Eagle River review. [volume] (Eagle River, Wis.) 1890-1927, 1891-11-12
LIVING WITHOUT EYES.
Creatures of the Caverns That Have No
Organs of Vision.


Organs of Vision.
There are many animals in the
world which pass all their lives in
darkness, never seeing a ray OF light.
Every one has heard Of the blind
fishes in the Mammoth Cave. This
cave is the biggest of 500 great cav
ems in the United States. All of
them are inhabited by numerous other
sorts of creatures that have no eyes
for vision Literally speaking, there
is no such thing as an eyeless fish,
since the most sightless of the finny
tribe possess visual organs in a rudi-
mentary condition.; but, through
want of use, the optic ganglia and
nerves have broken down and been
absorbed.
Among the animals in these caves
where Egyptian darkness ever dwells
are blind crayfsh, colOrless, which in
the water by tOrchlight look like
white phantOms of their outdoor
kind. Now and then in such places
one comes across a common frog, ema-
ciated and seemingly discouraged,
which has found it's way how no one
knows, to the Tartareal realms. Also,
one discovers curious cave rats of the
same color as domestic rats, but
with long bodies, like q Weasel's, more
developed Whiskers, and much bigger
ears.
OF bats there are multitudes in the
caverns, as one might expect, mas
much as they are creatures of dark
ness. Countless numbers of them fire.
quent the black hOllOWs of Mammoth
and Luray. There were times in the
past when these vast caves were the
resorts of gigantic beasts, such as the
megatherium, mylOdon, megalonyX
and other huge sloths wiped out by
the glacial epoch. With the bones
are found those of extinct tapirs and
peccarieS.
Spiders Of several kinds are found
in the caves. They are uniformly
small, weak and of sedentary habits.
No webs do they spin, save few ir-
regular threads sometimes. What
they live upon is rather a puzzle,
though it is supposed that they catch
stray mites and other such small fry.
Scavengers constitute large part OF
the population of the caverns. Car
nivorous beetles are plentiful, par
ticularly in those places where parties
take lunch.
No animals whatever are found in
the dry parts Of the caves. Damp
ness, or a certain degree of moisture,
seems to be essential to their exist
ence. Under the stones one finds
white, eyeleSs worms, and in the
damp soil around about are to be dis
covered blind beetles in little holes
which they eXcavate, and bugs Of the
thousand-leg sort.
So far as the insects Of the caves
are concerned, the loss of sight which
they gradually undergo is sufficiently
well understood. The first step is a
decrease in the number of the facets
which make up the compound eyes,
with a corresponding diminishment
of the lenses and retin9. After four
or five generations the eyes become
useless 1t would be most interest
ing to breed these or other blind crea
lures of the caves in the light, so as
to find out if they would get their
sight back. In all animals, includ-
ing man, it is found that nature tries
to compensate for loss of vision by
increasing the power Of sense of touch.
Thus the antennH of cave insects
grow remarkably long. 1t is very
curious to find that nothing in their
behavior suggests the fact that they
are blind. They walk, run, stop, eX-
plOre the ground and try to escape
from the grasp of the bug hunter just
rs. if they really saw. The light Of
candle Startles them as much as if
they perceived it usually.