Virginia citizen. (Irvington, Va.) 1891-1921, 1905-11-24
SENSE ORGANS IN PLANTS.
Isghs PerceivinE Leaves That Have
Eyes and Eyel.xha.

ESeNAnS Leaves That Have
Eyes and Eyelssbes. fE
Dr. G. Haberlandt, professor OF bot
any In the University OF Gratz. ceIe-
DRAFTED for his revelations on the sense
organs In plants, is their champion
who tells the world that, having eyes,
they see.
The first question for DIR. Haberlandt
to solve was what part OF the leaf was
sensitive to light. BY covering the
leaf with black paper he shows that
the principal and most delicate sensI-
uveness resides in the blade. although
a coarser and secondary sensitiveness
TO the incident light Is found in the
stalk
This meant that the blade OF the leaf
must contain the eyes, il eyes there be.
Anything corresponding TO an organ
for sight, he reasoned, would be on
the surface So he looked for the
oceili, as he terms the light percelving
organs or plants, i'm the epidermis COW
ering the upper surface OF the leaf.
1t can also be seen, as the botap-
tcal oculist discovered, that the rela-
ton OF the spot of light to the sur
rounding part, which is more or less
dark, changes when the light falls
obliquely. SO when n leaf is illumipat-
ed obliQuely he considers that It IL
) stimulated to curve by the fact that
the spots of light are not central in the
cells. and the curying ceases when the
brightest illumination is once more i'm
the center. So the plasmic membrane
OF this inner wall of each cell i'm the
ep1dermis becomes the retina OF the
eye Or in seientifc) phrase, has 4
quasi retinal function by which the
lear is believed 20 orientate itseif I'm re-
gard to light" aI-q -
Proceeding, DIR. Haberlandt exam
lned the eye and found that It was
good, well fitted to concentrate light. II
Is commonly lenslike in form, the outer
wall being convex, the inner wall el-
Their plain or curved. -rr- a -.--,--.
Plants have not only eyes. but eve
hshes. The tropaeolum. the handsome
cousin OF the fiorid fuchsia, is one of
the proud plants that can vaunt them.
serves on the luxurious comeliness of
me iashes. The leaves OF this plant nre
mwettabie, and when immersed re-
main coated with a silvery mantle Of
air. The waxy layer which gives This
quaIlty may be removed by painting
tne surface with diluted alcohol with
out injury TO the leaves. The result of
immersion is that normal leaves. pro-
tected by layer of air, react normal
~ to oblique misunderstanding Is.
they see. whereas the wettabie len Yes,
whose waxy bloom has been rennoyed
nave lost their eyesight, their power or
reacting, says the Chicago Tribune. III
IN all DIR. Haberlandt's experiments
he always has found his ocelli (eyes) ON
the upper and not the lower surface Of
leaves. And he also found them tend
ing to occur especially near the edges
OF leaves just in those regions where
the amount OF movement correspond
ing to curvature through given angle
IN greatest.
The position OF the eyes is in the
most advantageous position possible
Tor the eyes to receive the rays of the
sun and yet be shielded from exposure
The eyelashes drocp directly over fine
eye itself when showers come. and the
lear turns slightly SO that the eyelasbes
form a perfect protection. Also, IL the
lear is exposed to too great heat from
the sun the lashes droop again, shad-
ing them.
Inc eyes or leaves vary greatly. ac-
cording to the professor, in different
plants and trees. and he believes the
sense OF sight much more highly deyel-
oped In the rapid growing and tropical
plants than In others.-New York
World