10 M. Flourens' Historical Eloge of 



in short, is the aim and end of all other vegetative functions. 

 It is, therefore, says M. de Jussieu, in the embryo that natu- 

 ralists ought to look for their primary characters. 



When this method, founded upon reason, and which may 

 therefore be designated the rational method, fails, and it very 

 soon fails in botany, the author supplies its place by another 

 which is purely experimental, but nevertheless equally sure, 

 and which is, moreover, unfailing. In default of a function 

 which is not known, or which is but little known, or which, 

 at best, is not sufficiently knowTi to declare the importance of 

 the organ, he determines the importance of the organ by its 

 constancy. Nor is this all. As it is with an organ itself, so 

 is it with each circumstance appertaining to an organ ; the 

 most constant circumstance, in other words, the most general, 

 is always the most important. Linnaeus made the stamens 

 the base of his system ; their number, attachment, union, 

 proportion, and situation ; he considered all, he made use of 

 all, without perceiving that, among all these characters, one 

 only was of importance, and because it alone was constant, 

 namely the attachment of the stamens, or their insertion. 

 Tournefort again founded his system upon the corolla. He 

 regarded its presence, its absence, its situation, division, 

 and form, and employed all these characters, which are 

 variable, whilst he altogether overlooked the character drawn 

 from the attachment of the corolla, the one which alone 

 is constant. The natm-al order escaped the observation 

 of these two great men, and, as we have noticed, from the 

 same cause, because they were both ignorant of the relative 

 importance of characters. It will, moreover, be found, if 

 we direct attention to the progress of botanists since the time of 

 Gessner, that all those who have succeeded in their attempts, 

 having established some fragmentary portions of the natural 

 order, have followed, though unknown to themselves, the 

 principle of the importance of characters. Finally, as is gene- 

 rally known, thc'e are some natm-al families which are as it 

 were ready made to our hands, as the Graminece, the Comvositce, 

 and the Umhelliferce. In the study, then, of these families, 

 every character which varies in one of them is made subordi- 

 nate and secondary, and the primitive character, in other 



