Delpino long ago pointed out that the blossom is best adapted to pollen-collecting bees, which, alighting on the two long, protruding stamens, rub off pollen on their undersides while clinging for support to the wool on the three shorter stamens, whose anthers supply their needs. As a bee settles on another flower, the stigma is calculated to touch the pollen on his under side before he gets dusted with more; thus cross-pollination is effected. Three stamens furnish a visitor with food, two others clap pollen on him. Numerous flies assist in removing the pollen, too.英文原著 · 《WILD FLOWERS》
It is impossible to discuss the different results of cross-fertilisation; one point must, however, be emphasised, because Darwin attached considerable importance to it. It is inevitable that pollen of different kinds must reach the stigma. It was known that pollen of the same "species" is dominant over the pollen of another species, that, in other words, it is prepotent. Even if the pollen of the same species reaches the stigma rather later than that of another species, the latter does not effect fertilisation.英文原著 · 《Darwin and Modern Science》
Have you at Kew any Eucalyptus or Australian Mimosa which sets its seeds? if so, would it be very troublesome to observe when pollen is mature, and whether pollen-tubes enter stigma readily immediately that pollen is mature or some little time afterwards? though if pollen is not mature for some little time after flower opens, the stigma might be ready first, though according to C.C. Sprengel this is a rarer case. I wrote to Muller for chance of his being able and willing to observe this.英文原著 · 《More Letters of Charles Darwin Volume I》
The pollen-tube is one of the most important morphological characters of the Spermophyta as now existing--in fact the name Siphonogama is used by Engler in his classification, as expressing a peculiarly constant character of the Seed-plants. Yet the pollen-tube is a manifest adaptation, following on the adoption of the seed-habit, and serving first to bring the spermatozoids with greater precision to their goal, and ultimately to relieve them of the necessity for independent movement. The pollen-tube is constant because it has proved to be indispensable.英文原著 · 《Darwin and Modern Science》
i., 1583-88, 1914. [36] /Statutes/, 27 Eliz., c. [37] Burton-Pollen, op. cit., xvi. [38] Burton-Pollen, op. cit., xxiv. [39] Pollen, /Politics of the English Catholics during the reign of Elizabeth/ (/Month/, 1902-4). Law, /Jesuits and Seculars in the reign of Elizabeth/, etc., 1889.英文原著 · 《History of the Catholic Church-2》
[21] Grub, op. cit., ii., 89 sqq. [22] Pollen, op. cit., xlix. [23] On the mission of Gouda, cf. Pollen, op. cit., liv. [24] Pollen, op.英文原著 · 《History of the Catholic Church-2》
So, once a year, some sort of pollen is released into the air, and for two weeks, Cam has allergy-induced sleep apnea and has to use an apparatus in order to help him breathe.美剧 · 《Modern Family》
Michael, I can enhance the sound of a bee making pollen recorded from a satellite.美剧 · 《Suits》
Although I suppose bees do dance, But their dance lets other bees know where the pollen is, And yours does not.美剧 · 《The Big Bang Theory》
Gerberas produce excessive amounts of pollen, which can trigger migraines.美剧 · 《The Good Doctor》