PART II. 



SYSTEMATIC BOTANY. 



683. In the preceding chapters plants have been considered in 

 view of their structure and action. And when different plants have 

 been referred to and their diversities noticed, it has been in eluci- 

 dation of their morphology, — of the exuberantly varied forms or 

 modifications under which the simple common plan of vegetation is 

 worked out, as it were, in rich detail. The vegetable kingdom, that 

 is, vegetation taken as a great whole, presents to our view an im- 

 mense number of different kinds of plants, more or less resembling 

 each other, more or less nearly related to each other. It is the 

 object of Systejiatic Botany to treat of plants as members of a 

 system, or orderly parts of a whole, — and therefore to consider 

 them as to their ki7ids, marked by differences and resemblances, and 

 to contemplate the relations which the kinds, or individual members 

 of the great whole, sustain to each other. To this end the botanist 

 classifies them, so as to exhibit their relationships, or degrees of 

 resemblance, and expresses these in a systematic arrangement or 

 classification, — designates them by appropriate appellations, and 

 distinguishes them by clear and precise descriptions in scientific lan- 

 guage ; so that not only may the name and place in the system, the 

 known properties, and the whole history of any given plant, be read- 

 ily and surely obtained by the learner, but hkewise an interesting 

 view may be obtained of the general scheme or plan of the Ci'e- 

 ator in the Vegetable World. 



684. Our present endeavor will be to exj^lain the general prin- 

 ciples of natural-history classification, and the foundation, or facts 

 in natui-e, upon which it rests, and then cursorily to show how these 

 are applied to the actual arrangement of the known species of 

 plants. 



