346 
BAT. 
sight was not confined to the common bat, tried it 
on several other species, and, we are told, with the 
same success. He also tells us, that flying through 
the middle of a sewer which turned at right angles, 
the bats regularly bent their flight at the curvature, 
though two feet distant from the walls. They found 
a resting-place on the cornice, and even flew through 
threads hung perpendicularly from the ceiling with- 
out touching, though they were scarcely at a greater 
distance than that of their extended wings ; and 
when the threads were brought nearer, they con- 
tracted their wings to pass through them. They 
equally avoided every obstacle, though the whole 
head was covered with a varnish made of sandarach 
dissolved in spirit of wine. 
It seems from the observations of Mr. Carlisle, 
that the sense of hearing greatly assists them in 
avoiding those obstacles, which they would other- 
wise, when blinded, strike against. This gentle- 
man, says Dr. Shaw, collected several specimens of 
the vespertilio auritus, or large-eared bat, and ob- 
served that when the external ears of the blinded 
ones were closed, they hit against the sides of the 
room, without being at all aware of their situation. 
They refused every species of food for four days, as 
did a larger number which were afterwards caught 
and preserved in a dark box, for above a week. 
During the day-time they were extremely desirous 
of retirement and darkness ; and, while confined to 
the box, never moved or endeavoured to get out the 
whole day ; and when spread on the carpet, they 
