The sun., 1897-10-03
FEELERS IN PLACE OF EYES.
Some New Facts About Blind Fish-Can Live
Long without Food.
Prom The Lont.rille conrfer.yournol.

From the Lorfsrille Courfer.JournaL
The most abundant species OF blind fish is
about five inches long when full grown. Its
body is perfectly smooth and its skin has no
pigment SO that it is translucent, and the entire
fish has pinkish appearance, resembling q
skinned catfish" About the head. especially
In the young fish, are many ella or feelers, Civ
ing fuzzy appearance in the OF young
FISH. These fcelcrs take the place OF eyes 10
some extent, but In spite OF them the fish fire.
qucn:ly runs against the wall OF its cavern or
some other obstacle. 1t is protected from in.
jury, however. by its long lower Jaw which acts
as bumper. In its nati7e caverns the blind
fish has practically no enemies. 1t. therefore,
is quito devoid Of that shyness that character
ICES most fishes, and It may be taken with the
hand. If care Is observed about making any sud
den Jar that agitates the water. BY means Of
rs sensitive feeers 1t can recognize any mo.
noise AT tracts its attention for It seems to be
devoid OF ears as Of eyes.
1t Is not quito correct, however. TO imply that
the blind fish has no eyes. 1t is, indeed. abso-
lutcly blind, but II nevertheless has the rudi.
time when it's ancestors lived in the light and
could see ms well ns other fishes. Prof. Eidcn.
mann has mad" some highly important micro:
scOpic sections OF these rudimcntary eyes and
compared them with sections Of the eyes OF nor
nal fishes. lie finds in the degcnerated eyes
rudiments OF all the main layers OF cells that
are found in the normal eye, hui in a very
abortcd condition. Thus the crystalline lens
Sw e The ops nerve G
even more rudimcntary, SO tl.at there is abso-
lntcly no nervous connection between the, abor-
certain that the blind Ash cannot detect tho
slightest trace OF light with - rpdimentary
eye. Yet, strangely enough, II has been deter
mined by Prof. Eidenmann that the blind fish
may appreciate tho presence OF light in some
GnGr Its Sys S'gS, Ca I ss woSS
is. But II the fish II brought ont into the light
! II seems to appreciate tho change in its cond-
cnei the difference Between light and Gi darspess s
| Doubtless such rudmcninry sensitivcness 10
bodies, brt on" thai is ovcrookcd in view OF lie
| highly developed constituencies which the func-
oRHl eve has s biinS S though ur,n,o n
| has nm eye so also il has the pigment cells in
, its skin. though these are alone devoid OF pig.
! Of creatures Of ordinary habitat Is protection
from tn. sun or fr9n The eyes o, other c,rea-
| eun nor cyc penetrate. i has no need Of pro.
| tcctivc coloration. iut the fact that the un-
piigmcpted pigment cells are still found in Ing
| from n fsh that had use for such cells Like
| the Sightcss cycs, these pigment cells are proof
q the evolutionary origin q the blind hsh, and
! they supply, therefore addlt ionnl proof, whore
such Is needed, OF 20 truth o. The evolution
cells have bearing also on the Question of
variati ion through other processes than natu.
Tal selection; for it l. argued that c,catnre
| no productions enemies. Could hr neither brnc.
| fitted nor injured hy the presence ~ pigment in
its skin: hence that natural selection Pnrc and
| simple cannot account for the loss of pigment,
The blind hsh would seem, therefore, IN re.
! gard to iis rudimcntnry pigment cells. 10 offer
| an illustlation Of the change wrought by a
changed environment and OF loss through dis
| case.
This anomalous Ash has vet another strikinr
, popularity In IL manner OF breeding. Iu-'onh
| of dcpo.itnV her eggs in the bottom Of tho
water, like most other fishes. the female con
NcyS her cgl;' 20 her gill cases, where thry re.
main til they hatch and where FOR some time
the Young take refuge.
Food il probably not over abundant in tho
dark underground waters hut fortunately iEC
blind nrh Is n hardy creature, able to thrive on
VCr' mcaHre dict
Prof. Eigcnmann has shown TINT when
placed in an ordinary aquarium. the Great urC
win live for NJ least two years absolutely with
out food aud meantime appear strong and
aquarium were exhibited To the member. Of
the British association, and attracted much al
tcnton from the foreign biologists.