From Thomas Gold Appleton   5 December [1865]1

10 Commonwealth Avenue. [Boston, Mass.]

Dear Sir,

A gentleman Col Mr Charles C. Fuller2 has just returned to us from California, bringing with him a very curious fish which you may not have seen. It seems that the mountain lakes there very often suddenly dry up & the homeless fish are forced to wander in quest of new water. Nature to that end has furnished them with the legs you will see upon the specimen the Col above mentioned has been good enough to give me, for the purpose of sending it to you.

These fish have been met en route as I am confidently told. At least their migration is the general belief. If you or your friends should desire other specimens, I can procure another of which I know.—

The fish may be familiar to you and of no value to illustrate the object of your recent work, but to me it seems a most remarkable corroboration of your idea.3

If these legs do not illustrate the energy of the principle of the “Struggle for life” I know nothing of the matter.4

My sister wrote that you and Mrs Darwin were in London5   Hoping that this & the fish may find you there, and with the kindest regards to Mrs Darwin & ⁠⟨⁠t⁠⟩⁠he children   I am | very sincerely | T. G. Appleton

Decr 5th.

The year is established by the relationship between this letter and the letter from J. E. Gray, 28 February 1866 (Correspondence vol. 14; see n. 3, below).
Charles C. Fuller has not been further identified.
CD sent the specimen to John Edward Gray of the British Museum, who initially identified it as a larval form of a batrachian, noting its similarity to the axolotl (a larval salamander from Mexico, Ambyostoma mexicanum), and the ‘mud devil’ or ‘hellbender’ (Cryptobranchus alleganiensis, a North American salamander). See Correspondence vol. 14, letter from J. E. Gray, 28 February 1866, and letter to T. G. Appleton, 2 March [1866]. In Origin, pp. 107 and 330, and Descent 1: 204 and 212, CD described the Lepidosiren (lung-fish) as a transitional form between the fishes and amphibians.
For CD’s use of the expressions ‘struggle for life’ and ‘struggle for existence’ see, for example, Origin, pp. 60–3. Appleton had written favourably of Origin in his letter to CD of 24 April [1862] (Correspondence vol. 10).
Appleton’s sister was Mary Mackintosh. CD and Emma Darwin had been in London from 8 to 20 November (Emma Darwin’s diary (DAR 242)).

Please cite as “DCP-LETT-5296,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-5296