Ɛpsilon

To John Lubbock   26 September [1874]1

Down, | Beckenham, Kent.

Sept. 26

My dear Sir John

I have read your 2 articles in Nature & they seem excellently done;2 but my object in writing is to caution you, unless you have good evidence, about C. K. Sprengel’s notion of Bees being deceived by a nectar-less nectary. As far as my memory goes Orchids are his best case, & I think I have shown that he is here mistaken, & my conclusion has been supported by subsequent observations.3

I suppose you do not want more cases of coloured calyx, but our common Polygala is a remarkable case, as the calyx during flowering season is bright-coloured, & then turns green, whilst it protects the seed-vessel after the flowering season is over.4

Yours very sincerely | Ch Darwin

1
The year is established by the reference to Lubbock 1874.
2
CD refers to Lubbock’s two-part article ‘Common wild flowers considered in relation to insects’ (Lubbock 1874). See letter to John Lubbock, [before 17 September 1874] and n. 2.
3
Christian Konrad Sprengel had described orchids as ‘Scheinsaftsblumen’ or false nectar flowers, because their nectaries contained no fluid (Sprengel 1793, p. 403). Lubbock did not refer to Sprengel in his article; however, he made the general remark, ‘it appears that some flowers beguile insects by holding out the expectation of honey which does not really exist’ (Lubbock 1874, p. 404). In Orchids, CD expressed doubt that insects could be so deceived, and suggested that they drew nectar from a different source, by piercing the inner membrane of the tube (see Orchids, pp. 45–53; see also Orchids 2d ed., pp. 36–44).
4
Polygala vulgaris is common milkwort. In Lubbock 1874, p. 402, Lubbock noted that the calyx, though usually green, became brightly coloured in flowers where it was much exposed.

Please cite as “DCP-LETT-9659,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-9659