Corenso.— Botany of the North Island of New Zealand. 257 
only are found in New Zealand. Of the whole twenty-four or twenty-five 
species of those three great natural families found in New Zealand, only 
one species, the common tea-tree (Leptospermum scoparium), is found in 
Tasmania and Australia, while those countries possess upwards of 2,200 
known species, ` 
21. Darwin indeed states, that * New Zealand in its endemic plants 
is much more closely related to Australia, the nearest main land, than to 
any other region.”* Dr. Hooker, however, in his elaborate Introductory 
Essay to the Flora Tasmanie,;t does not go so far as this, although he, too, 
says, "that 216 or one-fourth of the New Zealand phenogams are natives 
of Australia, and of these 115 species are confined to these two countries dd 
and, “that of the 115 specimens peculiar to Australia and New Zealand, 
only twenty-six belong to genera peculiar to those countries, and only six to 
the long list of Australian genera which contain upwards of twenty 
species each.” Nevertheless it is believed that this comparison will be very 
materially altered when the whole of the flora of New Zealand and the 
many other Polynesian Islands shall be fully known. Already, since the 
publication of the Flora Nove-Zelandie, have new species been discovered 
in New Zealand, particularly in the South Island; where, too, are several 
South American genera hitherto not detected in the North Island (as 
Donatia, Rostkovia, Gaimardia, &c.), and, consequently, not referred to in 
this essay. And of those twenty-six species belonging to genera at present 
only common to Australia and New Zealand, may it not reasonably be 
expected that some of these will be also found in the many unexplored sub- 
tropical islands? Again, seeing that the striking characteristic Australian 
genera, while found in Tasmania, are wholly wanting in New Zealand, 
and that the characteristic New Zealand genera are also (as such) wanting 
in Australia, is it not evident that it is not so much from what is (the 
positive), as from what is not (the negative), that the better comparison can 
in this case be drawn, and the truer botanical affinity deduced? Reviewing, 
then, what is already known of New Zealand and southern insular botany, 
and looking forward expectingly to future kindred revelations, it is not 
unreasonably believed that the botany of the New Zealand group will be 
found to be peculiar, and not so closely related with the nearest main- 
land (Australia) as with many other small islands, and therefore forming 
with them a southern botanical insular region, of which New Zealand is 
probably about the existing centre. 
22. In bringing this necessarily imperfect outline of the botanical 
secum ecg eee IPE C M LE 
* Origin of Species, chap. xii. 
f Page 88. An admirable work, well worth the serious study of every student of New 
botany. 
33 
