352 Transactions of the South African Philosoi^hical Society. 



tions the Tropical African element is very nearly related to the 

 Indian* element, especially north of the Equator." 



" Besides, in the subxerophilous and xerophilous formations of 

 North-East Africa, and more in Somaliland than in Abyssinia, the 

 Mediterranean element is represented by numerous genera ; for 

 instance, l^'Z^^'Z^s, Pistacia, Farsetia, Diceratella, Malcomia, Gypsophila, 

 Micromeria, Lavandula, Carduncellus, Cistanche, Juniperiis, Callitris." 



" Finally, besides the Mediterranean, the boreal element has many 

 species in the microtherm formations of the high mountains of 

 Africa. These are relatively poor in plants originating from African 

 types, whereas the boreal and Mediterranean forms which have 

 immigrated into the higher mountains of Africa have developed in 

 their new area new species and varieties." 



" Lastly it must be mentioned that, in spite of the narrow 

 relations between the African mountain vegetation and the Mediter- 

 ranean Flora, there are wanting many genera and orders otherwise 

 distributed over large areas ; for instance, the Abietinece, Fagacece, 

 Betulacece, Pirolacece, Ericacece-BhododendroidecB, Aceracece, Cajpri- 

 foliacece (with exception of Samhucus ebukts), BosacecB-Spirceoidece^ 

 Coriariacece, Daphne, Aconitwn, Aquilegia, Draba, Euonymus, Geum, 

 Bibes, Bhus-sect. Trichocarpce, Hieracium, Gentiana, Iris, Lilium, 

 Fritillaria, Orchis, Ophrys. The fact that of all these groups no 

 members exist in the higher mountains of Africa proves that the 

 boreal element has immigrated from the North and East into the 

 Mediterranean regions, whereas, on the other hand, some types, 

 now believed to be properly African, for instance EncephalartoSy 

 extended their area as far as Southern Europe. Therefore the 

 hypothesis cannot be maintained that in the Tertiary period the 

 same mixed Flora was distributed over all the Old World, a Flora 

 from which the various elements should have differentiated by 

 and by." 



With reference to the subject under discussion, the connection of 

 the Flora of West Tropical Africa with the Flora of Tropical South 

 America pointed out by Engler is of particular interest, since it has 

 a bearing on the connection of our own Flora with the Flora of South 

 America generally. Already in the data of distribution w^hich I 

 submitted to illustrate the Southern origin of the typical South- 

 western Flora, a number of relations between the Flora of South 

 Africa and the Flora of Tropical Africa showed themselves. I need 

 only refer to the Iridacece — IridincB as compared with IridacecE — 

 Maricince and Iridacece — Cipurince. I would also recall the distri- 

 bution of Peripatus. Similar relations are indicated in the distri- 

 butional data which I gave about a few orders that are characteristic 



