My dear Sir

I am very sorry your papers on climbing plants never reached you.² They must be lost, but I put the stamps on myself, & I am sure they were right. I despatched on the 20^th all the remaining copies, except one for myself. Your letter of Mar 4^th contained much interesting matter,³ but I have to say this of all your letters.

I am particularly glad to hear that Oncidium flexuosum is endemic, for I always thought that the cases of self-sterility with orchids in hot-houses might have been caused by their unnatural conditions.⁴ 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.⁵ The lessened number of good seeds in the self-fertilized Epidendrons is to a certain extent a new case.⁶ You suggest the comparison of the growth of plants produced from self-fertilized & crossed seeds; I began this work last autumn & 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-fertilized & 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.⁷ Many thanks for the dimorphic rubiaceous plant.⁸ Three of your Plumbagos have germinated, but not as yet any of the lobelias.⁹ 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 & of any excursions which you might take. I feel certain that you might make a very valuable & interesting book, for every one of your letters is so full of good observations. Such books, for instance Bates’s Travels on the Amazons,¹⁰ are very popular in England.

I will give your obliging offer about Brazilian plants to D^r. Hooker, who was to have come here to day, but has failed.¹¹ He is an excellent good fellow, as well as naturalist: He has lately published a pamphet, which I think you w^d like to read, & I will try & get a copy & send you.¹²

Yours most sincerely. | C. Darwin