skip to content

Darwin Correspondence Project

From G. J. Romanes   [before 4 November 1875]1

Dunskaith:

November 7.

I have to-day sent you a beautifully successful graft. It is of a red and white carrot, each bisected longitudinally, and two of the opposite halves joined. You will see that the union is very intimate, and that the originally red half has become wholly white.2 The graft was made about three months ago, at which time the carrots were very small, but the colours very decided. I think, therefore, that unless red carrots ever turn into white ones—which, I suppose, is absurd— the specimen I send is a graft-hybrid so far as the parts in contact are concerned. It will be of great importance, as you observed in your last letter, in a case like this, to see if the other parts are affected—i.e. to get the plant to seed if possible.3 This, I suppose, can only be done at this late season with so young a plant by putting it in a greenhouse. Perhaps, therefore, you might pot it, as soon as it arrives, and keep it till I go up. If you do not care, to take charge of it altogether, I can then get a home for it somewhere in the South. It will not require a deep pot, for I see that I have cut through the end of one of the roots. It would be as well, before potting, to cut off the end of the other root also, so that the one half may not grow longer than the other, and thus perhaps assert an undue amount of influence during the subsequent history of the hybrid. If the plant when you get it, or after potting, shows signs of drooping, I should suggest clipping off the older leaves to check evaporation: having found this a good plan with beets, &c.

In the same box with the hybrid there is another carrot. This is for comparison, it having been from the same seed and grafted (upon the crown) at the same time as the originally red half of the hybrid.

I am doubtful about the potatoes I sent.4 On looking over a number of ‘red flukes,’ I find some here and there are mottled. At any rate, I shall try other varieties next year, and not say anything about this doubtful case.

I forgot to say that the hybrid carrot is the only specimen of longitudinal grafting which I tried with carrots, having been somewhat disheartened with this method by the persistent way in which beets and mangolds refuse to blend when grafted longitudinally. There have thus been no failures with carrots grafted in this way.

If it is not too late, I may suggest that the passage in the ‘Variation’ about the deformity of the sternum in poultry had better be modified. I have this year tried some experiments upon Brahma chickens, and find that the deformity in question is caused by lazy habits of roosting—the constantly recurring pressure of the roost upon the cartilaginous sternum causing it to yield at the place where the pressure is exerted. The experiments consisted merely in confining some of a brood of young chickens in a place without any roost, and allowing the others to go about with all the March chickens. The former lot have the sternum quite straight, and the latter lot have it deeply notched.5

Footnotes

The date is established by the relationship between this letter and the letter to G. J. Romanes, [4 November 1875]. An incorrect date of 7 November 1875 is given in E. D. Romanes 1896, p. 44. Romanes’s phrase, ‘keep it till I go up’, suggests that the letter was sent not from Dunskaith in Scotland but from his London address.
Romanes was experimenting with graft hybrids of tuberous and root vegetables to determine whether characteristics of one variety could be transmitted to another. He mentioned his success in grafting carrots in his letter of 29 September 1875.
The most recent extant letter from CD to Romanes was that of 8 October 1875.
Romanes had sent specimens from his potato-grafting experiments (see letter to G. J. Romanes, 8 October 1875).
In Variation 1: 287–8, CD had presented a table showing the reduced depth of the sternum in domestic fowls; he argued that this was caused by a curvature of the furcula arising from disuse of the pectoral muscles. See also Correspondence vol. 22, letter from G. J. Romanes, 10 July 1874 and n. 7.

Bibliography

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

Romanes, Ethel Duncan. 1896. The life and letters of George John Romanes M.A., LL.D., F.R.S. London, New York, and Bombay: Longmans, Green, and Co.

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

Summary

Sends successful graft-hybrid of red and white carrot.

CD should correct passage in Variation explaining deformation of sternum in fowls [Variation, 2d ed., 1: 287–8].

Chapter in Variation on Pangenesis is admirable.

Letter details

Letter no.
DCP-LETT-10249
From
George John Romanes
To
Charles Robert Darwin
Sent from
Dunskaith
Source of text
E. D. Romanes 1896, pp. 42–4

Please cite as

Darwin Correspondence Project, “Letter no. 10249,” accessed on 22 June 2021, https://www.darwinproject.ac.uk/letter/DCP-LETT-10249.xml

Also published in The Correspondence of Charles Darwin, vol. 23

letter