of Antoine Laurent De Jussieu. 615 



the Academie des Sciences ; and, in a second, presented in the 

 following year, upon the new order introduced into the plants 

 of the Jardin Royal, at Paris, we find, for the first time, the 

 fundamental principles of the natural method laid down with 

 clearness and precision. We there observe, above all, the 

 great principle of the subordination of characters, and of their 

 unequal value well appreciated, a principle unknown to Lin- 

 naeus and Adanson, evidently recognised by Bernard De Jus- 

 sieu, but of which Antoine Laurent De Jussieu was the first 

 to show the great importance, and which he afterwards so 

 skilfully applied. 



Thus, in the first of the papers cited above, we find this 

 passage : — " We have seen, by some general principles deve- 

 loped in the course of this paper, the affinity which exists be- 

 tween the parts of fructification ; we have recognised different 

 degrees of this affinity: all these characters have not the same 

 value, the same power to unite or separate plants. Some are 

 primitive, essential in themselves, and invariable; as the num- 

 ber of lobes of the embryo, its situation in the seed, the posi- 

 tion of the calyx and of the pistil, the connexion of the corolla 

 and the stamens. These serve for principal divisions ; the others 

 are secondary, they vary sometimes, and become essential only 

 when their existence is connected with one of the preceding" 

 ones; it is their assemblage which distinguishes the families." 



We may here very well see from the year 1773, the funda- 

 mental principles which have directed Antoine Laurent De 

 Jussieu in the arrangement of the Genera Plantarum, ex- 

 pressed with precision ; and, if he has sometimes deviated from 

 them, we perceive that it is rather a concession that he makes 

 to a facility of study, or to the old methods, than the result of 

 a true conviction. Thus, in the paper read in 1774, upon the 

 new order established in the Jardin des Plantes, he has evi- 

 dently departed from the rigorous principle of the insertions, 

 such as Bernard De Jussieu had admitted it in the Trianon 

 catalogues, by dividing the dicotyledonous plants into apeta- 

 lous, monopetalous, and polypetalous ; but we need only read 

 through the paper, to perceive that his sole purpose has been 

 to multiply the large classes, and to establish some relations 

 between the new order and the method of Tournefort, which 

 it took the place of, and which was generally known, not only 

 to the students, but to the greater number of contemporary 

 botanists ; and we must not lose sight of the origin of this part 

 of Jussieu's classification, when we would appreciate the method 

 followed in the Genera Plantarum, which does not differ sen- 

 sibly from it. 



From this period, until 1 785, Antoine Laurent De Jussieu 



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