96 THE MAMMOTH CAVE. 



" The general structure of the blind fishes was 

 described in a former number of .this journal 

 (July, 1843), but a more complete description 

 was given in the 'New York Journal of Medi- 

 cine' by Tellkampf, who, in company with J. 

 Miiller, of Berlin, for the first time detected the 

 existence of rudimentary eyes.* They are de- 

 scribed as one-twelfth of a line in diameter, 

 round, black, destitute of a cornea, having an 

 external layer of pigment, beneath which is a 

 colorless membrane. No nerve was detected in 

 connection with the eye, and the contents of the 

 globe were not determined with certainty. Pro- 

 fessor Owen has described the organ as a simple 

 eye-speck, 'as in the leech, consisting of a minute 

 tegumentary follicle, coated by dark pigment 

 which receives the end of a special cerebral 

 nerve.'f Dr. John C. Dalton, Jr., has also de- 

 tected the eyes, and describes them as minute 

 globular sacs containing blackish pigment, deeply 



* ''New York Journal of Medicine, vol. v. p. 84. 1845. Dr. 

 Dekay had previously mentioned the existence of eyes, but was 

 evidently misled by some other appearance, since he states that 

 eyes exist of the usual size, but are covered by the skin. He had 

 not dissected them. — Fauna of New York." — {Note by Prof. 

 Wyman.) 



t Lectures on Comparative Anatomy, vol. ii. p. 202. See also 

 his figure, p. 175. 



