182 SYSTEMATIC BOTANY. 



twenty-fourth, Cryptogamia, including all Flowerless Plants, was 

 a chaos when first established, and its subdivisions were not then 

 definable by single characters. As the Linnaean system is no longer 

 in use, further mention of it is not needed. 



Sect. 2. NATURAL CLASSIFICATION or PLANTS. 



In this method of classifying we pursue the same path by which 

 we arrived at the genera, and combine these into more general 

 groups, not according to arbitrarily chosen or isolated characters, 

 but according to their natural affinities that is, the agreement in 

 their total organization, and consequently their presumed degree 

 of kinship. (Jenera are thus gathered together into Families or 

 Orders, these into Cohorts and Classes, and finally the entire 

 Vegetable Kingdom becomes marshalled into a few Provinces or 

 Subkingdoms. 



It is evident from this, that a Natural System founded on a perfect 

 knowledge of all existing plants would present to us a kind of abstract 

 picture of the Vegetable Kino'dom, in which all its essential characters 

 would be represented in their real proportions, places, and connexion. 

 Not only, however, are we far from being acquainted with all exist- 

 ing plants (not to mention the numerous kinds now extinct), but the 

 essential peculiarities of a vast number of the known plants have been 

 as yet but imperfectly studied. Hence we have at present various plans 

 for* the Natural Arrangement of plants, presenting peculiarities depen- 

 dent upon the amount of knowledge, or the peculiar views, of their re- 

 spective authors ; which plans or Systems must be regarded as so many 

 rough draughts or sketches, to serve as material for the elaboration of the 

 true and complete Natural System. As the principles of classification are 

 fully recognized, and as the amount of plants thoroughly known is already 

 very large, there is a close agreement in the general features of the dif- 

 ferent "Natural Systems," and especially in the manner in which the 

 Orders of plants are defined. The chief diversities of opinion arise out of 

 the different estimations of affinities and differences of the families. 



Value of Characters. To characterize the Natural Method more 

 distinctly, it must be added that especial attention is paid to the 

 relative importance of the characters presented by each plant, a 

 determinate scale being formed, in which the organs are ranked 

 according to their "congenital" or "acquired" origin, their phy- 

 siological importance, the complexity of their construction, and 

 their comparative invariability. Congenital characters are common 

 to the largest number, and are the most constant, hence the most 

 important. 



Thus, while species of the same genus, distinguished generally by the 

 external characters of their vegetative organs, are combined by likeness 

 in their flowers, genera (in which difference of the floral envelopes, or of 

 the external character of the fruit, or some such character exists) are 



