448 Firtp Museum or Naturav History — Zootocy, Vou. XI. 
the air might readily be perceived and the walls of caves or branches of 
trees be thus avoided; but such an explanation seems hardly sufficient 
to account for the ability of blinded Bats to avoid, without actual 
contact, numerous silk threads stretched across a room, as claimed by 
Lazaro Spallanzani, whose often quoted experiments are worthy of 
repetition here. 
Dr. Godman writes:* ‘“‘In 1793 Spallanzani put out the eyes of a 
Bat, and observed that it appeared to fly with as much ease as before, 
and without striking against objects in its way, following the curve of 
a ceiling, and avoiding with accuracy everything against which it was 
expected to strike. Not only were blinded Bats capable of avoiding 
such objects as parts of a building, but they shunned, with equal 
address, the most delicate obstacles, even silken threads, stretched 
in such a manner as to leave just space enough for them to pass with 
their wings expanded. When these threads were placed closer together, 
the Bats contracted their wings, in order to pass between them without 
touching. They also passed with the same security between branches 
of trees placed to intercept them, and suspended themselves by the 
wall, etc., with as much ease as if they could see distinctly.” 
Dr. Joseph Schdbl} of Prague repeated Spallanzani’s experiments 
and confirmed his results. Bats were kept for a year alive in his room, 
but instead of putting out their eyes he adopted a more humane method, 
the desired results being obtained by covering them with adhesive 
plaster. 
The following account of similar experiments by Mr. A. Whitaker 
of Barnsley, England, is given by Millais:t 
“He obtained a Natterer’s Bat and covered its closed eyes with 
wax, fastening it with a little patch of rubber and solution, and then 
released the Bat in a room in which it had not been before 
this blinded Bat at first flew in a hesitating manner, and then gaining 
confidence went straight towards the closed door. It stopped when 
about six inches away, and hovered slowly along the line of the top 
and right down the side, without doubt keeping its position through 
its sensitiveness to the slight draft which came through the tiny chink 
It flew quickly, passing under chairs of which there were 
twelve in the room, besides other furniture, and never even touched 
anything with the tips of its wings. An attempt to catch it showed 
that, although incapable of sight, it was well able to dodge, but it 
constantly stopped in its flight, hovered, and scratched at the covering 
* Amer. Nat. Hist., I, 1826, p. 57. 
t Amer. Nat., V, No. 3, 1871, pp. 174-175. 
t Mamm. Great Brit. & Ir., I, 1904-6, pp. 96-97. 
