, 1900-01-13

AoV tIultS It's uldultlCE lHdl Is ~ say
if it is a white ball a foot in diameter,
it can be perceived at a distance of H.
$50 feet.
The eye of the blind-fish in the NAM
moth Cave is a r eye, having all the
parts. 1t is, however, covered by a
membrane, and it is probable that the
fish receive no more han Il mere i'm
preston of light.
The ostrich is believed to see objects
behind him as well as those in front.
Persons standing directly behind an
ostrich can see the pupils of his eyes,
and, of course, ale tnus easily seen by
the animal.
Bach became blind through a weak
ness of the eyes contracted when a boy.
lie copied a musical manuscript by
moonlight and thus caused a weakness
which troubled him all his life, and n
nally destroyed his sight.
A glass eye may, it is said, be used
only six to twelve months. The hui
mors of the eye corrode the glass, and
cause it to become rough, thus irritaL-
ing the delicate membrane and neces-
stating a renewal of the false optic.
The adjustment of the eye to exam
inc objects at different distances is eff
fected by Il difference in the arrange
ment of the crystalline lens, which be-
F,p,a- ,1u -. loco. ,,n,rnx ,n.,rIfnp
as the object is near at hand or far
away.
The owls eyes have no muscles by
which they can be moved. This de-
~iciency is atoned for by extraordinary
leXibility in the muscles of the neck,
by which the owl can move his head
with incredible rapidly in any direc-
ton.
A deer's eyes command a wide field
of vision, and the animal can see be-
hind as well as before, though not so
distinctly, for when alarmed by a noise
from the ear the deer will always
turn so as to gain a clearer view of the
object.
A mole's eyes are believed to give
the animal nothing more than IN i'm
preston of light, which is probably
painful or at least %annoving. the SEN
sation prompting the creature at once
to burrow into the earth and escape
the annoyance.
The eve of the cat. like that of the
horse. is provided with a false evelid.
which NAV be moved in~dependeptlv of
the outer or true lid If is often EN-
ployed by a cat when Obliged to face a
very bright light. and is believed to
act as a shade.
Oysters are proyided with ewes hui
the ovsters' eva Is NOT located where
nuhlic o~ninion nIaces if What is call
ed the eve of the OYSTER is the great
muscle which holds the shells togeth-
er, and which is separated by the knife
of the opener.
Tho contraction o,d diIo-ior ~ tho
nu,;l Of tbe owe 10 ono y, tho most
yordorfr1 ororotiors If nature II 10
offocted automatically ord rncor-
~sciously. by a series of muscles, which
contract or expand the opening in the
center of the iris.
The bioeronbers of Nanoieon differ
as IN the color of his ewes Ono saws
they were b,ue another declares them
to have heen gray II is nossib,o that
they were of that steely blue sometimes
found in the eyes of persons of cold,
calculating temperament.
Tho nunil of tho eve ;s circular in
man. but in rats and some other ami
mails If is oblong Tho nunil of man
in n very bright Iiqht will show on1v
a small round snot. whiIo Tho ave of ,
cat under the same conditions will ex-
hibit a vertical slit or line of black.
The eveball rests in n cushion of fat
nv which II is surrounded on every
side, When the system becomes great
" emaciated through disease. this fat
is absorbed and the eve sinks further
into the head Tins giving the sunken
appearance SO common IN disease.
Many insects in their perfect state
are provided with compound eyes; that
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