ARTHROPODS 175 



lustrated by the arthropods. In the case of the grasshopper, the 

 species group includes just that one kind of grasshopper and no 

 others so they are alike in all points; the genus includes several 

 species with a good many points of resemblance. The family in- 

 cludes the members of several genera which resemble each other 

 but less closely than the members of the genus. The order, or- 

 thoptera, includes several families with members as different as 

 the cockroach, locust, katydid, grasshopper, and crickets, while 

 the class insecta includes all the different orders of insects, such as 

 bees, moths, flies, and beetles which of course include many in- 

 dividuals but resemble each other in still fewer points. As stated 

 before, the Insecta is one of the three classes into which the ar- 

 thropod branch is divided and have the characteristics of that 

 enormous group, in common with the acerata and Crustacea. 



Value of Scientific Classification. This may seem very com- 

 plicated but is really very necessary, for if there were no way of 

 grouping the different forms, they could never be studied or un- 

 derstood, much less named and identified. Not only this, but 

 resemblance in points of structure shows actual family relationship, 

 those forms most alike being nearest related and those with less 

 points in common, more distantly connected. Classification is not 

 only a convenient arrangement to save labor in the study of living 

 things, but shows their relationship and descent, as well. 



Let us classify the grasshopper fully according to this outline, 

 and see how much is included in merely its proper scientific 

 classification. 



Kingdom: Animal ' 

 Branch: Arthropoda (jointed-foot animals) 



Class: Insecta (body " cut into " three regions) 

 Order: Orthoptera (straight-winged) 

 Family: Acrididae (locust family) 

 Genus: Melanoplus (black armored) 

 Species: femur-rubrum (red-legged) 



From just the translation of the names used, one can obtain a 

 fair description of the animal concerned, and if the characteristics 



