CHAPTER VII 
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. Plainly, 
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 by its manner of 
grouping the objects classified. 
To construct a classification of plants which 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 comparatively recent times it has en- 
gaged their attention almost exclusively. From their labors 
has at last resulted a classification which, although still 
incomplete in certain parts, is yet wonderfully adequate 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 achievements 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 was 
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 systematic botany. 
Thus far in our study 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 incidentally 
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