COLEOPTEROUS INSECTS. 109 



cave surface to the air, and maintaining the body in 

 a proper equilibrium. 



The aerial movements of these insects are not, 

 however, in general performed with that power and 

 ease of evolution which are so remarkable in biras, 

 and even in certain other tribes of their own class. 

 In the larger kinds especially, the weight of the 

 body seems somewhat disproportionate to the size 

 and motive apparatus of the wings, and their Hignt 

 is therefore heavy and laborious, and seldom sus- 

 tained for any considerable time. They rise into the 

 air but slowly, and although their motion soon be- 

 comes rather rapid and headlong, the frequency with 

 which they strike against any object that happens 

 to come within the line of their flight, shows them 

 to be incapable of exerting that degree of muscular 

 energy necessary to check suddenly the impulse 

 they have received, or speedily change its direction. 

 It is probably owing to this cause that they are so 

 often seen to come in contact with other objects, 

 rather than deficiency of sight, to which it is ascribed 

 in the saying, " blind as a beetle." Olivier asserts 

 that no coleopterous insect can fly against the wind, 

 and it is probable that the affirmation is correct, at 

 least in relation to the majority, and when the wind 

 is so high as to offer much resistance. Many of the 

 smaller beetles, however, and those whose habits 

 render a sustained flight necessary (such as the tree- 

 chafers, Melolonthce, &c.), possess considerable power 

 of wing. During a warm day in spring the air is 



