52 THE BOOK OF THE FLY 



unwary and sluggish ; it is seldom to be seen far from 

 .where horses or cattle are stationed or stabled ;. how- 

 ever, it will make very long journeys hovering about a 

 driven horse or reposing on the car. 



A plague of flies of local origin will not take many 

 weeks of summer weather to spread, but it is generally 

 observable that plagues of flies, like many other occur- 

 rences, are simultaneous co-incidences distributed over 

 wide areas and at places remote from each other. 



