Part YI. 



CLASSIFICATION OF PLANTS. 

 TAXONOMY. 



A system of classification is said to be artificial when it is 

 "based upon limited but constant characters. A system is said 

 to be natural when it is based upon all the characters of the 

 organism. Usually, however, the idea of " natural descent " is 

 associated with a natural system. It is supposed that descent 

 is the cause of the resemblance or similarity of the plants or 

 other organisms. It is generally admitted that the natural 

 system which is to be the expression of natural origin and 

 descent is being gradually discovered, hence does not yet 

 actually exist. It is customary at present to consider the 

 natural system' as directly opposed to the system of Linne." 

 Nevertheless the system of Liuue as well as the various natural 

 systems are at the same time natural and artificial. 



Many of the plant-families of the so-called natural systems 

 coincide more or less with the classes or orders of Linne's sys- 

 tem." The following table will illustrate this more clearly. 



The families given at the right harmonize with the following 

 classes and orders of Linne : 



' A. L. DE JussiEU is usually credited with having introduced the natural 

 system of pluuts. — Trans. 



^ See p. 388 for Linne's Classification. 



2 Acherson, Flora der Provinz Brandenburg. 



286 



