Yours of the 15th came this evening. To-morrow I am busy all day in college (where I began my course this year with lectures on Fertilization, developing your views on orchid-insect fertilization, dimorphism, etc., etc., to an interested class!), so I must drop a line for you into a letter for Boott, for Wednesday’s post. A friend has just handed me Morell’s new book, which, looking at psychology from the physiological side, I see brings up several notions which have been turning over in my mind for some years. He is coming out a good Darwinian, I see, and is quite of my way of thinking about design. You see I am determined to baptize [“The Origin of Species”], nolens volens, which will be its salvation. But if you won’t have it done, it will be damned, I fear.... Things move on here, on the whole, very well. Yes, I will promise not to hate you; quite the contrary! Our sensitiveness as to England was the natural result of the strong filial feeling on our part. It was very undignified, I dare say. But I think we are getting bravely over it, and getting really not to care what the Old Country may think or say, so it lets us alone. As to Rebeldom, there is now hardly any State that we have not got some foothold in. I do not do so much scientific work as before the war, but still I keep pottering away. From now till July, I can expect to do little besides my college duties. Ever, dear Darwin, your cordial friend and true Yankee, A. GRAY. May 18. Yesterday came by post the sheets B-I of your Orchid book. This evening (Sunday) I have opened the parcel and read introduction and chapter i. What a charming book it is! You are right in issuing it in this form. It would be a sin not to do so. I fear, though, that no publisher would reprint it here; though I may, on reading farther, conclude to offer it to the Appletons, who should have the refusal. But it will surely be popular in England, where orchids are popular and the species known to most intelligent and educated people. I hope soon to get the other sheets. I am perfectly delighted with O. pyramidalis, and must extract the whole account of its fertilization for “Silliman’s Journal.” Our only orchis, that is, O. spectabilis, I brought last summer from western New York, and planted. I shall in a week have three or four spikes coming into flower, and I will cover one and leave the others exposed. They are in a wooded part of the garden, like their natural habitat. The rest of our Ophrydeæ are Habenarias (Platanthera). I must recur to your letter about Cypripedium and see what you wanted of it, that is, what observation. If there be any adaptation, be it ever so pretty, I shall never see it without your direction. What a skill and genius you have for these researches! Even for the structure of the flower of the Ophrydeæ I have to-night learned more than I ever knew before. TO A. DE CANDOLLE. CAMBRIDGE, April 26, 1861.