G. M. Tuomson.—On the Origin of the New Zealand Flora. 499 
land ; 7* belong to genera which are chiefly found in Eastern Australia, 
from whence the species in question have probably spread themselves east 
and west ; and 7+ more are of genera of which I do not know the centre of 
dispersion. 
A close examination of the whole leads strongly to the conclusions that 
the basis of the floras of Eastern Australia and New Zealand are somewhat 
identical ; that both have received immigrants independently after their 
separation, from north and south,—Australia by reason of its northern land 
connections with New Guinea receiving the greatest number of tropical 
species, and New Zealand from its southern extension the greatest number 
of antarctic and American species; that the West Australian flora proved 
more aggressive than the Eastern, and thus overran the whole continental 
area, giving it its peculiarly characteristic facies; and that of the astern 
species only those having considerable powers of dispersion have succeeded 
in spreading themselves westwards. 
In considering the geographical distribution of a flora it is usual to 
bring under review only the phanerogamic or flowering plants, because the 
Spores of Cryptogams furnish them with a most remarkable power of dis- 
Persion by wind. Yet even the distribution of our ferns and other vascular 
Cryptogams bears its testimony in support of the theory of the origin of the 
flora enunciated by Mr. Wallace. Excluding the endemic species there are 
about 80 per cent. of remaining forms which are spread extensively over a 
great part of the globe, about 4 strictly American, another 30 of tropical, 
Asiatic, or Polynesian occurrence, and about 36 per cent. almost exclusively 
lian. Of the 85 species common to New Zealand and Australia, only 
— 15 occur also in West Australia, and these are all species of very wide and 
_ Seneral distribution. : 
In bringing to a conclusion these somewhat disconnected remarks, I 
: shall endeavour to show how they may be pieced together so as to give 
_ Some idea of the present standing of the whole question. In examining 
S such a matter, some starting point or line of demarcation must be taken, 
for were we to go far enough back we should have to account for the very 
a existence of flowering plants themselves. There are those who believe that 
all our species have been produced by development from a few forms origin- 
Ally created in this region of the world, while others ignore the idea of 
