THE MAMMOTH CAVE. 85 
eventually obliterated. In the never-ceasing 
darkness of the Cave, eyes are unnecessary or- 
gans to the fish that live in its waters. We 
have every reason to believe that these fish were 
originally possessed of eyes; but after their in- 
troduction into the Cave, and perhaps centuries 
of existence there, these useless organs grad- 
ually, through many generations, lost their ori- 
ginal character, and finally disappeared, only a 
trace of the orbit remaining.* 
Some months after our visit to the Cave our 
attention was drawn to a newspaper article, from 
an anonymous writer, which we believe originally 
appeared in the Chicago “Tribune,” August 18, 
1867. The writer contended that the permanent 
inhabitants of the Cave were not only blind, but 
deaf also. The original letter in the “Tribune” 
was entitled “Important Scientific Observations,” 
* «Their exclusion from the solar beam is well known to pro- 
duce organic alterations in the visual organs of animals, such as 
atrophy of the optic nerve, or those portions of the brain (the 
corpora quadrigemina) more immediately associated with the 
sight. It is supposed that the blindness observed among fish 
found in the dark caves of the Tyrol and Kentucky arises from 
the arrest in the development of the eyes as the result of a con- 
stant deprivation of light.”—Lght: ats Influence on Life and 
Health. By Forbes Winslow, M.D., etc., American ed. New 
York: Moorhead, Simpson & Bond, 1868, p. 13. 
8 ; 
