370 CLASSIFICATION. 



names derived from those of persons or countries, should always 

 be written with a capital initial letter. 



702. In an exposition of the natural system, some authors (such 

 as Jussieu and Endlicher) commence with the lower extremity of 

 the series, and end with the higher ; while others (as De Candolle) 

 pursue the opposite course, beginning with the most perfect Flow- 

 ering plants, and concluding with the lowest grade of Flowerless 

 plants. The first mode possesses the advantage of ascending by 

 successive steps from the simplest to the most complex structure ; 

 the second, that of passing from the most complete and best under- 

 stood to the most reduced and least known forms ; or, in other 

 words, from the easiest to the most difficult ; and is therefore the 

 best plan for the student. 



703. The arrangement of De Candolle, being most in use, has 

 been followed as nearly as practicable in the following illustrations, 

 so far as relates to the sequence of the orders. In the conspectus, 

 these have been thrown into small, and more or less natural groups, 

 the characters of which, imperfect as they must be, will serve 

 as a kind of key to the orders of each class or subclass, and facili- 

 tate in some degree the student's investigation.* It is by no means 

 necessary, or desirable, to introduce into our elementary illustra- 

 tions the little known and unimportant orders, especially those 

 which have no indigenous, naturalized, or commonly cultivated 

 representatives in the United States. Those more important ex- 

 otic families, however, which would otherwise be omitted, are 

 mentioned in the form of notes, placed at the bottom of the page, 

 under the indigenous orders to which they are respectively related. 

 Full descriptions of the orders have not been attempted, but the 

 easier distinguishing characters are given, to the exclusion of the 

 non-essential. An explanation of the technical terms, which, for 

 obvious reasons, are freely employed, (and which will serve to ini- 

 tiate the student into the language of descriptive botany,) may be 

 sought in the combined glossary and index at the end of the 

 volume. 



* In a Flora, or other systematic work based on the natural system, artifi- 

 cial analyses, contrived in various ways, are necessary to the unpractised stu- 

 dent, and afford him great assistance in disentangling the more or less compli- 

 cated characters of the orders. But they are hardly necessary in our sketch, 

 which is intended to give a cursory general view of the principal natural or- 

 ders, rather than a particular and systematic analysis. 



