The Washington times., 1922-01-22
HAT does the world look like

VIZ HAT does the world look like
" to the butterfly?
Is II as full of various
colors as It Is to US. or 10 the butter
fly color blind? DIR. H. Eltringham.
the well.known Oxford entomologist.
discussed these questions in an ex,
tremely interesting interview with
the scientific correspondent Of the
London Daily News. -
He explained. first. the wonderful
composition. Of the buttsrfly's eye.
which as II cannot move like the
human eye, 10 provided with 5000
little lenses. each set at the end-of a
column of eight delicate nerves.
These lenses enableh to sea clearly
in 5000 slightly different directions
at once.
They transmit the images to the
nerves the right ray UP, mot inverted
as with the human eye,. and all the
little parts Of the picture are pieced
together into a correct representa-
ton Of the butterfly's surroundings.
sHORT-SIGHTED. -.
A knowledge Of what the butter
fly saw could only be obtained by
literally seeing the, world through q
butterfly's eyes. This was actually
done BY looking through delicate
section of an eye. with the help Of
microscope. BY similar methods 1t
was discovered that the insects wers
short-sighted. Beyond the range Of
about three and one-half feet away
their vision becomes more and more
blurred. -,
Questioned as to whether or not
butterflies are color blind. Mr.. Eltring-
ham described some ingenius expert
ments that he has made during the
last few years to discover whether
butterflies eyes are sensitive to the
differences Of wave length Of light
which our eyes, interpret to us a.
differences in color. People who are
color blind at all are usually red
blind. II they look at the rainbow
colors Of the spectrum obtained by
passing q beam Of white through a
prism. they cannot see the red end Of
the spectrum. and II they put on
spectacles that only let red light
through that Ia. red spectacies).
they cannot see any colors at all.
"RED.BLIND."
Hence. to discover whether but
terflies are color blind to red. DR..
Birmingham caught several speoi-
mems. and by covering the outer
horny surface Of their eyes with \
harmless Transparent red varnish.
he provided each with what was in
effect . tiny pair Of red spectacles.
He then liberated them. and soon
made some remarkable discoveries.
The white butterfly. known as
the cabbage white.i' fluttersd
about aimlessly. showing that 1t
was at least partly red-blind. DR..
Birmingham watched another type.
in this case ''tortoiseshell" but
terfly. which has much red color
ing on it's wings. It's red spec
tacles did not seem to worry 1t at
all, It flew quite normally. and evil
IDENTIFY was not blind to red.
Continuing his researches. he
carefully watched and noticed the
visits Of butterflies to q bed of
purple, pink and white asters. Al.
together during the observations,
some five hundred separate visits
were made to this bed by different
butterflies.
Other things being equal. in
sects select the most conspicuous
flowers. White as a conspicuous
color Is a failure owing to the
large amount OF white light re-
Elected by shiny leaves. DR.. Eli
bingham found, however. that the
great majority Of the butterflies.
mostly tortoise shells. selected the
purple flowers. which,, owing to
their color contrast with the pale
green background, are also tho
most conspicuous to the human
eye.
FLIRTING
A series Of photographs was
then taken Of the asters, cutting
out, by means Of light filters. vari.
Gus parts Of the spectrum. The
plates were thus rendered red
blind, green blind, blue blind, ETC.,
in turn.
On examining these photographs
It was found that in every one Of
i n II NYo /