CHAPTER XXV.

LETTERS FROM DARWIN TO PROFESSOR MELDOLA (1871–82).

By the kindness of my friend Professor Meldola, and the courtesy of Mr. Francis Darwin, I am enabled to publish for the first time a series of letters written by Charles Darwin to the former. The whole series consists of 33 letters, written between January 28th, 1871, and February 2nd, 1882, only a few weeks before his death.

When we remember the immense amount of correspondence with which Darwin had to cope, the constant attention required by his investigations and publications, and the state of his health, it is deeply interesting to read these letters, written with such unfailing courtesy, to a younger worker in the lines that he had suggested, and who was thereby stimulated and encouraged to undertake the researches which are now so well known.

Reading these letters and remembering the circumstances of the writer, we can understand how it is that, although ill-health prevented his presence on occasions at which the younger scientific men are wont to meet--although he was known to but few of them--nevertheless the charm of his noble and generous nature was a most potent force in influencing and attracting men; and it was this, no less than his epoch-making discoveries, which has made it one of the chief regrets of many a scientific worker that he never saw Charles Darwin.

[Sidenote: LETTERS.]

The correspondence was opened by a letter from Meldola informing Darwin of a case of hexadactylism in a man at Turnham Green.

“_Jan. 28 [1871]._

“Down.

“DEAR SIR,--I am much obliged for your kindness in informing me of the hexadactylous case; but so many have been recorded that I do not think, except under very special circumstances, it would be worth your while further to investigate it.

“With my thanks, yours faithfully and obliged,

“CH. DARWIN.”

The next letter refers to Meldola’s communication to _Nature_ (he had recently written upon pangenesis and upon sexual selection), and his work on mimicry, protective resemblance, etc. In the latter part we meet with an interesting reference to the researches on cross-fertilisation which are now so famous.

“_June 9th [1871]._

“Down.

“DEAR SIR,--I am greatly obliged by your note. I have read with much interest and carefully perused your letter in Nature, and am looking out for a paper announced for Linn. Soc. Your remarks shall all be in due time fully considered. With respect to the separation of the sexes, I have often reflected on the subject; but there is much difficulty, as it seems to me and as Nageli has insisted, inasmuch as a strong case can be made out in favour of the view that with plants at least the sexes were primordially distinct, then became in many cases united, and in not a few cases re-separated. I have during the last 5 or 6 years been making a most laborious series of experiments, by which I shall be able, I think, to demonstrate the wonderful good derived from crossing, and I am almost sure but shall not know till the end of the summer that I shall be able to prove that the good is precisely of the same kind which the adult individual derives from _slight_ changes of conditions.

“With my sincere thanks for your interest in my work, I remain, dear Sir, Yours very faithfully,

“CH. DARWIN.”

The following letter is of great interest in relation to many problems of sexual selection, protective resemblance, mimicry, etc.:--

“_Jan. 23, 1872._

“Down.

“DEAR SIR--The point to which you refer seems to me a very difficult one. 1^{st} the comparison of the amount of variability in itself would be difficult. 2^{ndly} of all characters, colour seems to be the most variable, as we see in domesticated productions. (3) I fully agree that selection if long continued gives fixity to characters. We see the reverse of this in the great variability of fancy races, now being selected by man. But to give fixity, selection must be continued for a very long period: pray consider on this head what I have said in the Origin about the variability of characters developed in an extraordinary manner, in comparison with the same characters in allied species. The selection must also be for a definite object, and not for anything so vague as beauty, or for the superiority of one male in its weapons over another male, which can in like manner be modified. This at least seems to me partly to account for the general variability of secondary sexual characters. In the case of mimetic insects, there is another element of doubt, as the imitated form may be undergoing change which will be followed by the imitating form. This latter consideration seems to me, as remarked in my ‘Descent of Man,’ to throw much light on how the process of imitation first began.

“I enclose a letter from Fritz Müller which I think is well worth reading, and which please to return to me.

“You will see he lays much stress on the difficulty of several remotely allied forms all imitating some one species. Mr. Wallace did not think that there was so much weight in this objection as I do. It is, however, possible that a few species in widely different groups, before they had diverged much, should have accidentally resembled, to a certain extent, some one species. You will also see in this letter a strange speculation, which I should not dare to publish, about the appreciation of certain colours being developed in those species which frequently behold other forms similarly ornamented. I do not feel at all sure that this view is as incredible as it may at first appear. Similar ideas have passed through my mind when considering the dull colours of all the organisms which inhabit dull-coloured regions, such as Patagonia and the Galapagos Is. I suppose you know Mr. Riley’s excellent essay on mimicry in the last report on the noxious insects of Missouri or some such title.

