1923] 
Flower Visits of Insects 
165 
Muller (4,55) says: ^^More than nine-tenths of the flowers 
visited by bees with abdominal brushes are such as are adapted 
to dust the ventral surface of the bee with pollen {Echiiim, Pap- 
ilionacese, Compositse, etc.) without any action of the tarsal 
brushes. More rarely, bees with abdominal brushes may be 
seen feeding on flowers whose pollen gets applied to their backs; 
in such cases the bee makes use of its tarsal brushes to sweep 
off the pollen from the parts where it has fallen into the abdo- 
minal brushes.” Considering the composition of the flora 
Muller’s statement shows about what these bees would be 
expected to do without preference. Of 243 local flowers visited 
for pollen by long-tongued bees in general, only 11.1 per cent 
require the use of the tarsal brushes. Of 146 visited for pollen 
by the Dasygastrse, 5.2 per cent require the use of the tarsal 
brushes. It is not easy to separate such flowers, because the 
Dasygastrse often reverse on nototribe flowers so as to receive 
the pollen on their undersides, as in the case of Linaria vulgaris, 
Pentstenion, Impatiens and Pinguicula. They also reverse on 
some species of Gerardia and Viola, but these flowers compel 
them to turn head downwards. On tubular flowers with included 
anthers they collect the pollen which adheres to their tongues, 
Lithosper7num canescens. Verbena stricta. 
Compared with other groups the Dasygastrse show a 
marked predilection for sternotiibe flowers, 47.5 per cent of thei 
pollen visits. They do not equal the Euceridse in their prefer- 
erence for Compositse or antipathy to nototribe flowers. 
Muller (4,55) further says: “There can be little doubt 
therefore that the bees with abdominal brushes have adapted 
themselves to the flowers which were fitted to dust their ventral 
surfaces (Papilionacese, Compositse, Echium, etc.), and the con- 
trary view, that these flowers have become adapted to the bees, 
is untenable, for the flowers are visited and fertilized by other 
and far more numerous insects.” The Dasygastrse and Papi- 
lionacese have July maxima. There are several sternotribe 
flowers of which these bees are the most important and almost 
exclusive visitors. 
Panurgidce.. — Of 141 visits to 84 flowers, 44.6 per cent are 
to Mas, 31.9 to Mis, 50.3 to yellow and 60.2 to Compositse. 
