3GG 



THK PRINCIPLES OP 



716- Artificial systems are no longer used in botany, except as 

 keys cr helps in referring plants to their proper groups in natural 

 arrangements. But the celebrated Artificial System of Linnaeus 

 so long prevailed, and has exerted so great an influence over the 

 progress of the science, that it is still desirable for the student to 

 understand it. It will therefore be explained, after we have illus- 

 trated the principles of the Natural System of Botany. 



CHAPTER II. 



OF THE NATURAL SYSTEM OF BOTANY. 



717. The object proposed by the Natural System of Botany is 

 to bring together into groups those plants which most nearly resem- 

 ble each other, not in a single and perhaps relatively unimportant 

 point (as in an artificial classification), but in all essential particu- 

 lars ; and to combine the subordinate groups into successively more 

 comprehensive natural assemblages, so as to embrace the whole 

 vegetable kingdom in a methodical arrangement. All the charac- 

 ters which plants present, that is, all their points of agreement or 

 difference, are employed in the classification ; those which are com- 

 mon to the greatest number of plants being used for the primary 

 grand divisions ; those less comprehensive, for subordinate groups, 

 &c. ; so that the character, or description of each group, when fully 

 given, actually expresses the main particulars in which the plants it 

 embraces agree among themselves, and differ from other groups of 

 the same rank. This complete analysis being carried through the 

 system, from the primary divisions down to the species, it is evident 

 that the study of a single plant of each group will give a correct 

 general idea of the structure, habits, and even the sensible proper- 

 ties, of the whole. 



718. For it is evident that the relationships of plants are real; 

 that there is not only a general plan of vegetation (with which the 

 student has already become familiar), but also a plan in the relations 

 which subsist between one plant and another; that the species sustain 

 to each other the relation of parts to a whole, — so that this whole, 

 or vegetable kingdom, is an organized system. And this system, as 



