64 ANIMAL ACTIVITIES. 
But this scheme of classification seems too artificial, 
that is, too much like the classification of inanimate 
things like tables or chairs, which may be arranged for 
convenience into classes according to use or shape. 
The course of development from egg to adult is also 
an important factor in classifying living things, because 
it is thought to show better than anything else the 
natural relations or affinities, or we might say the 
blood-relations of animals: hence in classifying insects 
the matter of metamorphosis must be considered. In 
a superficial way we might divide insects into those 
having complete and those having incomplete meta- 
morphosis, or into those having terrestrial larve and 
those having aquatic larve; but more careful study 
shows that these differences alone are not sufficient for 
a clear and systematic classification, nor do they, 
alone, indicate relation by descent. In fact, it has 
been found that with the best of effort in the matter of 
classification, so many intermediate forms occur that a 
series of individuals rather than a few orders result. 
Still convenience demands a classification of some 
kind. Taking into consideration as many differences 
as possible, and ignoring some of the less obvious 
peculiarities, we may include all insects in nine orders: 
Name. Typical Insect. 
Thysanura. Springtails. 
Pseudoneuroptera. Dragon-fly. 
Orthoptera. Grasshopper. 
Hemiptera. Squash-bug. 
Neuroptera. Caddis-fly. 
Coleoptera. Colorado beetle. 
Diptera. House-fly. 
Lepidoptera. Butterfly. 
Hymenoptera. Bee. 
Characteristics of the Orders. We give below the 
characteristics of these orders, noting chiefly the facts 
ee 