“I hope your work may be in every way successful.

“I remain, dear Sir, yours faithfully, “CHARLES DARWIN.”

The next letter deals with mimetic resemblance:--

“_Mar. 28, 1872._

“Down.

“DEAR SIR--I thank you for your information on various subjects. The point to which you allude seems to me very obscure, and I hardly venture to express an opinion on it. My first impression is that the colour of an imitating form might be modified to any extent without any tendency being given to the retention of ancient structural peculiarities. The difficulty of the subject seems to me to follow from our complete ignorance of the causes which have led to the generic differences between the imitating and imitated forms. The subject however seems worth investigating. If the imitator habitually lives in company with the imitated, it would be apt to follow in some respects the same habits of life, and this perhaps would lead to the retention or acquirement of some of the same structural characters.

“I wish you all success in your essay, and remain, dear Sir, yours very faithfully,

“CH. DARWIN.”

The next very brief letter, acknowledging the receipt of a note, was written from Down, March 26th, 1873. It contained some sympathetic remarks upon the progress of Meldola’s work upon Mimicry. In the succeeding letter, printed below, we find a very definite statement of opinion as to the _rôle_ of monstrosities in evolution:--

“_Aug. 13th_ [1873].

“Down.

“DEAR SIR--I am much obliged for your present which no doubt I shall find at Down on my return home....

“I am sorry to say that I cannot answer your question; nor do I believe that you could find it anywhere even approximately answered. It is very difficult or impossible to define what is meant by a larger variation. Such graduate into monstrosities or generally injurious variations. I do not myself believe that these are often or ever taken advantage of under nature. It is a common occurrence that _abrupt_ and considerable variations are transmitted in an unaltered state, or not at all transmitted, to the offspring or to some of them. So it is with tailless or hornless animals, and with sudden and great changes of colour in flowers.--I wish I could have given you any answer.

“Dear Sir, yours very faithfully, “CH. DARWIN.”

The succeeding three letters show Darwin’s scrupulous care as regards the publication, although with every acknowledgment, of the results obtained by others. They refer to a letter from Fritz Müller which he had forwarded to Meldola. The latter had written to ask Darwin’s permission and advice as to the inclusion of some of F. Müller’s observations in his most interesting paper, “Entomological Notes bearing on Evolution” (_Ann. and Mag. Nat. Hist._, 1878, 5th series, Vol. I. p. 155), which he was then preparing:--

“_Sept. 14, 1877._

“Down.

“DEAR SIR--I have some doubts whether Fritz Müller would like extracts from his letters being published after so long an interval,--that is if the letter relates to the origin of mimicry; for he published about a year ago an excellent paper on this subject. I believe it was in the Jenaische Zeitschrift, but the paper is out of its proper place in my library and I cannot find it. If you thought it worth while to send me your copy I could then judge about the publication of extracts.

“I fear it is not likely that I shall have anything to communicate to the Entomological Soc. I quite agree with you that it is a great pity that our Entomologists should confine themselves to describing species.

“Dear Sir, yours faithfully, “CH. DARWIN.”

* * * * *

“_Sept. 22nd_ [1877].

“Down.

“MY DEAR SIR--I am doubtful whether speculations in a letter ought to be published, especially after a long interval of time. Any fact which he states, I feel pretty sure he would not at all object being used by anyone.--Pray do the best you can.--I should grieve beyond measure to be accused of a breach of confidence.--He has lately, as I mentioned, thrown much light on the first steps in mimicry.

“With respect to dimorphic Butterflies, those about which I have read appear at different seasons, and have been the subject of an _admirable_ essay by Prof. Weismann. It is some little time since I read the essay and one subject drives another out of my head, but I think he explains all such cases by the direct inherited effects of temperature. He tried experiments. If you read German, I believe I could find Weismann’s essays and lend them to you. In your present interesting case I really do not know what to think: it seems rather bold to attribute the 2 coloured forms to nat. selection, before some advantage can be pointed out.--May not the female revert in some cases? I do not doubt that the intermediate form could be eliminated as you suggest.

“I wish that my opinion could have been of any value....

“I remain yours very faithfully, “CH. DARWIN.”

