Life and Letters of Charles Darwin — Volume 2

[The two following letters are also of interest as bearing on my father's views on the action of isolation as regards the origin of new species:]

CHARLES DARWIN TO K. SEMPER. Down, November 26, 1878.

My dear Professor Semper,

When I published the sixth edition of the 'Origin,' I thought a good deal on the subject to which you refer, and the opinion therein expressed was my deliberate conviction. I went as far as I could, perhaps too far in agreement with Wagner; since that time I have seen no reason to change my mind, but then I must add that my attention has been absorbed on other subjects. There are two different classes of cases, as it appears to me, viz. those in which a species becomes slowly modified in the same country (of which I cannot doubt there are innumerable instances) and those cases in which a species splits into two or three or more new species, and in the latter case, I should think nearly perfect separation would greatly aid in their "specification," to coin a new word.

I am very glad that you are taking up this subject, for you will be sure to throw much light on it. I remember well, long ago, oscillating much; when I thought of the Fauna and Flora of the Galapagos Islands I was all for isolation, when I thought of S. America I doubted much. Pray believe me,

Yours very sincerely,

CH. DARWIN.

P.S. — I hope that this letter will not be quite illegible, but I have no amanuensis at present.

CHARLES DARWIN TO K. SEMPER. Down, November 30, 1878.

Dear Professor Semper,

Since writing I have recalled some of the thoughts and conclusions which have passed through my mind of late years. In North America, in going from north to south or from east to west, it is clear that the changed conditions of life have modified the organisms in the different regions, so that they now form distinct races or even species. It is further clear that in isolated districts, however small, the inhabitants almost always get slightly modified, and how far this is due to the nature of the slightly different conditions to which they are exposed, and how far to mere interbreeding, in the manner explained by Weismann, I can form no opinion. The same difficulty occurred to me (as shown in my 'Variation of Animals and Plants under Domestication') with respect to the aboriginal breeds of cattle, sheep, etc., in the separated districts of Great Britain, and indeed throughout Europe. As our knowledge advances, very slight differences, considered by systematists as of no importance in structure, are continually found to be functionally important; and I have been especially struck with this fact in the case of plants to which my observations have of late years been confined. Therefore it seems to me rather rash to consider the slight differences between representative species, for instance those inhabiting the different islands of the same archipelago, as of no functional importance, and as not in any way due to natural selection. With respect to all adapted structures, and these are innumerable, I cannot see how M. Wagner's view throws any light, nor indeed do I see at all more clearly than I did before, from the numerous cases which he has brought forward, how and why it is that a long isolated form should almost always become slightly modified. I do not know whether you will care about hearing my further opinion on the point in question, for as before remarked I have not attended much of late years to such questions, thinking it prudent, now that I am growing old, to work at easier subjects.

Believe me, yours very sincerely, CH. DARWIN.

I hope and trust that you will throw light on these points.

P.S. — I will add another remark which I remember occurred to me when I first read M. Wagner. When a species first arrives on a small island, it will probably increase rapidly, and unless all the individuals change instantaneously (which is improbable in the highest degree), the slowly, more or less, modifying offspring must intercross one with another, and with their unmodified parents, and any offspring not as yet modified. The case will then be like that of domesticated animals which have slowly become modified, either by the action of the external conditions or by the process which I have called the UNCONSCIOUS SELECTION by man — i.e., in contrast with methodical selection.

[The letters continue the history of the year 1872, which has been interrupted by a digression on Isolation.]

CHARLES DARWIN TO THE MARQUIS DE SAPORTA. Down, April 8, 1872.

Dear Sir,

I thank you very sincerely and feel much honoured by the trouble which you have taken in giving me your reflections on the origin of Man. It gratifies me extremely that some parts of my work have interested you, and that we agree on the main conclusion of the derivation of man from some lower form.

I will reflect on what you have said, but I cannot at present give up my belief in the close relationship of Man to the higher Simiae. I do not put much trust in any single character, even that of dentition; but I put the greatest faith in resemblances in many parts of the whole organisation, for I cannot believe that such resemblances can be due to any cause except close blood relationship. That man is closely allied to the higher Simiae is shown by the classification of Linnaeus, who was so good a judge of affinity. The man who in England knows most about the structure of the Simiae, namely, Mr. Mivart, and who is bitterly opposed to my doctrines about the derivation of the mental powers, yet has publicly admitted that I have not put man too close to the higher Simiae, as far as bodily structure is concerned. I do not think the absence of reversions of structure in man is of much weight; C. Vogt, indeed, argues that [the existence of] Micr-cephalous idiots is a case of reversion. No one who believes in Evolution will doubt that the Phocae are descended from some terrestrial Carnivore. Yet no one would expect to meet with any such reversion in them. The lesser divergence of character in the races of man in comparison with the species of Simiadae may perhaps be accounted for by man having spread over the world at a much later period than did the Simiadae. I am fully prepared to admit the high antiquity of man; but then we have evidence, in the Dryopithecus, of the high antiquity of the Anthropomorphous Simiae.

