To W. K. Bridgman   21 January [1869]¹

Dear Sir.

M^r Jeffreys has forwarded your letter which has interested me, as I remember speculating some few years ago, whether Aucuba was fertilised by the wind or insects.²

I do not remember whether the coincidence of the secretion of nectar & the opening of the Anthers has ever been observed and it would take a long search to discover— But it is a pretty fact which ought on some fitting occasion to be published   I rather doubt whether it will prove a general rule— So many flowers open their anthers before the Corolla even expands— The following fact has some bearing on your observation:—I have observed (& I think recorded dates) that during many days the flowers of the common Polygala—Linaria cymballaria and some of the smaller clovers may all be fully expanded and not a bee will visit them, and then suddenly swarms of bees will visit the flowers, which marks I believe the first secretion of nectar.—³

Again the stipules of the common Vetch secrete nectar (of no service for fertilisation) whilst the sun shines, & crowds of Hive Bees suck the stipules; the sun is obscured & in a very short time not a bee can be seen; again there is sunshine and again bees.—⁴ I observed this several times on the same day & wondered how the news spread so rapidly through the Hive, but I suppose that all the bees knew the fact, & did not need to communicate it.—

I wish I could have answered your query more precisely & I beg leave to remain— | Dear Sir. | Yours very faithfully. | Ch. Darwin.