Charles Darwin was Francis Galton's half-cousin, sharing the same grandfather, Erasmus Darwin. Erasmus had been a successful doctor and something of a polymath himself, co-founding the Lunar Club with Josiah Wedgwood and Joseph Priestley, among others. The Darwin and Galton family had some contact over the years, but it was not until Darwin and Galton were both mature working scientists that any serious contact took place. Darwin had initiated the contact, after he had read Galton's Narrative of an Explorer in Tropical South Africa, around 1853. Galton later read The Origin of Species, which he would later call a revolutionary effect on his own thinking, and a regular correspondence followed until Darwin's death.
Galton became a frequent visitor to Down House, and maintained his friendship with Darwin despite occasional strain, the most serious of which was caused by his decisive refutation of Darwin's theory of Pangenesis. Darwin adhered to a blood-mixing account of inheritance, in which "gemmules" in the blood transmitted characteristics, possibly even some acquired ones. Galton put this to the test by performing blood transfusions on rabbits, in experiments that Darwin enthusiastically followed. But the rabbits paid no attention to "pangenesis" and Galton was forced to conclude that Darwin was wrong. Darwin took this painfully, and fought a rear-guard action against the experiments, despite his close involvement in them from the beginning, and fudged the concepts to defend the theory. Galton did his best to assuage Darwin, whom he held in great esteem, and may have been diverted by Darwin from grasping fully the Mendelian account of genetic inheritance, something he came very close to in his own experiments on sweet peas.
Some of the extensive correspondence between Darwin and Galton is reproduced here.
Letter from Darwin to Galton
13, SEAHOUSES, EASTBOURNE, SUSSEX. July 24th, 1853.
You will probably be surprised, after the long intermission of our acquaintance, at receiving a note from me; but I last night finished your volume with such lively interest, that I cannot resist the temptation of expressing my admiration at your expedition, and at the capital account you have published of it. I have no doubt you have received praise, from so many good judges that you will hardly care to hear from me, how very much I admire the spirit and style of your book. What labours and dangers you have gone through: I can hardly fancy how you can have survived them, for you did not formerly look very strong, but. you must be as tough as one of your own African waggons !
If you are inclined at any time to send me a line, I should very much like to hear what your future plans are, and where you intend to settle. I so very seldom leave home, owing to my weakened health (though in appearance a strong man) that I had hardly a chance of seeing you in London, though I have often heard of you from members of the Geographical Society.
I live at a village called Down near Farnborough in Kent, and employ myself in Zoology; but the objects of my study are very small fry, and to a man accustomed to rhinoceroses and lions, would appear infinitely insignificant.
We have come to this for a few weeks for sea-bathing with all our children, now numbering seven.
I should very much like to hear something about your brothers Darwin and Erasmus: I very distinctly remember a pleasant visit at the Larches, Heaven knows, how many years ago, and having many rides with them on ponies, without stirrups. The only member of your family whom I have seen for years, is Emma, who gave myself and wife a very cordial greeting at the British Association at Birmingham, some few years ago.
I do not know, whether I ought not to apologise for troubling you with this note, but the spirit which makes me write, must be my excuse. Pray believe me,
From The Letters of Charles Darwin, as annotated by the editors that collection.
LETTER 82. FRANCIS GALTON TO CHARLES DARWIN.
42, Rutland Gate, London, S.W., December 9th, 1859.
Pray let me add a word of congratulation on the completion of your wonderful volume, to those which I am sure you will have received from every side. I have laid it down in the full enjoyment of a feeling that one rarely experiences after boyish days, of having been initiated into an entirely new province of knowledge, which, nevertheless, connects itself with other things in a thousand ways. I hear you are engaged on a second edition. There is a trivial error in page 68, about rhinoceroses (82/1. Down (loc. cit.) says that neither the elephant nor the rhinoceros is destroyed by beasts of prey. Mr. Galton wrote that the wild dogs hunt the young rhinoceros and "exhaust them to death; they pursue them all day long, tearing at their ears, the only part their teeth can fasten on." The reference to the rhinoceros is omitted in later editions of the "Origin."), which I thought I might as well point out, and have taken advantage of the same opportunity to scrawl down half a dozen other notes, which may, or may not, be worthless to you.
Darwin wrote an appreciative letter to Galton after reading Hereditary Genius. Galton wrote a grateful reply which is also reproduced here.
Letter from Darwin to Galton.
DOWN, BECKENHAM, KENT, S.E.
