XXXIx 
TABLE OF THE CLASSES, ORDERS, ETC., 
OF THE SOUTH AFRICAN FLORA. 
ee’ 
In the following pages I have endeavoured to group the 
Natural Orders of South African plants in such a manner as 
to afford some indication of the principles according to which 
they have been brought into the sequence adopted in this 
work by Dr. Harvey. _ This sequence is in the main that pro- 
posed by Jussieu, and carried out by De Candolle, and most 
subsequent authorities. In so far as the limitation and order 
of the Classes and Subclasses and of the Cohorts and Orders 
of Monocotyledons and Acotyledons is concerned, it is no 
doubt a very natural system; but this is not so with the 
Orders of Angiospermous Dicotyledons, the arrangement of 
which is very artificial. The principle upon which De Candolle 
arranged the latter Orders involved two assumptions : one, that 
plants with their floral whorls complete, and each whorl regular 
and composed of separate parts (as Polypetalee Thalamiflore), 
were more highly organized than those with fewer floral whorls, 
and these irregular, and their constituent parts combined (as 
in Monopetalee, etc.) ;—the other that the presence of but one 
whorl in the perianth, or of no perianth, indicated that such 
Orders should be kept apart from the rest. Advanced know- 
ledge has, however, carried conviction to many minds, that 
Dicotyledonous plants with combined organs are really more 
highly organized than those with these parts free ; that irre- 
gularity of flower prevails in the highest organized groups, 
and that the majority of the Orders with reduced floral enve- 
lopes are really members of other Orders whose prevailing 
features are of a complex and high type. 
The fact is, that the Dicotyledonous Orders cannot be ar- 
ranged in a linear series,—but as descriptions and arranged 
collections of them must follow a linear series, the Candollean 
is adopted for its facility, and because none better (though 
several others as good) has been proposed. It further pos- 
sesses this advantage, that most of the Orders of the highest 
