I am glad, also, to hear of the other analogous cases, all of which I will give briefly in my book that is now printing. The lessened number of good seeds in the self-fertilising Epidendrums is to a certain extent a new case. You suggest the comparison of the growth of plants produced from self-fertilised and crossed seeds. I began this work last autumn, and the result, in some cases, has been very striking; but only, as far as I can yet judge, with exotic plants which do not get freely crossed by insects in this country. In some of these cases it is really a wonderful physiological fact to see the difference of growth in the plants produced from self-fertilised and crossed seeds, both produced by the same parent-plant; the pollen which has been used for the cross having been taken from a distinct plant that grew in the same flower-pot. Many thanks for the dimorphic Rubiaceous plant. Three of your Plumbagos have germinated, but not as yet any of the Lobelias. Have you ever thought of publishing a work which might contain miscellaneous observations on all branches of Natural History, with a short description of the country and of any excursions which you might take? I feel certain that you might make a very valuable and interesting book, for every one of your letters is so full of good observations. Such books, for instance Bates' "Travels on the Amazons," are very popular in England. I will give your obliging offer about Brazilian plants to Dr. Hooker, who was to have come here to-day, but has failed. He is an excellent good fellow, as well as naturalist. He has lately published a pamphlet, which I think you would like to read; and I will try and get a copy and send you. (676/2. Sir J.D. Hooker's lecture on Insular Floras, given before the British Association in August, 1866, is doubtless referred to. It appeared in the "Gardeners' Chronicle," and was published as a pamphlet in January, 1867. This fact helps to fix the date of the present letter.)
LETTER 677. TO F. MULLER.
(677/1. The following refers to the curious case of Eschscholtzia described in "Cross and Self-Fertilisation," pages 343-4. The offspring of English plants after growing for two generations in Brazil became self-sterile, while the offspring of Brazilian plants became partly self-fertile in England.)
January 30th [1868].
...The flowers of Eschscholtzia when crossed with pollen from a distinct plant produced 91 per cent. of capsules; when self-fertilised the flowers produced only 66 per cent. of capsules. An equal number of crossed and self-fertilised capsules contained seed by weight in the proportion of 100 to 71. Nevertheless, the self-fertilised flowers produced an abundance of seed. I enclose a few crossed seeds in hopes that you will raise a plant, cover it with a net, and observe whether it is self-fertile; at the same time allowing several uncovered plants to produce capsules, for the sterility formerly observed by you seems to me very curious.
LETTER 678. TO F. MULLER. Down, November 28th [1868].
You end your letter of September 9th by saying that it is a very dull one; indeed, you make a very great mistake, for it abounds with interesting facts and thoughts. Your account of the tameness of the birds which apparently have wandered from the interior, is very curious. But I must begin on another subject: there has been a great and very vexatious, but unavoidable delay in the publication of your book. (678/1. "Facts and Arguments for Darwin," 1869, a translation by the late Mr. Dallas of F. Muller's "Fur Darwin," 1864: see Volume I., Letter 227.) Prof. Huxley agrees with me that Mr. Dallas is by far the best translator, but he is much overworked and had not quite finished the translation about a fortnight ago. He has charge of the Museum at York, and is now trying to get the situation of Assistant Secretary at the Geological Society; and all the canvassing, etc., and his removal, if he gets the place, will, I fear, cause more than a month's delay in the completion of the translation; and this I very much regret.