ORDER VII. TWO-WINGED INSECTS, OR FLIES. 301 



spots. The wings arc covered with millions of small hairs, 

 which give them a glistening appearance, as the minute 

 hairs can not be seen with the unassisted eye. 



The house-fly is an inhabitant of every country on the 

 globe ; it is found in the coldest countries of Greenland, as 

 well as the warmest portions of the torrid zone, and by 

 mankind every where is esteemed a great nuisance. In its 

 persevering impudence and provoking titillation it is no re- 

 specter of persons, attacking the king on his throne with as 

 much freedom as the beggar in the ditch, and leaving ev- 

 ery where the dirty remembrances of its offensive assaults. 

 Still the poor fly can not be blamed, as it is only seeking 

 its food, which consists in the juices of animals and the ex- 

 halations from their skin, as well as the moisture of plants 

 and vegetables, and the decayed particles of food and offal. 



These flies deposit their eggs in all kinds of manure, and 

 hence are found in greatest abundance in the neighborhood 

 of stables and farm-houses. Their maggots are also found 

 on the corpses of animals, and wherever there is any filth, 

 even in spittoons, if they are not constantly cleaned. They 

 transform themselves into reddish-brown pupas, from which 

 the perfect flies are constantly issuing throughout the sum- 

 mer. 



House-flies are often subject to a peculiar disease, the 

 symptoms of which are, a considerable swelling of the hind 

 body, which is filled with a greasy white substance, pene- 

 trating the skin, and accumulating on the surface of the 

 body. In this condition we often find them dead upon win- 

 dows or flowers, looking as if glued to them with their pro- 

 boscis. The cause of this fatal disease is, probably, their 

 intemperance in eating, or because they have partaken of 

 some poisonous substance. 



The house-fly is not only an inhabitant of every country, 

 but it is found at all seasons of the year, although it is 

 rarely seen in very cold weather except in warm rooms, or 



