PERCEPTIONS OF ANIMALS. 509 



Bats have been supposed to possess a peculiar, 

 or sixth sense, enabling them to perceive the situa- 

 tions of external objects without the aid either of 

 vision or of touch. The principal facts upon which 

 this opinion has been founded were discovered by 

 Spallanzani, who observed that these animals would 

 fly about rapidly in the darkest chambers, although 

 various obstacles were purposely placed in their 

 way, without striking against or even touching 

 them. They continued their flight with the same 

 precision as before, threading their way through 

 the most intricate passages, when their eyes were 

 completely covered, or even destroyed. Mr. Jurine, 

 who made many experiments on these animals, 

 concludes that neither the sense of touch, of hear- 

 ing, or of smell, was the medium through which 

 bats obtain perceptions of the presence and situa- 

 tion of surrounding bodies ; but he ascribes this 

 extraordinary faculty to the great sensibility of the 

 skin of the upper jaw, mouth, and external ear, 

 which are furnished with very large nerves.* 

 T.oThe wonderful acuteness and power of discri- 

 mination which many animals exercise in the dis- 

 covery and selection of their food, has often sug- 

 gested the existence of new senses, different from 

 those which we possess, and conveying peculiar 

 and unknown powers of perception. An organ, 

 which appears to perform some sensitive function 

 of this kind, has been discovered in a great num- 

 ber of quadrupeds by Jacobson. | In the human 



* Sir Anthony Carlisle attributes this power to the extreme deli- 

 cacy of hearing in this animal. 



t See Annales du Miisee; xviii. 412. 



