XXIV INTRODUCTION. 



Naturales disposita, — a book of wonderful sagacity and most profound 

 research. 



Since the appearance of that work Botany has assumed a new position in 

 the ranks of science, and the evidence from which conclusions are to be 

 drawn has multiplied beyond all that could have been anticipated. Twenty 

 thousand species at the utmost could have been known to Jussieu in 1789 ; 

 we have seen that the number actually on record at the present day amounts 

 to more than 82,000. Vegetable Anatomy, the foundation of Vegetable 

 Physiology, was at the former period in the state in which it had been left by 

 Grew and Malpighi ; it has since engaged the attention of the most acute and 

 indefatigable observers, now armed with optical instruments of surprising 

 excellence. The resources of Chemistry and Natural Philosophy have been 

 enlisted in its cause ; and the result is the accumulation of a prodigious 

 mass of facts, the best mode of arranging which is the great problem that 

 modern science has to solve. 



That no artificial mode of classifying the vast materials of Botany could 

 satisfy the human mind was clearly perceived and fully admitted by Linnaeus 

 himself, when he declared a Natiu-al System to be the primum et ultimum 

 in botanicis desideratum (Phil. Bot. § 77). That no insuperable obstacle 

 to its attainment could exist in the nature of things became evident the 

 moment that the work of Jussieu was before the world. That Botanist for 

 the first time proposed distinctive characters for the groups of genera, which 

 he called Natiu-al Orders, and those characters were framed with such skill 

 that a large proportion of his distinctions is still unafi*ected by the progress 

 of modern discovery. The manner in which he obtained the distinctions of 

 his Natural Orders was thus described by himself : — " C'est ainsi que sont 

 formees les families tres naturelles et generalement avouees. On extrait 

 de tous les genres qui composent chacune d'elles les caracteres communs a 

 tous, sans excepter ceux qui nappartiennent pas a la fructification, et la 

 reunion de ces caracteres communs constitue celui de la famille. Plus les 

 ressemblances sont nomhreuses, plus les families sont naturelles, et par suite 

 le caractere general est plus charge. En procedant ainsi, on parment plus 

 surement au but principal de la Science, qui est, non de nommer une 

 plante, mais de connoitre sa nature et son organisation entiere.'' 



The Natural Orders thus obtained were bound together into a system by 

 adopting the important distinctions of Acotyledons, Monocotyledons, and 

 Dicotyledons, and then by subdividing the two latter into Classes mainly 

 characterised by the insertion of the stamens or the condition of the coroDa ; 

 as will be more particularly explained hereafter. 



It was not, however, to be expected that the views of Jussieu should be 

 just in all respects, or that his scanty materials would enable him to form 

 a plan of classification sound and perfect in all its parts. On the contrary, 

 his system abounded in errors and imperfections, and, in fact, the latter 

 years of his Hfe were occupied in striving to improve and consolidate it. 

 The same object has been sought by great numbers of those who have 

 succeeded him, and every few years of late have witnessed the production 

 of some scheme of classification which, although founded essentially upon 

 the groundwork of Jussieu, difi'ered nevertheless in munerous details. In 

 another place, the principal of these schemes will be mentioned. It will be 

 for the present sufficient to say that, beginning with Brown in 1810, and 

 ending with Adolphe Brongniart in 1843, the mass of suggestions and 

 improvements which has been collected renders comparatively easy the task 

 of applying Jussieu 's principles of classification to the vast multitudes of 

 species now forming the Vegetable Kingdom. 



