OF THE CAMEROONS MOUNTAINS, ETC. 181 
Festuca gigantea, all of which, however, may have been hitherto 
overlooked in Abyssinia. 
Considering the total isolation of these tropical African moun- 
tains from the European regions by hot, low deserts, the existence 
of these plants in common is most singular, and explieable under 
two hypotheses: 1st, Mr. Darwin's theory, which assumes that 
during the glacial epoch the plants of the northern zones were 
driven southwards into the tropics, and on the return of warmth 
they both retreated northwards and ascended the intertropical 
mountains; and 2nd, transport by aérial currents and birds—in 
favour of which is to be urged that, of the whole, six present 
structural adaptations for clinging to the plumage of birds, and all 
the rest have small or very minute seeds, likely to be transported 
in mud on the feet of birds. Solanum nigrum has rather larger 
seeds, but with remarkable power of retaining their vitality, and, 
further, is found in North Africa and many intermediate countries, 
as are several of the others. 
4. The paucity of South-African types was alluded to in dis- 
cussing the 76 species of the Fernando Po mountain. The great 
accession of species from the Cameroons has added but few Cape 
forms; the principal are, Anthospermum, Anisorhamphus (perhaps 
referable to Hieracium), a species of Ilex, Lasiosiphon, Peddiea, 
Geissorhiza, Hypoxis, and a few others. 
5. Only one new genus has been found, Ardisiandra (see 
Plate I.)—a very well marked new form of Primulacez, not 
indicating an affinity with any other flora. 
6. Of the peculiar genera and species of St. Helena not one has 
been found ; and what genera are common to that island and these 
mountains are also natives of the Cape region, and far more 
abundant there. 
Florula of the Peaks of Biafra at and above 5000 feet elevation. 
1. RaNUNCULACES. 
1. CLEMATIS Stmensts, Fresen. (ante, vi. 4). 
Hab. Fernando Po and Cameroons Mountains, alt. 4000-8000 feet. (Fl. 
and frt. Dec.-Jan.) 
Fruiting specimens are identical with Abyssinian. The Came- 
roons Mountains! individuals have the flowers as large as the 
Abyssinian. 
2. THALICTRUM RHYNCHOCARPUM, A, Rich (ante, vi. 4). 
Hab. Fernando Po, alt. 10,000 feet. Cameroons Mountains, alt. 7000 l 
feet. (Fl. and frt. Nov.) 
