P.S.--You have paid me the highest conceivable compliment, by what you say of your work in relation to my chapters on distribution in the 'Origin,' and I heartily thank you for it.
[The following letters illustrate my father's power of taking a vivid interest in work bearing on Evolution, but unconnected with his own special researches at the time. The books referred to in the first letter are Professor Weismann's 'Studien zur Descendenzlehre' (My father contributed a prefatory note to Mr. Meldola's translation of Prof. Weismann's 'Studien,'
1880-81.), being part of the series of essays by which the author has done such admirable service to the cause of evolution:]
CHARLES DARWIN TO AUGUST WEISMANN.
January 12, 1877.
...I read German so slowly, and have had lately to read several other papers, so that I have as yet finished only half of your first essay and two-thirds of your second. They have excited my interest and admiration in the highest degree, and whichever I think of last, seems to me the most valuable. I never expected to see the coloured marks on caterpillars so well explained; and the case of the ocelli delights me especially...
...There is one other subject which has always seemed to me more difficult to explain than even the colours of caterpillars, and that is the colour of birds' eggs, and I wish you would take this up.
CHARLES DARWIN TO MELCHIOR NEUMAYR (Professor of Palaeontology at Vienna.), VIENNA.
Down, Beckenham, Kent, March 9, 1877.
Dear Sir, From having been obliged to read other books, I finished only yesterday your essay on 'Die Congerien,' etc. ('Die Congerien und Paludinenschichten Slavoneins.' 4to, 1875.)I hope that you will allow me to express my gratitude for the pleasure and instruction which I have derived from reading it. It seems to me to be an admirable work; and is by far the best case which I have ever met with, showing the direct influence of the conditions of life on the organization.
Mr. Hyatt, who has been studying the Hilgendorf case, writes to me with respect to the conclusions at which he has arrived, and these are nearly the same as yours. He insists that closely similar forms may be derived from distinct lines of descent; and this is what I formerly called analogical variation. There can now be no doubt that species may become greatly modified through the direct action of the environment. I have some excuse for not having formerly insisted more strongly on this head in my 'Origin of Species,' as most of the best facts have been observed since its publication.
With my renewed thanks for your most interesting essay, and with the highest respect, I remain, dear Sir, Yours very faithfully, CHARLES DARWIN.
CHARLES DARWIN TO E.S. MORSE.
Down, April 23, 1877.
My dear Sir, You must allow me just to tell you how very much I have been interested with the excellent Address ("What American Zoologists have done for Evolution," an Address to the American Association for the Advancement of Science, August, 1876. Volume xxv. of the Proceedings of the Association.)which you have been so kind as to send me, and which I had much wished to read. I believe that I had read all, or very nearly all, the papers by your countrymen to which you refer, but I have been fairly astonished at their number and importance when seeing them thus put together. I quite agree about the high value of Mr. Allen's works (Mr. J.A. Allen shows the existence of geographical races of birds and mammals. Proc. Boston Soc.
Nat. Hist. volume xv.), as showing how much change may be expected apparently through the direct action of the conditions of life. As for the fossil remains in the West, no words will express how wonderful they are.
There is one point which I regret that you did not make clear in your Address, namely what is the meaning and importance of Professors Cope and Hyatt's views on acceleration and retardation. I have endeavoured, and given up in despair, the attempt to grasp their meaning.
Permit me to thank you cordially for the kind feeling shown towards me through your Address, and I remain, my dear Sir, Yours faithfully, CH. DARWIN.
[The next letter refers to his 'Biographical Sketch of an Infant,' written from notes made 37 years previously, and published in 'Mind,' July, 1877.
The article attracted a good deal of attention, and was translated at the time in 'Kosmos,' and the 'Revue Scientifique,' and has been recently published in Dr. Krause's 'Gesammelte kleinere SchrifteN von Charles Darwin,' 1887:]
CHARLES DARWIN TO G. CROOM ROBERTSON. (The editor of 'Mind.')Down, April 27, 1877.
Dear Sir, I hope that you will be so good as to take the trouble to read the enclosed MS., and if you think it fit for publication in your admirable journal of 'Mind,' I shall be gratified. If you do not think it fit, as is very likely, will you please to return it to me. I hope that you will read it in an extra critical spirit, as I cannot judge whether it is worth publishing from having been so much interested in watching the dawn of the several faculties in my own infant. I may add that I should never have thought of sending you the MS., had not M. Taine's article appeared in your Journal. (1877, page 252. The original appeared in the 'Revue Philosophique' 1876.) If my MS. is printed, I think that I had better see a proof.
I remain, dear Sir, Yours faithfully, CH. DARWIN.
[The two following extracts show the lively interest he preserved in diverse fields of enquiry. Professor Cohn of Breslau had mentioned, in a letter, Koch's researches on Splenic Fever, my father replied, January 3:--"I well remember saying to myself, between twenty and thirty years ago, that if ever the origin of any infectious disease could be proved, it would be the greatest triumph to science; and now I rejoice to have seen the triumph."In the spring he received a copy of Dr. E. von Mojsisovics' 'Dolomit Riffe,' his letter to the author (June 1, 1878) is interesting as bearing on the influence of his own work on the methods of geology.