54 IMPORTANCE OF 



want of deep study of the subject, a confusion or in- 

 accuracy 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 Lin- 

 naeus justly declares as the test of a good botanist, 

 the knowledge of the greatest number of Species. 

 {Phil. Bot. sect. 256.) Now this knowledge, if 

 merely empirical, can be but of little value or cer- 

 tainty. Its dignity and solidity must consist in an 

 intimate acquaintance with the comparative or re- 

 spective importance of different characters, in dif- 

 ferent orders, tribes, or genera of plants. Several ge- 

 neral rules indeed may be given, but scarcely one of 

 those is without exception; and particular rules 

 apply to almost every natural assemblage throughout 

 the vegetable kingdom. The latter are only to be 

 attained by acute observation and great experience. 

 Yet the meanest compiler often presumes to judge 

 and correct the most learned botanists. 



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. I shall give an epitome of his principles, 

 recommending his reasons and illustrations, in the 

 chapter just cited, to the attentive consideration of 



