever emerging from this reiteration of a legend.