440 Trans. Acad. Sci. of St. Louis. 
the insertion of the petals and sepals. An outer circle of 
stamens has straight filaments and erect anthers. The 
anthers of this circle dehisce before the others. The 
stamens of the inner circle have their filaments inflected, the 
indehiscent anthers being held between the head of pistils and 
the raised edge of the receptacle. 
Nectar is deeroted and lodged in the groove near the bases 
of the filaments. The flowers are homogamous. Insects 
visiting the flowers may effect cross-pollination. The anthers 
of the outer circle do not readily come in contact with the 
stigmas. When those of the inner circle dehisce, they often 
touch the stigmas of the lower pistils, but most of the pistils 
can receive pollen only through the agency of insects. 
_ I have seen the flowers visited for nectar and pollen by 
Augochlora pura Say 9. 
FRAGARIA VIRGINIANA Mill., var. ILLINOENSIS Gr. — The 
plants are commonly collected in small patches. The scapes 
rise from one to two decimetres high and bear a few white 
flowers which expand horizontally from 15 to 25 millimetres. 
The flowers are gynodioecious, the female flowers being smaller 
and bearing aborted stamens. The hermaphrodite flowers are 
proterogynous, and. there is, accordingly, abundant oppor- 
tunity for cross-pollination of these flowers. The anthers 
stand so directly over the stigmas that, when the pollen is 
discharged, self-pollination may be effected by insects or by 
the pollen falling upon the stigmas. Nectar is secreted by a 
narrow portion of the receptacle and is held between the 
bases of the filaments and the outer pistils. It is, therefore, 
only imperfectly concealed and can be obtained by small bees 
and flies. The principal visitors are bees of the genus Halictus. 
The list contains visitors observed May 15th: — 
Hymenoptera — Apidae: (1) Synhalonia speciosa Cr. ¥', s.; (2) Ceratina 
dupla Say ¢', 8.; (3) Nomada superba Cr. 4’, s.; Andrenidae: (4) Halictus 
ligatus Say 9, s.; (5) H. fasciatus Nyl. 9, s., freq.; (6) H. pilosus Sm. 9°, 
8.; (7) H. confusus Sm. 9, s. and c. p., freq.; (8) H. tegularis Rob. 9, 5.3 
(9) Augochlora pura Say 9, s.; (10) A. similis Rob. 9, s. andc. p., ab»; 
(11) Prosopis affinis Sm. 4’, s.; (12) P. pygmaea Cr. 9, s. 
Diptera — Syrphidae: (18) Paragus bicolor F., s. and f. p., freq.; (14) 
Sphaerophoria cylindrica Say, s. and f. p.; (15) Tropidia mamillata Lw.; 
