Distribution. 
35 
Australia, and these, with one or two exceptions, are cosmo- 
politan ; while 28 occur in Asia, 28 in South America, and 19 in 
North America. More decided is the connection of the Natal 
ferns with those of India. 
Of the 130 Natal species, 52 occur in Asia, and at least 40 of 
this number in India, 27 of which do not extend south of Port 
Elizabeth, and many not south of Natal. 
The absence of European forms may be noted, only 14 being 
found, all cosmopolitan in similar climates, and all, except Pteris 
cretica and P. longifolia, found in England. 
The number of species found in South Africa is small com- 
pared with India, or Brazil, or the tropical islands, but is quite as 
large as in similar large areas outside the tropio6. To the whole 
of Europe Kuhn credits 123 species; in the whole of Australia 
Baron Mueller finds 244 species ; while Dr. Asa Gray allowed 
only 90 species for the Northern United States of America, of 
which 33 are fern allies. 
If the Karroo be excluded, the number of species to be found 
in any part of South Africa of equal size with Great Britain is 
about double the number found there. 
The total number of ferns and fern allies for the whole world 
is about 3500 species, so only about 4^ per cent, of the whole 
number are as yet known to be South African. 
Compared with the whole flora of South Africa, the ferns are 
remarkably few, for as it is estimated that there are 10,000 species 
of flowering plants within our area, ferns form only per cent., 
while in Australia, with about 9000 known species of plants, they 
form 2 2 /z per cent.; and in several sub-tropical islands they form 
from 20 to 50 per cent, of the whole flora. 
Not one of the numerous foreign ferns imported into the Cape 
for cultivation is as yet known to have thoroughly established 
itself anywhere in our forests, or even to have attempted escape, 
except the record of Pteris tremula in Natal, which doubtless was 
such a case. Possibly also the existence of Pteris longifolia at 
Uitenhage may be due to the garden formerly kept up there by 
Dr. Brehm. 
