From James Torbitt 14 March 1878
Belfast
14th. March | 1878
Ch. Darwin Esqr | Down
Dear Sir
I most respectfully beg to confirm my telegram of yesterday that I “agree with your letter (of 11th. Inst) perfectly”1 If any difference of opinion existed between us, I should feel certain that it was caused by defect in my own intellect.
A subscription to assist me in my experiments, headed by you I should look upon as an honour higher than I need mention at present.
No doubt the plan you have given as the one I am acting on is the wisest one, and I shall act on it, when I know it.
Mr Kennedy of Mayo whose report I had the pleasure to send you,2 ordered a ton of the new varieties, for distribution among his tenantry, and on making up the order I find that the ton comprises 30 varieties, thus a variety entering on the fourth year of life weighs on an average 74 lbs. It was in view of this slow increase of the variety that I thought it would be advisable for each farmer to grow a number of varieties keeping them separate as I did, which is easily done. I find there are no two varieties of exactly the same quality, and if one could test it I suspect no two reach maturity in exactly the same time, neither would they become cooked in the same time and if they did all three, and were mixed, the mixture would be worthless, because some of the varieties would be very susceptible to the attack of the fungus (some are so susceptible, as to be wholly destroyed the first year of life and therefore incapable under certain conditions of being propagated by the tuber) some hardly at all, and the whole wd give only an average of resistance to the Disease. In fact, if the produce of each seed is not kept by itself a selection cannot be made, and this is the very point wherein the gardeners have failed all over the three kingdoms.
In the Spring of 1876 and of 1877 I sent seed to each member of the Legislature, to addresses which I had obtained by advertising in the “Times” to the Magistracy of Ulster and to all who applied for it, and in every instance which I know of except two, they mixed the produce of the seeds, and many are now trying to disentangle them, and they cannot do it except by taking each tuber as a variety in itself.3
As to whether long continued selection might produce varieties which would come true by seed, that is a question on which I do not presume to form an opinion— it is for you, not for me.
I am fully convinced that it is “indispensable that a fungus-proof or nearly fungus-proof variety should be raised from seed, and this var. then propagated in the common way by the tubers”4 It is exactly what I believe, only that I think numbers of varieties should be so obtained, and I suspect that varieties originally fungus-proof become, after a number of years propagation by the tubers, susceptible to the attack of the fungus.
Therefore I think other varieties should be continually coming forward in order to replace those (as I believe) old failing varieties, and I hope tomorrow to have the honour of laying before you the reasons which have led me to come to this conclusion.
I cannot adequately express my sense of your great kindness and hope to hear of better health when I receive for perusal letter to Mr Farrer5 | I am dear Sir most respectfully and faithfully yours, James Torbitt
Footnotes
Bibliography
Bary, Anton de. 1876. Researches into the nature of the potato-fungus—Phytophthora infestans. Journal of the Royal Agricultural Society of England 2d ser. 12: 239–69.
DeArce, Miguel. 2008. Correspondence of Charles Darwin on James Torbitt’s project to breed blight-resistant potatoes. Archives of Natural History 35: 208–22.
Summary
Talk of a subscription to help JT’s experiments. Progress of experiment; loss of fungus-resistance in varieties as they age.
Letter details
- Letter no.
- DCP-LETT-11424
- From
- James Torbitt
- To
- Charles Robert Darwin
- Sent from
- Belfast
- Source of text
- DAR 178: 139
- Physical description
- ALS 6pp
Please cite as
Darwin Correspondence Project, “Letter no. 11424,” accessed on 24 April 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-11424.xml