INSECTS AND VERMES. 275 



their backs downward, by means of the 

 pressure of the atmosphere on those flaps; 

 the weight of which they easily overcome 

 in warm weather when they are brisk and 

 alert. But in the decline of the year, this 

 resistance becomes too mighty for their 

 diminished strength ; and we see flies la- 

 bouring along, and lugging their feet in 

 windows as if they stuck fast to the glass, 

 and it is with the utmost difficulty they 

 can draw one foot after another, and dis- 

 engage their hollow caps from the slippery 

 surface. 



Upon the same principle that flies stick 

 and support themselves, do boys, by way 

 of play, carry heavy weights by only a 

 piece of wet leather at the end of a string 

 clapped close on the surface of a stone. 



WHITE. 



TIPUL^E, OR EMPEDES. 



May. Millions of empedes, or fipula, 

 come forth at the close of day, and swarm 

 to such a degree as to fill the air. At this 

 juncture they sport and copulate ; as it 



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