"See how the is adapted to . Its s stand erect with s curving inward. The trough-like pollen cavities of the anthers, opening upward, expose their stores to the insect standing on top. So great is the excess of production over actual needs that the little bee wastefully and unwittingly scatters over the is enough for setting the seed. This store of choice food the flower reserves for its proper visitor—chiefly for this little bee. Large bees would have great difficulty in collecting pollen from flowers that hang on such slender stalks. Wingless insects, like ants, which, if gathering pollen, could run only from flower to flower upon the same plant, and which would thus be poor agents in , are rigidly excluded. Should they be able to run out along the slender flower stalk, and round the fringed border of the and get inside, they would still find between themselves and the pollen overhead a barrier of glandular hairs bearing an acrid and offensive secretion which they would choose to avoid contact."