66 BIOGRAPHIES OF SCIENTIFIC MEN 



the oldest in the world's history. Each of the classes is 

 subdivided into two or more orders. Such is an outline 

 of the system of classification of Linnaeus. The system 

 brings together, for no other purpose than for convenience 

 of reference, plants dissimilar in structure, habit, and 

 properties. It is an " artificial system," such as Linnaeus 

 always intended it to be. It has been superseded by the 

 "natural system" of De Candolle, which is based on 

 various natural systems. Linnaeus knew the value of a 

 natural system of classification. He says : " Methodi natur- 

 alis fragmenta inquirenda sunt. Primum et ultimum hoc 

 in botanicis desideratum est. Plantse omnes utrimque 

 affinitatem monstrant uti territorium in mappa geogra- 

 phic^. . . . Methodus naturalis est ultimus finis botanicis. 

 . . . Naturalis character ab omni botanico teneatur 

 oportet." He left a slight sketch of a natural system; 

 but the limited knowledge of genera and species in his 

 day would have rendered such a system of classification 

 imperfect and useless. Not so, however, "his artificial 

 system, which, still marked by the limits that he assigned, 

 not only offers facilities for forming an acquaintance with 

 the names of plants, but affords ready means of reference 

 to any system in which plants are arranged according 

 to their natural characters." Although superseded, the 

 system of Linnaeus is still useful as an index ; and even 

 the present natural system " cannot be regarded as being 

 perfectly evolved." Linnaeus established the binomial 



