Dr. Hooker has forwarded to me your letter as the best and simplest plan of explaining affairs. I am sincerely grieved to hear of the pecuniary problem which you have undergone, but now fortunately passed. I assure you that I have never entertained any feelings in regard to you which you suppose. Please to remember that I distinctly stated that I did not consider the sum which I advanced as a loan, but as a gift; and surely there is nothing discreditable to you, under the circumstances, in receiving a gift from a rich man, as I am. Therefore I earnestly beg you to banish the whole subject from your mind, and begin laying up something for yourself in the future. I really cannot break my word and accept payment. Pray do not rob me of my small share in the credit of aiding to put the right man in the right place. You have done good work, and I am sure will do more; so let us never mention the subject again.
I am, after many interruptions, at work again on my essay on Expression, which was written out once many months ago. I have found your remarks the best of all which have been sent me, and so I state.
CHAPTER 2.XI.—BOTANY, 1863-1881.
2.XI.I. Miscellaneous, 1863-1866.—2.XI.II. Correspondence with Fritz Muller, 1865-1881.—2.XI.III. Miscellaneous, 1868-1881.
2.XI.I. MISCELLANEOUS, 1863-1866.
LETTER 658. TO D. OLIVER. Down {April, 1863}.
(658/1. The following letter illustrates the truth of Sir W. Thiselton-Dyer's remark that Darwin was never "afraid of his facts." (658/2. "Charles Darwin" (Nature Series), 1882, page 43.) The entrance of pollen-tubes into the nucellus by the chalaza, instead of through the micropyle, was first fully demonstrated by Treub in his paper "Sur les Casuarinees et leur place dans le Systeme naturel," published in the "Ann. Jard. Bot. Buitenzorg," X., 1891. Two years later Miss Benson gave an account of a similar phenomenon in certain Amentiferae ("Trans. Linn. Soc." 1888-94, page 409). This chalazogamic method of fertilisation has since been recognised in other flowering plants, but not, so far as we are aware, in the genus Primula.)
It is a shame to trouble {you}, but will you tell me whether the ovule of Primula is "anatropal," nearly as figured by Gray, page 123, "Lessons in Botany," or rather more tending to "amphitropal"? I never looked at such a point before. Why I am curious to know is because I put pollen into the ovarium of monstrous primroses, and now, after sixteen days, and not before (the length of time agrees with slowness of natural impregnation), I find abundance of pollen-tubes emitted, which cling firmly to the ovules, and, I think I may confidently state, penetrate the ovule. But here is an odd thing: they never once enter at (what I suppose to be) the "orifice," but generally at the chalaza...Do you know how pollen-tubes go naturally in Primula? Do they run down walls of ovarium, and then turn up the placenta, and so debouch near the "orifices" of the ovules?
If you thought it worth while to examine ovules, I would see if there are more monstrous flowers, and put pollen into the ovarium, and send you the flowers in fourteen or fifteen days afterwards. But it is rather troublesome. I would not do it unless you cared to examine the ovules. Like a foolish and idle man, I have wasted a whole morning over them...