CHAPTER I. 



FIG. 1. 

 A Millipede (not an insect}. 



INSECTS : THEIR STRUCTURE AND FOOD. 



THE word insects recalls the many familiar butterflies, beetles and 

 other flying or crawling creatures that are so abundant. The term is, 



however, very loosely used 



and includes many crawling 



creatures that are not insects 



in the strict sense of the 



word, and with which this 



volume does not deal. It 



is not easy to give a clear 



idea of the animals included 



in the great class Insecta. 



Excepting birds and bats, insects alone can fly; but only a proportion 



of the insects one commonly sees have reached the flying stage or 



ever fly. We must, therefore, look for better distinguishing characters. 



The legs will help us. A great host of small creatures that crawl 



on earth have distinct small jointed legs. One thinks of spiders, 



of centipedes, of millipedes, of scorpions, as well as of beetles, 



.___ B caterpillars and the 



like. Of these, in- 

 sects have never 

 more than three 

 pairs of legs. A 

 centipede with over 

 40 legs is not an 

 insect, nor is a milli- 

 pede. A spider with 

 four pairs is not an 

 insect, nor is a scor- 

 pion. On the other 

 hand, a caterpillar 

 is, though it seems 

 to have many legs; 

 actually it has three 

 pairs of little jointed 





I 





FIG. 2. 

 Red Spider (not an insect"). 



B 



