NATURAL CLASSIFICATIOX. 



133 



1986. 



To know the true and absolute number of the organs of a 

 plant, we must trace them, with the help of the theory of 

 abortion and union, to the original type of the tribe or 

 family to which the plant belongs. When, for instance, I 

 remark that the Primuleae have almost all five parts in 

 their corolla and calyx, and five filaments, I cannot be led 

 into any mistake, although in the Trientalis and Tovaria I 

 commonly observe seven filaments. The original type is 

 five, to which our Trientalis sometimes returns. Also, the 

 four dissimilar filaments of Lindernia^ Limosella^ and Ceiv- 

 tunculus, cannot occasion any mistake, since these plants ap- 

 pear as Primuleae in all other respects. The fifth filament is 

 here abortive, as it is also in the Personatae, Acanthea?, and 

 Bignoniae. Among the Campanuleae, whose original number 

 is five, we yet find Canarina with six, and Michauxia witl^ 

 eight parts. 



199. 



We perceive from this, that it is a matter of more conse? 

 quence to know the relative number, than the absolute num- 

 ber of parts. It is of more importance, in particular tribes, to 

 know, that the number of the filaments is twice or three times 

 the number of the parts of the corolla and the calyx, than to 

 be able to state the precise number. This numerical propor- 

 tion, which the different parts maintain with respect to one 

 another, has often also an influence on the divisions of the 

 fruit, and even on the number of the seed. Thus in Alyssum 

 we observe a simple division of the silicula, four seeds, the 

 same number of parts in the calyx and corolla, and one 

 and a half times as many filaments. But in many genera 

 and families the number is altogether indefinite, especially in 

 the Ranunculeae and Magnoliae. 



200. 



In all regular flowers the relative number of the paits of 

 every system must be the first object of our examination ; but 

 in irregular flowers we must begin by examining the absolute 



