Ɛpsilon

To Thomas Rivers   8 June [1866]1

Down. | Bromley. | Kent. S.E.

June 8th

My dear Sir

I thank you most cordially for the Cytisus, after examining which I forwarded to Prof. Caspary at Kœnigsberg;2 so you have killed two birds with one act of kindness. The C. adami case gets more & more perplexing. I wish your experiments with the buds of the Negundo had succeeded.—3 If you will not think me an insufferable bore, I wish you wd. observe whether Cytisus purpureus-elongatus produces any pods & inform me:—4

With many thanks | My dear Sir | Yours very sincerely | Ch. Darwin

1
The year is established by the relationship between this letter and the letter from Thomas Rivers, 6 June 1866.
2
See letter from Thomas Rivers, 6 June 1866. CD was interested in Robert Caspary’s research on Cytisus adami (now +Laburnocytisus adami). See letter to Thomas Rivers, 27 April [1866] and n. 4.
3
See letter from Thomas Rivers, 6 June 1866 and n. 3. CD cited Rivers on the transmission of colour from the bud of a purple-leaved hazel to a rootstock of the common green-leaved hazel in Variation 1: 395.
4
See letter from Thomas Rivers, 6 June 1866 and n. 2. In Variation 1: 388–90, CD discussed the viability of ovules and pollen in Cytisus hybrids, and reported a case of a sterile hybrid of Cytisus purpureus (a synonym of Chamaecytisus purpureus, purple broom) and C. elongatus (a synonym of Chamaecytisus elongatus) that had been described by Alexander Carl Heinrich Braun (see Braun 1853, p. xxiii).

Please cite as “DCP-LETT-5115,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-5115