To Francis Darwin 23 October [1873]
Oct 23rd
See P.S
My dear F.
If in the collection there are specimens of Desmodium gyrans from different districts, observe whether the little lateral leaflets differ in size on full-grown leaves.1 Look out for any abnormal projection at apex of leaflet, though excessively improbable— or for the abortion of the blade alone.—
In my living specimens—some of the leaves have 2 leaflets, some one & some none. The 2 little leaflets either stand exactly opposite each other or not so. How are these points with plants in a state of nature?
I have a wild hypothesis that the little leaflets may be tendrils reconverted into leaflets, as I believe to be the case with the grass-like leaves of Lathyrus nissolia & almost certainly with the little stipule-like projection at the end of the leaf of the common Bean.—Vicia faba.2
Your affect | C. Darwin
P.S. | Thank Sanderson cordially for his most kind assistance.— The Hæmoglobin was at first very dark red-brown; I shd be very glad to know whether it is meta-hæmoglobin.—3
Footnotes
Bibliography
Climbing plants: On the movements and habits of climbing plants. By Charles Darwin. London: Longman, Green, Longman, Roberts & Green; Williams & Norgate. 1865.
Insectivorous plants. By Charles Darwin. London: John Murray. 1875.
Summary
Wants FD to look at the little lateral leaflets of Desmodium. CD has "a wild hypothesis that the little leaflets may be tendrils reconverted into leaflets".
Letter details
- Letter no.
- DCP-LETT-9110
- From
- Charles Robert Darwin
- To
- Francis Darwin
- Sent from
- Down
- Postmark
- OC 23 73
- Source of text
- DAR 271.3: 11
- Physical description
- ALS 2pp
Please cite as
Darwin Correspondence Project, “Letter no. 9110,” accessed on 28 March 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-9110.xml
Also published in The Correspondence of Charles Darwin, vol. 21