Rock Island Argus., 1898-05-28
CAAHY INSECT WORKERS.
They Fertilize Flowers For Strictly Utni-
tartan Reasons.


They Fsrtilize Flowers For Strictly Utfli-
tartan Reasons.
A correspondent writes: 1.-The theory
Of the origin Of flowers by the selection
of insects is one which has attracted
much attention both in scientific cir
cles and from the general public. Set
forth by Darwin in the Origin of Spe-
cies, it has been largely developed in
series of interesting publications by Sir
John Lubbock and Mr.. Grant Allen.
Some fresh and interesting light has
now been thrown ON it by series Of
experiments recently carried ont by
Professor Plateau of the University Of
Ghent. Professor Plateau has arrived at
the conclusion that insects are indiffer-
ent to the colors Of the flowers they
visit, and that they are guided to them
in very subordinate way by sight.
The experiments ON which the Belgian
professor bases his farreaching conclu-
sions are briefly these: Having covered
the brightly cOlored flowers Of single
dahlias in his garden with bits Of green
leaf, he found that they were still visit
ed by insects. This seemed so much ut
variance with the generally received
view that insects are attracted to flow
ers chiefly by their color that Professor
Plateau instituted a prolonged series of
experiments and observations to put the
matter still further to the proof. The
result has been to confirm and strength
en- the conclusions drawn from the first
experiments. Cutting off the brightly
coiored corollas of such flowers as To-
bella, evening primrose, foxglove, etc.,
he found the remaining green parts
were still visited. Again there are some
brightly colored flowers which are sell
dom or never visited by insects owing
to their lack of honey. Notable among
these is the scarlet geranium Of our gar.
den. But when "a little honey was placed
on geranium flowers bees came to them
at once. those blossoms which had not
received honey being passed over.
"Other conspicuous flowers We're tried
in similar way with like results. The
experiment of removing the honey bear.
ing parts of a flower and leaving the
brightly cnlored part, which was sup.
posed to be attractive, was also tried
with the single dahlia. Its inner fiorets
were removed, leaving the conspicuous
outer ones, a piece of yellow leaf being
placed in the center. No insects went
TO these honeyless flowers. But as soon
rs drop of nectar was placed OH them
they visited them as freely as before
Again, Professor Plateau made artificial
flowers with pieces of green leaf, each
furnished with little honey. These
were freely visited by insects. But arti-
fetal flowers made Of colcred material
were neglected, even when supplied
with honey.
I'm further support of his views Pro-
fessor Plateau is able to bring forward
the following facts as to the habits of
insects in visiting flowers: They will
pass freely and with apparent indiffer-
ence from one color to another of va
rieties of the same species growing to-
gether i'll our gardens; they visit great
number of green and greenish cOlored
| flowers; there are many small and in
conspicuous flowers which are also free
ly visited. Such is q brief outline of
Professor Plateau S observations and ex-
periments, from which he believes him
self justified in drawing the conclusion
that sight plays very subordinate part
i'll attracting insects to flowers. Their
bearing Oh the theory of the insect origin
| OF flowers Is obvious. London Times.