CHAPTER XIII. 



GENERAL PRINCIPLES OF CLASSIFICATION. 



473. THE term BOTANY is properly applicable to the whole of 

 the science which includes the study and investigation of the 

 Vegetable Kingdom. Hence the examination of the internal 

 structure of Plants, and of the various processes concerned in 

 their growth and reproduction, to the description of which, 

 under the title of Vegetable Physiology, the former part of this 

 Treatise has been devoted, strictly constitutes but a branch of 

 the Science of Botany, and may be designated Structural and 

 Physiological Botany. But by those who have made the study 

 of the Vegetable Kingdom a means of interesting recreation, 

 rather than a professed object of pursuit, and even by some who 

 have considered themselves scientific Botanists, this branch has 

 been entirely overlooked : and the whole attention has been 

 devoted to the other department of the Science, which concerns 

 the arrangement or classification of the many thousand species 

 (. 15) of Plants existing on the surface of the globe, into groups 

 or divisions ; each of which includes a number of species, that 

 have certain characters in common, and that differ from those of 

 other groups. The advantages of such a plan, in the saving of 

 time and labour, are obvious. If all the peculiarities of every 

 species of plant had to be studied and recollected by themselves, 

 it would require a long acquaintance and a retentive memory, to 

 become master of the characters of the 1400 or 1500 species of 

 Flowering-Plants which our own country produces ; and when 

 this number is multiplied by a hundred, which it probably must 

 be to represent the amount of species existing on the entire globe, 

 it is obvious that no single mind could be capacious enough to 

 grasp the vast amount of detail thus accumulated. 



474. It is the business of the Botanist, therefore, in the first 



