To J. D. Hooker 14 May [1860]
Down Bromley Kent
May 14th
My dear Hooker
I daresay you will be too busy to give instructions about the fertilisation of Leschenaultia;1 but in case you do, I write to say that I find the way to do it, is to move a camel-pencil, holding handle nearly parallel to the pistil & axis of flower, just in same direction & manner as the belly of a Bee would brush over the indusium, whilst crawling in to suck the copious nectar; & then the points of the brush hit against the rough protuberant lip, open the indusium, & some of the hairs enter & stir up the pollen splendidly & generally bring out some grains. So that the operation is done in a second, & I feel nearly sure that every bee which sucks this flower will open the indusium, stir up the pollen, remove some, & often leave pollen from other flowers within the indusium.
In fact I am at ease about Leschenaultia; but shd like excessively to prove that stirring up the pollen within the indusium is necessary or favourable to fertilisation. For then I shd look at this curious contrivance, as specially related to visits of insects; as I begin to think is almost universally the case. The evidence about dioicous condition of Cowslips & Auriculas seems to me to get clearer & clearer.—
And now I will (honour bright) not bother you with another note for a long time—that is if I can possibly resist
Yours affecty | C. Darwin
Poor dear Etty is a little better; not seriously ill, but our Doctor, who comes daily, says the Fever may run on for a considerable time. She eats hardly anything, but does not weaken so rapidly as I shd. have feared.2
P.S. | Very hearty thanks for your pleasant note (& Mrs. Hooker’s) just received. I daresay after all my vows I shall not resist answering it.—
I find before flowers are utterly withered of Cowslips the seeds of “females” are twice as big as seeds or ovules in the “Male” flowers— Hence I expect the latter will abort entirely. Out of 522 flower stalks gathered by the children I find 281 males & 241 Females.—3
Footnotes
Bibliography
Collected papers: The collected papers of Charles Darwin. Edited by Paul H. Barrett. 2 vols. Chicago and London: University of Chicago Press. 1977.
Summary
Instructs JDH on how to pollinate Leschenaultia.
Evidence of Leschenaultia and the dioecious condition of cowslips and Auricula is making necessity of insect pollination "clear and clearer".
Letter details
- Letter no.
- DCP-LETT-2800
- From
- Charles Robert Darwin
- To
- Joseph Dalton Hooker
- Sent from
- Down
- Source of text
- DAR 115: 55
- Physical description
- ALS 4pp
Please cite as
Darwin Correspondence Project, “Letter no. 2800,” accessed on 17 September 2023, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-2800.xml
Also published in The Correspondence of Charles Darwin, vol. 8