232 BOTANICAL GAZETTE [ann 
In the other group the conspicuousness of the inflorescence _ 
depends upon the individual flowers, whose petals are white and — 
widely expanded. The nectar is therefore freely exposed. 
The flowers are homogamous. In C. sanguinea Miiller (4, 8) 
observed that insects may effect cross or self-pollination, and is 
their absence that spontaneous self-pollination or geitonogamy 
may occur. 
Sprengel (1) observed that C. sanguinea was visited by® 
variety of insects. Miiller’s list shows fourteen beetles, five 4 
flies and one Pompilus. Delpino (3) includes this species in his 
“Tipo idrangeino,” which he regards as adapted to beetles. 1 
Cornus FLORIDA L,— Kerner (13) supposes that the bracts 
serve as attractive organs and as landing places for insects. But : 
insects visiting the flowers seldom alight on them. He also 
mentions what he calls “arrangements for geitonogamy, vee 
seem to me to be quite imaginary. 
This small tree occurs in only one place in my neighbor 
hood. A dozen or more flowers are collected in a head. bed ; 
four scales of the hibernaculum, which encloses the developing a 
head, greatly elongate and expand at base, at the wes 
assuming a white or pinkish color. Very frequently io 
inner scales remain united, so that by their basal’ expansion ' o 
form an arch over the head. These parts are often i ce 
inwards in the middle, with the result that the piers 
more conspicuous laterally than would be the case if al : 
scales were expanded horizontally. civs tube 
Nectar is secreted by an epigynous disk. ihe ‘i cous 
is about 1™™ deep. This with the four petals and ee 
has the effect of concealing the nectar in a tube abel — 
The petals are greenish yellow, their tips ies ‘strong 
the flower expanding about 4™™". The stamens ae rte 
divergent and are exserted about 4™™, the sty le p roe oe 
more than 1™™, : ae 
The flowers are homogamous. _ Insects crawlin pas wi 
the inflorescence get their heads and undersioe “tn th 
pollen. On sucking they easily effect pollinatio™ Ss 
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