INSECTS AND VERMES 433 



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

 whereby they are enabled to stick on 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 fast 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. 



TIPULAE, OR EMPEDES 



Millions of empedes, or tipulae, 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 ever remember to have seen such swarms, 

 except in the fens of the Isle of Ely. They appear 

 most over grass grounds, 



ANTS 



August 23. Every ant-hill about this time is in a 

 strange hurry and confLision ; and all the winged ants, 

 agitated by some violent impulse, are leaving their homes, 

 and, bent on emigration, swarm by myriads in the air, to 

 the great emolument of the hirundines, which fare 

 luxuriously. Those that escape the swallows return no 

 more to their nests, but looking out for fresh settlements, 

 lay a foundation for future colonies. All the females at 



