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Darwin to Walsh:

Down Bromley Kent, S.E.

October 21 1864

My dear Sir

Ill health has prevented me from sooner thanking you for your very kind letter, and several Memoirs.

I have been very much pleased to see how boldly and clearly you speak out on the modification of species. I thank you for giving me the pages of reference; but they were superfluous, for I found so many original and profound remarks, that I have carefully looked through all the papers. I hope that your discovery about the Cynips will hold good for it is a remarkable one, and I for one have often marvelled what could be the meaning of the case. I will lend your paper to my neighbour Mr Lubbock who I know is much interested in the subject. Incidentally I shall profit by your remarks on galls if you have time I think a rather hopeless experiment would be worth trying; any how I should have tried it had my health permitted— it is to insert a minute grain of some organic substance together with the poison from bees, sand wasps, ichneumons, adders, and even alkaloid poisons into the tissues of fitting plants, for the chance of monstrous growths being produced.

My health has long been poor and I have lately suffered from a long illness, which has interrupted all work, but I am now re-commencing a volume in connection with the "Origin" with sincere thanks for your letter and kind present.

Pray believe me my dear Sir yours sincerely Charles Darwin

P.S. If you write again I should very much like to hear what your life in your new country is…

Darwin to Walsh:

December 4 (1864)

I have been greatly interested by your account of your American life. What an extraordinary and self-contained life you have led! And what vigour of mind you must possess to follow science with so much ardour after all that you have undergone.— I am very much obliged for your pamphlet on Geograph. Distrib,—on Agassiz etc.— I am delighted at the manner in which you have bearded this lion in his den. I agree most entirely with all that you have written. What I meant, when I wrote to Agassiz to thank him for a bundle of his publications, was exactly what you suppose. I confess, however, I did not fully perceive how he had mistaken my views; but I only skimmed through his "Method of Study" and thought it a very poor Book.— I am so much accustomed to be utterly misrepresented that it hardly excites my attention….

I am glad that you have attacked Dana's wild notions: I have a great respect for Dana, but I declare I fear that his long illness has somewhat enfeebled his brain.— If you have opportunity read in Transact—Bates on mimetic Lepidoptera of Amazons; I was delighted with his paper.

I have got a notice of your views about the female Cynips inserted in N. Hist. Review; whether the notice will be favourable I do know not; but anyhow it will call attention to your views….

I enclose a Photograph made of me by one of my sons, and I have no other.— I wrote to Westwood for a (illegible) [carte] for you, but I have received no answer. I have been told that he is most bitter about species, and perhaps wishes to show his feelings by this want of common courtesy to us both.

[Walsh to Darwin, not transcribed]

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[Walsh to Darwin, not transcribed]

Darwin to Walsh:

March 27 (1865)

I have been much interested by your letter. I received your former paper on Phytophagic unity, most of which was new to me. I have since received your paper on willow-galls: this has been very opportune as I wanted to learn a little about galls. There was much in this paper which has interested me extremely, on gradations and so forth and on "your" unity of correlation [illegible]. This latter subject is nearly new to me, though I collected many years ago some such cases with birds; but what struck me most was when a bird-genus inhabits two continents the two sections sometimes display a somewhat different type of colouring. I should like to hear whether this does not occur with widely ranging insect-genera…

With respect to Dimorphism you may like to hear that Dr Hooker tells me that a dioicous parasitic plant allied to Rafflesia has its 2 sexes parasitic on 2 distinct species of the same genus of plants; so look out for some such case in the 2 forms of Cynips. I have posted to you copies of my papers on Dimorphism.

With respect to Agassiz's views there were many, and there are still not a few, who believe that the same species is created on many spots. I wrote to Bates and he will send you his mimetic paper, and I dare say others: he is a first rate man.

Your case of the wingless insects near the Rocky mountains is extremely curious; I am sure I have heard of some such case in the old world, I think on the Caucasus. Would not my argument about wingless insular insects perhaps apply to truly Alpine insects; for would it not be destruction to them to be blown from their proper home? I should like to write on many points at greater length to you, but I have no strength to spare

Darwin to Walsh:

July 9 (1865)

I must send you a line to thank you for your interesting letter of May 29th. I have been ill during the last two months and have done no scientific work. Sir Joseph Dalian Hooker (1817-1911). English botanist

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Many thanks for the case of Panagaeus; this genus is almost sacred to me from old Cambridge recollections.

I sent you a few weeks ago a paper by me on Climbing Plants; but I doubt whether you will find it worth reading.

I am very much pleased that you like Bates' paper. Pray read his Travels.

Darwin to Walsh:

December 19 (1865)

I am much obliged for your interesting letter of Nov. 12—I hope you meet with the success which you well deserve in solving the very curious problem of the Cynips.

I presume that you expect that the sexual brood, whenever it appears, would be more locomotive, and thus spread the species. On the other hand, the new gall which has appeared in England recently has spread very rapidly, and yet only females have been found. I received your paper on the potatoe bug and it seems to me uncommonly well done.

Sir J. Lubbock and Mr. Busk called here the other day and neither knew or believed in the male Daphnia laying eggs.

The former would be almost sure to have heard of it. He believes in Wagner's case of the breeding larva of the fly. I should not be very much astonished at the Daphnia case, for certain male and female Medusae whilst sexually mature throw off reproductive buds and if these buds were encased in a shell, they might be as indistinguishable from true eggs as the ovules and buds in Aphis.

It is curious about the post office that I some months ago was expressing much indignation at your government being so particular about writing in, and sending, single pamphlets. There are no such rules within England and it seems that they apply only to the transit from one country to the other.

I have done no work since April owing to my health, but I have just begun some easy jobs, such as counting seeds of experimental Primulas, and these afford widely different results from what he gives. I mention this because I see that you quote him….

[Walsh to Darwin, not transcribed]

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[Walsh to Darwin, not transcribed]

Darwin to Walsh:

August 20 (1866)

I am sorry to say that before receiving your letter of July 17th the new edt. of the Origin had been dispatched by Murray for you. I received safely your paper exposing Dana's mis-quotation. I never could persuade myself that there was much or anything in Dana's paper, but I see it is taking effect in the United States.

I have read Prof. Clark's book and was interested by it on psychological principles as shewing how differently two men viz. the writer and the reader can view the same subject. I am heartily glad that you are making progress with your Cynips experiment. The new gall which has spread so wonderfully in England (and about which by the way there was a letter 2 days ago in the Times) is attached not to the leaf but to twigs; so that the bushes are rendered conspicuous in the winter by their numbers. I do not think anyone can define an ovule from a bud; the only difference being, as many now view the case, the former must be fertilized…

Some of the Germans, as Prof. Claus, have been taking up a subject which I am glad of, namely to ascertain the amount in order to test my views, of the individual variability of some of the commoner lower animals; and that they find it very great…