CHAPTEI? ^'11 

 CLASSIFICATION AND DESCRIPTION 



82. Systematic classification. In Chapter I it was 

 pointed out that the large number of plants which botanists 

 have to study has made necessary some sort of classification 

 or orderly arrangement into groups within groups. Plainl}', 

 one of the chief requirements of such an arrangement is that 

 it shall bring nearest together those forms which are most 

 alike, while it separates proportionately those which differ 

 more or less from one another. Hence, in general, the most 

 useful classification is that which indicates most truly the 

 degrees of difference and resemblance bj' its manner of 

 grouping the objects classified. 



To construct a classification of plants whiidi shall meet 

 this important condition as fully as possible has long been 

 one of the chief tasks of the science of botany. Indeed, so 

 important has the solution of this great problem seemed to 

 botanists that until com]oaratively recent times it has en- 

 gaged their attention almost exclusively. From their labors 

 has at last resulted a clas.sification which, although still 

 incomplete in certain parts, is yet wonderfuUj' adeciuatc in 

 its main features; and whether we consider the vastness of 

 the undertaking or the success already attained, we must 

 recognize it as one of the greatest achie^'cments of the human 

 mind. By its means to-day the student is enabled to gain a 

 wider and deeper knowledge of the world of plants than -^^-as 

 ever possible to the most learned botanist of former times. 



In the remaining chapters one of our chief aims will be to 

 advance toward a general idea of modern sj'stematic l^otany. 

 Thus far in our studj' of useful plants, it has been most 

 helpful to arrange them according to their uses; and it was 

 sufficient for our purpose to mention merely incidentalh^ 



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