Darwin, C. R. to Henslow, J. S.
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Sends characters by which he can divide all primroses and cowslips into what he suspects will be male and female plants. Believes these forms are first step in formation of a dioecious plant.
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Transcription
Down Bromley Kent
May 17
My dear Henslow
Many thanks for your note & information about my opposers.— I have sent for Literary Gazette.— For the chance of your caring I send the characters by which I can divide all Primroses & cowslips into what I suspect will turn out Male & Female Plants. These two forms exist in about equal numbers.— I have marked a set of both forms to see about seeding. The difference in state of pollen is very clear & invariable.
I suspect it will turn out fine case for me: the first gradation in the formation of a dioicous plant.— The Holly forms a second step, for here the male plant has anthers but no pollen.— The male cowslips have abundant pollen, but all grains small-sized.—
It will be curious if I can show that so common a plant is dioicous or nearly so.
Auriculas are in same state as far as I have seen.—
This is reason why I wanted to know whether you had observed long & short pistils in any other flowers.
Yours affect
[Enclosure: 1]
*uCowslips Primroses MalePlants. Tube of corolla long, throat short—
Stamens long— pollen in water about
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- f1 2805.f1
The Literary Gazette, 12 May 1860, p. 582, included a report on Adam Sedgwick's and William Clark's remarks about Origin at the Cambridge Philosophical Society meeting on 7 May 1860. - +
- f2 2805.f2
See letter to J. S. Henslow, 14 May [1860]. - +
- f3 2805.f3
In CD's paper on the dimorphic condition of Primula, read on 21 November 1861, the measurements were changed to10-11/7000 of an inch for the pollen from short-styled plants and7 7000