My dear Darwin,--Many thanks for your valuable new edition of the "Orchids," which I see contains a great deal of new matter of the greatest interest. I am amazed at your continuous work, but I suppose, after all these years of it, it is impossible for you to remain idle. I, on the contrary, am very idle, and feel inclined to do nothing but stroll about this beautiful country, and read all kinds of miscellaneous literature. I have asked my friend Mr. Mott to send you the last of his remarkable papers--on Haeckel. But the part I hope you will read with as much interest as I have done is that on the deposits of Carbon, and the part it has played and must be playing in geological changes. He seems to have got the idea from some German book, but it seems to me very important, and I wonder it never occurred to Sir Charges Lyell. If the calculations as to the quantity of undecomposed carbon deposited are anything approaching to correctness, the results must be important. Hoping you are in pretty good health, believe me yours very faithfully, ALFRED R. WALLACE. * * * * * _Rose Hill, Dorking. July 23, 1877._ My dear Darwin,--Many thanks for your admirable volume on "The Forms of Flowers." It would be impertinence of me to say anything in praise of it, except that I have read the chapters on "Illegitimate Offspring of Heterostyled Plants" and on "Cleistogamic Flowers" with great interest. I am almost afraid to tell you that in going over the subject of the Colours of Animals, etc., for a small volume of essays, etc., I am preparing, I have come to conclusions directly opposed to _voluntary sexual selection_, and believe that I can explain (in a general way) _all_ the phenomena of sexual ornaments and colours by laws of development aided by simple Natural Selection. I hope you admire as I do Mr. Belt's remarkable series of papers in support of his terrific "oceanic glacier river-damming" hypothesis. In awful grandeur it beats everything "glacial" yet out, and it certainly explains a wonderful lot of hard facts. The last one, on the "Glacial Period in the Southern Hemisphere," in the _Quarterly Journal of Science_, is particularly fine, and I see he has just read a paper at the Geological Society. It seems to me supported by quite as much evidence as Ramsay's "Lakes"; but Ramsay, I understand, will have none of it--as yet.--Believe me yours very faithfully, ALFRED R. WALLACE. * * * * * _Down, Beckenham, Kent. August 31, 1877._