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Darwin Correspondence Project

To Asa Gray   15 January 1872

Down | Beckenham | Kent

Jan. 15— ’72

My dear Gray,

I have taken up an old subject which formerly interested me, namely the amount of earth brought to the surface by worms.1

I want to know whether you have in the States the little vermiform piles of earth which are so common on our lawns fields woods & waste lands.— Are they as numerous with you as they are with us?

I should have assumed that this would naturally be the case had it not occurred to me that the severe winters might make all the difference.—

A very few lines in answer would suffice.— It just occurs to me that if you had any correspondent in the Northern parts of Canada you might send this letter to him and thus get me some additional information on the subject.— Overworked as you are I hope you will forgive me for troubling you. Many thanks for Agassiz’s letter which from the handwriting I infer you sent me.—2

Pray give our very kind remembrances to Mrs Gray3 and | Believe me | Yours very sincerely | Ch. Darwin


CD’s first publication on earthworms was read to the Geological Society of London in 1837 (‘Formation of mould’). See also Correspondence vol. 17, letter to Gardeners’ Chronicle, 9 May [1869], for CD’s remarks on his later observations.
Gray probably sent CD a copy of a letter published by Louis Agassiz in the Bulletin of the Museum of Comparative Zoology at Harvard College prior to his departure on the Hassler expedition (J. L. R. Agassiz 1871; see Marcou 1896, 2: 184–5). In this letter, Agassiz stated his belief that if the world was the work of intelligence, not force and matter, then it should be possible for him to predict that, in accordance with the laws of correlation, primordial forms would be found at the deepest levels of the ocean. He also stated his intention of looking for evidence of glaciation in the southern hemisphere.


Agassiz, Louis. 1871. A letter concerning deep-sea dredgings, addressed to Professor Benjamin Peirce, superintendent United States Coast Survey. Bulletin of the Museum of Comparative Zoology at Harvard College 3 (1871–6): 49–53.

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

‘Formation of mould’: On the formation of mould. [Read 1 November 1837.] Transactions of the Geological Society of London 2d ser. 5 (1840): 505–9. [Shorter publications, pp. 124–7.]

Marcou, Jules. 1896. Life, letters, and works of Louis Agassiz. 2 vols. London and New York: Macmillan and Co.


Questions AG on earthworm activity in North America and would welcome information from northern Canada if AG has a correspondent there.

Letter details

Letter no.
Charles Robert Darwin
Asa Gray
Sent from
Source of text
Archives of the Gray Herbarium, Harvard University (99)
Physical description
LS 3pp

Please cite as

Darwin Correspondence Project, “Letter no. 8158,” accessed on 1 April 2023,

Also published in The Correspondence of Charles Darwin, vol. 20