RECORD: Darwin, C. R. 1867.05.24-1869.08.25. Viscaria oculata. CUL-DAR79.85-88. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 3.2023. 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-DAR 76-79 contain material for Darwin's book Cross and self fertilisation (1876).
(70
Viscaria oculata 1867
12 fl crossed yielded 10 pods ie 83 per cent
18 fl. artificially self-fert. & so no doubt self plant [illeg] yielded 12 pods ie 66 per cent.
I selected a gre large average pod (all seed being put into watch glasses) & found 284 seed; a good large average self-fert pod contained only 126. The self-fert. pods were in greater number bad. —
The crossed seed from 10 pods weighed 5.77 gr ∴ 12 pods wd have weighed 6.93
The self-fert seed from 12 pods weighed. 2.63. Therefore if seed from a certain number of crossed capsules weighed 100 gr, seed from equal number of self-fertilised capsules would weigh only 38 gr — And fewer capsules are produced in proportion of 66 to 83. N.B. The loaded Balance just turned to single seed.
(May 24th — 3 inch to top of stem, equal on both sides.)
(June 26 /68/ Germ seed sown on each side of pot of Cineraria tallest crossed & self 11 inches & equal.)
(July 8 /68/
Pot I II III |
Crossed inches 20— 38 1/2 39 97.5 |
Self inches 25 42 1/2 35 102 |
{Tallest pla flower-stem in each measured.— [calculations not transcribed]
(71
Viscaria oculata. Fresh Plant (1868.)
10 fl. crossed by self & yielded 10 pods containing 6.54 grain weight of seed
18 spont. fert. flower pods under net, 2 contained no seed, the 16 contained a good many, with few as many as the second-rate crossed Pods; but the 16 altogether contained 6.07 gr. by weight
Therefore as 16 pods : 10 pods :: 6.07 gr. : x = 3.79 gr.
Therefore produce of seeds for equal number as 6.54 : 3.79. or as 100 :
(July 16— 1869 The young plants 1/2 inch no difference on either side.)
(June 6' 1869. The plants now about 5 inches to tips of leaves no difference on either side.)
(71A
Aug 2d 1869. Viscaria oculata.
Plants almost finished flowering
Aug 25 69 Pods (with some few flowers included) counted
[Table partly excised, not transcribed]
71A
[calculations not transcribed]
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 30 May, 2023