RECORD: Darwin, C. R. n.d. Numbers of sexes. CUL-DAR86.A49. Edited by John van Wyhe (The Complete Work of Charles Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 3.2022. 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. The volumes CUL-DAR80-86 contain material for Darwin's book Descent of man (1871).
Darwin cited this in Descent 2: 7.
"Günther, Albert Karl Ludwig Gotthilf, (also Albert Charles Lewis Gotthilf Gunther), 1830-1914. German-born British zoologist and herpetologist. 1859 Staff of British Museum. 1858, 1860 and 1877 published descriptions of CD's reptile specimens. 1869 G gave CD information on sexual differences in fish. 1870 G arranged for cutting of blocks for Descent by Ford. 1871 Jan. 28 G at Down House. 1882 G was on "Personal Friends invited" list for CD's funeral." Paul van Helvert and John van Wyhe, Darwin: A Companion, 2021.
[A49]
Numbers of sexes In some Cyprinodonts male not half size of female, hence males wd escape thro' net & thus Günther accounts for excess of female specimens.
In sticklebacks do not breed till 2 or 3 years old. Probably die after breeding, hence difficult to estimate sexes.
In trout infertile females would with difficulty be distinguished from males. hence liable to error.
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 20 August, 2025