ARTICULATA. INSECTA. 



horny skin, in some assuming a shelly hardness. The 

 great majority have two pairs of wings, though in 

 one order the second pair are scarcely to be recog- 

 nised. They breathe by air-pipes (trachea), which 

 communicate with the air through breathing holes, 

 which are placed on each side. 



These little creatures fly in the air, crawl on the 

 earth, or swim in the water. They generally eat 

 living plants, but many prey upon each other, and 

 some devour decaying animal substances. As no 

 Insect grows after it has attained the perfect state, 

 food is chiefly needed in the earlier or caterpillar 

 stage. Many do, however, still continue to feed, 

 particularly such as are carnivorous. 



Latreille divides the Class into twelve Orders, 

 most of them distinguished by the presence, number, 

 and form of the wings. 



