94 THE MAMMOTH CAVE. 



of the geographical distribution of animals, that 

 they were created under the circumstances in 

 which they now live, within the limits over 

 which they range, and with the structural pecu- 

 liarities Avhich characterize them at the present 

 day. But this is a mere inference, and whoever 

 would settle the question by direct experiment 

 might be sure to earn the everlasting gratitude 

 of men of -science. And here is a great aim for 

 the young American Naturalist who would not 

 shrink from the idea of devoting his life to the 

 solution of one great question."* 



* It will be seen from the foregoing that Professor Agassiz main- 

 tains the opinion that the fish and the crawfish of the Cave, with 

 their structural peculiarities, "were created under the circum- 

 stances in which they now live," but, as he very frankly adds, 

 " this is a mere inference." 



We have already stated that the inference drawn from our 

 own observations and reflections is that these animals were 

 originally supplied with the organs of vision ; and since the 

 above was penned we have noticed tbat Professor Joseph Jones, 

 of Nashville, Tenn., has incidentally corroborated our view while 

 treating the subject of Albimsih. Referring to the effects of con- 

 tinued darkness upon various animals, Dr. Jones remarks : 



" After extended investigation and examination of thousands 

 of living specimens, I have never observed an albino among cold- 

 blooded animals. 



" When this class of animals have been confinecWn dark caves, 

 and excluded from the action of light, they present the appear- 

 ance of the albino ; and it is probable that, if the negro children. 



