THE MAMMOTH CAVE. 87 
vestigation, evidently destitute of the sense of | 
hearing.” ‘This writer bases his theory upon the 
assumption that there is no sound in the Cave to 
produce vibrations upon the auditory nerve, for- 
getting that the animals, the rats particularly, 
cause sounds by their own voices and move- 
ments. He does not confine his remarks, as to 
the deficiency of sight and hearing, to the fishes, 
put includes all “the permanent inhabitants of 
the Cave.” 
A portion of the said letter was afterward 
copied in some of the medical journals, and, 
among others, in the “ Medical and Surgical Re- 
porter,” of Philadelphia, vol. xvii. p. 479 (Nov. 
30,1867). We took occasion in a subsequent 
number of the same journal to express our dis- 
. sent from the promulgation of such unsupported 
assertions, and called upon the author for the ex- 
periments which were said to have been insti- 
tuted for determining the absence of the organ 
of hearing in the inhabitants of the Cave. He 
replied in an evasive and somewhat surly man- 
ner, without giving any experiments or argu- 
ments to sustain his theory. 
We will first describe the general character- 
istics of the fish, and afterward recur to the 
point above referred to. 
