54 IMPORTANCE OF 



or inability, from a want of deep study of the subject, 

 a con.fusipn or inaccuracy of ideas, a feebleness of style 

 or expression, or a want of command of language. 



I have chosen to conclude this chapter with the 

 subject of specific characters, because it is of the most 

 fundamental importance, and the most difficult in 

 practice. It is the only sure ground of what Linnaeus 

 justly declares as the test of a good botanist, the know- 

 ledge of the greatest number of Species. (Phil. Bot. 

 sect. 256.) Now this knowledge, if merely empirical, 

 can be but of little value or certainty. Its dignity and 

 solidity must consist in an intimate acquaintance with 

 the comparative or respective importance of different 

 characters, in different orders, tribes, or genera of 

 plants. Several general rules indeed may be given, 

 but scarcely one of those is without exception ; and 

 particular rules apply to almost every natural assem- 

 blage throughout the vegetable kingdom. The latter 

 are only to be attained by acute observation and great 

 experience. 



The 8th chapter of the Philosophia Botanica of 

 Linnaeus, entitled Differentia, contains a full display 

 of the ideas of that great writer, the first who ever 

 undertook to consider this matter in a philosophical 

 light, or to lay down any rules for the guidance of 

 others. We shall give an epitome of his principles, 

 recommending his reasons and illustrations, in the 

 chapter just cited, to the attentive consideration of 

 {he student, who, before he attempts to apply them to 



