PROGRESS TOWARDS A NATURAL SYSTEM. 407 



was this employment which first opened hjs eyes and rendered him a 

 botanist. In the memoir which he wrote, he explained fully the rela- 

 tive importance of the characters of plants, and the subordination of 

 some to others ; an essential consideration, which Adanson's scheme 

 had failed to take account of. The uncle died in 1777; and his 

 nephew, in speaking of him, compares his arrangement to the Ordines 

 Naturales of Linnaeus : " Both these authors," he says, " have satisfied 

 themselves with giving a catalogue of genera which approach each 

 other in different points, without explaining the motives which induced 

 them to place one order before another, or to arrange a genus under 

 a certain order. These two arrangements may be conceived as pro- 

 blems which their authors have left for botanists to solve. Linnaeus 

 published his ; that of M. de Jussieu is only known by the manuscript 

 catalogues of the garden of the Trianon." 



It was not till the younger Jussieu had employed himself for nine- 

 teen years upon botany, that he published, in 1789, his Genera Plan- 

 tarum ; and by this time he had so entirely formed his scheme in his 

 head, that he began the impression without having written the book, 

 and the manuscript was never more than two pages in advance of the 

 printer's type. 



When this work appeared, it was not received with any enthusiasm ; 

 indeed, at that time, the revolution of states absorbed the thoughts of 

 all Europe, and left men little leisure to attend to the revolutions of 

 science. The author himself was drawn into the vortex of public 

 affairs, and for some years forgot his book. The method made its 

 way slowly and with difficulty : it was a long time before it was com- 

 prehended and adopted in 'France, although the botanists of that 

 country had, a little while before, been so eager in pursuit of a natural 

 system. In England and Germany, which had readily received the 

 Linna3an method, its progress was still more tardy. 



There is only one point, on which it appears necessary further to 

 dwell. A main and fundamental distinction in all natural systems, is 

 that of the Monocotyledonous and Dicotyledonous plants; that is, 

 plants whioh unfold themselves from an embryo with two little leaves, 

 or with one leaf only. This distinction produces its effects in the 

 systems which are regulated by numbers ; for the flowers and fruit of 

 the monocotyledons are generally referrible to some law in which the 

 number three prevails ; a type which rarely occurs in dicotyledons, 

 these affecting most commonly an arrangement founded on the num- 

 ber five. But it appears, when we attempt to rise towards a natural 



