322 Transactions of the South African Philoso]jhical Society. 



and the legitimate conclusions which may be drawn from them, in 

 order to see whether they help us to make a step forward in our 

 knowledge of the origin and development of the Flora of South 

 Africa. 



Dealing with the origin of the Flora of South Africa, we have first 

 of all to cast a glance at the present distribution of flowering plants 

 of South Africa, the general features of which are now so well known 

 that I need not refer to them in detail. We recognise at once that 

 there is one region, the South- Western Eegion of Cape Colony (the 

 "Cape Province" of Marloth, 1905), which stands apart from the 

 other regions. The peculiar types characteristic of this region 

 have been mainly taken into consideration in speculations on the 

 origin of the Flora of South Africa. 



Nearly fifty years ago Dr. (now Sir Joseph) Hooker pointed out 

 the affinities of the South African Flora with the Flora of Australia 

 (Hooker, 1859). I will quote the exact words which he used, as his 

 cautious conclusions have frequently been interpreted as meaning 

 that the Australian and South- West African Floras are derived from 

 common ancestors which inhabited a vast Antarctic continent of 

 which the greater part has been submerged (see Bolus, 1905, p. 19). 

 He says on p. xcii: *' The most conspicuous characters that extra- 

 Tropical Africa presents in common with Australia, are the abun- 

 dance of species of the following orders : Proteacece, Comyositcey 

 Iridece, HcBmocloracece, Buettneriacece, PolygalecB, Bestiacece, EricecEy 

 EpacridecB, Decandrous Papilionacece, and tribes Podalyriece and 

 LotecE, Butacece, Thymelece, Santalacece, Anthospermous Buhiacece. 

 All these orders are far more abundantly represented in Australia 

 (especially South-Western) and South Africa than in any other part 

 of the world, added to which by far the greater number of the known 

 genera and species of Proteacece and Bestiacece are confined to these 

 two countries. Other marks of afiinity are the Cycadece, the genus 

 Encejjhalartos (to which Mueller reduces Macrozamia) being common 

 to both ; numerous terrestrial Orchidece, Droseracece, Zygo^jhyllecs, 

 LiliacecB, Smilaccce, and CajjparidecE ; the genera Pelargonium and 

 Mesembrianthemum, besides Metrosideros, Accena, Tctragoniay 

 Hermannia, Sarcostemma, Selxxa, Gallitris, Angiiillaria, Bestio, 

 Carphia, Uncinia, and Ehrharta. The rarity in both of AroidecEy 

 LaurinecB, and all BubiacccBy except the Anthospermian, is also 

 worthy of notice. With regard to the Natural Orders enumerated 

 above, their genera are almost unexceptionally different in the two 

 countries." 



" Succulents are comparatively rare in Australia, which almost 

 wants the conspicuous features of South African vegetation — the 



