378 THE LIFE OF AN INSECT. 



world is four, arranged in two pairs. But this 

 number is obscured by the modifications to which 

 in many instances one or other of the pairs 

 becomes subject ; and we should, if this were not 

 remembered, become somewhat confused at taking; 



o 



up the first insect that came in our way, which 

 would probably be the common fly, and finding 



that we could only 

 recognise two 

 large wings in- 

 stead of four. In 

 this tribe of insects 

 the hinder pair of 

 wings is reduced 

 to a pair of slender 



ignified. * 



knobbed filaments. 

 Some insects are without wings at all. The ant, the 

 bee, the dragon-fly, the house-fly, and many other 

 insects, are furnished with wings of gauze-like trans- 

 parency and structure, often crossed in a curious 

 manner by the nervures, of which we before had 

 occasion to speak. These wings are called mem- 

 branaceous. In the moth and butterfly tribes the 

 wings are covered with what appears to be a deli- 

 cate, beautiful powder, but is in reality a multi- 



