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Darwin Correspondence Project

To Journal of Horticulture   [before 18 June 1861]1

D of Deal,2 states, and, apparently, he is corroborated by Mr. Lightbody,3 that when Auriculas throw up side blooms these keep pretty true to their character;4 but that when they throw up a heart bloom— that is, from the axis of the plant, the flower, no matter what may be the colour of its edging, “is just as likely to come in any other class as in the one it belongs to.” This seems to be an extremely curious observation. It shows that some little light could be thrown on the laws of variation, if the many acute observers who read The Journal of Horticulture would contribute their knowledge on such points. I wish “D.” would have the kindness to give a few more details, such as out of so many heart blooms so many lost their character, and so many kept true; giving also the proportion in the side blooms which kept true.

As I am appealed to, I will make a few observations on this subject; but I have no doubt others could throw more light on the question. Professor Moquin-Tandon asserts, that with irregular flowers, as Snapdragons, the terminal flower in the axis of the plant is more apt to become regular, or peloric as botanists say, than the other flowers.5 I once found a Laburnum tree with the terminal flower on each raceme nearly regular, having lost its pea-blossom structure.6 With many Pelargoniums (I have one at present in my greenhouse, but I know not its name), the central flower in each truss every year comes regular, loses the two dark patches of colour on the two upper petals, and, what is very curious, loses the nectary, which may be seen in all the other flowers cohering to the flower-stalk. In the common Carrot the central floret in the umbel is dark purple and very different from the others; and I find that this central little flower is extremely variable. Are there not other cases of species which habitually have the central flower different from the others? It must, however, be confessed, that Mr. Masters, a high authority on such subjects, disputes that peloric flowers are apt to be central;7 but it seems to me extremely improbable that the several recorded cases should be due to chance, and all these facts seem to hang together and to indicate that in the flower nearest the axis there is a tendency to differ from the others, or to be variable, or to revert to a hypothetical regular form—that is, as I should look at it, to revert to the structure of a remote ancestor. The curious case of the Auricula apparently falls into this same group of facts.

I hope that some of your correspondents will state whether in the case of single buds sporting, as has so often occurred with Pelargoniums, it has been observed that such sports occur more frequently on one part of the plant than on another. I suppose it is not so, or it would have been noted. Having alluded to the central flower in certain Pelargoniums which have lost the two dark patches of colour and the nectary, I would venture to ask some skilful observer to try whether this flower could be made by artificial fertilisation and by pulling off some of the adjoining flowers to yield seed. The stigma should be fertilised with pollen from, if possible, a peloric flower on another plant; and access of other pollen should, of course, be prevented. Peloric flowers have generally been found quite sterile; but Willdenow got seeds from a peloric Snapdragon, and the peculiarity was inherited:8 hence it is possible, though not probable, that a new strain of quite symmetrically-flowered Pelargoniums might be thus raised. Experiments are tedious and very often fail; but it would be well worth while for any man endowed with plenty of patience to collect seed from the central floret and from the other florets on the same truss of any ordinary Pelargonium, and sow them separately and see which varied most. Of course, all the flowers should be fertilised by the same pollen and subsequently protected from insects.

The same law which causes the heart bloom on an individual Auricula not to keep so true as a side bloom, might cause the seedlings of the central flower of a Pelargonium or other plant to vary more than the seedlings from the other and exterior flowers. This would be a secret worth discovering and revealing.—

Charles Darwin, Down, Bromley, Kent.


CD’s letter appeared in the 18 June 1861 issue of the Journal of Horticulture under the heading: ‘Cause of the variation of flowers’.
‘D., Deal’ was a regular contributor to the Journal of Horticulture. CD was responding to a query that appeared in ‘D’s’ article entitled ‘The Auricula bloom of 1861’, Journal of Horticulture, 4 June 1861, pp. 174–6, in which the following query appeared: How comes it to pass, that if an Auricula throws up a side bloom it is pretty sure to be in character; but that if it be from the heart of the flower … it is just as likely to come in any other class as the one it belongs to? … Can Mr. Darwin, Mr. Beaton, or anybody enlighten me on the first of these points? Donald Beaton wrote a regular column for the Journal of Horticulture. CD and Beaton had been carrying on a public correspondence in the pages of the journal that touched upon a range of topics, including crosses, sports, and varieties. See letters to the Journal of Horticulture, [before 14 May 1861], and to J. D. Hooker, 14 May [1861].
In his contribution to the Journal of Horticulture (see n. 2, above) ‘D., Deal’ referred to a communication he had had with a Mr Lightbody of Falkirk. George Lightbody was a grower of auriculas who raised numerous varieties (R. Desmond 1977).
Primula auricula, commonly known as bear’s ear, was a great favourite with flower fanciers owing to the large number of trusses it produced. The summer of 1861 was particularly noted for the fine bloom of auriculas.
Moquin-Tandon 1841, p. 192. CD’s annotated copy of the volume is in the Darwin Library–CUL.
CD had mentioned this case of pelorism to Joseph Dalton Hooker many years earlier (see Correspondence vol. 4, letter to J. D. Hooker, [12 June 1847]; and vol. 6, letter to J. D. Hooker, 14 July [1857]).
The letter from Maxwell Tylden Masters discussing this point has not been found, but see the letter to M. T. Masters, 13 April [1860] (Correspondence vol. 8).
Karl Ludwig Willdenow. The reference has not been traced.


CD, commenting on a case of peloric flowering in Auricula, urges readers to send in their observations on whether flowers nearest the axis tend to differ from others on the plant. Such a law of variation would be worth discovering.

Letter details

Letter no.
Charles Robert Darwin
Journal of Horticulture
Sent from
Source of text
Journal of Horticulture, Cottage Gardener, and Country Gentleman n.s. 1 (1861): 211

Please cite as

Darwin Correspondence Project, “Letter no. 3188,” accessed on 17 November 2018,

Also published in The Correspondence of Charles Darwin, vol. 9