INTRODUCTORY OBSERVATIONS. XXI 



xnay be tranfmitted through channels very dif- 

 ferent from thofe known to us for the tranfmif- 

 fion of fenfe. Hearing and fight are very un- 

 certain in whole clafles of animals ; the ears ot 

 very few infeds have been difcovered ; fome mol- 

 lufcse and worms feem hardly to be fenfible of 

 found. In infedls, which form fo great and beau- 

 tiful ^ part of the creation, vifion is undoubtedly 

 very obfcure. No organs of vifion are found in an 

 infinity of worms ; and thofe that have eyes feem 

 to make very little ufe of them. Although many 

 infedls are fenfible of the impreflions of light, I 

 doubt whether they are capable of the perception, 

 of objects, or guided towards them by vifion ; 

 even the wonderful operations of the bee are per- 

 formed in utter darknefs. There are fomc infers, 

 however, that are fenfible of the prefence of adja- 

 cent objects, and adually recognife them as 1 have 

 demonft:rated by experiment. One fenfe mav 

 certainly fupply the place of another, which we 

 fee in the larger animals. A bat, deprived cff 

 fight, will traverfe the fame courfe, and avoid the 

 fame obft:acIes as before. Thefe creatures fly 

 through openings, nay, difcover new ones, and 

 without any embarraffment, pafs through them. 

 Some naturalifts thence concluded, that bats had 

 a fixth fenfe ; fome from experiment alTerted, they 

 were guided by hearing ; and others, that excel- ■ 

 five delicacy of feeling rendered them fenfible of 

 c 3 the 



