298 Historical Notice of 



quainted with the rules which directed him in his researches after 

 the natural method, it cannot he doubted that he acted on two prin- 

 ciples of this method which are still admitted as the most essential 

 and least liable to exception, namely, that the differences in the 

 structure of the embryo furnish characters of the first order, and 

 the different modes in which the parts of the flower are inserted, 

 supply characters of the second order. But when we examine the va- 

 rious catalogues which preceded the planting of the garden at Tri- 

 anon, we perceive that it was not by one trial that he arrived at this 

 result, and that he successively brought to perfection both the group- 

 ing of genera into families, and the distribution of these families. 



Such was the state of botany, viewed in relation to the natural 

 method, when Antoine Laurent de Jussieu, who was born at Lyons 

 in 1748, came to Paris in 1765, to complete his medical and scienti- 

 fic studies, under the direction of his uncle, Bernard de Jussieu. 

 The first years of his abode in this city were entirely devoted to 

 these studies, and he terminated them in 1770, by a thesis for the 

 degree of doctor in medicine. The subject of this thesis, and the 

 mode in which it is handled, show the direction already given to 

 his studies, and the philosophical spirit which animated him at first 

 entering upon his scientific career. That subject was, An econo- 

 •miam animalem inter el vegetalem analogia ? and it is, in fact, a 

 concise, elegant, and perspicuous exposition of what was positively 

 known at that period respecting the structure and functions of ve- 

 getables, and a comparison of them with the phenomena of animal 

 life. The manner in which this question is treated was evidently 

 a brilliant outset for a young man of twenty-two ; and when Le- 

 monnier, then professor of botany, became unable to attend at the Roy- 

 al garden, in consequence of the duties entailed on him by his situa- 

 tion as first Physician to the King, Bernard de Jussieu proposed 

 his nephew as his substitute, which was agreed to. Antoine- 

 Laurent de Jussieu then devoted himself, with renewed ardour, to 

 the study of that branch of science which he was thus called upon 

 to teach. 



The memoir on the family Ranunculi, which he read to the Aca- 

 demy of Sciences in 1773, proves how speedily he bad turned his 

 studies to some account, and how thoroughly his mind was imbu- 

 ed with the excellent principles, which, as above-mentioned, had 

 evidently directed Bernard de Jussieu in his attempts at natural 

 classification. 



In this memoir, which procured for its author admission into the 

 Academy of Sciences, and in a second memoir, presented the follow- 