I am glad to hear that you are at work on your fossil plants, which of late years have afforded so rich a field for discovery. With my best thanks for your great kindness, and with much respect, I remain,

Dear Sir, yours very faithfully, CHARLES DARWIN.

[In April, 1872, he was elected to the Royal Society of Holland, and wrote to Professor Donders: —

"Very many thanks for your letter. The honour of being elected a foreign member of your Royal Society has pleased me much. The sympathy of his fellow workers has always appeared to me by far the highest reward to which any scientific man can look. My gratification has been not a little increased by first hearing of the honour from you."]

CHARLES DARWIN TO CHAUNCEY WRIGHT. Down, June 3, 1872.

My dear Sir,

Many thanks for your article (The proof-sheets of an article which appeared in the July number of the 'North American Review.' It was a rejoinder to Mr. Mivart's reply ('North American Review,' April 1872) to Mr. Chauncey Wright's pamphlet. Chauncey Wright says of it ('Letters,' page 238): — "It is not properly a rejoinder but a new article, repeating and expounding some of the points of my pamphlet, and answering some of Mr. Mivart's replies incidentally.") in the 'North American Review,' which I have read with great interest. Nothing can be clearer than the way in which you discuss the permanence or fixity of species. It never occurred to me to suppose that any one looked at the case as it seems Mr. Mivart does. Had I read his answer to you, perhaps I should have perceived this; but I have resolved to waste no more time in reading reviews of my works or on Evolution, excepting when I hear that they are good and contain new matter... It is pretty clear that Mr. Mivart has come to the end of his tether on this subject.

As your mind is so clear, and as you consider so carefully the meaning of words, I wish you would take some incidental occasion to consider when a thing may properly be said to be effected by the will of man. I have been led to the wish by reading an article by your Professor Whitney versus Schleicher. He argues, because each step of change in language is made by the will of man, the whole language so changes; but I do not think that this is so, as man has no intention or wish to change the language. It is a parallel case with what I have called "unconscious selection," which depends on men consciously preserving the best individuals, and thus unconsciously altering the breed.

My dear Sir, yours sincerely, CHARLES DARWIN.

[Not long afterwards (September) Mr. Chauncey Wright paid a visit to Down (Mr. and Mrs. C.L. Brace, who had given much of their lives to philanthropic work in New York, also paid a visit at Down in this summer. Some of their work is recorded in Mr. Brace's 'The Dangerous Classes of New York,' and of this book my father wrote to the author: —

"Since you were here my wife has read aloud to me more than half of your work, and it has interested us both in the highest degree, and we shall read every word of the remainder. The facts seem to me very well told, and the inferences very striking. But after all this is but a weak part of the impression left on our minds by what we have read; for we are both filled with earnest admiration at the heroic labours of yourself and others."), which he described in a letter ('Letters, page 246-248.) to Miss S. Sedgwick (now Mrs. William Darwin): "If you can imagine me enthusiastic — absolutely and unqualifiedly so, without a BUT or criticism, then think of my last evening's and this morning's talks with Mr. Darwin... I was never so worked up in my life, and did not sleep many hours under the hospitable roof... It would be quite impossible to give by way of report any idea of these talks before and at and after dinner, at breakfast, and at leav-taking; and yet I dislike the egotism of 'testifying' like other religious enthusiasts, without any verification, or hint of similar experience."]

CHARLES DARWIN TO HERBERT SPENCER. Bassett, Southampton, June 10, [1872].

Dear Spencer,

I dare say you will think me a foolish fellow, but I cannot resist the wish to express my unbounded admiration of your article ('Mr. Martineau on Evolution,' by Herbert Spencer, 'Contemporary Review,' July 1872.) in answer to Mr. Martineau. It is, indeed, admirable, and hardly less so your second article on Sociology (which, however, I have not yet finished): I never believed in the reigning influence of great men on the world's progress; but if asked why I did not believe, I should have been sorely perplexed to have given a good answer. Every one with eyes to see and ears to hear (the number, I fear, are not many) ought to bow their knee to you, and I for one do.

