1899] FLOWERS AND INSECTS 43 
other group of native plants, and that, too, in spite of their 
dichogamy. If the flowers were greatly scattered, they no doubt 
would not attract so many bees, and the bees could carry off the 
pollen and not render any service by visiting the flowers after 
the stigmas appeared. But, as a result of the reduction of the 
flowers in size and the crowding of them in heads, we find a 
circle of flowers, each one of which ejects the, contents of five 
anthers in a convenient mass. Just without is a circle of flowers | 
with protruding stigmas. Bees sweep over the disk, filling their 
pollen-scope with the greatest facility, at the same time effec- 
tually pollinating the neighboring stigmas. 
As the homogamous flowers have largely been given over as 
adaptations to autogamy, so the crowded inflorescences have 
been given over as adaptations to geitonogamy. As a category 
Ido not accept Kerner’s geitonogamy. Kerner regards most of 
the crowded inflorescences as adaptations for geitonogamy, and 
founds a special category for their reception. This is accepted 
by Knuth and is incorporated in his recent Handbuch.” I do 
not believe in any adaptations for geitonogamy. I do not deny 
that it occurs, and under pseudo-ecological conditions may be 
advantageous, but it is only the name of an accident and does 
ahi account for any floral adaptations. Kerner does not makea 
distinction between a structure, or habit, which has a certain 
effect, and one which may be conceived to be developed for a 
certain purpose, or selected on a certain condition. He even 
Speaks of a “contrivance for securing hybridization.” Under 
“contrivances whereby the pollen is protected against wet” he 
Says: “In Podophyllum peltatum the pollen is sheltered by the 
bell-shaped flower, but in addition to this the peltate foliage- 
tes a also Spread out over the flowers and act as umbrellas.” 
ee ~ Category of protection by isolation in “_— he 
Avene a number of ordinary water plants and says: ‘Flies 
se pete which come through the air for honey and pollen 
valida cad Wetors, promoting, as they do, a crossing of the 
> Snails, centipedes, etc., are, on the other hand, kept 
7 Handbuch der Bliitenbiologie 1:51. 