This last letter, with others that followed it, directing Meldola’s attention to Weismann’s “Studies in the Theory of Descent,” resulted in the English translation which is so admirably rendered and edited. Many of the later letters are concerned with the progress of this publication. The remarks about dimorphic butterflies referred to Meldola’s observation, that in one of those years in which _Colias edusa_ was extremely abundant, a whole series of forms had been taken transitional between the normal orange female and the white variety _helice_:--

“_Sept. 27_ [1877].

“Down.

“MY DEAR SIR,--It is impossible for F. M. [Fritz Müller] to object to anything which you have said in your very interesting little essay.--I just allude to Butterflies preferring certain colours at p. 317 of 2nd Edit^{n.} of the Descent and to the case of the species of Castnia p. 315 which has ornamented hinder wings and displays them, whilst 2 other species have plain hind wings and do not display them. My son, who has charge of my library, returns home to-night and then we will search for Weismann. He gives splendid case of caterpillar with coloured ocelli like true eyes, _and which frightened away birds_.

“Yours sincerely, “CH. DARWIN.”

The reference in this letter is to Meldola’s paper, “Entomological Notes bearing on Evolution,” soon afterwards published in the _Annals and Magazine of Natural History_, 1878, Vol. I. p. 155. The caterpillar referred to is the well-known larva of the Large Elephant Hawk Moth (_Chærocampa elpenor_).

Darwin then wrote a brief note (October 19th, 1877) referring to a number of _Kosmos_ containing an article on “Sexual Selection.” He offered to send the number if it would interest his correspondent. The number was sent, as the succeeding letter shows:--

“_Oct. 22nd [1877]._

“Down.

“MY DEAR SIR,--I send Kosmos by this post....

“Prof. Weismann’s address is Freiburg.--I should think he would be glad of translation, and would probably arrange for stereotypes of Plates.--You could say as an introduction that I had lent you his book.--To find a publisher will be perhaps a difficulty. Should it be translated I must beg you to get another copy, as I cannot spare mine for such a length of time.--Wallace sent me his article and I was quite dissatisfied with it.--To explain a peacock’s tail by vital activity seems to me mere verbiage--a mere metaphysical principle.

“My dear Sir, yours faithfully, “CH. DARWIN.

“It will be a public benefit to bring out a translation.”

Then followed three letters, January 3rd, March 24th, and March 27th, 1878; the first written when Darwin was sending another number of _Kosmos_, the second when sending his photograph, the third enclosing a letter from Fritz Müller containing some very interesting observations on mimicry in South American butterflies.

He then wrote as follows:--

“_April 17/78._

“Down.

“MY DEAR SIR,--I should be very much obliged if you could get some one to name the photographs of the enclosed insect and read the enclosed letter. It seems a pretty, but I think not new case of protective resemblance. One might fancy that the large ocelli on the under wings were a sexual ornament.--Perhaps these photographs might be worth exhibiting at the Entomolog. Soc.--I do not want them returned (unless indeed Dr. Zacharias wants them back, which is not probable) or the enclosed letter.

“A single word with the name of the genus and if possible of the species, would suffice.--

“Pray forgive my troubling you and believe me

“Yours faithfully, “CH. DARWIN.

“I am glad that F. Müller’s letter interested you. He has published a paper with plates on the shape of the hairs or scales on the odoriferous glands of many butterflies, which I could send you, but I doubt whether you would care for it.”

Darwin then sent another letter from Fritz Müller containing some interesting notes on odoriferous organs in butterflies, and on the occasional failure of the female insect to deposit her eggs on a plant which can serve as the food of the young larvæ. The beetles alluded to were a species of _Spermophagus_. The two letters printed below refer to the same subjects:--

“_May 15 [1878]._

“Down.

“MY DEAR SIR,--I think the enclosed will interest you.--The letter to me need not be returned as I have had the only important passage for my work copied out.--In the letter F. M. [Fritz Müller] sent me seeds of _Cassia neglecta_ and several beetles arrived alive, having formed their cocoons, and gnawed their way out of the little peas or seeds.--These elegant beetles, with the knowledge of their manner of development may interest some Coleopterist.

“I hope to hear some time about Dr. Zacharias’ photographs. I received your obliging letter from Paris.

“Yours sincerely, “CH. DARWIN.”

* * * * *

“_May 25 [1878]._

“Down.

“MY DEAR SIR,--The living beetles and the cocoons were found in a small paper packet containing the seeds. Those from which the beetles had emerged were much broken, and the larvæ had evidently attacked some of the other seeds. I am sorry to say that some of the injured ones were thrown away. I am glad that you are going to draw up a paper from Fritz Müller’s letters.

