Alexandria gazette. [volume] (Alexandria, D.C.) 1834-1974, 1883-03-13
WONDERS OF THE EYE.

The eye-the organ OF sight, more valu-
able to us than we can possible Thinks
placed just where it is neened for USE
The snail in his shell, not wishing to como
out till he is able to see what harm may be-
fall him, has an eye on each of his two horns
SO that he can thrust those out and see il
the is any danger, before he exposes his
| body.
| Those animals that crawl on the ground
| having no special need of looking down,
but up anG on the level, have theirs near the
top Of the head; while birds that fly high in
the eye, feeding on what they may see and
capture below, not only have the eye lower
on the head, but have it like the telescope,
| SO moving one part Of it that they can see
objects at a great distance, or very near.
Birds that live on fish, in part, being obliged
to go under the water for them, have a thin
covering that they draw er-like rubber
coat-to keep the water out of the eye
The horse, also, has similar one TO clean
| his eye when dust gets into it, rubbing it so
quickly over it that you cannot easily see
the motion. t5,
The fishes in the Mammoth Cave, which is
perfectly dark, have no eyes, simply because
they have no use for them.
The eel, spending his winters in the mud
often boring his way far under the grassy
marshes, has q horn-lille covering for the
eye, through which he can see, as we do
through glass, this protecting the eye from
being scratched by the gravel
The spider has from eight to fourteen eyes,
not on the head, but on the forward part of
the back, perhaps that he may the better
see all parts Of his web which he so skill
fully makes rather ornamental, wonderfully
constructed, each thread Of which is some
times made Of four thousand smaller ones.
put together like ourropes, the principal use
CT which is to entrap flies and other small
! creatures, Oh which he lives
The lobster and the crab have their eyes
at the end Of small tubes, which they can
move in various directions, or make longer
or shorter as they may find il convenient.
The stariish has five eyes at the ends Of
the points Of the star, which give very good
sight. The body is composed mainly of
Jelly. thick at the centre, and is fiat like a
pancake when at rest, but is moved slowly
by bringing the edges together, making a
| kind OF cup which moves the body along
as the water is pressed out If this sngu
lar creature had only two eyes, in one
] place he could not see all around.as his ielly-
body is too thick. When he grows old, this
jelly is wasted away leaving the star plain
ly 10 he seen.
Some ofthc lower orders Of creation arc not
satisfied with two eyes only, but have them
by the thousands. What seems to be an
eye, on each side Of the head of the fly. very
large, is II compound eye having four thou
sand facets or eyes, each ono of which is
perfect eye, but not movable like ours
This is like pepperboN, the small eyes
corresponding with the holes in the cover
The fly has also three in the front Of the
head. in all making 5000 eyes Just for one
small creature, But there are other Great
urca still richer in sight. The holse-nv has
5000. the butterfly $1,000, the dragon fly,
$4,000, the beetle, 10O00! 1t is not strange
; therefore. that il is not easy to approach
any Of these creatures without being seen,
since every one Of these eyes is pointing in
a different direction like Il pistol Ifthese
creatures were compelled 10 wear gold
bowed glasses for each eye what an enor-
nous sum of money it would take to buy
the supply .-lo"ih'S Home Library.