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On the Eyeless Animals of the Mammoth Cave of Kentucky. 

 (Read before the Royal Physical Society, on exhibiting 

 Specimens of the Animals.) By Robert Chambers, Esq., 

 F.R.S.E. (Communicated by the Author.) 



The Mammoth Cave of Kentucky is situated on the Green 

 River, an affluent of the Ohio, midway between the towns of 

 Louisville and Nashville. The country is here composed of 

 an elevated plain of the mountain limestone, resting on Devo- 

 nian and Silurian rocks. The rivers form trenches in the 

 country about 350 feet deep, and the Mammoth Cave is nearly 

 the same depth below the surface. It is, as is well known, 

 of very great extent, not less, it is said, than ten miles, and is 

 composed of a great flexus of galleries — "branching, crossing, 

 inosculating in all directions, and at all levels/' — all afford- 

 ing a dry footing, and all pervaded by perfectly sweet air. 

 Though it is believed that there is but one passage into the 

 cave, there is constantly a stream of air coming outwards 

 when the temperature of the outer air is above 60° Fahren- 

 heit, and a stream going inwards when the outer tempera- 

 ture is below that point, apparently a consequence of the call 

 for the establishment of an equilibrium between the air-con- 

 tents of the cave, which are invariably at 60°, and the outer 

 air; from which Professor B. Silliman junior draws the in- 

 ference that the space of the excavations must be immense. 



Throughout the cave, even at the distance of several miles 

 from the mouth, are rivers and pools of water, which evi- 

 dently have some connection with the waters of the outer 

 world, as they are clear and palatable, and rise and fall with 

 the neighbouring rivers of the outer country, according to the 

 drought or wetness of the season. Mr Silliman is clearly of 

 opinion that the excavations are the effect of moving water, 

 and of no other cause. 



The Mammoth Cave affords a hybernating retreat for vast 

 numbers of bats ; but its constant inhabitants are alone en- 

 titled to notice. There is a rat of furry coat, bluish in the 

 body and white in the throat, possessed of large black eyes. 

 Mr Silliman caught two specimens, a male and female, and 

 he says of the former that he is satisfied it was entirely blind 



