CLASSIFICATION OF ANIMALS AND PLANTS 141 



hair and other structures, which showed that it was, a mam- 

 mal. It had hoofs and other structures similar to the cow, 

 deer, etc., and it therefore belonged to the order of hoofed 

 animals. And finally it had close similarity to members of 

 the antelope family. Closer comparison with the named 

 species of antelopes, of which descriptions have been published 

 and specimens stored in the great museums of the world, 

 will make it possible to determine the genus to which this 

 new specimen belongs. And then the naturalist who writes 

 a description of the specimen will give a name to the species, 

 so that the next man who looks for the name of this animal 

 can find it in the proper place in the scheme of classification. 

 Such, in essentials, is the story of the use of systems of 

 animal and plant classification whenever any one wants to give 

 a name to a new specimen or to find out whether it has been 

 given a name. It is simply necessary to begin with the charac- 

 teristics of the larger divisions, and then work down through 

 classes, orders, families, genera, to species ; and since the great 

 books on classification (e.g., Gray's " Manual of Botany," 

 or Jordan's " Manual of Vertebrates") are arranged in this 

 order, it is easy for one who carefully observes and compares 

 to trace out the name of a plant or animal specimen. This 

 practical use of classification is made every day by numerous 

 people who seek the names of organisms for the pleasure of 

 feeling acquainted with them, or by biologists whose pro- 

 fessional work makes it necessary for them to find the names 

 of their specimens. 



131. Practical Work in Classification. (D) A small collection of 

 crayfishes, shrimps, lobster, and various species of crabs may be 

 used to illustrate some of the chief principles stated above regarding 

 species, genera, and larger groups. A collection of insects in alcohol 

 is especially excellent for the same purpose. The specimens of 

 a mixed collection should be arranged in groups, according to 

 obvious similarity to grasshopper, butterfly, beetle, dragon-fly, and 

 house-fly. This exercise can be made to illustrate the leading prin- 

 ciples of classification without going into detailed study of the in- 



