RECORD: Darwin, C. R. [1878].03.26. Letter to T. H. Farrer / Draft of Cross and self fertilisation. CUL-DAR202.45. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 10.2022. RN1
NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin.
Draft of Cross and self fertilisation in the hand of Ebenezer Norman with corrections by Darwin.
"Norman, Ebenezer, 1835/6-1923. 1854- Schoolmaster at Down and from 1856 and many years thereafter copyist for CD. 1856 Aug. 17 First payment for copying in CD's Account book (Down House MS). Many thereafter. CCD6:444. 1857 CD to Hooker, "I am employing a laboriously careful Schoolmaster". CCD6:443. 1858 CD to Hooker, "I can get the Down schoolmaster to do it [i.e. transcribe] on my return". CCD7:130. 1871 Banker's clerk in Deptford." (Paul van Helvert & John van Wyhe, Darwin: A Companion, 2021)
[45]
[Letter not transcribed]
[45v]
59
Ipomoea
were not able to twine at all; and the tallest of them was only 3 1/2 inches in height.
Lastly, I sowed at the same time two lots of the same seed were sown in the midst of a bed of candy-tuft (Iberis) growing vigorously. The seedlings came up, but all the self-fertilised ones soon died, excepting one which never twined and grew to a height of only four inches. Many of the crossed seedlings on the other hand survived and some twined up the stem of an Iberis to the height of 11 inches. These cases prove that the crossed seedlings have an immense advantage over the self-fertilised, both when growing isolated under very unfavourable conditions & when put into competition with each other, or with other plants, as would occur happen in a state of nature.) or with each other; and when growing isolated under unfavourable conditions.
Crossed and self-fertilised plants of the fourth generation. (Ipomoea purpurea) . Seedlings raised as before from the crossed and self-fertilised plants
[Cross and self fertilisation, p. 34: "The crossed seedlings from the first looked the most healthy, but they twined up a stick only to a height of 7 1/4 inches; whilst the self-fertilised were not able to twine at all; and the tallest of them was only 3 1/2 inches in height.
Lastly, two lots of the same seeds were sown in the midst of a bed of candy-tuft (Iberis) growing vigorously. The seedlings came up, but all the self-fertilised ones soon died excepting one, which never twined and grew to a height of only 4 inches. Many of the crossed seedlings, on the other hand, survived; and some twined up the stems of the Iberis to the height of 11 inches. These cases prove that the crossed seedlings have an immense advantage over the self-fertilised, both when growing isolated under very unfavourable conditions, and when put into competition with each other or with other plants, as would happen in a state of nature.
Crossed and self-fertilised Plants of the Fourth Generation.—Seedlings raised as before from the crossed and self-fertilised plants of the third generation in Table III., gave results as follows:─"]
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 7 December, 2022