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Darwin Correspondence Project

To A. R. Wallace   26 January [1870]1

Down. | Beckenham | Kent. S.E.

Jan 26th

My dear Wallace

I have been very much struck, by your whole article (returned by this post), especially on the rate of denudation, for the still glaciated surfaces have of late much perplexed me.2 Also especially on the lesser mutations of climate during the last 60,000 years; for I quite think with you no cause so powerful in inducing specific changes through the consequent migrations. Your argument wd be somewhat strengthened about organic changes having been formerly more rapid, if Sir W. Thompson is correct that physical changes were formerly more violent & abrupt.3

The whole subject is so new & vast, that I suppose you hardly expect anyone to be at once convinced, but that he shd. keep your view before his mind & let it ferment. This, I think, everyone will be forced to do.— I have not as yet been able to digest the fundamental notion of the shortened age of the sun & Earth. Your whole paper seems to me admirably clear & well put.— I may remark that Rütimeyer has shown that several wild mammals in Switzerland since neolithic period have had their dentition & I think general size slightly modified.4 I cannot believe that Isthmus of Panama has been open since commencement of Glacial period; for notwithstanding the Fishes so few shell, crustacean & according to Agassiz not one echinoderm is common to the sides.—5 I am very glad you are going to publish all your papers on Nat Selection: I am sure you are right, & that they will do our cause much good.

But I groan over Man— you write like a metamorphosed (in retrograde direction) naturalist, & you the author of the best paper that ever appeared in Anth. Review!6

Eheu Eheu Eheu7 | Your miserable friend | C. Darwin


The year is established by the relationship between this letter and the letter from A. R. Wallace, 22 January 1870.
CD refers to Wallace 1870b (see letter from A. R. Wallace, 22 January 1870).
See letter from A. R. Wallace, 22 January 1870 and n. 2; CD refers to William Thomson and W. Thomson 1862.
Ludwig Rütimeyer mentioned the diminishing size of wild animals alongside the increasing size of domestic ones at prehistoric lake-dwellings in Switzerland in Rütimeyer 1861, p. 30 (see also Variation 2: 427).
In Wallace 1870b, p. 401, Wallace argued that before or during the glacial period, part of central America had been submerged, since a third of the known species of marine fish were identical on both sides of the isthmus of Panama. CD refers to Louis or Alexander Agassiz, and to A. Agassiz et al. 1869. There is an annotated offprint of A. Agassiz et al 1869 in the Darwin Pamphlet Collection–CUL; it is a set of reports from the Bulletin of the Museum of Comparative Zoology. The concluding report is by Louis Agassiz.
In an earlier paper Wallace had suggested that natural selection could not explain the origin of the moral and higher intellectual faculties of humans or some of their physical characteristics, such as the absence of body hair ([Wallace] 1869b, pp. 391–3; see also Correspondence vol. 17, letter to A. R. Wallace, 14 April 1869). Wallace had written a paper on the origin of human races for the Anthropological Review in 1864, in which he argued that human intelligence, moral qualities, and social instincts would have been to the benefit of the community from their earliest appearance and would therefore have become subject to the force of natural selection (Wallace 1864, p. clxii).
Eheu: alas (Latin).


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

Rütimeyer, Ludwig. 1861. Die Fauna der Pfahlbauten in der Schweiz. Untersuchungen über die Geschichte der wilden und der Haus-Säugethiere von Mittel-Europa. Basel, Switzerland: Bahnmaier’s Buchhandlung (C. Detloff).

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


Response to ARW’s MS on geological time ["The measurement of geological time", Nature 1 (1870): 399–401, 452–5].

Groans over [what is said about] man.

Letter details

Letter no.
Charles Robert Darwin
Alfred Russel Wallace
Sent from
Source of text
The British Library (Add MS 46434: 198–9)
Physical description
ALS 4pp †

Please cite as

Darwin Correspondence Project, “Letter no. 7086,” accessed on 15 April 2024,

Also published in The Correspondence of Charles Darwin, vol. 18