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Darwin Correspondence Project

To Horace Benge Dobell   16 February [1863]1

Down. | Bromley. | Kent. S.E.

Feb. 16th

Dear Sir

Absence from home & consequent idleness are the causes that I have not sooner thanked you for your very kind present of your Lectures.2 Your reasoning seems quite satisfactory (though the subject is rather beyond my limit of thought & knowledge) on the V.M.F. not being “a given quantity.”3 And I can see that the conditions of Life must play a most important part in allowing this quantity to increase as in the budding of a tree &c.— How far these conditions act on “the forms of organic life” (p. 46) I do not see clearly.—4 In fact no part of my subject has so completely puzzled me as to determine what effect to attribute to (what I vaguely call) the direct action of the conditions of life. I shall before long come to this subject & must endeavour to come to some conclusion, when I have got the mass of collected facts in some sort of order in my mind.5 My present impression is that I have underrated this action, in the “Origin”.—6 I have no doubt when I go through your Volume, I shall find other points of interest & value to me.—

I have already stumbled on one case, (about which I want to consult Mr Paget) namely on the Regrowth of supernumerary digits.7 You refer to “White on Regeneration &c. 1785.”8 I have been to Libraries of Royal & Linn. Soc, & to British Museum; where the Librarian got out your volume & made a special hunt, & can discover no trace of such a book.— Will you grant me the favour of giving me any clue, where I could see this Book? Have you it; if so & the case is given briefly, would you have great kindness to copy it.— I much want to know all particulars.9 One case has been given me, but with hardly minute enough details, of a supernumerary little finger which has already been twice cut off, & now the operation will soon have to be done for the third time.10

I am extremely much obliged for the genealogical table;11 the fact of the two cousins not, as far as yet appears, transmitting the peculiarity is extraordinary & must be given by me.—12

With very sincere thanks for your kindness.— | Pray believe me | Dear Sir | Yours truly obliged | Ch. Darwin


The year is established by the relationship between this letter and the letter from H. B. Dobell, 5 March 1863.
The reference is to Dobell 1861, which was sent with the letter from James Paget, 7 February 1863, and is in the Darwin Library–Down.
CD refers to ‘Vitalized mode of Force’, a term coined by Dobell for ‘the force manifested in the production, maintenance, growth, repair, and reproduction of the animal organism’ (Dobell 1861, p. 9). Dobell argued that ‘the V.M.F. may be altered in its attributes of quantity and quality by numerous causes’ (ibid. pp. 40–1).
CD refers to the following passage in Dobell 1861, p. 46: If I am right in affirming that the constitution of the animal, both in material and force, is dependent on the conditions of the external world, from which that force and material are accumulated, and if I am right in concluding that some of this force passes into the germs, and thus on into the organisms of the next generation; then the law of the conditions of existence, insisted on by [Georges] Cuvier, becomes invested with a new dignity and importance; for not only will these conditions determine the existence of the organic being which they surround, but will carry their influence forward to the next generation, which will thus be assimilated to the conditions into which it is born. In this manner, there will be maintained a constant correlation between the forms of organic life brought into the world and the conditions on which they depend for their existence. It does not appear that Mr. Darwin has recognised the influence which may thus be exercised by the ‘conditions of life.’ If my hypothesis is correct, it will lend new importance to his theory of ‘natural selection,’ and it will supply, in part at least, an element which some of his critics have thought wanting.
CD’s assessment of the ‘Direct and definite action of the external conditions of life’ was given in chapter 23 of Variation (Variation 2: 271–92). CD wrote a draft of the chapter between September and November 1863 (see ‘Journal’ (Correspondence vol. 11, Appendix II)).
See Origin, pp. 131–4, 206. In Origin, p. 132, CD stated: ‘How much direct effect difference of climate, food, &c., produces on any being is extremely doubtful. My impression is, that the effect is extremely small in the case of animals, but perhaps rather more in that of plants.’ CD revised subsequent editions of Origin to give more significance to the influence of external conditions (see Peckham ed. 1959, pp. 275–80). See also Correspondence vol. 10, letters to J. D. Hooker, 18 March [1862] and 26 [March 1862].
CD had written to James Paget for information on supernumerary digits (see letter from James Paget, 7 February 1863, and letter to T. H. Huxley, [8 February 1863], n. 3). Regeneration of amputated supernumerary digits in humans is discussed in Variation 2: 14–16.
The reference is to C. White 1782; see n. 9, below.
The case is given in Variation 2: 15.
CD cites this case in Variation 2: 36 n. 19: ‘in a large family, fingers with thickened joints were transmitted to several members during five generations; but when the blemish once disappeared it never reappeared’. CD used the case to illustrate the fact that ‘in some few cases the power of reversion wholly fails’.


Thanks HBD for his lectures On the germs and vestiges of disease [1861].

Thinks his reasoning that the V. M. F. ("force exhibited in the operations of life") is not a "given quantity" is satisfactory.

How far the conditions of life affect the forms of organic life puzzles CD more than any other part of his subject. Thinks he may have underrated its importance in Origin.

Asks for source of the quotation on regeneration in HBD’s work.

Letter details

Letter no.
Charles Robert Darwin
Horace Benge Dobell
Sent from
Source of text
Barton L. Smith
Physical description
** 6pp

Please cite as

Darwin Correspondence Project, “Letter no. 3990,” accessed on 20 July 2017,

Also published in The Correspondence of Charles Darwin, vol. 11