PROBLEM T,. Livifiif Thifigs Are Nauied and Class! Tied 



99 



Fig. 132 Polar bear. Polar and black bears be- 

 long to the sai7ie fa?!?ily but differe7it genera. 

 Bears, dogs, and foxes belong to one order, Car- 

 nivora. (national zoological park) 



Linnaeus did this for every plant and 

 animal he knew and biologists have ex- 

 panded and improved the scheme so that 

 now all organisms that have been named 

 have two names: a genus name and a 

 species name. Very rarely there are three 

 names but these exceptions need not 

 trouble you. 



Linnaeus' scheme of classification. You 

 know that the lion species and the cat 

 species resemble one another closely; 

 they fit into one genus. In the same way 

 some genera resemble other genera 

 closely. The genus Vulpes, including 

 some foxes, and the genus Cmiis, includ- 

 ing the dogs, are two similar genera. Such 

 similar genera are put together, and this 

 new and larger group is called a family. 

 \'ulpes and Canis thus belong to the same 

 family. See Figures 1 3 1 and 1 30. 



Similar families are put together into 

 a larger group called an order. See Fig- 

 ures 128-133. Orders that are alike are 

 included in a still larger group called 

 a class. Classes that have certain charac- 



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Fig. 133 Black bear, (national parks, canada) 



Fig. 134 Bighorn niotintain sheep. (American 



MUSEUM OF natural HISTORY) 



Fig. 135 Bison. Sheep and bison belong to dif- 

 ferent genera bitt to the same fa7iiily. How are 

 they alike? (u. s. forest service) 



