of Antoine Laurent De Jussieu. 6 1 7 



In 1785, Desfontaines succeeded Lemonnier and A. L. De 

 Jussieu discontinued the demonstrations which he had made, 

 as substitute for this latter. It was then that he began the 

 digest of the Genera Plantarum, secundum Ordines Naturales 

 disposita, which was nothing more than the developement of 

 the notes used in his lectures, which he had been successively 

 perfecting since 1774. We see, indeed, the materials pre- 

 pared for this work in a catalogue of genera, at the end of 

 which is added a list of all the new genera pointed out in 

 recent works, and which might now take their places in a 

 complete Genera, 



The four years of 1785 to 1789 were therefore employed in 

 the study of the materials which were to enter into the com- 

 position of the Genera, in the digesting and the printing even 

 of the work, the printing being done by degrees, as the author 

 wrote it down, without, however, this successive, and at the 

 same time definitive, digest having caused any error of import- 

 ance ; so weli had the general plan and the series of genera 

 been previously arranged. 



The fifty years which have almost elapsed since the pub- 

 lication of this work, and the numerous investigations of 

 which the natural method has been the object since this 

 period, will almost justify us in considering the present 

 opinion of the scientific world with regard to it as the opinion 

 of posterity; and this opinion is so general and so unani- 

 mous, that it would (so to speak) be useless to demonstrate 

 its merit and importance here. However, without pretending 

 to decide upon what has been already determined by the 

 most distinguished botanists of all countries, we may be 

 allowed to enquire to what kind of merit the Genera of 

 Antoine Laurent De Jussieu owes more particularly the in- 

 fluence which it has had, not only upon the progress of 

 botany, but also upon that of almost every branch of natural 

 history. 



Until the time of the publication of the Genera Plantarum, 

 the natural method, we may say, had not entered into the 

 domain of the public. The series of Linnaeus and Bernard 

 De Jussieu, which were verj' incomplete, and only nominal, 

 could only rouse consideration in men better able to arrive 

 at its principles; the work of Adanson, being without ge- 

 neral principles, and interrupting, in many instances, the 

 natural relations of plants, was, besides, presented under 

 a form which necessarily rendered it difficult to use, and 

 which never allowed the author to develope the principles by 

 which he had been directed in establishing this or that rela- 

 tion. So that, from 1763, the period of the publication of 



