182 THE BRITISH NATURE BOOK 



enabling the insect to see in many different directions without turning its 

 head. In addition, there are often three or four single eyes set between them. 

 An insect, then, is an animal whose body is in three divisions, and has six 

 legs in the perfect state ; it breathes through tracheae, and attains its full de- 

 velopment through changes or metamorphoses. 



The insect world is so vast that it has been necessarily classified into the 

 following groups or orders : 



I. ORTHOPTERA (Straight-winged Insects Earwigs, Cockroaches, etc). 



II. NEUROPTERA (Nerve-winged Insects the Dragon-flies, etc.). 



III. COLEOPTERA (Sheath-winged Insects or Beetles). 



IV. HYMENOPTERA (Membrane-winged Insects such as Ants, Bees, and 

 Wasps). 



V. LEPIDOPTERA (Scale-winged Insects Butterflies and Moths). 



VI. and VII. DIPTERA and HEMIPTERA (Two-winged and Half-winged 

 Insects such as Bugs, Frog-hoppers, Gnats, etc.). 



In the first three orders the mouth parts are adapted for biting. In the 

 fourth (Hymenoptera), usually for licking and sucking. In Orders V., VI., 

 and VII., for sucking, or for piercing and sucking. This arrangement, how- 

 ever, is inadequate, and the most modern classification recognizes nineteen 

 orders ; and though it is impossible to deal with them in any detail, it will 

 be best to adopt this latest scheme, in order that students may have at least 

 the right basis for their future studies. 



Order I. APTERA. 



As the name signifies, this order consists of " wingless " insects, and con- 

 tains the lowest of all the insect species, the "Bristle-tails" and "Fish-in- 

 sects," many of which are covered with shining scales. They are all very small. 

 One, Campodea staphylinus, is nearly white, and may often be found in gardens 

 under dead leaves. Another, Lepisma saccharina, known as the " Silver-fish," 

 is found in pantries and cupboards. It feeds upon all sorts of materials, and 

 often damages prints and books. Another species is found in bakehouses. 



"Spring-tails" are included in this order. They possess a curious fork 

 beneath the abdomen, by means of which they can jerk themselves into the 

 air. They may be found in decaying vegetation, in stagnant pools, under 

 bark, etc. 



Order II. DERMAPTERA. 



In this order the Earwigs are found. These insects have no fore-wings 

 proper, but in their place a pair of oblong plates, under which the hind-wings 

 are sheltered. These are beautiful fan-like structures, not often used, shaped 

 like an ear hence, according to some, the name " earwings," corrupted to 

 "earwigs"; but the popular derivation of the word is connected with the 

 supposed habit of this insect to crawl into people's ears ! This is, however, 



