Richmond planet. [volume] (Richmond, Va.) 1883-1938, 1897-04-17
ARGUS OUTPOINTED.
AN INSECT That IS CREDITED WITH
THlRTY-Six THOUSAND EYES.

Scientists Have Made Some Wonderful Dis
coveries IN This Line. but They Give the
Palm 20 tse Common Dragon F1y-In-
terestinx NaturaI History.
Thirty-six thousand eyes in one headi
This may appear a little like exaggera-
ton, but il is afact Science, backed by
the MICROSCOPE says so, and science
never stretches The truth. Should it do
so it would cease to be a science.
Argus was tabled TO have hundred
eyes, but Argus would be a very insig-
nificant curiosity compared with the
latest discovery in the insect kingdom.
There are numbers Of insects with 100
and even 500 eyes, but when the num-
Der of optics allotted to single insect
reaches up into tho 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 Is, 600 separate lenses, each eye
let having a distinct nerve connecting
| it with the brain ard acting entirely
independently Of it's myriads of COM
panions.
The theory most generally adopted
by scientists is that, while far superior
to the eye cf higher animal life as re-
CARDS moving objects, the power Of OBJ
servation Ct the composite eye is inferior
in its application 10 stationary things.
The reason is this: The moving object
is first observed by enc of the thousands
of facets, which reTcoives it for the in
fini;esimal part Of n second that il takes
to ret cut cf the arc CT 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 o.
a insect sees as many images of the objects
4 as he has eyes, or facets. For instance
!, does the dragon fly fancy he is fitting
2 over sc, 600 ponds. or does he see onl,
4 one? Probably one, for the two eyes o
a human being in normal condition show
- but a single image. Besides, apart from
y the lenses and cones in front, the eye i
: hollow sphere pierced by perforation
/, running down the facets toward tn
center. 1t follows that the light impres
; sions thus form single picture, or me
n sale, as il were, each facet presenting
h slightly different picture from its neigh
"A Dor and the group presenting a perfeC
"A whole.
II There are many other animals POI
20 sessed of an extraordinary number {
~ eyes James Francis Stevens, a note
- entomologist, is said to have recorde
Z 2, 900 such species In his garden in OF
afternoon, while Francis Pascoe, anou
er noted naturalist, counted 80 differel
s. specimens ON his library window
bo The common scallop, for instance, hi
Y many eyes scattered irregularly over i
es body. The lobster has masscd togeth
av in each orb more than a hundred di
nv tinct eyes, aud, unlike human eye
these are set forward, instead of beil
at things hundredfold? If so, possibly
he is in avoiding the 90 imaginary lobst
Use pots that he stumbles into the real on
X. The common house fly has 1900 eye
-as the cabbage butterfly II. 600, the dro
fly 5000, the honeybee $500. But st
at the head OF the list stands the mC
Int quito hawk, or dragon fly, with
" SO, 600. As his name suggests, VIII
not despising any of the smaller insec
his speciality is the mosquito Indeed
he has so succeeded In terrorizing these
& I tie pests that his lifeless form still fl
them with alarm. In localities wh'
mosquitoes are troublesome an effectI
mode of Kidding the place of them CT
tb sists in suspending a dead dragon
rs from the ceiling by a piece of thre;
er Those who have tried it say that it
tn never been known 10 fail
9S Up to a certain point these mul
,ls tudinous eyes may be compared TO w
dows fitted with innumerable panes
list glass. The panes, however, are OF
10 ferent forms Some, like those of
the bee and the ant, are six sided, remit
: IN ing us of the pattern so common
in Gothic architecture. Some, again,
nse diamond shaped and others square.
nc Another interesting branch Of this
mo- teresting SUBJECTS the study of the u
ons and far sighted insects. Johanna M
ces Ter long ago pointed out that the fiji
rich of insects depends upon their powe'
vision. This will account for the diff
ence in the flights of the common he
fly and the wasp. The one confines b
had self to shert flights. As his food is
ways to be found within a small a
he flies in short curves and circles
the wasp is remarkably sharp sigh
and the arrangement of the lenses sh
that his line of vision is decidedly
ward. Here, again, the dragon fly is
land eminent. He has well been called
tyrant of the air. He alone is abb
tn take perfectly straight lines at enorn
than speed for long distances, evidently
v it ing we'll what is ahead of him.