DESCRIPTIVE KOTAXV. 1,51 



however, we willingly abbreviate, as Thlaspi Bursa Pastona, 

 Hedysarum Caput galU, Lysimachla Linum utellatuvi. 



III. Delineatmi qf'CJiaracter.s. 



228. 

 Next to nomenclature, the delineation of characters is the 

 most important part of phytography. But we must under- 

 stand the method of delineating, and of correctly expressing 

 both generic and specific characters. This demands the ob- 

 servation of some general rules, which we are about to state. 

 The most essential requisite in a good character is, that it be 

 expressed in the generally understood technical language, and 

 neither contain undefined terms, nor comparisons with other 

 plants, or with other objects of nature and art. Comparison 

 and metaphorical expressions are objectionable on this ground, 

 that the character must give a positive acquaintance with the 

 object. But from this rule those terms of com})arison are 

 excepted, which are of common use in the artificial language. 



229. 



It is also a principal maxim in the delineation of characters, 

 that we should abstain from the introduction of all accidental 

 and non-essential things, because these lead only to confusion, 

 and are by no means invariable. 



Into the character of genus and sj-^ecies mc must admit only 

 those marks which distinguish plants from those that are re- 

 lated to them. This may be done without instituting com- 

 parisons, which belong much rather to tlie descri])ti(m and 

 diagnosis. The sum of the mai'ks which are found in rela- 

 ted plants, must always be before us wliilst we are delineating 

 the character ; on which account it is impossible to give the 

 character of a new genus or species, unless we kiiow tiie plants 

 which have a similar nature. 



