Volume I Part 44 (1/2)
(286/3. We owe to Professor Judd the following interesting recollections of Mr. Darwin, written about 1883:--
”On this last occasion, when I congratulated him on his seeming better condition of health, he told me of the cause for anxiety which he had in the state of his heart. Indeed, I cannot help feeling that he had a kind of presentiment that his end was approaching. When I left him, he insisted on conducting me to the door, and there was that in his tone and manner which seemed to convey to me the sad intelligence that it was not merely a temporary farewell, though he himself was perfectly cheerful and happy.
”It is impossible for me adequately to express the impression made upon my mind by my various conversations with Mr. Darwin. His extreme modesty led him to form the lowest estimate of his own labours, and a correspondingly extravagant idea of the value of the work done by others. His deference to the arguments and suggestions of men greatly his juniors, and his unaffected sympathy in their pursuits, was most marked and characteristic; indeed, he, the great master of science, used to speak, and I am sure felt, as though he were appealing to superior authority for information in all his conversations. It was only when a question was fully discussed with him that one became conscious of the fund of information he could bring to its elucidation, and the breadth of thought with which he had grasped it. Of his gentle, loving nature, of which I had so many proofs, I need not write; no one could be with him, even for a few minutes, without being deeply impressed by his grateful kindliness and goodness.”)
LETTER 287. TO COUNT SAPORTA. Down, August 15th, 1878.
I thank you very sincerely for your kind and interesting letter. It would be false in me to pretend that I care very much about my election to the Inst.i.tute, but the sympathy of some few of my friends has gratified me deeply.
I am extremely glad to hear that you are going to publish a work on the more ancient fossil plants; and I thank you beforehand for the volume which you kindly say that you will send me. I earnestly hope that you will give, at least incidentally, the results at which you have arrived with respect to the more recent Tertiary plants; for the close gradation of such forms seems to me a fact of paramount importance for the principle of evolution. Your cases are like those on the gradation in the genus Equus, recently discovered by Marsh in North America.
LETTER 288. TO THE DUKE OF ARGYLL.
(288/1. The following letter was published in ”Nature,” March 5th, 1891, Volume XLIII., page 415, together with a note from the late Duke of Argyll, in which he stated that the letter had been written to him by Mr. Darwin in reply to the question, ”why it was that he did a.s.sume the unity of mankind as descended from a single pair.” The Duke added that in the reply Mr. Darwin ”does not repudiate this interpretation of his theory, but simply proceeds to explain and to defend the doctrine.” On a former occasion the Duke of Argyll had ”alluded as a fact to the circ.u.mstance that Charles Darwin a.s.sumed mankind to have arisen at one place, and therefore in a single pair.” The letter from Darwin was published in answer to some scientific friends, who doubted the fact and asked for the reference on which the statement was based.)
Down, September 23rd, 1878.
The problem which you state so clearly is a very interesting one, on which I have often speculated. As far as I can judge, the improbability is extreme that the same well-characterised species should be produced in two distinct countries, or at two distinct times. It is certain that the same variation may arise in two distinct places, as with albinism or with the nectarine on peach-trees. But the evidence seems to me overwhelming that a well-marked species is the product, not of a single or of a few variations, but of a long series of modifications, each modification resulting chiefly from adaptation to infinitely complex conditions (including the inhabitants of the same country), with more or less inheritance of all the preceding modifications. Moreover, as variability depends more on the nature of the organism than on that of the environment, the variations will tend to differ at each successive stage of descent. Now it seems to me improbable in the highest degree that a species should ever have been exposed in two places to infinitely complex relations of exactly the same nature during a long series of modifications. An ill.u.s.tration will perhaps make what I have said clearer, though it applies only to the less important factors of inheritance and variability, and not to adaptation--viz., the improbability of two men being born in two countries identical in body and mind. If, however, it be a.s.sumed that a species at each successive stage of its modification was surrounded in two distinct countries or times, by exactly the same a.s.semblage of plants and animals, and by the same physical conditions, then I can see no theoretical difficulty [in]
such a species giving birth to the new form in the two countries. If you will look to the sixth edition of my ”Origin,” at page 100, you will find a somewhat a.n.a.logous discussion, perhaps more intelligible than this letter.
LETTER 289. W.T. THISELTON-DYER TO THE EDITOR OF ”NATURE.”
(289/1. The following letter (”Nature,” Volume XLIII., page 535) criticises the interpretation given by the Duke to Mr. Darwin's letter.)
Royal Gardens, Kew, March 27th [1891].
In ”Nature” of March 5th (page 415), the Duke of Argyll has printed a very interesting letter of Mr. Darwin's, from which he drew the inference that the writer ”a.s.sumed mankind to have arisen...in a single pair.” I do not think myself that the letter bears this interpretation.
But the point in its most general aspect is a very important one, and is often found to present some difficulty to students of Mr. Darwin's writings.
Quite recently I have found by accident, amongst the papers of the late Mr. Bentham at Kew, a letter of friendly criticism from Mr. Darwin upon the presidential address which Mr. Bentham delivered to the Linnean Society on May 24th, 1869. This letter, I think, has been overlooked and not published previously. In it Mr. Darwin expresses himself with regard to the multiple origin of races and some other points in very explicit language. Prof. Meldola, to whom I mentioned in conversation the existence of the letter, urged me strongly to print it. This, therefore, I now do, with the addition of a few explanatory notes.
LETTER 290. TO G. BENTHAM. Down, November 25th, 1869.
(290/1. The notes to this letter are by Sir W. Thiselton-Dyer, and appeared in ”Nature,” loc. cit.)
I was greatly interested by your address, which I have now read thrice, and which I believe will have much influence on all who read it. But you are mistaken in thinking that I ever said you were wrong on any point.
All that I meant was that on certain points, and these very doubtful points, I was inclined to differ from you. And now, on further considering the point on which some two or three months ago I felt most inclined to differ--viz., on isolation--I find I differ very little.
What I have to say is really not worth saying, but as I should be very sorry not to do whatever you asked, I will scribble down the slightly dissentient thoughts which have occurred to me. It would be an endless job to specify the points in which you have interested me; but I may just mention the relation of the extreme western flora of Europe (some such very vague thoughts have crossed my mind, relating to the Glacial period) with South Africa, and your remarks on the contrast of pa.s.sive and active distribution.
Page lxx.--I think the contingency of a rising island, not as yet fully stocked with plants, ought always to be kept in mind when speaking of colonisation.
Page lxxiv.--I have met with nothing which makes me in the least doubt that large genera present a greater number of varieties relatively to their size than do small genera. (290/2. Bentham thought ”degree of variability... like other const.i.tutional characters, in the first place an individual one, which...may become more or less hereditary, and therefore specific; and thence, but in a very faint degree, generic.”
He seems to mean to argue against the conclusion which Sir Joseph Hooker had quoted from Mr. Darwin that ”species of large genera are more variable than those of small.” [On large genera varying, see Letter 53.]) Hooker was convinced by my data, never as yet published in full, only abstracted in the ”Origin.”
Page lxxviii.--I dispute whether a new race or species is necessarily, or even generally, descended from a single or pair of parents. The whole body of individuals, I believe, become altered together--like our race-horses, and like all domestic breeds which are changed through ”unconscious selection” by man. (290/3. Bentham had said: ”We must also admit that every race has probably been the offspring of one parent or pair of parents, and consequently originated in one spot.” The Duke of Argyll inverts the proposition.)