The Growth-Forms of Natal Plants. 
635 
species which depend on the presence of Phanerophytes, as explained above. 
The high percentage of Chamaephytes also shows the effect of drought. 
Aden, it will be seen, shows a similar effect. If the temperature were lower 
in winter there would be fewer Chamaephytes and more Hemicryptophytes, 
as shown by the figures for colder, temperate regions. Denmark, for 
instance, has only 3 per cent. Ch. and 50 per cent. H. 
That this is not explained by the Chamaephytes being increased by the 
presence of Phanerophytes, is shown by the figures for Seychelles, which has 
a more Phanerophytic climate than that of Natal. They are 6 per cent. 
Ch. and 12 per cent. H. 
The climate of Natal may be looked upon as mainly Chamaephytic, but 
not pronouncedly so. The high percentage of C-eophytes (six times the 
normal) is so characteristic of Natal (and of South Africa as a whole), that 
this might be called the country of G-eophytes. 
The class, H.H., as will be seen from the table, varies greatly in different 
countries. In Natal we have 5*5 per cent., which seems to be about an 
average, though Eaunkiaer gives 1 per cent, as the normal, a figure which is 
surely too low. This class of growth form composes the vlei formation of 
Natal. Vleis are very numerous at all altitudes, but nowhere very large. 
There are no lakes. 
Therophytes in Natal are not very abundant. The percentage is 6 '5, 
or exactly half the normal. Natal is certainly far removed from the desert 
type, and it is not under high cultivation. Probably the west side of South 
Africa has a much higher percentage of Therophytes, owing to the much 
more arid conditions prevailing there. 
LITEEATUEE CITED. 
(1) Bews, J. W., 1912.— The Vegetation of Natal. Annals of Natal 
Museum, vol. ii, pt. 3. 
(2) • 1913.— An Ecological Survey of the Midlands of Natal, with 
special reference to the Pietermaritzburg district. Annals of Natal 
Museum, vol ii, pt. 4. 
(3) Coulter, Barnes, and Cowles. — Text-book of Botany, vol. ii ; 
Ecology. 
(4) Drude, 0., 1890. — Handbuch der Pflanzengeographie. 
(5) 1896. — Deutschlands Pflanzengeographie. 
(6) Haberlandt, 1909. — Physiologische Pflanzenanotomie. 
(7) Humboldt, A., 1805. — Aspects of Nature. Eng. Ed., Lond., 1849. 
(8) 1806.— The Physiognomy of Plants. Eng. Ed., Lond., 1849. 
(9) 1807. — Essai sur le geographie de plantes. Paris. 
(10) Krause, E. H. L., 1891. — Die Eintheilung der Pflanzen nach ihrer 
Dauer. Ber. Deut. Bot., G-es. ix. 
