346 OBSER VA TIONS ON INSE CTS. 



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 atmos- 

 phere 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^, OR EMPEDES. 



May. Millions of empedes, or tipulce, 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 grows 

 more dark they retire. All day they hide in the hedges. 

 As they rise in a cloud they appear like smoke. 



I do not remember to have seen such swarms, except in 

 the fens of the Isle of Ely. They appear most over grass 

 grounds. — White. 



APHIDES. 



On the 1st August, about half an hour after three in the 

 afternoon, the people of Selborne were surprised by a 

 shower of aphides which fell in these parts. They who 

 were walking in the streets at that time found themselves 

 covered with these insects, which settled also on the trees 

 and gardens, and blackened all the vegetables where they 



