A Sixth Sense 



tions, they settled on some object for the sake of rest, they would 

 immediately rise again on an attempt being made to seize them with 

 the hand. 



" From these experiments it was perfectly clear that in threading 

 the galleries of caverns and other narrow and pitch-dark places 

 to which bats commonly resort for their diurnal repose, these 

 animals were guided by some other sense than that of sight, and 

 the worthy abbe set himself to ascertain what this sense might 

 be. He commenced operations by covering the body of one of 

 his blind bats with varnish, and found that this had no effect in 

 rendering its movements uncertain. He then stopped up the ears 

 with wax, and finally with melted sealing-wax, and still the bats 

 obstinately persisted in avoiding obstacles placed in their way. 

 Consequently they did not hear their way in the dark. There 

 remained the senses of smell and taste. To test the former the 

 nostrils were stuffed up, but the only effect of this operation was to 

 bring the creature speedily to the ground, owing to difficulty of 

 breathing. Little fragments of sponge impregnated with musk, 

 camphor, or storax were fastened in front of the nostrils, and then 

 the bats flew about as freely as ever, and showed the same power of 

 avoiding contact with objects in their path. The removal of the 

 tongue, as might be expected, produced no result." 



During the last century several others have experimented 

 with a view of ascertaining the manner in which bats are 

 able to detect objects in their vicinity without the use of eyes. 

 It was believed by many that they had an unknown organ 

 which enabled them to find their way about in the darkest 

 places without the use of either eyes or ears, and it was 

 believed that this unknown organ was situated in the head. 



a Cuvier, however, who was the first really to appreciate the 

 results of these experiments, arrived at the conclusion, now 

 generally accepted, that the wonderful power possessed by bats 

 of directing their flight in places so dark as to render the 

 sharpest eyes useless was due to an exceptional development of 

 the sense of touch, residing especially in the great delicate mem- 

 branous expanse of the wings. These organs are really of the 



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