I can plainly see that the glands of Drosera, from rapid power (almost instantaneous) of absorption and power of movement, give enormous advantage for such experiments. And some day I will enjoy myself with a good set to work; but it will be a great advantage if I can get some preliminary notion on other sensitive plants and on roots.
Oliver said he would speak about some seeds of Lythrum hyssopifolium being preserved for me. By the way, I am rather disgusted to find I cannot publish this year on Lythrum salicaria; I must make 126 additional crosses. All that I expected is true, but I have plain indication of much higher complexity. There are three pistils of different structure and functional power, and I strongly suspect altogether five kinds of pollen all different in this one species! (617/3. See "Forms of Flowers," Edition II., page 138.)
By any chance have you at Kew any odd varieties of the common potato? I want to grow a few plants of every variety, to compare flowers, leaves, fruit, etc., as I have done with peas, etc. (617/4. "Animals and Plants," Edition II., Volume I., page 346. Compare also the similar facts with regard to cabbages, loc. cit., page 342. Some of the original specimens are in the Botanical Museum at Cambridge.)
LETTER 618. J.D. HOOKER TO CHARLES DARWIN.
(618/1. The following is part of Letter 144, Volume I. It refers to reviews of "Fertilisation of Orchids" in the "Gardeners' Chronicle," 1862, pages 789, 863, 910, and in the "Natural History Review," October, 1862, page 371.)
November 7th, 1862.
Dear old Darwin,
I assure you it was not my fault! I worried Lindley over and over again to notice your orchid book in the "Chronicle" by the very broadest hints man could give. (618/2. See "Life and Letters," III., page 273.) At last he said, "really I cannot, you must do it for me," and so I did--volontiers. Lindley felt that he ought to have done it himself, and my main effort was to write it "a la Lindley," and in this alone I have succeeded--that people all think it is exactly Lindley's style!!! which diverts me vastly. The fact is, between ourselves, I fear that poor L. is breaking up--he said that he could not fix his mind on your book. He works himself beyond his mental or physical powers.
And now, my dear Darwin, I may as well make a clean breast of it, and tell you that I wrote the "Nat. Hist. Review" notice too--to me a very difficult task, and one I fancied I failed in, comparatively. Of this you are no judge, and can be none; you told me to tell Oliver it pleased you, and so I am content and happy.
LETTER 619. TO W.E. DARWIN. Down, 4th [about 1862-3?]
I have been looking at the fertilisation of wheat, and I think possibly you might find something curious. I observed in almost every one of the pollen-grains, which had become empty and adhered to (I suppose the viscid) branching hairs of the stigma, that the pollen-tube was always (?) emitted on opposite side of grain to that in contact with the branch of the stigma. This seems very odd. The branches of the stigma are very thin, formed apparently of three rows of cells of hardly greater diameter than pollen- tube. I am astonished that the tubes should be able to penetrate the walls. The specimens examined (not carefully by me) had pollen only during few hours on stigma; and the mere SUSPICION has crossed me that the pollen- tubes crawl down these branches to the base and then penetrate the stigmatic tissue. (619/1. See Strasburger's "Neue Untersuchungen uber den Befruchtungsvorgang bei den Phanerogamen," 1884. In Alopecurus pratensis he describes the pollen as adhering to the end of a projection from the stigma where it germinates; the tube crawls along or spirally round this projection until it reaches the angle where the stigmatic branch is given off; here it makes an entrance and travels in the middle lamella between two cells.) The paleae open for a short period for stigma to be dusted, and then close again, and such travelling down would take place under protection.