"MY DEAR GALTON,--I have only read about 50 pages of your book (to the Judges), but I must exhale myself, else something will go wrong in my inside. I do not think I ever in all my life read anything more interesting and original--and how well and clearly you put every point! George, who has finished the book, and who expressed himself in just the same terms, tells me that the earlier chapters are nothing in interest to the later ones! It will take me some time to get to these latter chapters, as it is read aloud to me by my wife, who is also much interested. You have made a convert of an opponent in one sense, for I have always maintained that, excepting fools, men did not differ much in intellect, only in zeal and hard work; and I still think this is an eminently important difference. I congratulate you on producing what I am convinced will prove a memorable work. I look forward with intense interest to each reading, but it sets me thinking so much that I find it very hard work; but that is wholly the fault of my brain and not of your beautifully clear style.--Yours most sincerely,
(Signed) "CH. DARWIN"
This appears in The Letters of Charles Darwin as LETTER 410.
To enhance readability, a facsimile of the letter has been split into sheets. Note that Darwin's handwriting is very hard to read at times. He was also prone to leave out exact dates in his correspondence.
Galton to Darwin
"It would be idle to speak of the delight your letter has given me, for there is no one in the world whose appreciation in these matters can have the same weight as yours."
LETTER 474. TO FRANCIS GALTON.
(474/1. Mr. Galton had written on November 7th, 1872, offering to send to various parts of Africa Darwin's printed list of questions intended to guide observers on expression. Mr. Galton goes on: "You do not, I think, mention in "Expression" what I thought was universal among blubbering children (when not trying to see if harm or help was coming out of the corner of one eye) of pressing the knuckles against the eyeballs, thereby reinforcing the orbicularis.")
Down, November 8th .
Many thanks for your note and offer to send out the queries; but my career is so nearly closed that I do not think it worth while. What little more I can do shall be chiefly new work. I ought to have thought of crying children rubbing their eyes with their knuckles, but I did not think of it, and cannot explain it. As far as my memory serves, they do not do so whilst roaring, in which case compression would be of use. I think it is at the close of the crying fit, as if they wished to stop their eyes crying, or possibly to relieve the irritation from the salt tears. I wish I knew more about the knuckles and crying.
What a tremendous stir-up your excellent article on prayer has made in England and America! (474/2. The article entitled "Statistical Inquiries into the Efficacy of Prayer" appeared in the "Fortnightly Review," 1872. In Mr. Francis Galton's book on "Enquiries into Human Faculty and its Development," London, 1883, a section (pages 277-94) is devoted to a discussion on the "Objective Efficacy of Prayer.")
LETTER 412. TO FRANCIS GALTON.
Down, January 4th, 1873.
Very many thanks for "Fraser" (412/1. "Hereditary Improvement," by Francis Galton, "Fraser's Magazine," January 1873, page 116.): I have been greatly interested by your article. The idea of castes being spontaneously formed and leading to intermarriage (412/2. "My object is to build up, by the mere process of extensive enquiry and publication of results, a sentiment of caste among those who are naturally gifted, and to procure for them, before the system has fairly taken root, such moderate social favours and preference, no more no less, as would seem reasonable to those who were justly informed of the precise measure of their importance to the nation" (loc. cit., page 123).) is quite new to me, and I should suppose to others. I am not, however, so hopeful as you. Your proposed Society (412/3. Mr. Galton proposes that "Some society should undertake three scientific services: the first, by means of a moderate number of influential local agencies, to institute continuous enquiries into the facts of human heredity; the second to be a centre of information on heredity for breeders of animals and plants; and the third to discuss and classify the facts that were collected" (loc. cit., page 124).) would have awfully laborious work, and I doubt whether you could ever get efficient workers. As it is, there is much concealment of insanity and wickedness in families; and there would be more if there was a register. But the greatest difficulty, I think, would be in deciding who deserved to be on the register. How few are above mediocrity in health, strength, morals and intellect; and how difficult to judge on these latter heads. As far as I see, within the same large superior family, only a few of the children would deserve to be on the register; and these would naturally stick to their own families, so that the superior children of distinct families would have no good chance of associating much and forming a caste. Though I see so much difficulty, the object seems a grand one; and you have pointed out the sole feasible, yet I fear utopian, plan of procedure in improving the human race. I should be inclined to trust more (and this is part of your plan) to disseminating and insisting on the importance of the all-important principle of inheritance. I will make one or two minor criticisms. Is it not possible that the inhabitants of malarious countries owe their degraded and miserable appearance to the bad atmosphere, though this does not kill them, rather than to "economy of structure"? I do not see that an orthognathous face would cost more than a prognathous face; or a good morale than a bad one. That is a fine simile (page 119) about the chip of a statue (412/4. "...The life of the individual is treated as of absolutely no importance, while the race is as everything; Nature being wholly careless of the former except as a contributor to the maintenance and evolution of the latter. Myriads of inchoate lives are produced in what, to our best judgment, seems a wasteful and reckless manner, in order that a few selected specimens may survive, and be the parents of the next generation. It is as though individual lives were of no more consideration than are the senseless chips which fall from the chisel of the artist who is elaborating some ideal form from a rude block" (loc. cit., page 119).); but surely Nature does not more carefully regard races than individuals, as (I believe I have misunderstood what you mean) evidenced by the multitude of races and species which have become extinct. Would it not be truer to say that Nature cares only for the superior individuals and then makes her new and better races? But we ought both to shudder in using so freely the word "Nature" (412/5. See Letter 190, Volume I.) after what De Candolle has said. Again let me thank you for the interest received in reading your essay.
