CHAPTER VII 
THE NATURAL HOME OF THE FERNS 
The area dealt with in our first edition was nominally 
that part of continental Africa lying south of the Tropic of 
Capricorn. As explained elsewhere, the present edition deals 
with South Africa up to the Zambesi and that parallel, thereby 
including the whole Union of South Africa, Southern Rho- 
desia, part of Portuguese East Africa and part of German 
West Africa. The whole of this area is now much more 
accessible than it was 22 years ago when our first edition 
was published, and most of it has been more or less carefully 
examined by botanists or botanical collectors, and the physical 
features of the country are now well known. 
The distribution of ferns usually accompanies the presence 
of suitable conditions. Presumably the exceedingly small 
and light spores are carried immense distances by the wind 
without their vitality being destroyed. At least we have the 
fact that wherever conditions are just right ferns abound, often 
many miles away from the nearest similar locality where the 
same kinds also occur, but these ferns do not appear between. 
Thus at Broughton, Molteno, on the high Stormberg 
plateau, an isolated kloof contains many species of ferns. 
So also at Wellington, Rosetta, a sheltered hillside has a 
small patch of scrub bush containing many fern species, 
though the whole neighbourhood except that patch is subject 
to intense frost and has almost no ferns. And even in the 
Karroo certain species seem to have sufficient drought- 
resisting power to find a satisfactory habitat among the 
rocks of the kopjes. Of course each kind selects its own 
class of habitat, or to put this in another form, a species 
s. f. s. A. 
4 
