202 Dr Daubeny on the Writings and 



"We thus see that the germs of two of his most important 

 publications existed in the mind of M. Decandolle at an early 

 period of his life, for in 1804, when he delivered his inau- 

 gural dissertation, and gave his first course on Botany, he was 

 only 26 years of age. 



The basis also of two other great undertakings was laid at 

 a period not much later, for in 1805 commenced, as I have 

 already stated, the publication of the third edition of the 

 Flore Fran false, under the joint auspices of Lamarck and 

 Decandolle ; and in 1806, we owe to the subject of this sketch 

 a Botanical Chart, in Avhich France is divided into six re- 

 gions, distinguished by the character of their respective vege- 

 tations, to which are appended some remarks on the geogra- 

 phical distribution of plants, serving as a prelude to that more 

 detailed exposition of the subject, which we shall find to have 

 been given, in the year 1820, in the Dictionnaire des Sciences 

 Naturelles. 



The former editions of the Flore Fran^aise, as Cuvier ob- 

 serves,* had no pretensions to be considered as a complete 

 history of the species of plants indigenous to France, — their 

 aim was rather that of exemplifying, by means of the plants 

 which former botanists had enumerated, the peculiar artifi- 

 cial method of determining the name of a species, which La- 

 marck had proposed as a substitute for the then popular one 

 of Linnasus. 



This system consists in setting out with the most general 

 forms, dividing and subdividing always by two, and only al- 

 lowing the choice between two opposite characters, so as to 

 conduct the reader, step by step, almost infallibly to the deter- 

 mination of the plant of which he desires to discover the 

 name. 



The services, therefore, which Decandolle rendered to Bo- 

 tany by associating himself with Lamarck in the publication 

 of the third edition, may be easily estimated by this circum- 

 stance alone, that whereas the preceding Floras of France 

 contained an enumeration of only 2700 plants, he had aug- 

 mented the number, in the third edition of this work, to no 

 less than 4700. 



* See Memoh'e of M. de Lamarck. 



