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Darwin Correspondence Project

To Lawson Tait   25 March [1876]1

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R.

March 25

My dear Sir

I have read your two interesting articles in the Spectator, in which you greatly honour me. I think that you have made good your point about the survival of the fittest; & that the distinction ought to be kept in mind.2

Since reading your 1st article, Dr Rüdinger has written to me & sent me an Essay in which he gives the results of the most extensive enquiries from all eminent surgeons in Germany & all are unanimous about non-growth of extra digits after amputation. They explain some apparent cases as Paget did to me. By the way I struck out of my 2d Edit. a quotation from S. J. Simpson about regrowth in the womb, as Paget demurred, & as I could not say how a rudiment of a limb due to any cause cd. be distinguished from an imperfect regrowth.3

Two or three days ago I had another letter from Germany from good naturalist Dr Kollmann, saying he was sorry that I had given up atavism & extra digits & telling me of new & good evidence of rudiment of a rudimentary 6th digit in Batrachian (which I had myself seen, but given up owing to Gegenbaur’s views); but with regrowth failing me I could not uphold my old notion.4

I have many letters to write so remain. | Yours sincerely | Ch. Darwin


The year is established by the reference to Tait’s two-part article in the Spectator (see n. 2, below).
In the second part of his review of Variation 2d ed. (L. Tait 1876b), Tait drew the following distinction: ‘“Survival of the fittest” is, therefore, the agency by which modifications are made useful, whilst “survival by fitness” is that by which they are rendered permanent.”’ He communicated the distinction to CD in his letter of 21 February 1876, but CD saw the distinction as too fine to be appreciated by the public (see letter to Lawson Tait, 22 February [1876]).
Tait discussed polydactylism and regrowth of supernumerary digits in the first part of his review of Variation 2d ed. (L. Tait 1876b). Nicolaus Rüdinger’s letter has not been found. His essay on polydactylism was published in a collection of three lectures (Rüdinger 1876). On p. 30, Rüdinger quoted from Variation 2: 16, and on pp. 32–4, he discussed the cases from German surgeons. For his previous work on the subject, see Correspondence vol. 23, letter from Anton Bachmaier, 4 February 1875 and n. 3. James Paget doubted apparent cases of the regrowth of human digits after amputation (see Correspondence vol. 23, letter from James Paget, 14 August 1875). Tait’s review also discussed the apparent amputation and regrowth of limbs in human foetuses. In Variation 2: 15, CD cited examples that had been described in a paper by James Young Simpson (Simpson 1848); he removed the discussion from the main body of the second edition, noting Paget’s doubts about Simpson’s facts in a footnote (see Variation 2d ed. 2: 358 n. 22).
Julius Constantin Ernst Kollmann’s letter of 19 March 1876 referred to an article by Gustav Jakob Born (Born 1876) in support of the view that the appearence of six digits in some animals represented reversion to an ancestral form. Batrachia is a former order of amphibians that included frogs and toads; it is roughly similar to the modern order Anura. In Variation 2: 13 n. 28, CD used the work of Carl Gegenbaur (Gegenbaur 1864–72) to argue that the hinder foot of the toad (dissected as soon as it sprouted from the tadpole) only seemed to possess a sixth digit.


Born, Gustav Jakob. 1876. Die sechste Zehe der Anuren. Morphologisches Jahrbuch 1: 435–51.

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

Gegenbaur, Carl. 1864–72. Untersuchungen zur vergleichenden Anatomie der Wirbelthiere. Leipzig: Wilhelm Engelmann.

Rüdinger, Nicolaus. 1876. Beiträge zur Anatomie des Gehörorganes: der venösen Blutbahnen der Schädelhöhle, sowie der überzähligen Finger. Munich: Literarisch-artistische Anstalt (Th. Riedel).

Simpson, James Young. 1848. Cases of spontaneous amputation of the forearm, and subsequent rudimentary regeneration of the hand in the fœtus. Monthly Journal of Medical Science n.s. 2: 890.

Variation 2d ed.: The variation of animals and plants under domestication. By Charles Darwin. 2d edition. 2 vols. London: John Murray. 1875.

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.


RLT’s two articles in Spectator [4 Mar and 25 Mar 1876] greatly honour CD.

Tait has made a good point about "Survival of the Fittest".

Dr Rudinger’s extensive inquiries show that all eminent German surgeons are unanimous about non-growth of extra digit after amputation.

J. Kollmann has written regretting CD has given up atavism and extra digits [in 2d ed. of Variation]; gives new evidence of a rudimentary sixth digit in batrachians.

Letter details

Letter no.
Charles Robert Darwin
Robert Lawson (Lawson) Tait
Sent from
Source of text
DAR 221.5: 33
Physical description
4pp (Photocopy)

Please cite as

Darwin Correspondence Project, “Letter no. 10428,” accessed on 21 April 2021,

Also published in The Correspondence of Charles Darwin, vol. 24