OF NATURAL HISTORY. 93 



fary to arrange them into different tribes or families. Thefe 

 tribes are diftinguiflied from one another by certain peculi- 

 arities in the ftrudlure of their bodies. 



The moft general divifion of infedls is derived from the 

 circumflance of their having or wanting v/ings, and from the 

 number and fubftances of v^rhich thefe inftruments of motion 

 are compofed. They are diftinguiflied from all other ani- 

 mals by many peculiarities of form. None of the other 

 clafles have more legs than four. But moft infers have fix 5 

 and many of them have eight, ten, fourteen, flxteen, eighteen, 

 and even a hundred, legs. Beiide the number of legs, in- 

 fects are furniflied with antennae or feelers. Thefe feelers, 

 by which infedls grope and examine the fubftances they meet 

 with, are compofed of a great number of articulations or 

 joints. Linnaeus, and other Naturalifts, maintain, that the 

 ufes of thefe feelers are totally unknown. But the flighteft 

 attention to the manner in which fome infe^ls employ their 

 feelers will fatisfy us of at leaft one ufe they derive from 

 thefe organs. When a winglefs infect is placed at the end 

 of a twig, or in any fituation where it meets with a vacuity, 

 it moves the feelers backward and forward, elevates, depref- 

 fes, and bends them from fide to fide, and will not advance 

 farther, left it fliould fall. Place a ftick, or any other fub- 

 ftance, within reach of the feelers ; the animal immediately 

 applies them to this new object, examines whether it is fufHcient 

 to fupport the weight of its body, and inftantly proceeds in its 

 journey. Though moft infefts are provided with eyes, yet 

 the lenfes of which they confift are fo fmall and convex, that 

 they can fee diftin^lly but at fmall diftances, and, of courfe, 

 muft be very incompetent judges of the vicinity or remote- 

 nefs of objects. To remedy this defeat, infedls are provided 

 with feelers, which are perpetually in motion while the ani- 

 mals walk. By the fame inftrumeots, tliey are enabled to 

 walk with fafety in the dark. 



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