8 
New Zealand Ferns 
To paraphrase Darwin, we are so profoundly ignor- 
ant of the plants living round us, that no one can tell 
why one species spreads and is numerous, and another 
has a narrow range and is rare. 
Take that most puzzling genus Asplenium. One could 
not have more divergent-looking species than A. bulbi- 
fcnnn and A. flaccidum; the one terrestrial, viviparous, 
with a broad succulent frond; the other epiphytic, gen- 
erally non-viviparous, with narrow tough fronds. Yet 
they are connected with each other by a series of inter- 
mediate forms. 
One is forced to Darwin’s conclusion that the term 
species is arbitrarily given for the sake of convenience. 
The manner of bearing seeds in Asplenium gives us a 
convenient and easily-recognised guide to a large group 
of ferns. The collector must not expect every rarity he 
finds to be a new species or even a new variety; it may 
be only one of the puzzling connecting links. 
No doubt locality has something to do with the diver- 
gent forms. I remember spending a day on the Moro-tiri 
Islands; the leaves of all the trees had a slightly different 
appearance from those on the mainland. There seems a 
probability that Asplenium lucidum and A. obtusatum 
— the roots of one luxuriating in the rich vegetable 
mould of the shady forest, the other existing precari- 
ously on storm-beaten cliffs near the sea — are really the 
same species growing in different environments, though 
it is not likely that they could be brought together again. 
The stunted, dwarfed obtusatum must have existed in 
its present habitat for such countless ages that it would 
possibly take as long' a period to re-develop and re-ex- 
pand its growth to the extent of A. lucidum. 
Botanists, who are by no means at one on the question 
of species, may be divided into two camps — what might 
be called Liberals and Conservatives — those who would 
increase the number of genera and species, and those 
who would reduce them. Until the advent of Hooker the 
Liberals held the field ; the number of varieties recorded 
