a Study in Taxonomic Distribution . 25 
to itself alone. In its relations to South Island it occupies a position like 
that of Ceylon in relation to South India. 
It has the same indented rocky coast as South Island, and is similarly 
mountainous, Mt. Anglem reaching 3,200 feet. Geologically it is chiefly 
composed of archaean rocks, like those in the extreme south-west of South 
Island. It is clear from the soundings (see map) that it must have received 
its flora by way of New Zealand proper, and, being closer to the main 
islands, and probably not divided from New Zealand at an earlier period 
than the Chathams and Aucklands, 
it has received many more plants 
than they, and has double the flora 
of either of them. 
Stewart Island being thus away 
from the general centres of distri- 
bution of the New Zealand flora, 
which in the previous paper we 
have seen to have been, one prob- 
ably in the North Island, the other 
somewhere about the middle of the 
southern half of the South Island, 
a brief consideration of its relation- 
ships from the standpoint of age 
and area enables us to say that its 
flora will be composed of species 
which in comparison to those of New 
Zealand proper will be old . 1 We shall work upon this as a fundamental fact 
and go on to study the flora by the method of prediction and verification. 
Composition of the Flora of Stewart Island, 
As showing that age and area lends itself to prediction, we shall begin 
by endeavouring to predict as far as may be the actual composition of the 
flora, assuming that we know nothing about Stewart other than its position, 
but that we know the floras of New Zealand and the other outlying islands 
to the extent described by Cheeseman ( 1 , 2 ). 
To commence with the actual size of the flora : we have seen that the 
falling off in number of species from their zones of greatest concentration is 
fairly regular (8, p. 343 2 ), and we should expect, if Stewart were in land 
connexion, that the flora would be about 550, but as the formation of the 
strait must have been early enough to prevent many species from crossing 
which have since reached the strait from the north, we shall not expect so 
1 The same conclusion follows almost as clearly from the usual interpretation of the hypothesis 
of Natural Selection. 
2 Species endemic to New Zealand and islands are not given in this list. 
New Zealand and outlying islands. The dotted 
line is the 1,000 fathom limit. 
