The Opelousas courier., 1892-03-12
THEY LIVE In THE DARK.
MANY ANIMALS WHICH NEVER
SEE DAYLIGHr.
Blind Inhabitants in the Mammoth
Caye~How the Sight is Lost-
Compensatory Attributes

0aye~-f1OW tuS BIZ Ut ~ 4tOaL-
Compensatory Attributes
There are many animals in the world
which pass all their lives in darkness,
never seeing a ray of light. Every one Ia:
heard of the blind fishes of the Mammoth
Cave. The latter is the biggest of SOC
great caverns in the United States. AL
of them are inhabited by numerous other
sorts of creatures that have no eyes foi
vision. Literally speaking, there is no
such a thing as a blind fish, since the
most sightless of the finny tribe possesses
visual, organs in a rudimentary condition
But, through want fuse, the optic
ganglia and nerves have broken doWn
and been absorbed.
Among the animals in these caves
where Egyptian darkness ever wells are
blind crayiish, coIorless, whfh in the
water by torchlight look like white
phantoms Of their outdoor kind. No"
and then in such places one comes across
a common frog, emaciated and seemingly
discouraged, which has found its way,
how no one knows, to the Tartarean
realms. Also one discovers curious cave
rats, of the same color as the domestic
rats, but with longer bodies, like a
vessels, more developed whi5kers aud
much bigger ears. OF bats there are
muItitudes in the caverns, as Que might
expect, inasmuch as they are creatures Of
darkness.
Spiders of several kinds are found in
The caves. They are uniformly small,
weak and of sedentary habits. No webs
do they spin, save a few irregular threads
sometimes. Whatthey live upon is rather
4 puzzle, though it is supposed that they
catch stray mites and other such small
fry. Scavengers constitute a large part
of the population OF the caverns. CaT-
niyorous beetles are plentiful, particular-
ly in those places where parties take
lunch. The proce sses of decay seem tc
be accomplished chiefly by a few fungi.
1t is said that meat hung up at the mouth
of one of these caverns remains fresh fol-
a long time, and it is surmised that the
bacteria which causes things to become
putrid are probably rare in. the under
ground atmosphere.
No animals whatever are found in the
dry parts of the caves. Dampness, or
certain degreed of moisture, seems to be
essential to their existence. Under the
stones one finds white, eyeless worms,
and in the damp soil around about are &c
be discovered blind beetles in little holes
xrij,h {J,nv- EVAN ynta and 1tT.rs of the
thousand leg sort. These th~ousand-leg
bugs, which in the upper world devoui
fragments of dead leaves and other veg
table debris, sustain life in the caverns
by feeding upon decayed wood, fungss
growths and bats dung. Kueellng in a
beaten path one can see numbers of them
gathered about hardened drips of tallow
from tourists candles. There are plen-
ty of crickets also.
So far as the insects of the cave 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 CORE
spending diminishment Of the lenses and
refine. After four or five generations
the eyes become useless. It would be
most interesting to breed these Or other
blind creatures of the caves in the light,
so as to find out if they would get their
sight back. In all animals, including
man, it is found that nature tries to COM
pensate for loss of vision by Increasing
the power Of the sense of touch. Thus
the artenne of cave insects grow re-
markedly long. 1t is very curious to
find that nothing i'll their behavior sug-
gests the fact that they are blind. They
walk, run, stop, explore the ground ami
try TO escape from the grasp of the bug
hunter just if they really saw The.
light of a candle starttes them as much
as if they perceived it usually. It is al
remarkable fact, proving that the ances-
tors CT these creatures could see. that in
5he embryo stage of their existence they
have eyes well developed.
In the abysses of the oceans, below
800 fathons, many animals have either
imperfect eyes or none. Their condition
a this regard affords Il suggestive paral-
ell to that of cave life aud the causes are
the N Science is of the
that all deep sea life originally
migrated from the shadows. The
,reatures which dwelt in the darkness of
he depths naturally lost their powers Of
rision after a while. 1t is the same way
With the mole, which is doubtless de-
from progenitors which could
lee. Blindness in the mole is the result
if a degeneration Of the optic nerve, the
consequence of which is that images
'ormed in the eye itself are not trans
nitted to the animals consciousness.
Occasionally a mole a see a little out
If n eye which has retained its CON-
with the brain. 1t is not
hat the mole is born blind, but that it
a tendency to atrophy of the
visual organs just as people derive from
heir parents an inclination to consump-
ion or other diseases. Some day in the
future there may be no such thing as a
mole that Is not entirely aud hopelessly
blind.