skip to content

Darwin Correspondence Project

To Asa Gray   4 June [1877]1

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R.

June 4th

My dear Gray

Prof. Bessey’s case has come too late for me, as the sheets on this subject are printed off.2 Nor indeed if it had come earlier, should I have known what to do with it. The pollen-grains & stigmas ought to be compared. The case seems to be well worth careful investigation & I wd. have given my eyes for seeds formerly; but now I have done with the subject. If Prof. Bessey likes experimental work he might raise seedlings & fertilise short & long pistils with pollen from long & short stamens from distinct plants & on the same plant: counting the proportion of flowers which set fruit, when fertilised in the various ways & the number of seeds per fruit. His diagram shows the nature & the difference between the flowers excellently. I will send him my book, when published in 4 or 5 weeks, & if he thinks it worth reading he can see how to experimentise on the plants.—3 The case may be one merely of great variability, but it may be one of incipient heterostylism; & under this point of view I would formerly (if I could) have investigated it most carefully.—

When you reeive my little book, you will see that I have done an audacious deed with respect to you.—4

I am now trying to make out the use or function of “bloom” or the waxy secretion on the leaves & fruits of plants, but am very doubtful whether I shall succeed.—5 Can you give me any light? Are such plants commoner in warm than in colder climates? I ask because I often walk out in heavy rain & the leaves of very few wild dicotyledons can be here seen with drops of water rolling off them like quicksilver. Whereas in my flower garden, greenhouse & hot-houses there are several. Again are bloom-protected plants common on your dry western plains; Hooker (Sir Joseph Hooker) thinks that they are common at the C. of Good Hope.— It is a puzzle to me if they are common under very dry climates, & I find bloom very common on the Acacias & Eucalypti of Australia.6 Some of the Eucalypti which do not appear to be covered with bloom have the epidermis protected by a layer of some substance which is dissolved in boiling alcohol.— Are there any bloom-protected leaves or fruit in the Arctic regions?— If you can illuminate me, as you so often have done, pray do so; but otherwise do not bother yourself by answering

Yours affecty | C. Darwin


The year is established by the relationship between this letter and the letter from Asa Gray, 22 May 1877.
Gray had forwarded a letter from Charles Edwin Bessey on a possible case of dimorphism in Lithospermum longiflorum (a synonym of Lithospermum incisum, fringed gromwell; see letter from Asa Gray, 22 May 1877). CD’s manuscript of Forms of flowers was sent to the publisher on 11 April (see letter to R. F. Cooke, 11 April 1877 and n. 1); he remarked that the proof-sheets had all been corrected in his letter to J. V. Carus, 17 June [1877].
Bessey’s name appears on CD’s presentation list for Forms of flowers (see Appendix IV). He later published the article ‘The supposed dimorphism of Lithospermum longiflorum’ (Bessey 1880).
CD dedicated Forms of flowers to Gray, ‘as a small tribute of respect and affection’.
For CD’s interest in bloom, see the letter to Fritz Müller, 14 May 1877 and n. 2.
CD had recently resumed experiments on Australian eucalyptus and acacia, having previously worked on these plants in 1873; his notes are in DAR 209.12: 148.


Bessey, Charles Edwin. 1880. The supposed dimorphism of Lithospermum longiflorum. (L. angustifolium Michx. of Gray’s synoptical flora.) American Naturalist. 14: 417–21.

Forms of flowers: The different forms of flowers on plants of the same species. By Charles Darwin. London: John Murray. 1877.


C. E. Bessey’s case [see 10969] came too late, as the sheets had been printed, but CD thinks it should be carefully investigated as a possible case of incipient heterostyly.

Is trying to make out the function of "bloom", the waxy secretion on leaves and fruits.

Letter details

Letter no.
Charles Robert Darwin
Asa Gray
Sent from
Source of text
Gray Herbarium of Harvard University (119)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 10982,” accessed on 7 May 2021,