I am very glad to hear that you are beginning a book, but do not let it be "little," on Distribution, etc. I have no hints to give about maps; the subject would require long and anxious consideration. Before Forbes published his essay on Distribution and the Glacial Period I wrote out and had _copied_ an essay on the same subject, which Hooker read. If this MS. would be of any use to you, _on account of the references_ in it to papers, etc., I should be very glad to lend it, to be used in any way; for I foresee that my strength will never last out to come to this subject. I have been pretty well since my return from Wales, though at the time it did me no good. We shall be in London next month, when I shall hope to see you.--My dear Wallace, yours very sincerely, CH. DARWIN. * * * * * _9 St. Mark's Crescent, N.W. December 4, [1869]._ Dear Darwin,--Dr. Adolf Bernhard Meyer, who translated my book into German, has written to me for permission to translate my original paper in the _Linnean Proceedings_ with yours, and wants to put my photograph and yours in it. If you have given him permission to translate the papers (which I suppose he can do without permission if he pleases), I write to ask which of your photographs you would wish to represent you in Germany--the last, or the previous one by Ernest Edwards, which I think much the best--as if you like I will undertake to order them and save you any more trouble about it. It is, of course, out of the question our meeting to be photographed together, as Mr. Meyer coolly proposes. Hoping you are well, believe me yours very faithfully, ALFRED R. WALLACE. P.S.--I have written a paper on Geological Time, which will appear in _Nature_, and I _think_ I have hit upon a solution of your greatest difficulties in that matter.--A.R.W. * * * * * _Down, Beckenham, Kent, S.E. December 5, 1869._ My dear Wallace,--I wrote to Dr. Meyer that the photographs in England would cost much and that they did not seem to me worth the cost to him, but that I of course had no sort of objection. I should be greatly obliged if you would kindly take the trouble to order any one which you think best: possibly it would be best to wait, unless you feel sure, till you hear again from Dr. M. I sent him a copy of our joint paper. He has kindly sent me the translation of your book, which is splendidly got up, and which I thought I could not better use than by sending it to Fritz Müller in Brazil, who will appreciate it. I liked your reviews on Mr. Murphy very much; they are capitally written, like everything which is turned out of your workshop. I was specially glad about the eye. If you agree with me, take some opportunity of bringing forward the case of perfected greyhound or racehorse, in proof of the possibility of the selection of many correlated variations. I have remarks on this head in my last book.