To Fritz Müller [before 10 December 1866]1
Down Bromley Kent
My dear Sir
I have so much to thank you for that I hardly know how to begin. I have received the bulbillas of Oxalis & your most interesting letter of Oct 1st.2 I have planted half the bulbs & will plant the other half in the spring. The case seems to me very curious & until trying some experiments in crossing I can form no conjecture what the abortion of the stamens in so irregular a manner can signify.3 But I fear from what you say the plant will prove sterile like so many others which increase largely by buds of various kinds. Since I asked you about Oxalis Dr. Hildebrand has published a paper showing that a great number of species are trimorphic like Lythrum, but he has tried hardly any experiments.4
I am particularly obliged for the information & specimen of Cordia & shall be most grateful for seed: I have not heard of of any dimorphic species in this Family.5 Hardly anything in your letter interested me so much as your account & drawing of the valves of the pod of one of the Mimoseæ with the really beautiful seeds.— I will send some of these seeds to Kew to be planted.6 But these seeds seem to me to offer a very great difficulty. They do not seem hard enough to resist the triturating power of the gizard of a gallinaceous bird, though they might resist that of some other birds, for the skin is as hard as ivory. I presume that these seeds cannot be covered with any attractive pulp. I soaked one of the seeds for 10 hours, in warm water which became only very slig〈htly〉 mucilaginous. I think I will try whether they will pass through a fowl uninjured.7 I hope you will observe whether any bird devours them, & could you get any young man to shoot some & observe whether the seeds are found low down in the intestines. It would be well worth while to plant such seeds with undigested seeds for comparison. An opponent of ours might make a capital case against us by saying that here beautiful pods & seeds have been formed not for the good of the plant but for the good of birds alone. These seeds would make a beautiful bracelet for one of my daughters if I had enough. I may just mention that 〈E〉uonymus Europæus is a case in point; the seeds are coated by a thin orange layer which I find is sufficient to cause them to be devoured by birds.8 I have received your paper on Martha; it is as wonderful as the most wonderful orchis:9 Ernst Haeckel brought me the paper & stayed a day with me. I have seldom seen a more pleasant, cordial & frank man. He is now in Madeira where he is going to work chiefly on the Medusæ10 His great work is now published & I have a copy, but the german is so difficult I can make out but little of it, & I fear it is too large a work to be translated.11
Your fact about the number of seeds in the capsule of the Maxillaria came just at the right time as I wished to give one or two such facts.12 Does this orchid produce many capsules? I can not answer your question about the aerial roots of Catasetum.13 I hope you have received the new Edition of the “Origin”—14 Your paper on climbing plants is printed & I expect in a day or two to receive the spare copies, & I will send off three copies as before stated, & will retain some in case you should wish me to send them to anyone in Europe, & will transmit the remainder to yourself15
With cordial thanks for all your great kindness, believe me, | My dear Sir, | Yours sincerely | Ch. Darwin
Hildebrand’s paper on trimorphism in Oxalis ["Über den Trimorphismus in der Gattung Oxalis", Monatsber. K. Preuss. Akad. Wiss. Berlin (1866): 352–74].
Problems of explaining brightly coloured, attractive seeds.
Haeckel has visited Down.
FM’s climbing plants paper is printed [J. Proc. Linn. Soc. Lond. (Bot.) 9 (1867): 344–9].