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Darwin Correspondence Project

To E. S. Morse   23 April 1877

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R. [2 Bryanston Street, London.]

April 23d./77

My dear Sir

You must allow me just to tell you how very much I have been interested with the excellent Address which you have been so kind as to send me & which I had much wished to read.—1 I believe that I had read all or very nearly all the papers by your countrymen to which you refer, but I have been fairly astonished at their number & importance, when seeing them thus put together. I quite agree about the high value of Mr Allen’s works, as showing how much change may be effected, apparently through the direct action of the conditions of life.2 As for the fossil remains in the west, no words will express how wonderful they are.—3 There is one point which I regret that you did not make clear in your Address,—namely what is the meaning & importance of Prof. Cope & Hyatts views on Acceleration & Retardation: I have endeavoured & given up in despair the attempt to grasp their meaning.—4

Permit me to thank you cordially for the kind feeling shown toward me througout your Address, & I remain | My dear Sir | Yours faithfully | Ch. Darwin


Morse had given the vice-presidential address, ‘What American zoologists have done for evolution’, to the natural history section at the meeting of the American Association for the Advancement of Science at Buffalo, New York, in August 1876 (Morse 1876). CD’s annotated offprint of the address is in the Darwin Pamphlet Collection–CUL. Myron Leslie Baxter had told CD about the address in his letter of 28 September 1876 (Correspondence vol. 24).
Morse had referred to Joel Asaph Allen’s observations on geographical variation in birds and mammals, summarised in Proceedings of the Boston Society of Natural History 15 (1872–3): 156–9, and to Allen’s paper on colour variation in North American squirrels (J. A. Allen 1874; see Morse 1876, pp. 146–8). Much of this section of Morse 1876 is scored in CD’s copy (see n. 1, above).
See Morse 1876, pp. 160–3.
Edward Drinker Cope and Alpheus Hyatt promoted a theory of evolution based on acceleration and retardation of development. CD mentioned their work in Origin 6th ed., p. 149. For CD’s views and uncertainty on the topic, see Correspondence vol. 20, letter to Alpheus Hyatt, 10 October [1872]. For more on the background and development of Cope’s and Hyatt’s ideas, see S. J. Gould 1977, pp. 85–96.


Allen, Joel Asaph. 1874. On geographical variation in color among North American squirrels; with a list of the species and varieties of the American Sciuridæ occurring north of Mexico. [Read 4 February 1874.] Proceedings of the Boston Society of Natural History 16: 276–94.

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

Gould, Stephen Jay. 1977. Ontogeny and phylogeny. Cambridge, Mass.; London: Belknap Press of Harvard University Press.

Morse, Edward Sylvester. 1876. Address to section B. [What American zoologists have done for evolution.] Proceedings of the American Association for the Advancement of Science 25 (1876): 137–76.

Origin 6th ed.: The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. 6th edition, with additions and corrections. By Charles Darwin. London: John Murray. 1872.


Thanks for ESM’s address ["What American zoologists have done for evolution", Proc. Am. Assoc. Adv. Sci. 25 (1876)].

J. A. Allen’s work is important as apparently showing change through direct action of [external] conditions.

CD has given up trying to understand E. D. Cope and Alpheus Hyatt on acceleration and retardation.

Letter details

Letter no.
Charles Robert Darwin
Edward Sylvester Morse
Sent from
London Down letterhead
Source of text
Peabody Essex Museum: Phillips Library (E. S. Morse Papers, E 2, Box 3, Folder 11)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 10938,” accessed on 18 June 2021,