PROBLEM 3. Living Things Are Na?ned and Classified 



Fig. 127 i/.'f t'crsiiVi cat, the leopard, ajid the pmiia are placed in the same genus be- 

 cause of their si7>iilarity. However, they differ from each other, too. For this reason 

 each is placed in a different species, (national zoological park) 



in the details of classification are still be- 

 ing- made as new facts are discovered. 



Just as it becomes necessary to make 

 more and • more subdivisions in coin or 

 stamp collections when you get more 

 specimens, so with plants and animals 

 the first large groups had to be subdi- 

 vided further and further. Of course, 

 this was not all done at one time nor by 

 one man; many contributed. But a more 

 complete scheme than had appeared be- 

 fore was developed and established by 

 Carolus Linnaeus (1707- 1778). Linnaeus 

 did two important jobs: he established 

 a system of classification and he estab- 

 lished a new method of naming plants 

 and animals. To find out something 

 about Linnaeus, do Exercise 4. 



Naming in the early days. Centuries 

 ago plants and animals were known only 

 by common names. This is sensible 

 enough for local everyday discussion but 

 it does not work for a biologist, for 

 sometimes the same animal or plant goes 

 by different names in different parts of 

 the country and sometimes the same 

 name is used for different animals or 

 plants. For example, in this country, to- 



day, the common name "gopher" is used 

 for several kinds of ground squirrels in 

 the west, means "tortoises" in the far 

 south, and is applied to a snake in the 

 southwest. 



To avoid this difficulty biologists 

 formerly wrote a long description of an 

 organism and used that for the name. 

 The more they knew about an organism 

 the longer the description; sometimes it 

 was four or five lines long. This did not 

 make matters simple. 



Linnaeus named many animals and 

 plants. Linnaeus' scheme provides a short, 

 simple name for every organism; this 

 name may also partly describe the or- 

 ganism. Let us see how the system works. 



Certain animals such as cats, lions, 

 tigers, and leopards are plainly much 

 ahke, so Linnaeus put them together in 

 a group called a gemis (jee'nus — plural 

 geiiera — ]en^er-a) . In the same way he 

 grouped wolves and dogs together in 

 a second genus. He did this for all the 

 kinds of animals and plants he knew, 

 finally arriving at many, many genera. 

 The subdivisions of a genus he called a 

 species (spee'shees). Thus there would 



