148 
IOWA ACADEMY OF SCIENCES. 
furrows only can be seen, but when probed several times the 
filaments separate. The thorax and back of the insect are cov- 
ered with pollen, as it falls out very easily. An insect fre- 
quently probes the other slits of the androecium. When an 
insect goes to a pistillate flower it passes over the stigmas and 
down to the nectar which is here found in an open cup. The 
amount of nectar contained in flowers is large. In some pistil- 
late flowers, which were covered with bags, it was found outside 
of the nectary. In one or two cases a half teaspoonful of sweet 
nectar might easily have been obtained. The pollen grains are 
very large and spiny. The flowers usually last only a day and 
open early in the morning. In this latitude, however, late in 
the season, after cold weather begins, they last more than one 
day. They usually begin to wilt and close before 12:00 m., but 
the day and the time of the year makes some difference. It is 
much later in the afternoon in September than in August. 
Insect Visitors — 
Hymenoptera — ApidaB: (1) Apis melUJica Linn.; (2) Borribus 
pennsylvanica DeGeer; Formicidae: (3) Formica rufa? Linn. 
Coleoptera — Chry somelid^ : (1) Diabrotica punctata Oliv., Z>. 
vittata Fab., (3) D. longicornis Say. 
Of these visitors the honey bee and the bumble bee are the 
chief -pollinators. The striped cucumber and other beetles 
may also effect pollination as they are often found covered with 
pollen. The red ants feed on the nectar contained in the flower. 
In addition the following insects were observed from the first 
of August to the first of October, 1894: 
Hymenoptera — Apidae: (1) Apis mellijica, Linn., frequent 
especially during the latter part of the season, when three or 
four were present in every flower, often the only visitors except 
the beetles, . (2) Bombus pennsylvanica DeGeer, ^ ; (3) Xenoglossa 
p)ruinosa Say, $ ; (4) Melissoclos bimaculata Si. Farg., 9 ^ , almost 
invariably present in the earlier part of the season, (5) Mclis- 
sodcs sp. 9 $ , , {V) Callioy)sis cmclreniformis Sm. 9 ; Andrenidm: (7) 
Andrena sp., 9 ; (8) Agpostcmon sp. ; (9) AngocMora pura Say, 9 ; 
(10) Halictus albipennis Rob., 9 , (11) H. tegularis Rob., 9 , {12) H. 
fasciatus Nyl., $ ; (13) Halictus ZejAiyrus sm.; (14) Xenoglossa sp., 
Cucurbita pejm, Linn. 
The different forms of this species have the general arrange- 
ment and structure as are found in G. niaxinia. Theodor of the 
large yellow flowers is not so pleasant as in that species, but 
