P.S.--I have kept back for a day the enclosed owing to the arrival of your most interesting letter. I knew it was a mere chance whether you could inform me on the points required; but no one other person has so often responded to my miscellaneous queries. I believe I have now in my greenhouse L. trigynum (155/7. Linum trigynum.), which came up from seed purchased as L. flavum, from which it is wholly different in foliage. I have just sent in a paper on Dimorphism of Linum to the Linnean Society (155/8. "On the Existence of the Forms, and on their reciprocal Sexual Relation, in several species of the genus Linum.--"Journ. Linn. Soc." Volume VII., page 69, 1864.), and so I do not doubt your memory is right about L. trigynum: the functional difference in the two forms of Linum is really wonderful. I assure you I quite long to see you and a few others in London; it is not so much the eczema which has taken the epidermis a dozen times clean off; but I have been knocked up of late with extraordinary facility, and when I shall be able to come up I know not. I particularly wish to hear about the wondrous bird: the case has delighted me, because no group is so isolated as Birds. I much wish to hear when we meet which digits are developed; when examining birds two or three years ago, I distinctly remember writing to Lyell that some day a fossil bird would be found with the end of wing cloven, i.e. the bastard-wing and other part, both well developed. Thanks for Von Martius, returned by this post, which I was glad to see. Poor old Wagner (Probably Johann Andreas Wagner, author of "Zur Feststellung des Artbegriffes, mit besonderer Bezugnahme auf die Ansichten von Nathusius, Darwin, Is. Geoffroy and Agassiz," "Munchen Sitzungsb." (1861), page 301, and of numerous papers on zoological and palaeozoological subjects.) always attacked me in a proper spirit, and sent me two or three little brochures, and I thanked him cordially. The Germans seem much stirred up on the subject. I received by the same post almost a little volume on the "Origin." I cannot work above a couple of hours daily, and this plays the deuce with me. P.S. 2nd.--I have worked like a slave and been baffled like a slave in trying to make out the meaning of two very different sets of stamens in some Melastomaceae. (155/9. Several letters on the Melastomaceae occur in our Botanical section.) I must tell you one fact. I counted 9,000 seeds, one by one, from my artificially fertilised pods. There is something very odd, but I am as yet beaten. Plants from two pollens grow at different rates! Now, what I want to know is, whether in individuals of the same species, growing together, you have ever noticed any difference in the position of the pistil or in the size and colour of the stamens? LETTER 156. TO T.H. HUXLEY. Down, December 18th [1862].