Asks DO to look for nectar in Stanhopea saccata labellum. CD's theory predicts nectar should be present, but afraid there is none.
Down. | Bromley. | Kent. S.E.
My dear Sir
I am perfectly ashamed to trouble Hooker again.— Would you have kindness to look at well-opened flower of Stanhopea saccata & see whether any nectar is in hollowed out base or cup of Labellum; or in other species of Stanhopea, if they have hollowed out base or cup to Labellum.—
I have particular reason to enquire; but I daresay the plant will have none, though it ought to have some.— But Nature, as Agassiz says, does not lie, & therefore it must have nectar,—else a theory of mine is wrong which is clearly impossible!—
In Haste | Ever yours | C. Darwin
- f1 3279.f1The year is given by the relationship to the letter to J. D. Hooker, 6--7 October  and to the letter to J. D. Hooker, 13 October .
- f2 3279.f2The idea that Stanhopea flowers `ought' to have nectar in the base of the labellum is explained in Orchids, pp. 282--3: `As in Epipactis the cup at the base of the labellum serves as a nectar-receptacle, I expected to find that the analogous cup in Stanhopea, Acropera, &c., would serve for the same purpose; but I never could find a drop of nectar in it.'
- f3 3279.f3CD was fond of quoting this aphorism attributed to Louis Agassiz. See, for example, Correspondence vol. 6, letter to Asa Gray, 1 January .