Down Bromley Kent
Mar 6. 1863
Dear Sir
I have been unwell for 12 days, & must write more briefly even than usual.—1 I used to think the husked Maize was wild & there is some evidence for S. America but I now hear from Asa Gray that it is very variable, I do not believe that it is the wild form.2 I do not know where seed could be got.
I enclose information about Passiflora.3 The experiment with P. quandrangularis which fruits in some places & not in others, would be specially good to try with other pollens.4 Thank you for the attempt to give me information on weeping trees.5 I have got much from Mr Rivers.6 I understand now about variability & bi-sexuality. I have been much interested by what you tell me on Primula, & hope to see all in detail in your paper.7 I am extremely glad that you are experimenting on Primulas of different colours. I sent Asa Gray’s Review by this morning’s post.8 I am very much interested about Gongora & fear more & more that I shall prove completely wrong about Acropera—9
I thank you for your criticisms on the Origin, which I have not time to discuss; but I cannot help doubting from your expression of an “innate.....selective principle” whether you fully comprehend what is meant by Natural Selection.10 Certainly when you speak of weaker (i.e less well adapted) forms crossing with the stronger, you take a widely different view from what I do on the struggle for existence; for such weaker forms could not exist except by the rarest chance.
With respect to utility reflect that ths part of the structure of each being is due to inheritance of formerly useful structures. Pray read what I have said on “correlation”:11 Orchids ought to show us how ignorant we are of what is useful.12 No doubt hundreds of cases cd be advanced of which no explanation cd be offered; but I must stop. Your letter has interested me much—
I am very far from strong & have great fear that I must stop all work for a couple of months for entire rest & leave home.— It will be ruin to all my work.—
Pray believe me | Dear Sir | Yours very faithfully | Ch. Darwin
Passiflora
Lecoq De la Fécondation p. 70. says that several kinds cannot be fertilised by own pollen; but can be fertilised by that of other species; names not given.—13
(Transact. of Hort. Soc. of London Vol. 7. p. 95 Mr Mowbray I think (I see P. racemosa & alata set best by using pollen of one to other) gives names of species which he tried with same result.—)14
Bosse in German. Hort. Periodical (quoted by Gärtner Bastard s. 64) makes similar statements; & G. can confirm that P. racemosa can be more easily fertilised with pollen of P. cœrulea than with own;— &c &c—15
I have received 3 other private accounts of analogous cases; but cannot spare time to hunt them up; nor do I know whether names of species were given.16
I have found one case, viz that the Granadilla wd never set with own pollen, but would with pollen of Passiflora Edulis. Mr Scott. Gardener to Sir G. Staunton17
Lobelia
Gärtner (s. 357) twice found that L. fulgens, though producing certainly good pollen, could not be fertilised by it, but cd be fertilised by pollen of L. syphilitica & L. cardanalis.—18
Kölreuter (2d. Fortsetz. & 3d. Fort.) found that Verbascum phœniceum could be fertilised by 4 distinct species, but not by its own apparently good pollen.—19
Please cite as “DCP-LETT-4031,” in Ɛpsilon: The Charles Darwin Collection accessed on