Believe me, yours most sincerely, C. DARWIN.

CHARLES DARWIN TO J.D. HOOKER. Down, July 12 [1872].

My dear Hooker,

I must exhale and express my joy at the way in which the newspapers have taken up your case. I have seen the "Times", the "Daily News", and the "Pall Mall", and hear that others have taken up the case.

The Memorial has done great good this way, whatever may be the result in the action of our wretched Government. On my soul, it is enough to make one turn into an old honest Tory...

If you answer this, I shall be sorry that I have relieved my feelings by writing.

Yours affectionately, C. DARWIN.

[The memorial here referred to was addressed to Mr. Gladstone, and was signed by a number of distinguished men, including Sir Charles Lyell, Mr. Bentham, Mr. Huxley, and Sir James Paget. It gives a complete account of the arbitrary and unjust treatment received by Sir J.D. Hooker at the hands of his official chief, the First Commissioner of Works. The document is published in full in 'Nature' (July 11, 1872), and is well worth studying as an example of the treatment which it is possible for science to receive from officialism. As 'Nature' observes, it is a paper which must be read with the greatest indignation by scientific men in every part of the world, and with shame by all Englishmen. The signatories of the memorial conclude by protesting against the expected consequences of Sir Joseph Hooker's persecution — namely his resignation, and the loss of "a man honoured for his integrity, beloved for his courtesy and kindliness of heart; and who has spent in the public service not only a stainless but an illustrious life."

Happily this misfortune was averted, and Sir Joseph was freed from further molestation.]

CHARLES DARWIN TO A.R. WALLACE. Down, August 3 [1872].

My dear Wallace,

I hate controversy, chiefly perhaps because I do it badly; but as Dr. Bree accuses you (Mr. Wallace had reviewed Dr. Bree's book, 'An Exposition of Fallacies in the Hypothesis of Mr. Darwin,' in 'Nature,' July 25, 1872.) of "blundering," I have thought myself bound to send the enclosed letter (The letter is as follows: — "Bree on Darwinism." 'Nature,' August 8, 1872. Permit me to state — though the statement is almost superfluous — that Mr. Wallace, in his review of Dr. Bree's work, gives with perfect correctness what I intended to express, and what I believe was expressed clearly, with respect to the probable position of man in the early part of his pedigree. As I have not seen Dr. Bree's recent work, and as his letter is unintelligible to me, I cannot even conjecture how he has so completely mistaken my meaning: but, perhaps, no one who has read Mr. Wallace's article, or who has read a work formerly published by Dr. Bree on the same subject as his recent one, will be surprised at any amount of misunderstanding on his part. — Charles Darwin. August 3.) to 'Nature,' that is if you in the least desire it. In this case please post it. If you do not AT ALL wish it, I should rather prefer not sending it, and in this case please to tear it up. And I beg you to do the same, if you intend answering Dr. Bree yourself, as you will do it incomparably better than I should. Also please tear it up if you don't like the letter.

My dear Wallace, yours very sincerely, CH. DARWIN.

CHARLES DARWIN TO A.R. WALLACE. Down, August 28, 1872.

My dear Wallace,

I have at last finished the gigantic job of reading Dr. Bastian's book ('The Beginnings of Life.' H.C. Bastian, 1872.) and have been deeply interested by it. You wished to hear my impression, but it is not worth sending.

He seems to me an extremely able man, as, indeed, I thought when I read his first essay. His general argument in favour of Archebiosis (That is to say, Spontaneous Generation. For the distinction between Archebiosis and Heterogenesis, see Bastian, chapter vi.) is wonderfully strong, though I cannot think much of some few of his arguments. The result is that I am bewildered and astonished by his statements, but am not convinced, though, on the whole, it seems to me probable that Archebiosis is true. I am not convinced, partly I think owing to the deductive cast of much of his reasoning; and I know not why, but I never feel convinced by deduction, even in the case of H. Spencer's writings. If Dr. Bastian's book had been turned upside down, and he had begun with the various cases of Heterogenesis, and then gone on to organic, and afterwards to saline solutions, and had then given his general arguments, I should have been, I believe, much more influenced. I suspect, however, that my chief difficulty is the effect of old convictions being stereotyped on my brain. I must have more evidence that germs, or the minutest fragments of the lowest forms, are always killed by 212 degrees of Fahr. Perhaps the mere reiteration of the statements given by Dr. Bastian [by] other men, whose judgment I respect, and who have worked long on the lower organisms, would suffice to convince me. Here is a fine confession of intellectual weakness; but what an inexplicable frame of mind is that of belief!