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Letter 4559

Darwin, C. R. to Flower, W. H.

11 July [1863]

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    Discusses rudimentary sixth toe of frogs.


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

July 11th

My dear Sir

I am truly obliged for all the trouble which you have taken for me & for your very interesting note.— I had only vaguely heard it said that Frogs had a rudiment of a sixth toe; had I known that such great men had looked to the point, I should not have dreamed of looking myself. The rudiment sent to you was from a full-grown frog; so that if these bones are the two Cuneiforms they must, I shd. think, be considered to be in a rudimentary condition.— This afternoon my gardener brought me some tadpoles, with the hind-legs alone developed, & I looked at the rudiment. At this age it certainly looks extremely like a digit, for the extremity is enlarged like that of the adjoining real toe, & the transverse articulation seems similar— I am sorry that the case is doubtful, for if these Batrachians had six toes, I certainly think it would have thrown light on the truly extraordinary strength of inheritance in Polydactylism in so many animals, & especially on the power of regrowth in amputated supernumery digits.

With very sincere thanks | believe me | My dear Sir | Yours very faithfully | Ch. Darwin

    Footnotes Add

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    f1 4559.f1
    The year is established by the relationship between this letter and the letter to T. H. Huxley, 3 July [1863].
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    f2 4559.f2
    The letter from Flower has not been found, but see n. 3, below.
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    f3 4559.f3
    Having learned that Peter Mark Roget had stated that frogs have the rudiment of a sixth toe (Roget 1834, 1: 544), and having heard other such reports, CD had dissected a specimen, asking Thomas Henry Huxley to give his opinion of the dissection (see letters to T. H. Huxley, 16 February [1863] and 27 June [1863]). Huxley declined, but offered to ask Flower to answer CD's questions (see letter from T. H. Huxley, 2 July 1863, and letter to T. H. Huxley, 3 July [1863]). The `great men' referred to in Flower's letter have not been identified; however, see Variation 2: 12--17.
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    f4 4559.f4
    Henry Lettington.
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    f5 4559.f5
    CD referred briefly to the possible occurrence in frogs of a rudimentary sixth toe, in his extensive discussion of polydactylism and inheritance in Variation 2: 12--17 (on p. 14).
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