Marshall County independent. (Plymouth, Marshall County, Ind.) 1897-1902, 1898-04-08

Thirty-six thousand eyes in one headi
This may appear little like exaggera-
ton, but it is a fact Science, backed by
the microscope, says so, and science
never stretches the truth. Should 1t do
So 1t would cease to be science.
Argus was tabled to have hundred
eyes, but Argus would be very insig
nifcant curiosity compared with the
latest discovery in the insect kingdom.
There are numbers of insects with 100
and even 800 eyes, but when the num-
Der of optics allotted to single insect
reaches up into the thousands the idea
is startling.
Naturalists have recently been engag-
ed in the study of this most interesting
subject Each succeeding day brings
more marvellous results until the as
founding discovery has been made that
the common dragon fly, or mosquito
hawk, while seemingly possessed Of
only two visual organs, really has as
many as sc, 600, each of the two visible
TO the ordinary observer being subdivid-
ed into $4,000 separate lenses, each eye
let having a distinct nerve connecting
it with tie brain and acting entirely
independently of its myriads OF COM
panions.
The theory most generally adopted
by scientists is that, while far superior
to the eye of higher animal life as re-
CARDS moving objects, the power of OBJ
servation of the composite eye is inferior
in its application to stationary things.
The reason is this: The moving object
is first observed by one of the thousands
of facets, which perceives it for the in
fnitesimal part of a second that 1T takes
to get out of the arc OF vision of that
particular lens and pass into that of an
other, each movement being separately
telegraphed to the brain by the facet on
duty But with a stationary object 1t is
different since for some reason the
minor organ fails to focus accurately.
and so render the object less distinct
than when viewed by eyes of only one
lens each
A question which continues to puzzle
the scientists is whether the animal or
insect sees as many images of the objects
as he has eyes, or facets. For instance.
does the dragon fly fancy he is fitting
over 81, 600 ponds, or does he see only
one? Probably one, for the two eyes OF
human being in normal condition show
but single image. Besides, apart from
che lenses and cones in front, the eye is
a hollow sphere pierced by perforations
cumming down the facets toward the
center 1t follows that the light impress
sions thus form single picture, or mo-
sale, as it We're, each facet presenting a
slightly different picture from its neigh
Dor and the group presenting perfect
whole
There are many other animals pos
sessed of an extraordinary number OF
eyes James Francis Stevens, noted
entomologist, is said to have recorded
1000 such species in his garden in one
afternoon, while Francis Pascoe, anoth-
er noted naturalist, counted so different
specimens on his library window.
The common scallop, for instance, has
many eyes scattered irregularly over its
body The lobster has massed together
in each orb more than hundred dis.
tinct eyes, and, unlike human eyes,
these are set forward, instead Of being
sunk inward Does the poor lobster see
things hundredfold? If so, possibly il
is in avoiding the SO imaginary lobster
pots that he stumbles into the real one,
The common house fly has 1000 eyes
the cabbage butterfly 1900, the dront
fly 5000, the honeybee $500. But still
at the head of the list stands the mos
quito hawk, or dragon fly, with hi!
SO, 900. As his name suggests, while
not despising any of the smaller insects
his specially is the mosquito. Indeed hi
has so succeeded in terrorizing these lit
tie pests that his lifeless form still fill
them with alarm. In localities wher
mosquitoes are troublesome an effectua
mode of Kidding the place Of them con
sists in suspending dead dragon d
from the ceiling by piece of thread
Those who have tried 1t say that it ha
never been known to fail.
Up to a certain point these multi
tudinous eyes may be compared to win
dows fitted with innumerable panes o
glass. The panes, however, are of diff
ferent forms. Some, like those of tn
bee and the ant, are six sided, remind
ing US of the pattern so common i
Gothic archi lecture. Some, again, al
diamond SHAPED and others square.
Another liz Geresting branch of this in
teresting subject is the study of the nea
and far sighted insects. Johanna Mul
Ter long ago pointed out that the fiigh
of insects depends upon their power {
vision. This will account for the differ
ence in the flights of the common hous
fly and the wasp. The one confines hin
self to short flights. AS his food is a
ways to be found within small area
he flies in short curves and circles Br
the wasp is remarkably sharp sighted
and the arrangement of the lenses show
that his line of vision is decidedly fo
ward Here, again, the dragon f1y is pr
eminent. He has well been called I'll
tyrant Of the air. He alone is able
take perfectly straight lines at enormol
speed for long distances, evidently Sc
ing well what is ahead of him.
Orleans Times Democrat.