PROGRESS TOWARDS A NATURAL SYSTEM. 369 



of all the organs of each. A single one neglected, 

 may lead to relations the most false ; and Adanson 

 himself, in spite of the immense number of hts 

 observations, exemplifies this in some instances. 



We may add, that in the division of the struc- 

 ture into organs, and in the estimation of the gra- 

 dations of these in each artificial system, there is 

 still room for arbitrary assumption. 



In the mean time, the two Jussieus had pre- 

 sented to the world a "Natural Method," which 

 produced a stronger impression than the "Universal 

 Method" of Adanson. The first author of the sys- 

 tem was Bernard de Jussieu, who applied it in the 

 arrangement of the garden of the Trianon, in 1759, 

 though he never published upon it. His nephew, 

 Antoine Laurent de Jussieu, in his Treatise of the 

 Arrangement of the Trianon\ gave an account of 

 the principles and orders of his uncle, which he 

 adopted when he succeeded him; and, at a later 

 period, published his Genera Plantarum secundum, 

 Ordines Naturales disposita ; a work, says Cuvier, 

 which perhaps forms as important an epoch in the 

 sciences of observation, as the Chimie of Lavoisier 

 does in the sciences of experiment. The object of 

 the Jussieus was to obtain a system which should 

 be governed by the natural affinities of the plants, 

 while, at the same time, the characters by which 

 the orders were ostensibly determined, should be as 

 clear, simple, and precise, as those of the best arti- 



6 Mem. Ac. P. 1774. 

 VOL. III. B B 



