Chapter I 

 THE FORM OF INSECTS 



To wonder at a thousand insect forms, 



Whose shape would make them, had they bulk and size, 



More hideous foes than fancy can devise, 



With helmet-heads and dragon-scales adorned. — Cowper. 



What is an Insect ? — Adam, in the Book of Genesis, 

 to whom every living creature was brought to be 

 named, is a striking picture of the men of our day, 

 learning to look with wondering interest on the 

 myriads of animals that share with us this earth as a 

 dwelling-place. Their vast numbers and the variety 

 of their forms and habits seem at first to render their 

 systematic study a hopeless task. But a general 

 survey of the animal world teaches us that we can 

 recognise several large groups, each marked off from 

 the rest by some special plan of structure. The 

 animals of one such group (to which we ourselves 

 belong), with inner bony skeleton and two pairs of 

 limbs, are distinguished as Back-boned (Vertebrates) ; 

 those of another group — soft, boneless, and limbless 

 creatures, like snails and oysters, often protected by 

 a hard, limy shell, as Soft-bodied {Molluscs). Such 

 great groups are often spoken of as the animal Sub- 

 kingdoms. But most modern naturalists, regarding 

 the living inhabitants of the earth to-day as the modi- 

 fied offspring of the vanished races of the past, and 

 believing that between all creatures there is some 

 relationship, distant or near, prefer to call each of 



A 



