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EFFECTS OF DIFFERENT KINDS OF POLLEN.

I HOPE that you will grant me a little space to thank some of your correspondents and Mr. Beaton for his interesting information how to test the effects of different kinds of pollen on the divisions of the same stigma of a Pelargonium, for my special purpose of ascertaining whether one variety is prepotent over another.¹ I fear that the Scarlet Pelargoniums include at least two wild forms, which botanists would rank as distinct species. If Mr. Beaton is at any time writing on these plants, perhaps he would tell us what he knows about the wild parent of the Horseshoe and other Scarlets.

I am very glad that "P." sent a list of his Pelargoniums with the central flower regular; for I was not aware how common the case was.² Will "P." be so obliging as to observe and report whether any of the regular central flowers set seed—that is, if the kinds specified are such as ever produce seed?

With respect to the fertilisation of Wheat: several years ago I examined the flowers day by day, and came to the same conclusion as that which "H. C. K." expresses so forcibly.³ Mr. Beaton apparently does not much venerate botanical authorities, but he might easily quote a long list of great names to show that Wheat is always fertilised in the bud; what has misled so many botanists I cannot imagine. But stranger assertions of the same kind may be met with: for instance, that cruciferous plants are generally fertilised before the flower opens! As I am away from home I write without my notes;⁴ but I remember that the Chinese have the singular belief that certain varieties of Wheat are always fertilised in the night-time. Col. Le Couteur, who attended so carefully to the varieties of Wheat, entertains no doubt that the different varieties, when growing near each other, cross.⁵ On the other hand, a full account has been published of a large number of varieties, I think 150, which were cultivated close together in some continental garden during several years, and never crossed each other.⁶ This account has much perplexed me; and I have sometimes been tempted to doubt whether any eye, however accurate, could have distinguished so many varieties, and that, perhaps, after all the

¹ Darwin 1861. See Correspondence vol. 9.

² Regular flowers in Pelargoniums. Journal of Horticulture, 2 July 1861, p. 253.

³ 'H. C. K.' When is wheat fertilised? Journal of Horticulture, 2 July 1861, p. 257. 'H. C. K.' was Henry Cooper Key (1819-1879), Rector of Stretton-Sugwas, Herefordshire.

⁴ Darwin and his family were staying in Torquay, see Journal p. 39.

⁵ John Le Couteur (1794–1875), army officer, administrator and agricultural reformer in Jersey; founded the Royal Jersey Agricultural and Horticultural Society. His scientific contributions to the study of wheat led to a fellowship of the Royal Society in 1843, author of a well-known work on wheat, Le Couteur 1836.

⁶ Loiseleur-Deslongchamps 1842-3, pp. 45, 70. Darwin referred to this in Variation 1: 314-15.

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varieties did cross, Mr. Beaton might advance this case in support of his belief that Wheat is fertilised in the bud.

As Mr. Beaton alludes to some mistake which he has made, might I venture to suggest to him to punish himself by telling sooner than he intended by what means he can produce from pollen of the same flower placed on the stigmas of the same variety two different sets of seedlings?¹ That is a mystery which it is tantalising to wait for.—CHARLES DARWIN, Down, Bromley, Kent.

¹ Cross-breeding plants. Journal of Horticulture, 25 June 1861, pp. 232-4. Beaton challenged young gardeners to discover his technique for cross-breeding. See Correspondence vol. 9, p. 198.