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Darwin Correspondence Project

To J. T. Moggridge   10 March 1873

Down Beckenham

Mar. 10. 1873

My dear Sir

I am very much obliged for the seeds. I had some vague reasons for suspecting that Ammonia vapour hastened and acid vapours retarded the germination of seeds; so after reading your interesting account I resolved to make this trial, which is a wild-goose chase. I have obtained formic acid for the experiment; but as we are going to London for a month, I shall be able to do nothing until our return.1

I am glad to hear of your spider observations: if you can state positively that your young spiders had never seen an old spider or one of their own webs, I think every one of their actions ought to be recorded. Your paper would then make a worthy complement to Mr. Spalding’s admirable article in Macmillan’s Mag. for Feb. on blinded chickens.2

With many thanks, my dear Sir, | Yours sincerely | Ch. Darwin


No letter from Moggridge enclosing seeds has been found, but presumably he had supplied CD with seeds recovered from ants’ nests. CD and Joseph Dalton Hooker had discussed the possibility that formic acid might retard the germination of seeds after reading Moggridge’s observations on seeds stored in ants’ nests (Moggridge 1873; see letter to J. D. Hooker, 27 January [1873] and n. 9, letter from J. D. Hooker, 20 February 1873 and n. 3, and letter to J. D. Hooker, 21 February [1873]). The details of CD’s experiments are not known, but see the letters from J. T. Moggridge, 22 July 1873 and 30 July 1873, in which he describes the experiments he carried out at CD’s suggestion. The Darwins were in London from 15 March until 10 April 1873 (see ‘Journal’ (Appendix II)).
No letter from Moggridge referring to specific observations on spiders has been found, but in a supplement to his work on ants and trapdoor spiders he published an account of various experiments on captive spiders carried out during 1873; these included experiments that suggested young spiders constructed their traps by instinct (Moggridge 1874, pp. 242–6). Douglas Alexander Spalding had described experiments in which chicks that had been hooded while still incompletely hatched were nevertheless immediately able, once the hoods were removed, to peck for food and judge distances (Spalding 1873).


Moggridge, John Traherne. 1873. Harvesting ants and trap-door spiders: notes and observations on their habits and dwellings. London: L. Reeve & Co.

Moggridge, John Traherne. 1874. Supplement to Harvesting ants and trap-door spiders: with specific descriptions of the spiders by the Rev. O. Pickard-Cambridge. London: L. Reeve & Co.

Spalding, Douglas Alexander. 1873. Instinct. With original observations on young animals. Macmillan’s Magazine 27 (1872–3): 282–93.


Much obliged for seeds. Will expose seeds to chemical vapours.

Comments on JTM’s spider experiments.

Letter details

Letter no.
Charles Robert Darwin
John Traherne Moggridge
Sent from
Source of text
DAR 146: 379
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 8805,” accessed on 26 October 2021,

Also published in The Correspondence of Charles Darwin, vol. 21