54 NATURE STUDY. 



pry open the mouth of a grasshopper or cricket and of a 

 beetle, and see the difference. 



Another thing that they have in common is the structure 

 of their wings, when they have any — and even the walk- 

 ing-sticks in the tropics have wings, although those in the 

 North are wingless. All the insects of this kind, like the 

 grasshoppers, crickets, cockroaches, walking-sticks and 

 the mantis, have wings with many " veins," or ribs, that 

 are straight and parallel, or nearly so, from the base of the 

 wing to the tip, or apex, and the wings themselves, when 

 not in use, are folded up like a fan. All insects with this 

 kind of wings belong to the order Orthoptera, or " straight- 

 wings." The grasshoppers, some with long horns or an- 

 tennae, and some with shorter ones, the crickets, the cock- 

 roaches, the walking-sticks and the mantis belong to this 

 group, or order, of straight-winged insects, and should be 

 put in a pile by themselves. lyater, when they have been 

 pinned, and we can study them at leisure, we shall find that 

 the grasshoppers may be separated into two smaller groups, 

 or families, the crickets into another family, the cock- 

 roaches into another, and so with the walking-sticks and 

 the mantis, each in family groups by themselves — each 

 having some characteristic that the others do not, although 

 they all have biting mouth-parts and straight wings, and 

 so belong, all together, in the order Orthoptera. 



Next, let the children select the bees, wasps and other 

 insects that look somewhat like them and have four wings, 

 by which they are distinguished from the true flies, with 

 only two wings, that often resemble, or "mimic," them. 

 Some of these insects have long tongues, like the bumble- 

 bees, while others, as the wasps, do not ; but many have 

 jaws, and some have very stout ones, with which they bite 

 and chew, killing and eating other insects, and even mak- 

 ing wood into paper for their nests. 



Thus there is a great difference in the mouth-parts of 



