PART THIRD. 

 SYSTEMATIC BOTANY. 



CHAPTER I. 



GENERAL PRINCIPLES OF CLASSIFICATION. 



451. Systematic Botany has for its object the ar- 

 rangement of Plants into Groups and Families accord- 

 ing to their characters, for the purpose of facilitating 

 the study of their names, affinities, habits, history, 

 properties, and uses. In this department the prin- 

 ciples of Organic and Physiological Botany are applied 

 and brought into practical use. 



452. But there is another and higher import in the 

 study of Systematic Botany. It shows us Plants as 

 related to each other and constituting one magnificent 

 system. It reveals the Almighty Creator at once em- 

 ployed in the minutest details and upon the boundless 

 whole ; equally attentive to the perfection of the indi- 

 vidual in itself, and to the completeness of the System 

 of which that individual forms a necessary part. 



453. The necessity for such an arrangement of the Species will appear 

 when we consider their immense number. They meet us in ever-varying 

 forms at every step, clothing the hills, mountains, valleys, and plains. They 

 spring up in hedges and by the way-side. They border the streams and lakes, 

 and sprinkle over their surface. They stand assembled in forests, and cover 

 with verdure even the depths of the Ocean. Not less than 150,000 kinds are 

 already distinguished, and the catalogue is still growing. 



