636 Wisconsin Academy of Sciences, Arts, and Letters. 
him on the verge of hysterics; but a few suggestions on my part 
shamed him into self-control. 
Then we tried to re-light our candles, but every match seemed 
to attract more bats to blow it out, until we both sat down, put 
the candles between us, held our big sombreros at the sides and 
lit up. 
We then discerned that the very ground on which we sa't was 
literally a mass of moving, crawling spiders or spider-shaped 
insects. Taking more careful note of our surroundings, we 
found that the rock, so apparent at the entrance, was nowhere 
exposed, unless, perhaps, on the roof, which we could not see 
distinctly. The floor for at least two feet deep—how much 
deeper we had no way of telling—was composed of a dry, spongy 
guano, into which we sunk at least a foot at every step. The 
sides were the same; and some places where it had warped away 
from the walls, showed it to be not less than eighteen inches 
thick. 
Anxious to see what there was beyond, we went on, and time 
after time experienced repetitions of the bat storm. The squeak¬ 
ing would swell into a shrill piping, augmented, echoed and re¬ 
echoed by the walls of the cavern; the scarcely audible swish 
of wings would grow into a roar; the zigzag flight of a few 
hundred bats, dodging one another in intricate flight, would, by 
increase, become blurred into a seeming stream of dark bodies 
and then our lights and even our hats would succumb to their hur¬ 
ricane, and we would patiently stand and take our punishment 
until the wave swept by with its mad swirl of shrieking bats, 
and we could light up again. In this way we went on until we 
reached a steep incline that would be difficult and exceedingly 
disagreeable to climb, on account of the peculiar nature of the 
floor. ITow far we had come I do not know, probably not over 
1,000 feet after getting into the bat territory, but that they ex¬ 
tended still farther was evinced by the guano and the multitudes 
of bats on the walls that apparently had not been disturbed. 
My experience with hats has been that while some few species 
seem to prefer only a mild sort of twilight, where the human 
eye has no difficulty in seeing, others will penetrate to such dark 
recesses that the eye cannot discern the faintest indication 
of light; though I doubt not that the bats are still able to see. 
When the caves have been long enough and passable I have 
many times gone heyond the range of the bats, and have fancied 
