Ɛpsilon

To John Lubbock   12 August [1871]1

Haredene Albury | Guildford

Aug 12

My dear Lubbock

You will see where we are, & where we remain for 3 weeks more.2

I hope the proof sheets having been sent here will not inconvenience you. I have read them with infinite satisfaction, & the whole discussion strikes me as admirable.3 I have no books here & wish much I cd see a plate of Campodea. I never reflected much on the difficulty which you indicate, & on which you throw so much light.4 I have only a few trifling remarks to make. At p. 44. I wish you had enlarged a little on what you have said of the distinction between developmental & adaptive changes; for I cannot quite remember the point & others will perhaps be in the same predicament.5 I think I always saw that the larva & the adult might be separately modified to any extent. Bearing in mind what strange changes of function parts undergo with the intermediate states of use, it seems to me that you speak rather too boldly on the impossibility of a mandibulate insect being converted into a sucking insect;6 not that I in the least doubt the value of yr explanation.

Cirrepedes passing through what I have called a pupal state, as far as their mouths are concerned, rather supports what you say at p. 52.7

At p. 40 yr remarks on the Argus pheasant (tho’ I have not the least objection to them) do not seem to me very appropriate as being related to the mental faculties8

If you can spare me these proof sheets when done with I shd be obliged as I shall be correcting a new Ed. of the Origin when I return home, tho’ this subject is too large for me to enter on9

I thank you sincerely for the great interest which yr discussion has given me, & with thanks for your congratulation on an event that gives us great satisfaction10 | believe me yours very since⁠⟨⁠rely⁠⟩⁠ | Ch. Darwin

I return by this Post, the sheets

LS(A)

1
The year is established by the address (see n. 2, below).
2
The Darwins stayed at Haredene from 28 July to 25 August 1871 (CD’s ‘Journal’ (Appendix II)).
3
CD refers to the proof-sheets of Lubbock’s Monograph of the Collembola and Thysanura (Lubbock 1873).
4
Campodea (the bristle-tail) is a genus of arthropods formerly classed together with springtails and silverfish in the insect order Thysanura, but since reclassified as a separate group within the order Diplura, which is in the class Entognatha. Lubbock supported Fritz Müller’s contention that metamorphosing insects had evolved from non-metamorphosing ones, and followed Friedrich Brauer in arguing that insects had developed from a common stock resembling Campodea, pointing out the resemblance between Campodea and the larval stages of some insects (Lubbock 1873, pp. 40–54 and plate 50). This, he suggested, helped explain the different mouth-types present within the same species of insect, which he thought ‘one of the greatest difficulties in the theory of natural selection’ (Lubbock 1873, p. 52; see n. 6, below).
5
In Lubbock 1873, p. 44, Lubbock restated the distinction between ‘developmental’ and ‘adaptational’ or ‘adaptive’ change during metamorphosis in insects that he had first drawn in his study of Chloeon (now Cloeon). Changes that produced the features of the mature adult Lubbock described as ‘developmental’; changes that were irrelevant to the adult form but benefited the larvae he called ‘adaptational’, and argued that these were acquired through natural selection (Lubbock 1863–5, p. 490).
6
Lubbock thought that a mandibulate insect (one that fed by chewing) could not evolve into a suctorial one (one that fed by sucking) because ‘the intermediate stages would necessarily be injurious’ (Lubbock 1873, p. 52). He argued that Collembola (springtails or snow flies) and Campodea, having loosely attached mandibles, could have evolved into either form, or into metamorphic forms in which the mouths were mandibulate in the larval stage and suctorial in the adult (Lubbock 1873, pp. 50–2).
7
See Living Cirripedia (1854), pp. 110–11. Lubbock argued that an inactive ‘pupa’ stage in insects was necessitated more by the changes to the mouth parts than by those in any other part of the body (Lubbock 1873, pp. 51–2).
8
There is no reference to the Argus pheasant in the published version of Lubbock 1873; page 40 is the first page of a chapter in which Lubbock discussed the evolution of metamorphic insects and the difficulty he thought it posed for Darwinian theory. CD had argued that the striking plumage of the male Argus pheasant was the result of sexual selection (Descent 2: 90–3, 134–51).
9
CD worked on the sixth edition of Origin from 18 June to 29 October 1871 (CD’s ‘Journal’ (Appendix II)).
10
Henrietta Emma Darwin was engaged to be married to Richard Buckley Litchfield; the marriage took place on 31 August 1871 (CD’s ‘Journal’ (Appendix II)).

Manuscript Alterations and Comments

7.1 I … sheets] added in CD’s hand

Please cite as “DCP-LETT-7904,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-7904