Many thanks about the rabbits; your letter has been sent to Balfour: he is a very clever young man, and I believe owes his cleverness to Salisbury blood. This letter will not be worth your deciphering. I have almost finished Greg's "Enigmas." (412/6. "The Enigmas of Life," 1872.) It is grand poetry--but too Utopian and too full of faith for me; so that I have been rather disappointed. What do you think about it? He must be a delightful man.
I doubt whether you have made clear how the families on the Register are to be kept pure or superior, and how they are to be in course of time still further improved.
LETTER 271. TO FRANCIS GALTON.
Down, November 7th, 1875.
I have read your essay with much curiosity and interest, but you probably have no idea how excessively difficult it is to understand. (271/1. "A Theory of Heredity" ("Journal of the Anthropological Institute," 1875). In this paper Mr. Galton admits that the hypothesis of organic units "must lie at the foundation of the science of heredity," and proceeds to show in what respect his conception differs from the hypothesis of pangenesis. The copy of Mr. Galton's paper, which Darwin numbered in correspondence with the criticisms in his letter, is not available, and we are therefore only able to guess at some of the points referred to.) I cannot fully grasp, only here and there conjecture, what are the points on which we differ. I daresay this is chiefly due to muddy-headedness on my part, but I do not think wholly so. Your many terms, not defined, "developed germs," "fertile," and "sterile germs" (the word "germ" itself from association misleading to me) "stirp," "sept," "residue," etc., etc., quite confounded me. If I ask myself how you derive, and where you place the innumerable gemmules contained within the spermatozoa formed by a male animal during its whole life, I cannot answer myself. Unless you can make several parts clearer I believe (though I hope I am altogether wrong) that only a few will endeavour or succeed in fathoming your meaning. I have marked a few passages with numbers, and here make a few remarks and express my opinion, as you desire it, not that I suppose it will be of any use to you.
1. If this implies that many parts are not modified by use and disuse during the life of the individual, I differ widely from you, as every year I come to attribute more and more to such agency. (271/2. This seems to refer to page 329 of Mr. Galton's paper. The passage must have been hastily read, and has been quite misunderstood. Mr. Galton has never expressed the view attributed to him.)
2. This seems rather bold, as sexuality has not been detected in some of the lowest forms, though I daresay it may hereafter be. (271/3. Mr. Galton, op. cit., pages 332-3: "There are not of a necessity two sexes, because swarms of creatures of the simplest organisations mainly multiply by some process of self-division.")
3. If gemmules (to use my own term) were often deficient in buds, I cannot but think that bud-variations would be commoner than they are in a state of nature; nor does it seem that bud-variations often exhibit deficiencies which might be accounted for by the absence of the proper gemmules. I take a very different view of the meaning or cause of sexuality. (271/4. Mr. Galton's idea is that in a bud or other asexually produced part, the germs (i.e. gemmules) may not be completely representative of the whole organism, and if reproduction is continued asexually "at each successive stage there is always a chance of some one or more of the various species of germs... dying out" (page 333). Mr. Galton supposes, in sexual reproduction, where two parents contribute germs to the embryo the chance of deficiency of any of the necessary germs is greatly diminished. Darwin's "very different view of the meaning or cause of sexuality" is no doubt that given in "Cross and Self Fertilisation"--i.e., that sexuality is equivalent to changed conditions, that the parents are not representative of different sexes, but of different conditions of life.)
