TEN INDIANA CAVES. 147 



can see absolutely nothing, swiftly and unerringly 

 through openings but a foot or two in diameter, 

 without hitting the walls. The direction of flight 

 seems to be, however, one of instinct or training 

 rather than of reason, since when a door was first put 

 in an opening in the cave through which they had 

 been wont to pass in numbers, they flew blindly 

 against it and were killed by thousands. 



At Wyandotte, as elsewhere, the bats pass in num- 

 bers into the deepest recesses, being found abundantly 

 in the "Senate Chamber" and sparingly near "Craw- 

 fish Spring," two miles or more from the entrance. 



As is well known, bats are crepuscular in habit. 

 They spend the day in darkness and the night in 

 search of food. Such habits have, in the course of 

 ages, rendered their eyes exceedingly small, their ex- 

 ternal ears large, their flight, like that of the owls and 

 whip-poor-wills, noiseless. Several questions of inter- 

 est, \vhich to my mind are unanswered, arise regarding 

 the cave life of these animals : 



First. In a cave where the temperature is 54 F. 

 the year round, how do they determine when warm 

 weather has begun out of doors? 



Second. How do those which spend the days of. 

 the summer season in the cave determine the approach 

 of dusk? 



Third. How do they distinguish, in the intense 

 darkness, those portions of the roof which are smooth 

 from those which are rough enough to furnish a foot- 

 hold? 



On the right side and about fifty feet from the 

 entrance to Odd Fellows' Hall is a pit-hole or per- 