“Yours sincerely, “CH. DARWIN.”

After another short note, dated July 24th, 1878, Darwin wrote the following letter, which explains how it was that he came to write the preface to the translation of Weismann’s “Studies”:--

“_October 31 [1878]._

“Down.

“MY DEAR SIR,--As you are inclined to be so very liberal as to have a translation made of Weismann’s Essays on your own risk, I feel bound to aid you to the small extent of writing a short prefatory notice. But this is a kind of job, which I do not feel that I can do at all well and therefore do not like; but I will do my best. It must, however, be short for I am at present working very hard. I do not quite understand whether you intend asking some Publisher to bring out the book on commission at your cost for if so there will be no difficulty in finding a Publisher. But if you expect any Publisher to publish at his risk and cost; I think from recent experience you will have much difficulty in finding one.--I suppose that you have asked Weismann’s concurrence.

“Down is rather an awkward place to reach, as we are 4 miles from nearest station, Orpington. But I shall be in London for a week on Nov^r 17th or 18th and could see you then at any time, and perhaps you could come to luncheon.

“But if you would prefer to come here, I shall be very happy to see you either Saturday or Sunday, if you would let me know hour.--I am, however, bound to tell you that my health is always doubtful, and that my head does not allow me to converse long with anyone.

“With the most cordial sympathy in your undertaking, I remain, my dear Sir, yours very faithfully,

“CH. DARWIN.”

In November, 1878, Darwin was in London, staying at his daughter’s house at 4, Bryanston Street. On the 19th he wrote asking Meldola to lunch to talk over the proposed English edition of Weismann, and on the 25th sent the MS. of the Preface with the following letter:--

“4 Bryanston St., “Portman Sq^{re}.

“_Nov. 25_ [1878].

“MY DEAR SIR,--I send my little Preface, which I do not at all like, but which I cannot improve. I should like hereafter to see it in type. Mr. Bates tells me that Hardwick and Bohn of Piccadilly intend to go in for publishing solid books; and if your present publisher should change his mind: Mr. Bohn might be worth applying to.

“Yours sincerely, “CH. DARWIN.”

Professor Meldola then wrote, suggesting that Darwin should, in his Preface, point out, by references to the “Origin of Species” and his other writings, how far he had already traced out the lines which Weismann had pursued in his researches. The suggestion was made because in a great many of the Continental writings upon the theory of descent a number of the points which had been clearly foreshadowed, and in some cases even explicitly stated, by Darwin had been independently rediscovered and published as though original. In the editorial notes to Meldola’s translation full justice to Darwin has been done in this respect. Darwin’s characteristic reply is deeply interesting.

“_Nov 26^{th}_ [1878].

“4 Bryanston St.

“MY DEAR SIR,--I am very sorry to say that I cannot agree to your suggestion.--An author is never a fit judge of his own work, and I should dislike extremely pointing out when and how Weismann’s conclusions and work, agreed with my own.--I feel sure that I ought not to do this, and it would be to me an intolerable task. Nor does it seem to me the proper office of the Preface, which is to show what the book contains and that the contents appear to me valuable. But I can see no objection for you, if you think fit, to write an introduction with remarks or criticisms of any kind. Of course I would be glad to advise you on any point as far as lay in my power, but as a whole I could have nothing to do with it, on the grounds above specified that an author cannot and ought not to attempt to judge his own works or compare them with others. I am sorry to refuse to do anything which you wish.--

“We return home early to-morrow morning.--Your green silk seems to me a splendid colour, whatever the æsthetics may say.--My dear Sir, yours faithfully,

“CH. DARWIN.”

The “green silk” referred to some specimens of coal-tar colours sent to show Darwin what modern chemistry had been able to accomplish in the way of artificial colouring matters. They were at that time of particular interest in connection with a discussion which had arisen in Bryanston Street about the so-called “æsthetic” school, which had become rather predominant at the period, and which affected an abhorrence of all brilliant colouring, in spite of the circumstance that nature abounds in the most gorgeous hues, especially in the tropics.

The next letter refers to the adoption of the word “phyletic” in the translation of Weismann.

“_Dec. 14_ [1878].

“Down.

