Shoshone journal. [volume] (Shoshone, Idaho) 1884-1931, 1896-04-24
OUR THIRD EYE.
Scientists Claim That We Have
an Extra Optic.
This Recently Discovered Organ Exists
Also in Vertebrates OF the Lower
Orders Where 1t is
Located.


Recent researches prove that mar
and all yertebrates seem TO possess the
rudiments Of a third eye. This discoy.
cry is not only very interesting, but
also remarkably instructive, since the
rudimentary third eye Of a man has, by
one of the most noted philosophers of
modern days, been looked upon as be-
ing the seat of the soul.
As organs by proper use develop in
strength and perfection, so they be-
come weak by lack of use. If for many
generations an organ should remain
without use, it's structure in time be-
comes simpler and more imperfect. If
such a process continues throughout
ages, an organ, by constant disuse, will
become reduced to a mere rudiment OF
what it was in the species using the
same. Thus, species of birds that only
walk and run, but never fly, have only
rudimentary wings, as the ostrich;
while in the eagle and the albatross
the wings are seen In a state of perfec-
ton.
Now, in closely examining the skulls
OF certain lizards, il was found that
near the top of head, under the dark,
opaque skin, and often in the very bone,
an almost perfect eye exists, although
no ray of light ever could reach it. This
eye shows IA crystalline lens, retina of
very complex structure and an optic
nerve; in fact, all the essential parts
of perfect eye. But being covered by
the opaque skin of the animal it is abb
sOlutely useless. If this optic nerve is
traced to the brain il is found TO con-
meet the eye with the so-called pineal
gland of the brain. This pineal gland
is, OF course, in no sense Of a word n
real gland, but n definite portion of the
nervous tissue of the brain, invariably
located just back and partly over the
cerebrum, and in front OF the rounded
brain-mass which generally is consid-
cred to correspond to the corpora
quadrigemina in man.
This third eye of the spotted lizard
is called the pineal 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 it is covered by
Opaque skin, and in others even deep
~ bedded in bone il would seem proba-
BILE that in an earlier stage Of develop
ment this pineal eye was not rudi-
mentary, but in constant use. A very
slight modification would accomplish
lhis-namely, the transparency of the
skin covering the eye. This is exact
y the condition of the normal eyes in
reptiles to-day; the skin covers them,
mt il is transparent where it passes
,vcr the eye. In the skulls of some of
he gigantic reptiles of the earlier age
# this globe, paleontologis have long
go found large round pcrforation.
'robably this was the socket of the
bird or pineal eye of the ichthyosau-
us, the plesiosaurus and the labyrin- r
hodon
But a much more important conclu-
ion must be drawn from this discov-
ry-namely, that in all vertebrates,
ven including man, the traces of this
bird eye remain to-day. The pineal
We of lizards being connected with the
rge pineal gland of the same. il
ould seem that the pineal gland itself
but the nerve center or optic thalmus
" this third eye. In all reptiles and
nphibia the pineal gland is large; so
IS also in fishes. In higher animals
e cerebrum develops very much. over
owing the more posterior portions of
e brain. BY this preponderance of
c nerve mass the pineal gland be-
mes covered by the cerebrum and as
mes more and more rudimentary
rms. But il remains with obstinate
1t is even always present
man-though here only of the size of
'ea and rudely resembling pine cone
shape. 1t seems also degenerated in -
'ucture, having hardly any nervous
sue. These facts OF form and struct-
have given rise to its name, that of
heal gland.-Popular Science Month