272 THE JUSSIEUS AND THE NATURAL METHOD. 



Everything depends, then, on the principle of the relative importance of charac- 

 ters. But how is this relative importance to be learned ? By two means equally 

 sure, and which M. de Jussieu has himself explained : one, founded on reasoning, 

 infers directly the importance of the character from the importance of the appa- 

 ratus which furnishes it. Everything in the vegetable tends to the formation 

 of the flower; everything in the flower tends to the formation of the embryo, 

 of the new being; the formation of thi.s new being, the embryo, is therefore 

 the aim and end of all the other vegetable functions. " It is in the embryo, 

 then," says M. de Jussieu, "that naturalists must seek their principal charc- 

 ters." (Diet, des Sc. naturelles, article Methode naturelle.) In his memoir 

 of 1774, he had said: "A diff'erent conformation in the vegetable embryo 

 occasions, in the development and organization of the plant, remarkable difier- 

 euces, which constitute so many characters; these differences being dependent on 

 those of the embryo, the characters which they give depend equally on a single 

 one which determines their existence; whence it follows that the character 

 derived from the embryo must have a value equal to that of all the others 

 united. 



So much for the first means, that founded on reasoning — the rational means. 

 When this fails, M. de Jussieu supplies it by another purely experimental, and 

 which never fails. In defect of the function which is not known or is badly 

 known, he determines the importance of the organ by its constancy. Nor is this 

 all; it is with each circumstance of an organ, as with the organ itself: the cir- 

 cumstance the most constant, that is to say, the most general, is always the most 

 important. Linnaeus has made of the stamens the base of his system; the num- 

 ber, attachment, union, proportion, situation of these parts, are all considered, 

 all employed ; and he does not see that, among all these characters, one only 

 has importance, because it alone has constancy, namely, the attachment of the 

 stamens, or their insertion. Tournefort has founded his system on the corolla. 

 He considers the absence, presence, situation, division, form of the corolla, 

 and employs all these characters which are variable, while he neglects precisely 

 the character derived from the attachment of that organ, which alone is constant. 

 The natural order has escaped both these sagacious men, and has escaped both 

 from the saine cause, because of their not having recognized the relative import- 

 ance of characters. Still further, if we take the botanists from Gesner onward, 

 all those who have been fortunate in their attempts, who have discerned some 

 fragments of the natural order, all, without knowing it, were guided by the prin- 

 ciple of the importance of characters. Yet more, there are natural families 

 already formed, such as those of the graiJiinece, i\\Qcomposit(B, the umbellifera: ; if 

 we study these families, every character which varies in the family is subordi- 

 nate, is secondary ; the primitive and essential character, the important character, 

 embraces the entire family. There is, therefore, a gradation, an order in charac- 

 ters; and, as I have elsewhere said, the true problem is to begin by classifying 

 these characters, according to which the objects, in turn, are classified. 



But it will be said, perhaps, and with reason, are the important characters 

 always accessible, always easy to be determined, to be seen; and then how shall 

 we be governed in reference to the inferior, the accessories ? To know this, we 

 need only refer to M. de Jussieu : "All the characters," he says in his memoir 

 of 1773, ' have not the same value, the same eflScacy in uniting or separating 

 plants. Some are primary, essential in themselves and invariable, like the num- 

 ber of lobes of the embryo, its situation in the seed, the position of the calyx 

 and the pistil, the attachment of the corolla and the stamens ; these serve for 

 the principal divisions. The others are secondary ; they sometimes vary, and 

 only become essential wJien their existence is intimately connected ivith that oj 

 the preceding ; it is their assemblage which distinguishes families. It is true 

 that the fundamental characters of any order whatever should always be taken 

 in the fructification, but at the same time it is necessary to regard those which 



