GENERAL PRINCIPLES OF CLASSIFICATION. 185 



the same manner ; hence they are grouped together and constitute the Genus 

 Ranunculus. 



458. Orders. But natural affinities do not end here. The genera are yet 

 too numerous for the ready and systematic study of the naturalist. He, there- 

 fore, would generalize still further, and reduce the genera to still fewer and 

 broader groups. On comparing the genera with each other, he finds that they 

 also possess in common certain important characters which are of a more 

 general nature than those which distinguish them from each other. By these 

 general characters the genera are associated into Orders. 



459. For example : comparing such genera as the Mustard, Radish, Cab- 

 bage, Cress, Wallflower, etc., it is seen that, while they differ sufficiently in 

 their generic characters, yet they all have certain marked resemblances in 

 their didynamous stamens, siliquous fruit, whereby they are obviously asso- 

 ciated in the same Order the Cruciferee. So, also, the Pines, the Spruces, 

 the Cedars, the Larches, and the Cypress, while as genera they are obviously 

 distinct, yet all bear cones of some form, with naked seeds ; hence they are 

 naturally grouped into one Order the Coniferae. 



460. glasses. In like manner the Orders, by traits of resemblance still 

 more general, are associated in a few groups, each of great extent, called 

 Classes. 



461. Intermediate Groups, formed on the same principles, are recog- 

 nized as Subgenera, Suborders or Tribes, and Subclasses or Cohorts, which 

 will be particularly noticed in another place. Of the same nature, also, are 

 Varieties, which are groups subordinate to species, already described in 28. 



462. Systems. Two independent and widely dif- 

 ferent methods of classifying the genera have been 

 generally approved the Artificial Method of Linnaeus, 

 and the Natural System of Jussieu. The former is 

 founded solely on characters relating to the organs of 

 fructification, leaving all other natural affinities out of 

 view. It is simply an arrangement devised by Linnaeus 

 for convenience in the analysis of plants as words in 

 a dictionary, for convenience of reference, are arranged 

 alphabetically, without regard to their nature. It is 

 now superseded by 



463. The Natural System. This method or system 

 of classification, on the contrary, makes use of every 

 natural character and takes for its basis all those 

 natural affinities and resemblances of plants whereby 

 Nature herself has distinguished them into groups and 



