RECORD: Darwin, C. R. & Emma Darwin. 1841.07.01. [Observations on bees at Maer and Shrewsbury]. CUL-DAR49.25-26. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 4.2021. 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-DAR49 contains notes for Natural selection chap. 3 on 'On...organic beings occasionally crossing' or dichogamy.


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[25]

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At Maer, watched pretty well Honeysuckle and never saw Bee;

July 1st 1841. at Shrewsbury, very many Humbles were at work; they suck at base of upper Petal, towards which stamens bend slightly.

Pollen searching Humbles visited only flowers not open; if quite closed, they could not succeed; but if any one petal, in the slightest manner opened, they dexterously extracted all the pollen from anthers, and stigma escaped out.

Shrewsbury, Coral Tree, anthers and stigma naturally protrude from keel. ? wings abortive like a white scale. In easy state standard curls round keel & acts or wings –

In Didynamous mimulus plant in which stigma closes like forceps, anthers hairy, placed below stigma, and both pressed against upper petal, so that insects would probably be acquired; hairs on lower sides of petals in face of anthers, as in fox-gloves.

I remember formerly thinking gillyflower [had] difficulty nov

July [2d] when stigma ready I see it projects a little beyond anther & flower is "common"

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In Magnolia Pears &c Thrips are very numerous in every flower & even buds, & closed flowers siculum Antirrhinum

[illeg] I never observed [illeg] or gillyflower till one & two following days saw many common Bees [illeg] from Bush to Bush

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[26]

Shrewsbury July 1841

Polerium sanguisorba – Stems upright, stamens longish slightly depending pollens tolerably abundant 1/700 placed at bottom of head of flowers.

Stigmas at top of do, projecting like stamens and exceedingly fimbriated, like a [mopohis] plant. I should think essentially diœcious.

Euphrorbia peplus. The several abortive flowers in involucrum with one central fertile was considered Dodecandria monogynia by Linn;

& maybe so by my theory

anthers small – pollen 1/1000 not abundant grains certainly slightly cohering; when pollen is spilt, anthers just project above crescent-shaped glandiferous organs; in this state, footstalk  of central female flower much longer, much deflected, stigmas very short, and separated from minute anthers by big germen; whole flowers very minute, and buried among the leaves so that impregnation appears to me curiously difficult = a less interesting plant cannot be imagined =

[annotated sketch of flower" germen anthers]

Reflection of central fertile flower – generic character by Smith.

of now the size of the germen, possibly stigmas are impregnated by foreign, and earlier pollen, than that of its own flowers, but from position of flowers, there seems no facility for this, though I much suspect it is so.

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In early stage, which central flower projects considerably, but is not deflected, its own anthers are concealed by glands, and are quite immature; I do not know whether stigma is ready at this time, or not.

From appearance of stigma alone, & disregarding large germen I should certainly think it was ready at times when anthers are bursting.


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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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