RECORD: Darwin, C. R. 1868.05.17-1870. Nemophila insignis. CUL-DAR79.23-27. (John van Wyhe ed., 2002-. The Complete Work of Charles Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and John van Wyhe, edited by John van Wyhe 3.2023. RN2
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).
(45
Nemophila insignis
12 flowers crossed 18 self-fert.
The 12 crossed flowers gave 6 pods with 110 seed, — average 18.3
The 18 self- ― [do] 10 pods with 127 seed, — average 12.7
So more self- flowers set but yielded poorer average.— In two of self- capsules, which contained on 2 or 4 seeds, these were extremely large, & this no doubt cause anomalous result that with equal number of self & crossed seeds, the self weigh most
The 110 crossed seed weighed 3.86 ∴ 127 would weigh 4.46
The 127 self- seeds weigh as 100 : 105 to self-fert, seeds.
(May 17th in Pot. II. all the self plants, after se germinating seeds had been planted died. The seeds have all germinated badly.)
(June 7th Pot III. is the only one with both sides alive the self flowered first)
(July 13th Pot III. Plants have now done flowering
crossed Pl. 28 1/2 inches 2 ft : 8 1/2 inches high (In Greenhouse)
self Pl. 1 ft : 9 1/4 inch inch high
46
122.125 [÷] 11 [=] 11.10 Average 60 [÷] 11 [=] 5.45 Average
366.875 [÷] 11 [=] 33.35 Average 177.75 [÷] 9 [=] 19.75 Average
399.375 [÷] 12 [=] 33.28 199 [÷] 10 [=] 19.9 [x] 12 [=]
Cross— 35 [+] 70 [=] 105 6 [+] 24 [=] 30
(46
Nemophila insignis—
Some flowers in fresh plants were crossed & produced 4pods with 7, 5, 16 & 24 seeds —
Some flowers were self-fert & produced 5 pods with 6, 16, 16, 18, & 10 seeds — So crossing apparently does not increase fertility. —
June 5' 1869
Pot |
Crossed |
Self |
I |
7 4/8 |
9 |
II |
8 4/8 |
4 3/8 |
III |
7 |
|
June 5. 1869 |
|
|
Aug 2d 1869.— measured to tops of stems trained up |
|
|
Pot. |
Crossed |
Self |
Crossed |
Self |
|
I II |
12 5/8 |
7 6/8 |
|
|
I Crossed side first |
II. |
12 4/8 |
6 3/8 |
|
|
Crossed fl. first |
III |
12 4/8 |
10 1.8 |
|
|
Crossed flowered first |
IV |
11 4/8 |
9 4/8 |
|
|
flowered at same time |
Measured to extreme tips of longest leaves. |
|
|
366 7/8 |
177 6/8 |
|
|
122 1231/8 |
60 |
399 3/8 |
199 |
|
(over)
[46v]
Aug 2d
Owing to great inequality of size of plants the self-plants produced very few pods, compared with the crossed plants. —
Then Pot II was placed under net, insects excluded with 3 plants on each side, & left to be spont. self-fertilised. —
The crossed produced 35 pods
The self- [do] 6 pods, (of which 3 contained no seed, so only 3 good)
Pot IV. (3 plants being left on each side)
The crossed [text excised] 24 70 pods
The self [text excised] 24 pods.
As [text excised] were grown in small pot [text excised] fertility was not great — & as [text excised] much smaller cd produce not so many pods.
The seeds [text excised] (just above) were geminated on sand [text excised]ated on opposite sides, to see if [text excised] growth inherited & whether a second self-fertilisation is very injurious. —
46A
110.125 [÷] 7 [=] 15.75 Average
147 [÷] 7 [=] 21 Average
(46A
Nemophila insignis. 1870
Some plant on last page, in which the crossed & selfs differed so greatly in development were allowed to seed excluded from insects.
So self-plants, are self-fert for 2 generations. (Trained up sticks; greenhouse)
Pot |
Crossed |
Self |
|
|
|
|
Self flowered first. |
|
|
|
do |
|
|
|
did not flower |
|
|
|
do |
|
self-fert plant from crossed pl |
Self-fert plants from self-fert plants |
|
All the plants grew very poorly & in Pot 3 & 4 could hardly live & died while young.— I cannot account for advantage of self-, as on both sides there was self-fertilisation — The case is a lesson of prudence — I suppose crossed seeds from crossed plants happened not to be well ripened.
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 27 December, 2025