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Darwin Correspondence Project

To Daniel Oliver   22 January [1861]1

Down Bromley Kent

Jan. 22.

My dear Sir

You mentioned to me Kurr on Nectaries2 & in doing this you did me a great service,—that is if helping a man to ride his hobby-horse can be called a “great service”! To watch flowers & insects has been a very old hobby of mine.—3 Some statements in Kurr lead me to ask you, to give me some information on one point, if in your power, & if it can be done without much trouble.— But I have no idea whether you have the plant alive at Kew, or whether dried plants would serve.— Half-opened flowers do not do, for pistil bends subsequently. The point is, that I as yet find it a rule that if the pistil is curved to one side, it curves to the side of the nectary, so that the stigma lies in the gangway to the secreting nectary or to the honey-receptacle.—4 The converse proposition does not hold good; the nectary may be lie one side, without the pistil being curved, but in this case it nevertheless lies in the gangway.— One of the best cases is Saxifraga, in which in 2 or 3 species (names unknown to me) the nectary goes all round & the pistil is straight; but in S. sarmentosa the pistil is curved & the nectary is one sided & lies on side towards which pistil bends.— Now Kurr, as you will see in enclosed paper gives name of some species with one-sided & others with circular nectaries; can you find out at any time for me how the pistils are? Analogous facts occur in several genera of Proteaceæ & Caprifoliaceæ: can you aid me?—

The rule interests me in several ways, & any the most trifling generalisation, such as this, seems worth making out.— I have already got a good many facts.— But you must not waste much time on it.—

Ever yours very truly | C. Darwin


Kurr) | (Kew) this till flowering season if necessary p. 32 Grevillea & Hakea nectary on one side. Embothrium Is the pistil bent Lomatia to that side? Stenocarpus

I imagine the other genera have not lop-sided nectary. p. 54 Caprifoliaceæ in most (if I understand) the nectary on one side; but in some as Cornus & Viburnum not on one side— how are pistils?

p 57   In Saxifraga punctata, umbrosa & cuneifolia nectar secreted on one side whereas in S. decipiens, trifurcata, mutata cressifolia & granulata it surrounds the germen. How is pistil in the 3 first species. In S. sarmentosa the nectary is on one side & pistil is bent to the side.— p. 71. In Melianthus major, nectary lateral; how is pistil?


Dated by the reference to Kurr 1833 (see n. 2, below).
Kurr 1833. An annotated copy of this work is in the Darwin Library–CUL. Tipped into the volume are two pages of notes in CD’s hand that are dated 14 and 19 January 1861, respectively.
Some of CD’s notes on this topic are in DAR 76. Several of the slips are dated from the 1840s.
For CD’s first expression of this general rule, see Correspondence vol. 8, letter to J. D. Hooker, 12 July [1860].


Thanks for mentioning J. G. Kurr on nectaries [Untersuchungen über die Bedeutung der Nektarien in den Blumen (1833)]. Requests observations on flowers with curved pistils. Finds they curve toward nectary, thus lying in path of insect.

Letter details

Letter no.
Charles Robert Darwin
Daniel Oliver
Sent from
Source of text
Down House (MS 10: 5)
Physical description
4pp enc

Please cite as

Darwin Correspondence Project, “Letter no. 2661,” accessed on 25 June 2017,

Also published in The Correspondence of Charles Darwin, vol. 9