Wallace's 'Natural Selection' (1870), a collection of essays reprinted with certain alterations of which a list is given in the volume:]
CHARLES DARWIN TO A.R. WALLACE. Down, April 20 [1870].
My dear Wallace,
I have just received your book, and read the preface. There never has been passed on me, or indeed on any one, a higher eulogium than yours. I wish that I fully deserved it. Your modesty and candour are very far from new to me. I hope it is a satisfaction to you to reflect--and very few things in my life have been more satisfactory to me--that we have never felt any jealousy towards each other, though in one sense rivals. I believe that I can say this of myself with truth, and I am absolutely sure that it is true of you.
You have been a good Christian to give a list of your additions, for I want much to read them, and I should hardly have had time just at present to have gone through all your articles. Of course I shall immediately read those that are new or greatly altered, and I will endeavour to be as honest as can reasonably be expected. Your book looks remarkably well got up.
Believe me, my dear Wallace, to remain, Yours very cordially, CH. DARWIN.
[Here follow one or two letters indicating the progress of the 'Descent of Man;' the woodcuts referred to were being prepared for that work:]
CHARLES DARWIN TO A. GUNTHER. (Dr. Gunther, Keeper of Zoology in the British Museum.) March 23, [1870?].
Dear Gunther,
As I do not know Mr. Ford's address, will you hand him this note, which is written solely to express my unbounded admiration of the woodcuts. I fairly gloat over them. The only evil is that they will make all the other woodcuts look very poor! They are all excellent, and for the feathers I declare I think it the most wonderful woodcut I ever saw; I can not help touching it to make sure that it is smooth. How I wish to see the two other, and even more important, ones of the feathers, and the four [of] reptiles, etc. Once again accept my very sincere thanks for all your kindness. I am greatly indebted to Mr. Ford. Engravings have always hitherto been my greatest misery, and now they are a real pleasure to me.
Yours very sincerely, CH. DARWIN.
P.S.--I thought I should have been in press by this time, but my subject has branched off into sub-branches, which have cost me infinite time, and heaven knows when I shall have all my MS. ready, but I am never idle.
CHARLES DARWIN TO A. GUNTHER. May 15 [1870].
My dear Dr. Gunther,
Sincere thanks. Your answers are wonderfully clear and complete. I have some analogous questions on reptiles, etc., which I will send in a few days, and then I think I shall cause no more trouble. I will get the books you refer me to. The case of the Solenostoma (In most of the Lophobranchii the male has a marsupial sack in which the eggs are hatched, and in these species the male is slightly brighter coloured than the female. But in Solenostoma the female is the hatcher, and is also the more brightly coloured.--'Descent of Man,' ii. 21.) is magnificent, so exactly analogous to that of those birds in which the female is the more gay, but ten times better for me, as she is the incubator. As I crawl on with the successive classes I am astonished to find how similar the rules are about the nuptial or "wedding dress" of all animals. The subject has begun to interest me in an extraordinary degree; but I must try not to fall into my common error of being too speculative. But a drunkard might as well say he would drink a little and not too much! My essay, as far as fishes, batrachians and reptiles are concerned, will be in fact yours, only written by me. With hearty thanks.
Yours very sincerely, CH. DARWIN.
[The following letter is of interest, as showing the excessive care and pains which my father took in forming his opinion on a difficult point:]
CHARLES DARWIN TO A.R. WALLACE. Down, September 23 [undated].
My dear Wallace,
I am very much obliged for all your trouble in writing me your long letter, which I will keep by me and ponder over.