(667/2. We believe that the Adlumia which came up year by year in flower boxes in the Down verandah grew from seed supplied by Asa Gray.) I have just got a plant with sensitive axis, quite a new case; and tell Oliver I now do not care at all how many tendrils he makes axial, which at one time was a cruel torture to me.
LETTER 668. TO J.D. HOOKER. Down, November 3rd [1864].
Many thanks for your splendid long letter. But first for business. Please look carefully at the enclosed specimen of Dicentra thalictriformis, and throw away. (668/1. Dicentra thalictrifolia, a Himalayan species of Fumariaceae, with leaf-tendrils.) When the plant was young I concluded certainly that the tendrils were axial, or modified branches, which Mohl says is the case with some Fumariaceae. (668/2. "Ueber den Bau und das Winden der Ranken und Schlingpflanzen. Eine gekronte Preisschrift," 4to, Tubingen, 1827. At page 43 Mohl describes the tips of the branches of Fumaria [Corydalis] clavicualta as being developed into tendrils, as well as the leaves. For this reason Darwin placed the plant among the tendril- bearers rather than among the true leaf-climbers: see "Climbing Plants," Edition II., 1875, page 121.) You looked at them here and agreed. But now the plant is old, what I thought was a branch with two leaves and ending in a tendril looks like a gigantic leaf with two compound leaflets, and the terminal part converted into a tendril. For I see buds in the fork between supposed branch and main stem. Pray look carefully--you know I am profoundly ignorant--and save me from a horrid mistake.
LETTER 669. TO J.D. HOOKER.
(669/1. The following is interesting, as containing a foreshadowing of the chemotaxis of antherozoids which was shown to exist by Pfeffer in 1881: see "Untersuchungen aus dem botanischen Institut zu Tubingen," Volume I., page 363. There are several papers by H.J. Carter on the reproduction of the lower organisms in the "Annals and Magazine of Natural History" between 1855 and 1865.)
Down, Sunday, 22nd, and Saturday, 28th [October, 1865].
I have been wading through the "Annals and Mag. of N. History." for last ten years, and have been interested by several papers, chiefly, however, translations; but none have interested me more than Carter's on lower vegetables, infusoria, and protozoa. Is he as good a workman as he appears? for if so he would deserve a Royal medal. I know it is not new; but how wonderful his account of the spermatozoa of some dioecious alga or conferva, swimming and finding the minute micropyle in a distinct plant, and forcing its way in! Why, these zoospores must possess some sort of organ of sense to guide their locomotive powers to the small micropyle; and does not this necessarily imply something like a nervous system, in the same way as complemental male cirripedes have organs of sense and locomotion, and nothing else but a sack of spermatozoa?
LETTER 670. TO F. HILDEBRAND. May 16th, 1866.
Since writing to you before, I have read your admirable memoir on Salvia (670/1. "Pringsheim's Jahrbucher," Volume IV., 1866.), and it has interested me almost as much as when I first investigated the structure of orchids. Your paper illustrates several points in my "Origin of Species," especially the transition of organs. Knowing only two or three species in the genus, I had often marvelled how one cell of the anther could have been transformed into the moveable plate or spoon; and how well you show the gradations. But I am surprised that you did not more strongly insist on this point.
I shall be still more surprised if you do not ultimately come to the same belief with me, as shown by so many beautiful contrivances,--that all plants require, from some unknown cause, to be occasionally fertilised by pollen from a distinct individual.
(PLATE: FRITZ MULLER.)
2.XI.II. CORRESPONDENCE WITH FRITZ MULLER, 1865-1881.
(671/1. The letters from Darwin to Muller are given as a separate group, instead of in chronological sequence with the other botanical letters, as better illustrating the uninterrupted friendship and scientific comradeship of the two naturalists.)
LETTER 671.