The principal part of your letter was high laudation of Darwin's book.
Well, the book has reached me, and I finished its careful perusal four days ago; and I freely say that your laudation is not out of place.
It is done in a MASTERLY MANNER. It might well have taken twenty years to produce it. It is crammed full of most interesting matter—thoroughly digested—well expressed—close, cogent, and taken as a system it makes out a better case than I had supposed possible...
Agassiz, when I saw him last, had read but a part of it. He says it is POOR—VERY POOR!! (entre nous). The fact [is] he is very much annoyed by it,... and I do not wonder at it. To bring all IDEAL systems within the domain of science, and give good physical or natural explanations of all his capital points, is as bad as to have Forbes take the glacier materials... and give scientific explanation of all the phenomena.
Tell Darwin all this. I will write to him when I get a chance. As I have promised, he and you shall have fair-play here... I must myself write a review of Darwin's book for 'Silliman's Journal' (the more so that I suspect Agassiz means to come out upon it) for the next (March) No., and I am now setting about it (when I ought to be every moment working the Expl[oring] Expedition Compositae, which I know far more about). And really it is no easy job, as you may well imagine.
I doubt if I shall please you altogether. I know I shall not please Agassiz at all. I hear another reprint is in the Press, and the book will excite much attention here, and some controversy...
CHARLES DARWIN TO ASA GRAY. Down, January 28th [1860].
My dear Gray,
Hooker has forwarded to me your letter to him; and I cannot express how deeply it has gratified me. To receive the approval of a man whom one has long sincerely respected. And whose judgment and knowledge are most universally admitted, is the highest reward an author can possibly wish for; and I thank you heartily for your most kind expressions.
I have been absent from home for a few days, and so could not earlier answer your letter to me of the 10th of January. You have been extremely kind to take so much trouble and interest about the edition. It has been a mistake of my publisher not thinking of sending over the sheets. I had entirely and utterly forgotten your offer of receiving the sheets as printed off. But I must not blame my publisher, for had I remembered your most kind offer I feel pretty sure I should not have taken advantage of it; for I never dreamed of my book being so successful with general readers; I believe I should have laughed at the idea of sending the sheets to America. (In a letter to Mr. Murray, 1860, my father wrote:—"I am amused by Asa Gray's account of the excitement my book has made amongst naturalists in the United States. Agassiz has denounced it in a newspaper, but yet in such terms that it is in fact a fine advertisement!" This seems to refer to a lecture given before the Mercantile Library Association.)