RECORD: Darwin, C. R. & Francis Darwin. 1864.10.22. Note on 'The power of remaining for a long but unknown period constant'. CUL-DAR45.154. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 2.2021. RN1
NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library William Huxley Darwin. The volume CUL-DAR45 contains notes for Natural selection chap. 4 'Variation under nature'.
[154]
Oct. 22/64 — The power of remaining for a long but unknown period constant or distinct from some other form is the essence of a species; for this implies that the one does not vary into or cross with the other. But combined, with this there must be an appreciable amount of difference between the two deserving distinct names & we assumed that if the two forms habited the same country the difference wd suffice to prevent them crossing.
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 31 October, 2023