RECORD: Darwin, C. R. 1863.04.24-.07.21. Clarkia elegans. CUL-DAR205.8.6. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 1.2022. 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 volume CUL-DAR205.8 contains notes on the genus Monochaetum and other plants.


[6]

Clarkia elegans

Ap. 24th Plant in greenhouse

1 fl with pollen of little anther Black Thread

1 fl with pollen of large anther White Thread

For future part more pollen of small anthers.

Pollen of short anther mature long before long anther – Both mature long before stigma but pollen having about 8 threads to old anther gets often on the stigma without insect & ovarium swells.

May 20th I find 6 flowers in which there was no pollen on stigma & were castratednow

set pods! Parthenogenesis! I have marked them with Black worsted.

May 20th fertilised 3 old castrated flowers with pollen of short anthers Black Thread; & 3 flowers with pollen of long purple anthers white Thread.

[6v]

May 23d two Black Thread 1. White Th.

- 24th 1. Bl. 2. White Th.

July 21. 63

Six flowers were fertilised with pollen of long anthers, but I got only 2 pods & one with seed bad. Six flowers were fertilised with pollen of short anther, & I got five pods, but 2 seen with seed bad. Taking good seed there were about as many in the one as in the other. Cause of difference is, I have no doubt that to be safe I always put more pollen of short anther than of long.

This case, & of melastomeæ, merely shows that with tendency to abortion, colours of anthers change

That it is a tendency to abortion cannot be doubted by comparison with other Clarkias. The 6 flowers castrated with no pollen, produced 5 small pods, containing each some seed, but then only empty husks. – A step to Parthenogenesis.

Corelation & Abortion Laws

5 Black pods 2 bad

2 white pods 1 bad about equal seed


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Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)

File last updated 25 September, 2022