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Darwin Correspondence Project

From Edward Frankland   30 April 1874

14 Lancaster Gate | Hyde Park W.

April 30/74.

My dear Mr. Darwin

I have this morning tried the experiments you suggested & now enclose specimens of the results.1

I think the Undercliff bullfinches2 have inherited a more utilitarian character than that possessed by the Kent birds. At all events my bullfinch always bites out the ovary from the primrose. Only once have I succeeded in getting a bite above the ovary & in this case the flower was in such a position behind the wire of the cage as to prevent him reaching his tit-bit. I also enclose the result of this abnormal bite.

You are quite right in supposing that the bird only presses & does not swallow the part bitten out. At all events he works the calyx gradually out of the side of his beak & lets it drop.

I never made such experiments with animals before & I am very much impressed with the result of this one. It has all ⁠⟨⁠the precision of a chemical reaction; the result of putting a primrose within its reach can be almost as certainly predicted as that of putting a plate of iron into a solution of sulphate of copper.⁠⟩⁠3

The destruction of bullfinches amongst primroses & cowslips must be enormous. My bullfinch can easily destroy 20 flowers in 3 minutes, even when they are given to him singly & he is allowed time to make the most of each, & as the amount of matter taken out of each flower is so small it is impossible to say how long it would take to satisfy him.

⁠⟨⁠about 8 lines excised⁠⟩⁠

Yours ⁠⟨⁠sincerely⁠⟩⁠| E. Frankland

CD annotations

4.2 result … all] del pencil; opening square bracket before ‘It’ pencil


The bird that Frankland observed had come from an area known as the Undercliff on the Isle of Wight (see letter from Edward Frankland, 26 April 1874 and n. 4).
The excised text has been restored from CD’s letter to Nature, 7 and 11 May [1874], where CD quoted from Frankland’s letter.


Variation in bullfinches’ instinctive ability to remove nectaries and ovaries from cowslips.

Letter details

Letter no.
Edward Frankland
Charles Robert Darwin
Sent from
London, Lancaster Gate, 14
Source of text
DAR 164: 211
Physical description
4pp inc

Please cite as

Darwin Correspondence Project, “Letter no. 9435,” accessed on 25 October 2021,

Also published in The Correspondence of Charles Darwin, vol. 22