Philosophical Character of Decandolle. 227 



We, therefoi'e, obtain four groups, viz. : — ■ 



Isostemones polypetaloe. 

 Isostemones gamopetalse . 



Diplostemones polypetalse. 

 Diplostemones gamopetalai. 



These distinctions Decandolle delineates by the device of a 

 circle, for the whole family taken collectively, divided into 

 four equal parts, to represent the four tribes alluded to, whilst 

 the genera placed circularly nearest to the central point, are 

 those which shew the general characters of the family in the 

 most perfect manner, and in each division those in the bor- 

 ders indicate the genera which are more anomalous. 



Thus in the division entitled Isostemones polypetalae, we 