“MY DEAR SIR,--I am very glad that you are making good progress with the book.--You could not apply to a worse person than myself on any philological question. I presume that ‘phyletische’ has been adopted or modified from Häckel. As the latter uses the word, it has nearly the sense of genealogical. It always applies to the lines of descent, and therefore differs somewhat from ‘innate’; for an inherited character, though derived from the father alone or only a single generation, would be innate in the child. I should think ‘phyletic’ would do very well, if you gave the German word and an explanation, in a foot-note.

“There has been a delay in answering your letter, but I have just heard from my son who is away from home, and he says that he is sorry but he cannot well spare the time to lecture.

“My dear Sir, yours very faithfully, “CH. DARWIN.”

Then followed two letters (January 20th, and February 7th, 1879), the first written when Darwin was sending a number of _Kosmos_; the second referring to it and other papers, and asking that his name should be put down as a subscriber to the forthcoming translation of Weismann.

Later on the number of _Kosmos_ for May, 1879, was sent, containing (p. 100) Fritz Müller’s paper “_Ituna_ and _Thyridia_.” This paper, although it did not attract sufficient attention at the time, was of the highest importance in relation to the theory of mimicry, as Meldola at once perceived.

Bates in his epoch-making paper in the Transactions of the Linnean Society (Vol. XXIII. 1862) had founded the theory of mimicry. Those rarer forms which have diverged from their near allies and, in superficial appearance, approached some distantly related, but abundant, species inhabiting the same tract have been, according to Bates’s theory, benefiting themselves in the struggle for existence. The mimicked species are, he suggested, abundant because they possess some special means of protection, such as an unpleasant taste or smell, and they have an unpleasant reputation which greatly aids them in the struggle for life; while the mimicking species, by their superficial resemblance, are enabled to live upon that reputation without possessing the special means of defence.

Certain facts well-known to Bates, and brought forward in his paper, were not explicable by this theory, viz. the resemblance that often exists between the abundant and specially protected species themselves. Although a few tentative suggestions were made, such as the production of a common appearance by similarity of climate, or food, etc., these facts remained an unexplained mystery until this paper of Fritz Müller’s in the May number of _Kosmos_. He there suggests that the mutual resemblance between the specially protected forms is advantageous, in reducing for each of them the number of individuals which must be sacrificed during the process of education which their youthful enemies must undergo, before they learn what is fit and what unfit for food. The arrangement is, in fact, much like that between a couple of firms that issue a common advertisement, and so save about half the expense of advertising alone. It is only another added to the numerous examples of the production by natural selection, and without the introduction of consciousness, of a result which could not be bettered by the deliberate action of the most acute intelligence.

Meldola at once wrote to Darwin asking his advice about the translation of F. Müller’s paper, and received the following reply:--

“_June 6th, 1879._

“Down.

“MY DEAR MR. MELDOLA,--Your best plan will be to write to ‘Dr. Ernst Krause, Friedenstrasse, 10 II. Berlin.’ He is one of the editors with whom I have corresponded. You can say that I sent you the Journal and called your attention to the paper, but I cannot take the liberty of advising the supply of clichés. He is a very obliging man. Had you not better ask for permission to translate, saying the source will be fully acknowledged?

“F. Müller’s view of the mutual protection was quite new to me.

“Yours sincerely, “CH. DARWIN.”

The clichés were obtained and Meldola’s translation published in the Proceedings of the Entomological Society for 1879, p. 20. The new contribution to the theory of mimicry was at first somewhat severely criticised, even Bates being adverse to it. Subsequent work has abundantly justified it as by far the most important addition to the subject since Bates’s original paper. In fact, many cases which have been up to the present explained under the theory of true (Batesian) mimicry are now believed to come under that which we owe to F. Müller--viz. convergence between specially protected forms for mutual benefit.

An interesting paper by Dr. F. A. Dixey, published in the Transactions of the Entomological Society for the present year (1896), contains convincing arguments in favour of this view as regards some of the _Pieridæ_ of South America in relation to the _Heliconidæ_ and _Papilionidæ_ which they resemble.

It is of the highest interest to learn that the first introduction of this new and most suggestive hypothesis into this country was due to the direct influence of Darwin himself, who brought it before the notice of the one man who was likely to appreciate it at its true value and to find the means for its presentation to English naturalists.

In the next year Meldola wished to translate further papers of Fritz Müller’s, and received the following letter on the subject:--

“_Nov. 25/80._

“Down.

“MY DEAR SIR,--I can well believe that your labour must have been great, and everyone is bound to aid you in any way.

“No. I. of F. Müller’s paper is in the August no. for 1877.

“No. II.--is in the October no. for 1877.

