634 Transactions of the Royal Society of South Africa. 
more than the temperate regions of the Northern Hemisphere. Denmark has 
only 7 per cent., Stuttgart 10 per cent. Aden approaches nearest to Natal, 
but it has no Mesophanerophytes. All its trees are below 8 metres. 
The presence of 1 per cent, of Epiphytes is interesting. The normal is 
3 per cent., the same as Seychelles. Epiphytes are confined practically to 
countries with some degree of a Phanerophytic climate. The Danish West 
Indies also has 1 per cent., the same as Natal. 
Natal does possess a Phanerophytic climate — in parts. The trees have 
to contend with adverse factors generally, but in certain situations these are 
lessened ; or, to put it otherwise, a Phanerophytic climate is not general in 
Natal. Forests are confined to the south-eastern slopes of the hills, and in 
other plant-formations trees occur but grow isolated — e.g. in the Thorn Yeld. 
In the forests a very large number of species of Phanerophytes grow 
intermingled. There is not the same uniformity and marked dominance of 
one or two species that is found in the forests of the Northern Hemisphere. 
Considering how much more extensive the veld is than the bush in Natal, it 
is surprising to find that the percentage of Phanerophytes is so great as it is. 
The individual species show great plasticity and consequently great variation, 
according to differences in environmental conditions. In the larger classes the 
species may be arranged in a series showing increased xeromorphy. There 
must be taken into consideration, not only the effect of the non-living environ- 
ment, but also the influence of one part of the vegetation on the rest. The 
Phanerophytes thus not only influence one another (and one class of 
Phanerophytes another class), but also other distinct classes. A considerable 
number of Chamaephytes are present in the bush, and owe their existence 
there to the presence of the Phanerophytes. 
Hemicryptophytes and G-eophytes, on the other hand, are not abundant 
in the evergreen bush of Natal as they are in deciduous woodland elsewhere. 
There is a large number of lianes among Natal Phanerophytes. 
Considering next the three classes Ch., H., and Gr., we find that the 
percentages for Natal are respectively 19, 18, 18 as compared with 9, 27, 
and 3 in the normal spectrum. The climate of Natal to a great extent 
favours the greater protection of renewal buds, and therefore a much greater 
area is occupied by veld formation made up of those classes of growth-forms. 
The grasses are either Ch. or H., but the present tendency is for the 
latter to oust the former. The high proportion of Gr. is explained when we 
take into consideration the fact that this type is best suited for association 
with the grasses in the veld owing to the necessity for early flowering, etc., 
as well as protection during winter, and, being more deeply situated in the 
soil, they do not directly compete with the grasses. The increase in the 
number of C-eophytes corresponds to a decrease in the number of Hemicrypto- 
phytes. They are both veld types. 
The numlier of Chamaephytes has })een increased by the inclusion of 
