of Anloine Laurent De Jussieu. 623 



ment with what certainty his appreciation of characters, of 

 their value, their subordination, or their incompatibility, di- 

 rected him in this difficult discussion. We there distinguish 

 plainly the method which directed him in connecting numerous 

 exotic genera, often such as were imperfectly known, and 

 which he has classed, almost always so happily, in his 

 immortal work. 



The last of these papers that was published by A. L. De 

 Jussieu appeared in 1820, in the sixth volume of the Memoirs 

 of the Museum. It had for its subject the family of the 

 Rubiaceae, of which it showed all the genera, distributed and 

 described as the author intended they should be in the new 

 edition which he then projected of the Genera Plantarum, for 

 which he was constantly collecting materials. This last work, 

 published at the age of seventy-two, is worthy of that of 1789: 

 we find there the same order, the same clearness of ideas, the 

 same simple and precise arrangement. 



From this period, Antoine Laurent De Jussieu, whose sight 

 had so much failed him as to render it necessary he should 

 confine himself to studying the labours of others, and re- 

 nounce the examination of nature, has only furnished the 

 science with some articles inserted in the Dictionnaire des 

 Sciences Natureltes, both upon families and upon plants cited 

 by travellers under their vulgar name, and which he had ap- 

 plied himself to restoring to their genus or their family. The 

 materials he has deposited in this collection were what he had 

 been a long time employed in obtaining, and in which we still 

 recognise a man who joins an acquaintance with nature to an 

 erudition the most extensive. 



We ought to point out in this collection the article Methode 

 Naturelle, published in 1824, in which the same great natural- 

 ist has displayed, with his usual clearness, the history of the 

 natural method in botany, and the principles upon which it 

 rests. 



At length, in the later years of his life, from the year 1826, 

 a son worthy of himself having supplied his place in the 

 functions he exercised in the Museum d'Histoire Naturelle, 

 he passed a great part of the year in the country, and divided 

 his time between the perusal of the most modern works upon 

 botany, and the arrangement and analysis of those among his 

 works which appeared to him most important to the science. 



Combining recent discoveries with the knowledge acquired 

 during his long career, he made them the subject of a new 

 edition of the Introduction to his Genera Plautarum. 



We find in this Procemium, written in the clear and elegant 

 Latin of the introduction to the Genera, a part of the ideas 