“Both these articles I remember thinking excellent.

“I am not one of the editors of Kosmos, only a kind of patron(!) and therefore cannot give permission; but when you write to the editors you can say that I have expressed a hope that permission would be granted, you acknowledging source of papers.

“Heartily wishing you success and in haste to catch first post, I remain yours very faithfully,

“CH. DARWIN.”

Shortly after the date of the last letter Professor Meldola came across a copy of Thomson’s “Annals of Philosophy” on a bookstall. It bore the name “Erasmus Darwin” on the first page, and Meldola offered it to Charles Darwin, thinking it might have belonged to his grandfather.

“_March 12th, 1881_ [The date was evidently May, and not March].

“Down.

“DEAR MR. MELDOLA,--It is very kind of you to offer to send me the book, but I feel sure that it could not have belonged to my grandfather.--My eldest brother’s name is Erasmus and he attended to chemistry when young, and I suppose that the ‘Annals of Philosophy’ was left at my Father’s house and sold with the Library which belonged to my sisters.--I will look to the few words of Preface to Wiesmann [_sic_], whenever I receive a proof.--With many thanks.--

“Yours very faithfully, “CH. DARWIN.”

Then followed a brief note dated “Aug. 8, 1881,” referring to some point in the work upon which Meldola was then engaged, and which cannot now be ascertained. Another letter of the same date referred to the translation of Weismann, and contained some encouraging words upon the interest created by the work and upon the success of the Essex Field Club, in which Meldola had taken a leading part. Another brief note of August 10th, 1881, apparently refers to some paper which cannot now be identified.

The following interesting letter is of uncertain date:--

“_? 19th, ? 1881._

“Down.

“DEAR MR. MELDOLA,--When I read the F. M. [Fritz Müller] paper your doubt occurred to me and I must say this, I would rather have expected that the knowledge of distasteful caterpillars would have been inherited, but I distinctly remember an account (when Wallace first propounded his warning colors) published of some birds, I think turkeys, being experimented upon and they shook their heads after trying some caterpillars as if they had a horrid taste in their mouths. I fancied this thing was published by Mr. Weir or could it have been by Mr. Butler? It would be well to look in Mr. Belt’s ‘Nicaragua’ as he tried some experiments. I am not sure that there is not some statement of the kind in it.

“Yours faithfully, “CHARLES DARWIN.

“I daresay Mr. Wallace or Bates would remember the statement of some birds shaking their heads to which I refer.”

The statement about the turkeys evidently refers to Stainton’s experiment with young birds of this kind, which immediately devoured numerous protectively coloured moths, but, after seizing, invariably rejected, a conspicuous white species (_Spilosoma menthastri_). It was Belt’s ducks which shook their heads after tasting a very conspicuous Nicaraguan frog. Darwin wished to show by this evidence that there was no instinctive knowledge such as would have saved the birds from an evidently unpleasant experience.

The last letter, deeply interesting both on its own account and because it was written so near the end of Darwin’s life, was a reply to one from Meldola in which he had said that the publishers were complaining that the list of subscribers was disappointing, and that they had expressed the wish that Mr. Darwin could see his way to writing a much longer introductory notice than he had done.

“_Feb. 2nd [1882]._

“Down.

“DEAR MR. MELDOLA,--I am very sorry that I can add nothing to my very brief notice without reading again Weismann’s work and getting up the whole subject by reading my own and other books, and for so much labour I have not strength. I have now been working at other subjects for some years, and when a man grows as old as I am, it is a great wrench to his brain to go back to old and half-forgotten subjects. You would not readily believe how often I am asked questions of all kinds, and quite lately I have had to give up much time to do a work, not at all concerning myself, but which I did not like to refuse. I must however somewhere draw the line, or my life will be a misery to me.

“I have read your Preface and it seems to me _excellent_. I am sorry in many ways, including the honour of England as a scientific country, that your translation has as yet sold badly. Does the publisher or do you lose by it? If the publisher, though I should be sorry for him, yet it is in the way of business; but if you yourself lose by it, I earnestly beg you to allow me to subscribe a trifle, viz. ten guineas, towards the expense of this work, which you have undertaken on public grounds.

“Pray believe me, yours very faithfully, “CH. DARWIN.”

Darwin’s generous offer, although gratefully declined, was a warm encouragement in the laborious, and in some respects thankless, task of translator and editor--a task which, in the case of the English edition of Weismann’s “Studies in the Theory of Descent,” was carried out in so admirable a manner.