504 The Ohio Naturalist. [Vol. XII, No. 6, 



which are of two lengths, are united with the corolla tube for some 

 distance above the stigmatic surface. As the bee's proboscis is 

 inserted into the flower it pushes past the retrorse anthers to the 

 nectar at the base of the tube. As the proboscis is withdrawn, in 

 passing the anthers it bends them upward so that the dehisced 

 surfaces, which nonnally lie downward and against the corolla 

 tube, deposit pollen upon the tip of the proboscis wet with nectar. 

 Should insect visits fail, automatic self-pollination may occur 

 between the shorter stamens and the stigma, according to Knuth. 

 Visitors — Lepidoptera; Epargyreus tityrus, vSpragueia ona- 

 grus, Lycaena scudderi: Diptera; Syritta pipiens, Allograpta 

 obliqua, Sphaerophora cylindrica, Tropidia quadrata, Helophilus 

 latifrons, Phthiria cyanoceps; Hymenoptera; Microbembex mono- 

 donta, Agapostemon radiatus, Ceratina dupla, Odynerus for- 

 aminata, Megachile latimanus. 



EXPLANATION OF PLATE XXIV. 



Fig. 1. Blephilia ciliata. 



Fig. 2. Stachj^s tenuifolia, showing relative po-sition of anthers and stigma. 



Fig. 3. Teucrium canadense, showing relation of anthers to stigma. 



Fig. 4. Dianthera americana showing separated anther lobes. 



Fig. 5. Mimulus ringens. 



Fig. 6. 'Verbena hastata. 



Fig. 7. Longitudinal section of V. hastata, showing ring of hairs in throat 



of corolla, retrorse anthers with dehiscent surfaces downward and 



against corolla tube. 



