132 SYSTEMATIC POMOLOGY 



tween 1,500 and 2,000 different named varie- 

 ties of apples growing in North America, 

 some 500 to 600 varieties of plums, 200 to 300 

 of pears, and of other fruits in like propor- 

 tion, with more coming every year, then one 

 must see that, unless some method of topical 

 study can be secured, no man can ever get 

 even a superficial knowledge of our porno- 

 logical wealth. If those varieties which are 

 alike can be grouped together, then one can 

 understand several of them at once by famil- 

 iarizing himself with their generic charac- 

 ters. And thus from every side, and much 

 more urgently than can be here written down, 

 do we need more and better classification of 

 our varieties of fruit. 



Methods of Classification 



There are two radically different methods 

 of classification used in all fields of natural 

 science. These are commonly designated 

 the natural and the artificial methods. 



It would be more accurate and more sug- 

 gestive to call the latter the arbitrary method 

 rather than the artificial method. 



The essential difference between these two 

 methods is that the arbitrary method arranges 



