Ɛpsilon

To Eugène Dupuy   21 July 1878

Down,| Beckenham, Kent. | Railway Station | Orpington. S.E.R.

July 21st. 1878

Dear Sir

I am much obliged for your interesting letter.1 I have always thought that Brown-Sequard’s discovery of the inherited effects of injury to certain nerves the most important observation ever made on inheritance; & I read your confirmation & extension of his conclusions with extreme interest.2

I have no suggestions to offer, but will remark on the importance of attending to the circumstance whether a mutilation (which yields inherited effects) was attended with morbid action.—

I have been struck with the circumstance that in most of the cases with the lower animals, in which some injury has been said to be inherited, (for instance the loss of a horn,) it is generally stated that suppuration followed the injury.3

The law of inheritance at corresponding ages, with deviations towards an earlier age in the offspring is one of the highest importance, as it seems to me, in throwing light on evolution & embryology.—4

I heartily wish you success in your observations.— Pray excuse this untidy note, as I am not well today.—

I remain | Dear Sir | Yours faithfully | Ch. Darwin

1
No letter from Dupuy has been found, but CD later mentioned receiving unpublished information from him (see n. 2, below).
2
Charles Édouard Brown-Séquard had published his findings in the Lancet (Brown-Séquard 1875). Dupuy’s research on the inherited effects of lesions of the sympathetic nerve and corpora restiformia on the eye had been published in 1877 (Dupuy 1877). There are two copies of this paper in the Darwin Pamphlet Collection–CUL; both have been annotated. In a letter to Nature, 21 July 1881, p. 257 (see also letter to Nature, 13 July [1881], Calendar no. 13245), CD mentioned that Dupuy had sent him unpublished observations confirming Brown-Séquard’s experimental results.
3
CD suggested that mutilations associated with morbid action were more likely to be inherited, giving as evidence the case of a cow that lost a horn by suppuration, and later produced three calves with a bony lump instead of a horn on the same side of their heads (Variation 2d ed. 1: 457). CD explained this form of inheritance by his pangenesis hypothesis: the gemmules with the potential to repair the injured part would be attracted to the site of the injury, but destroyed by any morbid action, making it impossible for anything but the injured part to be reproduced in the offspring (ibid. 2: 392).
4
Dupuy suggested, following Brown-Séquard, that inheritance of injury occurred because of the transmission of ‘a morbid state of the nervous system’, which caused alterations in utero that resulted in the offspring bearing injuries identical to those in their parents (Dupuy 1877, p. 255). This section of Dupuy’s paper is scored in both copies in the Darwin Pamphlet Collection–CUL; in one, the quotation is underlined in pencil.

Manuscript Alterations and Comments

2.2 mutilation] after del ‘multi’
3.2 said to be] interl
3.3 stated] above del ‘said’
4.2 in the offspring] interl

Please cite as “DCP-LETT-11622,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-11622