RECORD: Darwin, C. R. & Emma Darwin. n.d. Conclusions Unions of 1864 & 65 Mitchella repens. CUL-DAR110.B89. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 1.2023. RN1

NOTE: Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volumes CUL-DAR108-111 contain material for Darwin's book Forms of flowers (1877). See record in the Darwin Online manuscript catalogue, enter its Identifier here.


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Conclusions Unions of 1864 & 65 Mitchella repens

(New look at WM of notes, except description of pollen & flowers) ─ see Back

Gray tells me dimorphic ─ most kindly sent me plant, collected at [hazard] & both forms nearly equal in number ─ Describe differences.─ Two flowers always in pairs form one berry ─ I did not know, hence single flower often fert. in 64 but so many of them failed that they must be all excluded & anther form a perfect berry-like case of pin

I suspect number of seed from berry, with both fl. fert is not double that of one flower fert. ─ In 65 I always fertilised fl. in pairs & from these alone give proportion which set, but have added a few from 64/ which I happened to fertilise in pairs to get larger average of seed ─

In 64 both forms were under net & therefore & set many pods but one form will do this when freely visited by insect, as known from Edinburgh But in 65 I kept both forms entirely separate & they set very few pods.

Long-styled 9 pairs of flowers were heterofert. & produced 8 berries: 10 berries yielded an average of 4.6 full-sized seeds. Eight pairs of flowers were fert. homo-y & produced only 3 berries: 6 5 berries gave average of 1.8 2.2. full-sized seeds; for last year 2 pairs of fl. thus fert. yielded 2 & 4 seeds.


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

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