Arrangements of Plants. 103 



fourteenth of his classes ; his fifteenth and last being composed 

 of diclinous or irregular plants, not properly reducible to any 

 other head. 



Independent, therefore, of the distinctions arising from the 

 cotyledons, which, however well founded, have been shown to 

 be of little practical utiUty, the system of Jussieu is the system 

 of Tournefort; in which Jussieu has, it seems, discovered ad- 

 vantages resulting from the incidental connection between the 

 stamina and the corolla, of which Tournefort himself was not 

 aware*. It must also be observed that the primary distinc- 

 tions of Linnaeus extend at once through the twenty-four 

 classes, whilst those of Jussieu, arising from the cotyledons, 

 extend only to three ; the secondary, founded on the corolla, 

 form only three more; and the subdivisions of these by the 

 stamina and antherce, including the anomalous class of Dicluies 

 irrcgulares, form in the whole only fifteen classes, thus obtain- 

 ing much less in point of distinction by four separate processes 

 than LinnfBus has obtained by one. 



The consecjuence of this is, that there are on an average a 

 much greater number of plants in each of the classes of Jussieu 

 than in those of Linnaeus. In order to designate these classes, 

 Linnaeus has recourse solely to the stamina, from the number, 

 proportion, and situation of which he has formed all his di- 

 stinctions, which he has comprised in one single expressive 

 word, fully indicative of the grounds upon which the class is 

 founded. Jussieu, on the contrary, in order to arrive at the 

 distinctions of his classes, has taken a more circuitous path, and 

 instead of referring to a single part, and defining it by a single 

 word, has recourse to various ]:)eculiarities, as well in the mode 

 of germination as in the fructification. Thus the compound 

 flowers, forming a natural order, are designated by Linnaeus 

 by the term Syngenesia; whilst Jussieu denominates them 



coroll-a supprimitur, ut in apetalis ; vel est simjilcx, in mediatnm fortulta 

 niutabilis, diiiii corolla existens non gerit stamina, ct tamen ferre interdiim 

 potest, ut in picris<|ue polypetalis," &c. — Juss. Gen. 11. p. 79- 



• " Tria inde eruinitur signa priniaria, fere esscntialia ac ceteris specta- 

 biliora, jam in Tournefortiana methodo tcliciter adiiibita, singula ter divi- 

 dcnda a situ staiiiinum in apetalis ct polypetalis, corollie in monopetalis." — 

 Juss. Gen. PL [). 80. 



" On retroiive done ici line des grandes divisions de Tournefort prise 

 de la coroUc, organe tres secondaire en lui-nieme, mais qui, par son union 

 avec un organe principal et essentiel dont Tournefort n'avoit pas connois- 

 sance, se trouve passer au premier rang." — E.vtrait des liegistres de la Sue. 

 lioi/. de Med. a Paris. 



But had Jussieu [jrescrved a strictly natural method, he would Iiave 

 adopted tlie distinctions on the cotyledons, as suggested by Linna;us. In 

 deserting these lie has evidently fallen into an artificial one, h.-wing no con- 

 nection whatever with the foundation on which iiis system is built. 



J'lantcf 



