174 LAMARCK, HIS LIFE AND WORK 
ber of the French Academy, have been already 
recounted. 
Lamarck was thirty-four when his Flore /rancaise 
appeared. It was not preceded, as in the case of 
most botanical works, by any preliminary papers 
containing descriptions of new or unknown species, 
and the three stout octavo volumes appeared to- 
gether at the same date. 
The first volume opens with a report on the work 
made by MM. Duhamel and Guettard. Then fol- 
lows the Dzscours Préliminaire, comprising over a 
hundred pages, while the main body of the work 
opens with the Prznczpes Elémentaires de Botanique, 
occupying 223 pages. The work was a general ele- 
mentary botany and written in French. Before this 
time botanists had departed from the artificial system 
of Linné, though it was convenient for amateurs in 
naming their plants. Jussieu had proposed his system 
of natural families, founded on a scientific basis, but 
naturally more difficult for the use of beginners. To 
obviate the matter Lamarck conceived and proposed 
the dichotomic method for the easy determination of 
species. No new species were described, and the 
work, written in the vernacular, was simply a guide 
to the indigenous plants of France, beginning with 
the cryptogams and ending with the flowering plants. 
A second edition appeared in 1780, and a third, 
edited and remodelled by A. P. De Candolle, and 
forming six volumes, appeared in 1805-1815. ‘This 
was until within a comparatively few years the 
standard French botany. 
Soon after the publication of his Flore Francaise he 