4. I have ordered "Fraser's Magazine" (271/5. "The History of Twins," by F. Galton, "Fraser's Magazine," November, 1875, republished with additions in the "Journal of the Anthropological Institute," 1875. Mr. Galton explains the striking dissimilarity of twins which is sometimes met with by supposing that the offspring in this case divide the available gemmules between them in such a way that each is the complement of the other. Thus, to put the case in an exaggerated way, similar twins would each have half the gemmules A, B, C,...Z., etc, whereas, in the case of dissimilar twins, one would have all the gemmules A, B, C, D,...M, and the other would have N...Z.), and am curious to learn how twins from a single ovum are distinguished from twins from two ova. Nothing seems to me more curious than the similarity and dissimilarity of twins.
5. Awfully difficult to understand.
6. I have given almost the same notion.
7. I hope that all this will be altered. I have received new and additional cases, so that I have now not a shadow of doubt.
8. Such cases can hardly be spoken of as very rare, as you would say if you had received half the number of cases I have.
(271/6. We are unable to determine to what paragraphs 5, 6, 7, 8 refer.)
I am very sorry to differ so much from you, but I have thought that you would desire my open opinion. Frank is away, otherwise he should have copied my scrawl.
I have got a good stock of pods of sweet peas, but the autumn has been frightfully bad; perhaps we may still get a few more to ripen.
LETTER 273. TO FRANCIS GALTON.
December 18th .
George has been explaining our differences. I have admitted in the new edition (273/1. In the second edition (1875) of the "Variation of Animals and Plants," Volume II., page 350, reference is made to Mr. Galton's transfusion experiments, "Proc. R. Soc." XIX., page 393; also to Mr. Galton's letter to "Nature," April 27th, 1871, page 502. This is a curious mistake; the letter in "Nature," April 27th, 1871, is by Darwin himself, and refers chiefly to the question whether gemmules may be supposed to be in the blood. Mr. Galton's letter is in "Nature," May 4th, 1871, Volume IV., page 5. See Letter 235.) (before seeing your essay) that perhaps the gemmules are largely multiplied in the reproductive organs; but this does not make me doubt that each unit of the whole system also sends forth its gemmules. You will no doubt have thought of the following objection to your views, and I should like to hear what your answer is. If two plants are crossed, it often, or rather generally, happens that every part of stem, leaf, even to the hairs, and flowers of the hybrid are intermediate in character; and this hybrid will produce by buds millions on millions of other buds all exactly reproducing the intermediate character. I cannot doubt that every unit of the hybrid is hybridised and sends forth hybridised gemmules. Here we have nothing to do with the reproductive organs. There can hardly be a doubt from what we know that the same thing would occur with all those animals which are capable of budding, and some of these (as the compound Ascidians) are sufficiently complex and highly organised.
LETTER 549. TO FRANCIS GALTON.
Down, March 8th .
Very many thanks for your note. I have been observing the [worm] tracks on my walks for several months, and they occur (or can be seen) only after heavy rain. As I know that worms which are going to die (generally from the parasitic larva of a fly) always come out of their burrows, I have looked out during these months, and have usually found in the morning only from one to three or four along the whole length of my walks. On the other hand, I remember having in former years seen scores or hundreds of dead worms after heavy rain. (549/1. "After heavy rain succeeding dry weather, an astonishing number of dead worms may sometimes be seen lying on the ground. Mr. Galton informs me that on one occasion (March, 1881), the dead worms averaged one for every two-and-a-half paces in length on a walk in Hyde Park, four paces in width" (loc. cit., page 14).) I cannot possibly believe that worms are drowned in the course of even three or four days' immersion; and I am inclined to conclude that the death of sickly (probably with parasites) worms is thus hastened. I will add a few words to what I have said about these tracks. Occasionally worms suffer from epidemics (of what nature I know not) and die by the million on the surface of the ground. Your ruby paper answers capitally, but I suspect that it is only for dimming the light, and I know not how to illuminate worms by the same intensity of light, and yet of a colour which permits the actinic rays to pass. I have tried drawing triangles of damp paper through a small cylindrical hole, as you suggested, and I can discover no source of error. (549/2. Triangles of paper were used in experiments to test the intelligence of worms (loc. cit., page 83).) Nevertheless, I am becoming more doubtful about the intelligence of worms. The worst job is that they will do their work in a slovenly manner when kept in pots (549/3. Loc. cit., page 75.), and I am beyond measure perplexed to judge how far such observations are trustworthy.