The Washington times., 1923-05-12
INSECTS
SEE VIOLET
RAYS
Are Not Attracted by Perfumes
as Was Formerly Believed,
Professor Says.
copYRIoHT by HARRIS 4 EWING
BY ELSIE MCCORMICK.
Cosmopolitan News Service.


NEW YORK, May 12.-That sun
flowers are. ultraviolet as well as
yellow, that insects see colors in
visible to human eyes, and that
ultraviolet rays rather than odor
may be the attraction between bees
and flowers are some of the con-
illusions today resulting from ex.
periments of DIR. Frank e. LutZ,
entomologist of the American Mu-
scum of Natural History. The
fact that a large number of flowers
give off ultraviolet rays was
proved both by the delicate tests
of physics and by actual photog-
raphy, a camera with quartz lens
being used in the experiments.
There are more colors in the
universe than human beings are
able to see," said DIR. Lutz. Be-
hind each end of the visible spec
trum there are vibrations OF the
same general nature as those which
give us the sensations of colors.
Those beyond the red end we call
heat waves because they give us
the sensation of heat. Those at
the other extreme of the spectrum
are called ultra violet or chemical
waves, because they are beyond the
violet and they actively bring about
changes in certain chemicals such
as are used in Photographic plates.
That some insects are able to see
ultra violet was indicated in an ex-
pertinent made by DR.. Lutz and
Prof. F. K. Richtmyer, of Cornell
University, during which red-eyed
fruit flies, swarmed straight across
dark room toward ultra violet
light invisible to human beings.
Some time previously, Sir John
Lubbock had proved that ants were
also susceptible to ultra violet. In
his next set of experiments DIR.
Lutz intends to test the color per-
ceptions Of bees in regard to colorS
at the far ends of the spectrum.
"In our tests with flowers, we
discovered that some we've strong.
ly ultra violet all over their petals,
some were patterned with ultra
violet, and others were not ultra
violet at ALL" DR.. LutZ explained.
1.-The strange part Of it was that
those strongest in ultra violet rays
were neither" blue nor purple; they
were violently yellow. Thus the
golden glow, the wild sun flower
the most decided reactions, while
the blue larkspur and the white
poppy gave almost no reaction at
all
Another point is that flowers
which are all of one color, to the
human eye. some times prove to be
patterned when photographed with
a quartz lens. The petals OF the
sunflower are decidedly marked
I'm this way, the reason being that
they are more strongly ultra violet
at the tips than at the base. Be-
cause Of the effect of the rays on
a Photographic plate, the tips ap.
pear much lighter in a picture and
| the pattern is quite distinct. The
quartz lens is used because ordi-
nary glass Is opaque to ultra violet. "
In an endeavor to discover wheth.
er insects were attracted to flowers
primarily by odor, Dr. Lutz Sc.
cured samples of several hundred
chemicals used in the manufacture
Of perfume, mixed them with lard,
placed them in glass dishes and set
| them in a garden.
Bees, butterflies and other IN,
scots were all about, but although
I watched day after day until my
ewes ached, not a flower-visiting in.
sect came near the Dishes" said
DIR. LutZ
probably the insects were no
more fond of chemical perfumes
than the average man is.
take the kids off the streets" at
any price.
The association has a membership
of more than three hundred resi-
dents. It's officers are Thomas ].
Donovan, president; Charles Fahy,
vice.president; w. J. Hollohan, sec
ond vice-president; John Mcmahon.
secretary, and HI. G. Reinhardt.