362 ARTICULATA. INSECTA. 



surface of standing water, lays an oblong egg per- 

 pendicularly in the angle formed by the crossing 

 of her hind legs. Other eggs are placed parallel 

 to and touching this, until a little oval boat of at- 

 tached eggs is formed, which floats on the surface. 

 The grubs are hatched in the form of little fishes 

 with great heads, which wriggle to and fro, fre- 

 quently coming up to breathe through a tube placed 

 on one side of the tail. In due time a pupa is 

 produced, somewhat resembling a lobster in form, 

 very nimble in its movements, swimming by means 

 of a fin at the tail, which is bent under the body. 

 It now breathes by two projections on the thorax. 

 By and by, it comes to the surface for the last time, 

 the skin splits, and the perfect Gnat is evolved from 

 its precarious bark. 



The vast tribe of House-flies, Blow-flies, &c., 

 (Musca,*) some of which are injurious to us, by 

 attacking our provisions, the long-legged Crane-flies, 

 (Tipula*) and the Whame-flies, (Tabanus*) and 

 Bot-flies (Oestrus^} that infest our cattle, belong to 

 this Order. 



* Latin names of Insects. t O7<r<rgj, oistros, their Greek name. 



