RECORD: Darwin, C. R. 1869. Eschscholtzia Californica. CUL-DAR76.B31-B32. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 12.2022. 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-DAR 76-79 contain material for Darwin's book Cross and self fertilisation (1876).


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Eschotzia [Eschscholtzia] Californica— 1869

Many plants were raised from crossed ie self sterile fl seed from self-sterile plants, from S. Brazil, from sent by F. Müller. Two plants were covered with nets; & 8 flowers on both the 2 plants were crossed with pollen from distinct plants, & all produced very fine pods; a medium one chosen contained 80 seed & none contained much fewer seed.

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(8 flowers on both the 2 plants were fertilised with pollen from same flower & produced 7 Pods; the finest of these contained 25 seed, the next finest 16 seed & several others from 4 to 7 or 8 seed; average about 12 seed.

Later in season, though the uncovered plants still produced pods, 12 flowers were self-fert. & they produced only 2 pods, containing 3 & 6 seeds; so the colder temperature checked self-fertilisation.—

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Eschotzia [Eschscholtzia]

There was this difference between the 2 covered plants, that one spontaneously produced only 1 pod with no seed yet it produced some when artificially self-fertilised); whilst the other spontaneously produced 8 pods, one the finest of which contained 30 seed, the next finest 12 & several other from 3 to 6 seed; — average about 10 seed.— Hence these 2 plants certainly differed a little in their self-sterility.

It was most curious to observe the more sterile plants of the two after it had been uncovered for about a week & insects had access, how it was became completely covered with young pods.— wonderfully proof good evidence of benefit of a cross. — These Brazilian plants appear in one under our climate much more self-fertile than their parents in Brazil, & very much less less self-fertile than our English plants— Effect partly inherited, partly the result of external conditions. —


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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 1 June, 2023