The copper country evening news. [volume] (Calumet, Mich.) 18??-1907, 1897-04-12
ARGUS OUTPOINTED.
AN INSECT THAT is CREDITED WITH
THIRTY-Slx THOUSAND EYES.
Scientists Rave Made Some Wonderful Dis
coveries In This Line. but They Give tho
Palm tn the Common Dragon Fiy-In-
teresting Natural History.

|
Palm to the Common Dragon Fiy-In-
teresting Natural History.
Thirty-six thousand eyes in one head!
This may appear "a little like exaggera
ton, but il is fact Science, backed by
the microscope, says so, and science
never stretches the truth. Should il do
so il would cease TO be a science.
Argus was tabled 10 have hundred
ryes, but Argus would be very insig-
nificant curiosity compared with the
latest discovery IN the insect kingdom.
There aIe numbers of insects with 100
and even 80 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
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 rs
many as 36, 900, each of the two visible
to the ordinary observer being subdivid-
ed into IS, 600 separate lenses, each eye
let having distinct nerve connecting
it with the brain and acting entirely
independently of its myriads of COM
| panions.
The theory most generally adopted
by scientists is that, while far superior
20 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
finitesimal part of "a second that it 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 it 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 SO, 600 ponds, or does he see only
one? Probably one, fer the two eyes of
human being in normal condition show
but single image. Besides, apart from
the lenses and cones in front, the eye is
hollow sphere pierced by perforations
running down the facets toward the
center. 1t follows that the light impress
sions thus form single picture, or mo-
sale, as il were, each facet presenting
slightly different picture from its neigh
Dor and the group presenting perfect
whole.
There are mahy 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 ore
afternoon, while Francis Pascoe, anoth-
er noted naturalist, counted so different
specimens ON his library window.
The common scallop, for instance, has
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 it
is in avoiding the 80 imaginary lobster
pots that he stumbles into the real one.
The common house fly has 1000 eyes,
the cabbage butterfly II, 200, the drone
fly 5000, the honeybee $500. But still
at the head of the list stands the mos
quito hawk, or dragon fly, with his
&c. AS his name suggests, while
not despising any of the smaller insects,
his specially is the mosquito. Indeed he
has so succeeded in terrorizing these lit
tie pests that his lifeless form still fills
them with alarm. In localities where
mosquitoes are troublesome an effectual
mode of Kidding the place of them con-
sists in suspending dead dragon fly
from the ceiling by piece of thread.
Those who have tried it say that it has
never been known to fail.
Up to a certain point these multi
tudinous eyes may be compared to win
dows fitted with innumerable panes of
glass The panes, however, are Of diff
ferent forms. Some, like those Of the
bee and the ant, are six sided, remind
ing us of the pattern so common in
Gothic architecture. Some, again, are
diamond shaped and others square.
Another interesting branch of this in
teresting subject is the study of the near
and far sighted insects. Johanna Null
Ter long ago pointed out that the flight
of insects depends upon their power of
vision. This will account for the differ
cncc in the flights of the common house
fly and the wasp. The one confines him
self to short flights. AS his food is al
ways to be found within small area,
he flies in short curves and circles But
the wasp is remarkably sharp sighted,
and the arrangement of the lenses shows
that his line of vision is decidedly for
ward. Here, again, the dragon fly is pre-
eminent. He has well been called the
tyrant of the air. He alone is able to
take perfectly straight lines at enormous