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 ihe 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, 

 but 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. 



