1 02 Mr. Roscoe on Artificial and Natural 



without affording an adequate advantage, and throws a doubt 

 over the great mass of individuals of the vegetable kingdom, 

 to be removed only by inquiring into the mode of their early 

 growth, in order to separate from the rest some detached 

 plants which are equally as well separated by other distinc- 

 tions quite as natural and more permanent, and which it is 

 indeed impossible should be confounded with them. 



This peculiarity in the method of Jussieu being considered, 

 the two systems, as far as tliey regard the great mass of the 

 vegetable kingdom, may now be placed in more direct com- 

 parison. Linnteus has founded his primitive distinctions on 

 the number and proportions of the stamina; not omitting the 

 diversities arising from their situation. Jussieu, disregarding 

 in his primary distinctions the number of the stamina, has re- 

 course merely to their situation, which he distinguishes into 

 three different manners, as being placed upon, around, or be- 

 low the germen, under the appellations o^ Epigijna, Perigyna^ 

 and Upogyna *. This distinction is applied however only to 

 his apetalous and polypetalous plants, the monopetalous plants 

 being distinguished not innnediately by the stamina, but by 

 the situation of the corolla. This necessarily compels him to 

 commence his definitions by the corolla, and accordingly he 

 first divides his dicotyledonous plants into apetalous, mo7io- 

 petalous, and polypetalous. Of these the apetalous are to be 

 again subdivided by the stamina, which ai'e considered with 

 respect, not to the number, but the situation ; and as in the 

 absence of the corolla the stamina are inserted directly into 

 the style or germen, this is denominated the absolutely imme- 

 diate insertion of the stamina, constituting the fifth, sixth, and 

 seventh, of his classes. The monopetahv, distinguished into 

 separate tribes by the corolla, which is for the most part sta- 

 miniferous, and is therefore said to exhibit the mediate inser- 

 tion of the stamina, form the eighth, ninth, tenth, and eleventh, 

 classes ; and the polypetahc, characterized again by the situa- 

 tion of the stamina, the insertion of which is here called sim- 

 ply immediate, as it accidentally varies at times into the mediate 

 insertion, or in other words is found sometimes on the germen 

 and at others on the corolla f, form the twelfth, thirteenth and 



fourteenth 



* With respect to these distinctions, the most important in the arrange- 

 ment of Jussieu, the reader {fiiuov" A(^pYiu 'icro) may consult Mr. Salisbury's 

 " Observations on the Perigynous Insertion of tiie Stamina of Plants;" 

 ■where he has undertaken to show that such perigynous insertion is entirely 

 factitious, and that there is no instance whatever, in the whole vegeta- 

 ble kingdont, of stamina being inserted in the calyx. — V. Tians. Linn. Soc, 

 vol. viii. p. 1. 



t " hisertio immediata vel est absoluta in nicdiatam mutari ncscia, dum 



corolla 



