THE THORAX. 113 



natural order to which the bees are assigned is named 

 Hymenoptera, from the strongly membranous wings 

 they possess. 



We can readily understand the importance to these 

 insects of having their organs of flight powerful, and 

 yet not weighty, tough without being clumsy. Con- 

 sidering the length of their daily journeys, and the 

 constant and rapid movements they require to make, 

 we easily discern how well suited to their needs is 

 the structure of their wings. But we must call 

 attention to a remarkable provision for the further 



^^^&d/^/^^Ji\ 



FlG. 31. HOOKLETS OF A BEE'S WlNG. 



utility of these organs. Under a Jens of medium 

 power may be seen, along the anterior edges of the 

 hind wings, a series of booklets of hair, while on the 

 posterior edge of the front wings is a rib, or bar, 

 which the booklets can grasp. By this means the 

 two wings, when used for flight, become practically 

 one, thus presenting unbroken resistance to the air, 

 and, in consequence, greatly increasing the power 

 of propelling the body. When at rest, the unhook- 

 ing of the edges enables the wings to be folded out 

 of the way no mean advantage in the crowded 

 hive. 



