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
Footnotes
Summary
Variation in bullfinches’ instinctive ability to remove nectaries and ovaries from cowslips.
Letter details
- Letter no.
- DCP-LETT-9435
- From
- Edward Frankland
- To
- Charles Robert Darwin
- Sent from
- London, Lancaster Gate, 14
- Source of text
- DAR 164: 211
- Physical description
- ALS 4pp inc
Please cite as
Darwin Correspondence Project, “Letter no. 9435,” accessed on 6 October 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-9435.xml
Also published in The Correspondence of Charles Darwin, vol. 22