MOUNTAINS OF RASTERN EQUATORIAL AFRICA. 395 



of the western flora is in European types not hitherto detected 

 in the east. 



4. The Affinity of the Flora with that of the Highlands of 

 Abyssinia is very marked, as was to have been expected. Most 

 of the genera are in fact Abyssinian, as are all, or nearly all, of 

 the following species : — Banunculus oreophytus, Viola abyssinica, 

 Sparmannia abyssinica, Geranium simense ?, Trifolium simense, 

 Lotus tigrensis ?, Lythrum rotundifolium, JEpilobium stenophyllum, 

 Diplolophium abyssinicum, Caucalis melanantha, Coreopsis abyssi- 

 nica, Lightfootia abyssinica, Erica arborea, Swertia Schimperi, S. 

 pumila, and Juniperus procera. Besides the above, the Abyssi- 

 nian affinity is shown by the presence of an Ueberlinia, a genus 

 hitherto known only as a monotypic Abyssinian one, and by the 

 species of several of the other genera being more nearly allied to 

 plants of that country than of any other. 



5. On the Origin of the Flora. — The most striking feature of 

 the flora thus first explored by Mr. Thomson is the discovery 

 in Lykipia of three such typical forest -trees in close association 

 as the Juniperus procera of Abyssinia, the Calodendron capense 

 of South Africa, and the noble JPodocarpus, a close ally both of 

 the Cape P. elongata and of the eastern tropical P. Mannii, 

 discovered on the top of the peak of the island of St. Thomas 

 by the naturalist whose name it bears. And these three plants 

 no doubt indicate the affinities of the flora being most strong 

 with the countries north and south of it, and less so with that 

 far to the east of it. This is what the configuration of the con- 

 tinent would indicate as most probable, the loftier mountains 

 being on the east side, and being connected by more or less con- 

 tinuity of high land from Abyssinia to the Cape Colony. That 

 the flora of the latter country extended into the former was well 

 known ; and this renders the discovery of a locality in the line 

 of continuous migration or distribution, where the most marked 

 type of the northern flora '(Juniperus) meets the most marked of 

 the southern (Calodendron), and this at the respective limits of 

 each, a most interesting one, and only second in importance to 

 the general result of Mr. Thomson's labours, which is the dis- 

 covery of so many northern forms in the comparatively isolated 

 equatorial tracts which he has been the first to explore. 



Thus I think it may be regarded as most probable that the 

 Equatorial African mountain-flora is in the main an immigrant 

 one from Abyssinia, possessing many genera and species that 



