228 INSECTS. 



jects, therefore, that are delineated on these, must 

 be millions of times less than those formed on the 

 human eye. Many insects still smaller have eyes, 

 no doubt, contrived so as to discern objects some 

 thousands of times less than themselves, for such 

 the minute particles on which they feed must cer- 

 tainly be. How astonishing, therefore, must be the 

 magnifying power of such eyes! And what extra- 

 ordinary discoveries might be made, were it possi- 

 ble to obtain glasses through which we could see 

 as these little creatures do ! 



With respect to the wings of insects, the two 

 first orders of Linna:us have theirs defended by a 

 pair of crustaceous cases called elytra. The three 

 subsequent orders have four membranaceous wings, 

 without elytra. All the insects of the sixth order 

 have but two wings, and under each ot these, at its 

 base, there is a poise or balancer like a little knob. 

 These poises are commonly little balls, placed on 

 the top of a slender stalk, and moveable everyway 

 at pleasure. In some they stand alone, but in others, 

 as in the whole Flesh-fly tribe, they have little co- 

 vers or hollow membranaceous scales, each of which 

 somewhat resembles a spoon without a handle : 

 every time the insect strikes the air with its wings, 

 a very quick motion may be perceived in the ba- 

 lancer ; and in the flesh-flies, when this moves, it 

 strikes against the little scale, and thus assists in pro- 

 ducing the well-known buzzing sound that is made 

 by flies when on the wing. The use of the balancers 

 to an insect seems to be precisely the same as that 

 of a long pole, loaded at each end with lead, is to a 



