LETTER 759. TO H. VOCHTING. Down, December 16th, 1880.
Absence from home has prevented me from sooner thanking you for your kind present of your several publications. I procured some time ago your "Organbilding" (759/1. "Organbildung im Pflanzenreich," 1878.) etc., but it was too late for me to profit by it for my book, as I was correcting the press. I read only parts, but my son Francis read the whole with care and told me much about it, which greatly interested me. I also read your article in the "Bot. Zeitung." My son began at once experimenting, to test your views, and this very night will read a paper before the Linnean Society on the roots of Rubus (759/2. Francis Darwin, "The Theory of the Growth of Cuttings" ("Linn. Soc. Journ." XVIII.). [I take this opportunity of expressing my regret that at page 417, owing to neglect of part of Vochting's facts, I made a criticism of his argument which cannot be upheld.--F.D.].), and I think that you will be pleased to find how well his conclusions agree with yours. He will of course send you a copy of his paper when it is printed. I have sent him your letter, which will please him if he agrees with me; for your letter has given me real pleasure, and I did not at all know what the many great physiologists of Germany, Switzerland, and Holland would think of it ["The Power of Movement," etc.]. I was quite sorry to read Sachs' views about root-forming matter, etc., for I have an unbounded admiration for Sachs. In this country we are dreadfully behind in Physiological Botany.
LETTER 760. TO A. DE CANDOLLE. Down, January 24th, 1881.
It was extremely kind of you to write me so long and valuable a letter, the whole of which deserves careful consideration. I have been particularly pleased at what you say about the new terms used, because I have often been annoyed at the multitude of new terms lately invented in all branches of Biology in Germany; and I doubted much whether I was not quite as great a sinner as those whom I have blamed. When I read your remarks on the word "purpose" in your "Phytographie," I vowed that I would not use it again; but it is not easy to cure oneself of a vicious habit. It is also difficult for any one who tries to make out the use of a structure to avoid the word purpose. I see that I have probably gone beyond my depth in discussing plurifoliate and unifoliate leaves; but in such a case as that of Mimosa albida, where rudiments of additional leaflets are present, we must believe that they were well developed in the progenitor of the plant. So again, when the first true leaf differs widely in shape from the older leaves, and resembles the older leaves in allied species, is it not the most simple explanation that such leaves have retained their ancient character, as in the case of the embryos of so many animals?
Your suggestion of examining the movements of vertical leaves with an equal number of stomata on both sides, with reference to the light, seems to me an excellent one, and I hope that my son Francis may follow it up. But I will not trouble you with any more remarks about our book. My son will write to you about the diagram.
Let me add that I shall ever remember with pleasure your visit here last autumn.
LETTER 761. TO J. LUBBOCK (Lord Avebury). Down, April 16th [1881].
Will you be so kind as to send and lend me the Desmodium gyrans by the bearer who brings this note.
Shortly after you left I found my notice of the seeds in the "Gardeners' Chronicle," which please return hereafter, as I have no other copy. (761/1. "Note on the Achenia of Pumilio argyrolepis." "Gardeners' Chronicle," 1861, page 4.) I do not think that I made enough about the great power of absorption of water by the corolla-like calyx or pappus. It seems to me not unlikely that the pappus of other Compositae may be serviceable to the seeds, whilst lying on the ground, by absorbing the dew which would be especially apt to condense on the fine points and filaments of the pappus. Anyhow, this is a point which might be easily investigated.