150 BULLETIN OF WISCONSIN NATURAL HISTORY SOCIETY. VOL. 1. NO. 3. 
corolla are arranged so, that the outer one forms a lower lip, 
a convenient landing place for insects, while the 2 adjoining lobes 
are directed laterally and the 2 remaining ones, which are hardly 
separated from each other, represent the upper lip. The slightly 
divergent stamens protrude from the flower for a length of 6 mm. 
and shed their pollen at about the same time the stigma becomes 
receptive. The latter reaches as far as the middle of the dehis- 
cent anthers and may easily come in contact with them and cause 
spontaneous self-fertilization to take place. There is a change 
of color in the older flowers, they become yellowish. The nectar 
is protected by thin, wdiite hairs arising from the walls of the 
tube as also from the style. The sweet-scented flow-ers attract 
num.erous visitors belonging to the following species: 
A. Bees, 
Apidae : (i) Boinhus americanorum, F. 9 , s. ; (2) B. 
himaciilatus, Cr. 9 , s. ; (3) B. consimilis, Cr. 9 , s. ; (4) B. ter- 
narms, Say. ? ; s. ; (5) B. virginicus, Oliv. 9-; s. ; (6) Megachilc 
brevis, Say 9 , s. and cp. ; (7) Osmia alhiventris, Cr. 9 , s. and 
cp. ; (8) O. distincta, Cr. 9, s. and.cp. ; Andrenidae: (9) 
Halictus similis, Sm. 9 , s. ; (10) H. fasciatus, Nyl. 9 , s.; (11) 
H. quadrimaculatus, Rob. 9 , s. 
B, Flies. 
Syrphidae: (12) Mesogramma marginata, Say, f.p. 
Hawk-Moths. 
Heterocera: (13) Hcmaris diffinis, Bdv., s. 
D. Birds. 
(14) Trochiliis cohibris, L., s 
The bumble-bees and the smaller bees of the genus Halictus 
usually insert their heads between the anthers and the stigma 
and transport pollen on the sides of their heads from one flower 
to another. The bees belonging to the genera Megachile and 
Osmia collect pollen from the flowers and to this end they press 
the brushes on the ventral surface of their abdomen down against 
the anthers, thereby coming in contact w^ith the stigma and effect- 
ing either cross- or self-fertilization. On account of the short- 
nes of the style and the stamens, the visiting hawk-moth, Hemaris 
dMnis rarely touches the anthers or the estigma with the under 
side of its body, its visits are for this ,eason of little or no avail 
to the flowers.' The visit of the small-sized Syrphid-fly is of no 
