The Anaconda standard., 1895-11-02
WE HAVE THREE EYES.
Science Declares That Man and Other An
imals Have Rudimentary Third Optic. e


From the Popular Science Monthly.
Recent researches prove that man
and all vertebrates seem to possess the
rudiments of a third eye. This dfscov-
cry is not only very interesting, but
also remarkably instructive, since the
rudimentary third eye of man has, by
one OF the most noted philosophers of
modern DAYS. been looked upon as be-
ing the seat of the soul. a.
AS organs by proper use develop dn
strength and perfection, so they be-
come weak by lack of use. If for many
generations an organ should remain
without use. its structure in time be-
comes simpler and more IMPERFECT If
such process continues throughout
ages, an organ, by constant disuse
will become reduced to a mere rudi-
ment of what 1t was in the species
using the same. Thus, species of birds
that only walk and run, but never fly
have only rudimenuary wings, as the
ostrich; while in the eagle and the al
batross the wings are seen in a state
of perfection.
Now, In closely examining the skulls
of certain lizards, Ii was found that
near the top Of the head. under the
dark, Opaque skin. and often in the
very bone, an almost perfect eye ex-
lists, although no ray of light ever
could reach it. This eye shows a crys-
talne lens. a retina of very complex
structure and an optic nerve; in fact,
all the essential parts of a perfect eye
But being covered by the opaque skin
of the animal 1t is absolutely useless
If this optic nerve is traced to the
brain Ii is found to connect the eve
with the so-called pineal gland of the
brain. This pineal gland is. of course,
in no sense of "a word a real gland, but
a definite portion of the nervous tis-
sue of The brain. Invariably located
just back and partly over the cere-
brum, and in front of the rounded
brain-mass which generally is consid-
cred to correspond to the corpora quad
rigemina in a man.
This third eye of the spotted lizard
is called the pineial eye, on account of
the nerve connection of the retina with
the pineal gland. Now. while in GER
tain lizards this highly developed eye
Is useless because II is covered by
opaque skin. and in others even deeply
bedded in bone. 1t would seem probab BILE
that in an earlier stage OF development
this pineal eve was not rudimentary
but In constant use. A very slight
modification would accomplish this;
namely, the transparency of the skin
covering the eye. This is exactly the
condition of the normal eyes in rep
tiles to-day: the skin covers them, but
IL is transparent where IL passes over
the eye. In the skulls OF some of the
gigantic reptiles of the earlier age of
this globe. paleontologists have long
ago found a large round perforation.
Probably this was the socket of the
third or pineal eve of the ichthyosau-
rus. the plesiosaurus and the labyrin-
uhodon.
But a much more important conclu-
sion must be drawn from this discov-
cry; namely. that in all vertebrates,
even including man. the traces of this
third eye remain to-day. The plneal
eye Of lizards being connected with the
large pineal gland of the same, 1t
would seem that the pineal gland it,
self Is but The nerve center or optic
thalmus for this third eye. In all rep
tiles and amphibia the pineal gland is
large; 80 II is also in fishes. In higher
animals the cerebrum develops very
much. overgrowlng the more poster!or
portions of the brain. BY this prepon-
derance Of the nerve mass the pineal
gland becomes covered by the ceTe-
brum and assumes more and more ru-
dimentary forms. But II remains with
obstinate perdnacity. IL is even al
ways present in man-Uhough here
only Of the size Of a pea and rudely
resembling a pine cone in shape. 1t
seems also degenerated in structure.
having hardly any nervous tissue
These facts OF form and structure have
given rise TO its name. that of pdneal
gland.
The Cause of Idiocy.