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Darwin Correspondence Project

To J. V. Carus   4 May 1869

Down. | Beckenham | Kent. S.E.

May 4. 1869

My dear Sir

I am pleased to hear about the Origin, for I am now completing a new edit., which will be published in a month’s time or less.1 I have gone very carefully thro’ the whole, trying to make some parts clearer, & adding a few discussions & facts of some importance. The new ed. is only 2 pages, at the end, longer than the old; though in one part 9 pages in advance, for I have condensed several parts, & omitted some passages. The translation, I fear will cause you a good deal of trouble; the alterations took me 6 weeks, besides correcting the press; you ought to make a special agreement with M. Koch.2 Many of the corrections are only a few words, but they have been made from the evidence on various points appearing to have become a little stronger or weaker.3

Thus I have been led to place somewhat more value on the direct & definite action of external conditions,—to think the lapse of time as measured by years not quite so great as most geologists have thought,—& to infer that single variations are of even less importance, in comparison with individual differences, than I formerly thought.4 I mention these points because I have been thus led to alter in many places a few words; & unless you go thro’ the whole new edition, one part will not agree with another, which wd be a great blemish. I cd lend you the corrected sheets, which wd shew where changes had been made, but then some corrections have been added in the proofs, which wd not appear in the above sheets. Please sometime to inform me whether you wish for the loan of the corrected sheets, & whether you wd like a bound copy, or clean loose sheets for yr translation.

I am pleased to hear about the sale of “Domestic Animals,”5 Altho’ I am never idle my new book makes very slow progress; & I will assuredly inform you as soon as it goes to the printers.6

Believe me | my dear Sir | yours very sincerely | Charles Darwin


See letter from J. V. Carus, 29 April 1869. CD refers to the fifth edition of Origin. For more on the publication of the edition, see the letter to J. V. Carus, 5 February 1869 and n. 5.
Eduard Koch.
For CD’s list of additions and corrections, see Origin 5th ed., pp. xi–xiii.
On the direct and definite action of external conditions, see Origin 5th ed., pp. 165–8. CD also refers to evidence for the age of the earth from astronomical calculations (see, for example, letter from James Croll, 4 February 1869, and Origin 5th ed., pp. 348–54). For CD’s discussion of ‘individual differences’, see Origin 5th ed., pp. 104–5; see also letters to A. R. Wallace, 22 January [1869] and 2 February [1869].
Carus reported on sales of Variation in his letter of 29 April 1869.
CD refers to Descent.


Origin 5th ed.: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. 5th edition, with additions and corrections. By Charles Darwin. London: John Murray. 1869.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.

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


Discusses changes in 5th edition of Origin owing to new evidence. CD now places more value on action of external conditions; thinks lapse of time [required for development of species] not so great as some geologists have thought, and single variations [saltations] of even less importance compared with individual differences.

Please cite as

Darwin Correspondence Project, “Letter no. 6726,” accessed on 26 September 2020,

Also published in The Correspondence of Charles Darwin, vol. 17