RECORD: Darwin, C. R. n.d. Draft of Cross and self fertilisation, sheet no 296, published pp. 264-265. CUL-DAR70.133r. (John van Wyhe ed., 2002-. The Complete Work of Charles Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Text prepared and edited by John van Wyhe. 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. The volume CUL-DAR70 contains material for Darwin's book Orchids (2d ed. 1877).
133r
(296) Conclusion
Andrew Knight, Mr Laxton & myself, that a cross between two varieties increases immensely the height (in one case as 100 to 60) as well as the vigour of the offspring.
So that this case is almost exactly parallel with that of the Mimulus, in which a cross between plants self-fertilised for six previous generations gave the offspring no advantage over the self-fertilised plants of the seventh generation; whereas a cross by a fresh stock almost doubled their height & vigour & increased their fertility, above thirty fold.
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
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