XXXIX 



TABLE OF THE CLASSES, ORDEES, ETC., 

 OF THE SOUTH AFRICAN FLORA. 



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 Gandolle, 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 Polypetalecd TlialamiflorcB) ^ 

 were more highly organized than those with fewer floral whorls, 

 and these irregular, and their constituent parts combined (as 

 in ^fonopetalece, 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 Avith 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 ari'anged 

 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 



