CLASS YlX lAnD 



■I nil _ I IP 



^^€^. Cte*sr^ lYt A^D? 



.:i^;.*«eic 



XwtT.^ 7 





Figure 6-1. A practical kind of classification based chiefly 

 on susceptibility of the soil to erosion, widely used by the 

 Soil Conservation Service in determining the capability of 

 land for various uses. (U.S.D.A. Soil Conservation Service.) 



essential aid in organizing facts and in promoting clear thinking. 

 There are many kinds of data arrangement, and even a classifica- 

 tion of classifications was presented as long ago as 1813 by de 

 Candolle,^"^ who recognized the following types: 



( 1 ) Empirical, such as alphabetical, not based on the intrinsic 

 nature of the objects 



(2) Rational, based on the nature of the objects 



{a) Practical, concerned with values to man (Figure 6-1) 

 {b) Artificial, using characters that facilitate arrange- 

 ment and identification 

 {c) Natural, employing affinities between organisms 



].7<ft • Classificatioxft of ComMn«mB«ities 



