92 Artificial Systems and Terminology of [BOOKI. 



methodical study which he bestowed on the distinguishing of 

 genera and species ; this system of nomenclature he endea- 

 voured to extend to the whole of the then known vegetable 

 world, and thus descriptive botany in its narrower sense 

 assumed through his instrumentality an entirely new form, 

 which, serving as a model for the naming and defining of 

 the larger groups, could be applied without modification to the 

 founding and completing the natural system. When at a later 

 time Jussieu and De Candolle marked out their families and 

 groups of families, their mode of proceeding was in the main 

 that of Linnaeus when distinguishing his genera by abstraction 

 of specific differences. This merit has been always assigned 

 to Linnaeus without reserve. The second merit has been less 

 recognised, and yet it is at least of equal importance ; it is that 

 of having first perceived that the attempt made by Cesalpino 

 and his successors to found a system, that shall do justice 

 to natural affinities, on predetermined marks can never 

 succeed. Linnaeus framed his artificial sexual system, but he 

 exhibited a fragment of a natural system by its side, while he 

 repeatedly declared that the chief task of botanists is to dis- 

 cover the natural system. Thus he cleared the ground for 

 systematic botany. He made use of his own system, because 

 it was extremely convenient for describing individual plants, 

 but he ascribed all true scientific value exclusively to the 

 natural system ; and with what success he laboured to advance 

 it may be gathered from the fact, that Bernard de Jussieu 

 founded his improved series of families on the fragment of 

 Linnaeus, and that his nephew, A. L. de Jussieu, by simply 

 adopting Linnaeus' conception of the principle which lies at 

 the foundation of the natural system, succeeded in carrying it 

 on to a further stage of development. 



The main features of Linnaeus' theoretical botany can best 

 be learned from the ' Philosophia Botanica,' which may be 

 regarded as a text-book of that which Linnaeus called botany, 

 and which far surpasses all earlier compositions of the kind in 



