420 OBSERVATIONS ON INSECTS AND VERMhS. 



a sudden, hang in the air in a stationary position for some time, 

 and then fly off again ; but do not recollect having ever seen 

 it strike its tail against the ground, or any other substance.- - 

 MARKWICK. 



MUSCLE. FLIES. 



In the decline of the year, when the mornings and evenings 

 become chilly, many species of flies (Muscce) retire into houses, 

 and swarm in the windows. 



At first they are very brisk and alert ; but as they grow more 

 torpid, one cannot help observing that they move with difficulty, 

 and are scarce able to lift their legs, which seem as if glued to 

 the glass ; and by degrees many do actually stick on till they die 

 in the place. 



It has been observed that divers flies, besides their sharp 

 hooked nails, have also skinny palms, or flaps to their feet, 

 whereby they are enabled to stick on the glass and other smooth 

 bodies, and to walk on ceilings with 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 labouring along, and lugging their feet in windows as if they 

 stuck to the glass, and it is with the utmost difficulty they can 

 draw one foot after another, and disengage 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 tipula, come forth at the close of 

 dav, and swarm to such a degree as to fill the air. At this 

 juncture they sport and copulate; as it grows more dark they 



