8 Introduction. 



arrangement adapted for ready reference. It is true that the 

 botanists of the i7th century and Linnaeus himself often spoke 

 of facility of use as a great object to be kept in view in con- 

 structing a system ; but every one who brought out a new 

 system did so really because he believed that his own was 

 a better expression of natural affinities than those of his pre- 

 decessors. If some like Ray and Morison were more influenced 

 by the wish to exhibit natural affinities by means of a system, and 

 others as Tournefort and Magnol thought more of framing a 

 perspicuous and handy arrangement of plants, yet it is plain 

 from the objections which every succeeding systematist makes 

 to his predecessors, that the exhibition of natural affinities was 

 more or less clearly in the minds of all as the main object of 

 the system ; only they all employed the same wrong means for 

 securing this end, for they fancied that natural affinities could 

 be brought out by the use of a few easily recognised marks, 

 whose value for systematic purposes had been arbitrarily de- 

 termined. This opposition between means and end runs 

 through all systematic botany from Cesalpino in 1583 to 

 Linnaeus in 1736. 



But a new departure dates from Linnaeus himself, since he 

 was the first who clearly perceived the existence of this discord. 

 He was the first who said distinctly, that there is a natural 

 system of plants, which could not be established by the use of 

 predetermined marks, as had been previously attempted, and 

 that even the rules for framing it were still undiscovered. In 

 his Fragments of the date of 1738, he gave a list of sixty-five 

 groups or orders, which he regarded provisionally as cycles of 

 natural affinity, but he did not venture to give their character- 

 istic marks. These groups, though better separated and more 

 naturally arranged than those of Kaspar Bauhin, were like his 

 founded solely on a refined feeling for the relative resemblances 

 and graduated differences that were observed in comparing 

 plants with one another, and this is no less true of the enumer- 

 ation of natural families attempted by Bernard de Jussieu in 



