1907.] Graenicher, Pollination of Wisconsin Floivers. 89 
tact with the stigmas of the same or of another flower. Following 
is a list of the bees and flies observed on the flowers : 
A. Hymenoptera. 
Apidse: (i) Ceratina dupla Say., female, s. ; Andrenidse: 
(.2) Augochlora confusa Rob., female, s. ; (3) HalicHis quadri- 
maculatus Rob., female, s. and c. p.; (4) H. pilosiis Sm., female, 
s. and c. p.; (5) H. aVoipcnnis Rob., female, s. and c. p.; (6) 
H. hortensis Lov., female, s. and c. p. 
B. Diptera. 
Syrphidse: (7) Paragtis hicolor Fab.; (^8) AUograpta 
ohliqua Say.; (9) Mesogramina inarginata Say.; (10) Splnero- 
plioria cylindrica Say all s. or f. p. 
FAM. grossulariace;e. 
Within the genus Ribes (currants and gooseberries) the 
species differ considerably in the structure of the flowers, and 
accordingly in their adaptation to insects, as has been shown by 
Hermann Mueller (3) for several species of Europe. The same 
is clearly illustrated by the 5 species of our region considered 
below\ We have on one side the primitive and saucer-shaped 
flowers of R. rubrum receiving the attention of small and poorly 
adapted insects ; on the other side, the campanulate flowers of 
R. gracile and R. floriduin adapted to the largest among the spe- 
cialized bees (the bumble bees), and between the two extremes we 
find R. oxyacanthoides and R. Cynoshati, adapted to bees in 
general. 
They all bloom close together, as will be seen from the follow- 
(3) H. Mueller. Weitere Beobachtimgen, pp. 298-300. See also 
P. Knuth Handb. d. Bluetenbiologie, Vol. II, p. 437. 
