GEOGRAPHICAL BOTANY. 385 



might form the boundary between the flora of the Cape, 

 and of the CafTre country ; for here certain types of tropical 

 Natal commence, whilst the Proteacese, Ericaceae, Sela- 

 ginese, &c., diminish. The shrub-formations in Algoa 

 Bay are taller and thicker than in the western districts ; 

 they serve as places of concealment for large Pachyderinata. 

 Characteristic . forms of plants : Celastrinea3, Euphorbia 

 Canariensis, Strelitza, Zamia, Tamus, Pelargonium, &c. 

 This remarkable difference between the eastern and 

 western provinces of the Cape Colony, which Bunbury 

 also (London Journal of Botany, 1844, pp. 230-63) men- 

 tions and enlarges upon more in detail, is by no means 

 to be so simply explained as the tropical peculiarities 

 of the flora of Natal. At Graham's Town in Albany, 

 Bunbury only found 13 plants in the extensive surround- 

 ing country, and these occur also at the Cape. Ericaceas 

 and ProteaceaB are rare, arborescent Euphorbias common, 

 and the Restiacese replaced by Grasses. Extending along 

 the Great Fish River, we find the wildest thickets of shrubs 

 with arborescent Euphorbias, Strelilzia, and Zamia horrida; 

 these are more impenetrable, and from the presence of 

 spinous trees, more inaccessible than the natural Brazilian 

 forests : they merely form the abode of large Pachydermata 

 and border-robbers of the Caffre race. Tropical families 

 of plants, single species of which only occur at the Cape, 

 become numerous in Albany, especially Acanthacese, 

 Apocynese, Bignoniacese, Rubiacese, and Capparidaceae. 

 These and other similar facts evidently indicate an ap- 

 proximation to the flora of Natal, although by no means 

 to the extent these two authors suppose, viz. that the 

 vegetation of Albany and Natal gradually run into each 

 other. As long as the intermediate districts of the Caffre 

 country are so little known, this must remain hypothetical, 

 but is rendered extremely improbable by climatic laws. 

 A resemblance of certain families and forms is by no 

 means a resemblance of species and their combination 

 into formations. But the increase of tropical forms in 

 Albany is even considerably more mysterious than the 



25 



