Ɛpsilon

To John Lubbock   17 November 1871

Down, | Beckenham, Kent.

Nov 17. 1871

My dear Lubbock

Your essay is capital, & not at all too rash.1

If it is any satisfaction to you I’ll swear that every word is true. Your case of polynema passed thro’ my mind when I was thinking on the subject; but do not you suppose that the wings of this insect have been reduced for the special purpose of swimming?2

I have put a pencil alteration to shew what I mean, & have made 2 other suggestions in pencil which you can easily rub out. That is a good remark of yours about the different methods of aquatic respiration of larvæ.3

Farewell— I am very glad to have learnt with certainty how insects acquired their wings! | Ever yours | Ch. Darwin

LS

1
CD refers to Lubbock’s article ‘On the origin of insects’ (Lubbock 1871b).
2
Lubbock suggested that the wings of insects had originated as organs for aquatic locomotion and respiration. He gave the example of the aquatic insect, Polynema natans (a parasitic wasp of the family Mymaridae; now Caraphractus cinctus), which used its wings for swimming (see Lubbock 1871b, p. 425). Lubbock had first described the insect in 1862 (see Correspondence vol. 10, letter from John Lubbock, 23 August 1862, and Lubbock 1863).
3
Lubbock described the vibration of the branchiae (gills) in respiration, noting that the branchiae are located in different places in different insect groups, and suggesting how thoracic and abdominal branchiae could become specialised (Lubbock 1871b, p. 425).

Please cite as “DCP-LETT-8072,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-8072