Abstract
Varous plants have anthers which open by apical pores; in some (Cassia in the Leguminosae and Solal2u1n wendlandii in the Solanaceae) the pollen does not readily come out of these pores, yet is abundant and is collected and used by females of certain large and moderate sized bees. A bee obtains pollen by curling its body over the ends of the anthers and then vibrating its wings (wings held in folded position) . The vibrations, which produce a loud sound, cause the pollen grains to shoot out of the pores in the anthers; many of them lodge on the body of the bee from which they are transferred to the pollen-carrying scopal hairs. A vibrating knife blade touched to the anthers also causes palIen to be discharged through the pores.
The bees concerned are all polylectic, i.e., they obtain pollen from many different plants. Most individuals of most of the species never have an opportunity to use the collecting method described above. The potentiality to learn this method must be inherent in a number of groups of bees, but so far as known is absent in others such as Apis.