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Darwin Correspondence Project

To Adolf Ernst   5 January 1880

Down, | Beckenham, Kent.

Jan 5. 1880

Dear Sir,

I have read your paper in ‘Nature’ with great interest & you have added a new family with heterostyled plants.1 Your plan of trying the pollen grains in abs: alcohol seems to me very good.2 But I have taken the liberty of writing to urge you to ascertain whether the illegitimate seedlings when legitimately fertilised are less fertile than the legitimate seedlings legitimately fertilised. I believe that you possess my ‘Forms of Flowers’ (if you do not I should be happy to send you a copy) and I would suggest your reading my experiments on the fertility of the illegitimate seedlings of Lythrum & Primula.3 The establishment of such infertility in other cases seems to me important as bearing on the sterility of hybrids. This opinion is not confined to me, for some years ago Fritz Müller in S. Brazil told me that he intended to repeat my experiments, but I suppose that other investigations interfered.4

Wishing you success in all your future researches, | I remain, dear Sir, | Yours faithfully | Charles Darwin


Ernst’s note ‘On the heterostylism of “Melochia Parvifolia”’ was published in Nature, 1 January 1880, p. 217. Melochia parvifolia is a species in the mallow family. In Forms of flowers 2d ed., p. v., CD remarked that Ernst had added the Byttneraceae to the ranks of families with heterostyled members. The Byttneraceae is now the neotropical subfamily Byttnerioideae of the Malvaceae (mallow family).
Ernst found that pollen-grains of the short-styled form of Melochia parvifolia shrank more in alcohol, from which he concluded that the protoplasm of that form contained a larger percentage of water than that of the long-styled form.
Ernst compared the number of seeds produced from crossed and self-fertilised plants, using charts like those in Forms of flowers for legitimate and illegitimate offspring of Lythrum and Primula.
No letter from Fritz Müller on this subject has been found.


Has read AE’s paper in Nature [21 (1880): 217] on Melochia, a new family of heterostyled plants, and suggests some crosses to be carried out to determine the fertility of illegitimate seedlings.

Letter details

Letter no.
Charles Robert Darwin
Adolf Ernst
Sent from
Source of text
State Darwin Museum, Moscow (GDM KP OF 8972)
Physical description
LS 3pp

Please cite as

Darwin Correspondence Project, “Letter no. 12402,” accessed on 25 June 2022,