THE ORIGIN OF THE FAUNA AND FLORA OF NEW ZEALAND. 269 
species which do not occur in New Zealand, it is evident that 
their floras are not altogether derived from New Zealand, but 
that the antarctic plants came through them and spread north- 
ward. Itis true that there are also antarctic species in New 
Zealand which are not found in the southern islands; but this is 
only what we should expect, when we consider the relative size 
of the places, and reflect that these islands are merely the remains 
of a more extensive land. But granting that these plants came 
to New Zealand from the south, did they spread from S. America 
to the east or to the west? Mr. Wallace says that the route by 
which the Fuegian plants may have reached New Zealand is 
easily marked off. It is by South Shetland Islands, Graham’s 
Land, the Antarctic Continent to Victoria Land, thence to Adelie 
Island, Young Island, and Macquarie Island.* Thus passing 
from Graham’s Land in a westerly direction at the high latitude 
of more than 70° S. to Victoria Land, along a coast where no 
vegetation now exists. He gives, however, no reasons for adopt- 
ing this route, and it does not seem to be quite consistent with 
his previously expressed opinion of a “‘long persistent more or 
less glaciated condition” of the southern hemisphere. On the 
other hand, Sir J. Hooker points out that there are five groups 
of islands between Fuegia and Kerguelen Land, then none to 
Macquarie and Campbell Islands, and none across the whole 
Pacific Ocean from Campbell Island to Fuegia. He says that 
“Tierra del Fuego and the neighbouring southern extremity of 
the American continent appear to be the region of whose botani- 
cal peculiarities all the other antarctic islands, except those in 
the vicinity of New Zealand, more or less evidently partake. It 
presents a flora characterising isolated groups of islands extend- 
ing 5000 miles to the eastward of its own position. Some of 
these detached spots are much closer to the African and Aus- 
tralian continents, whose vegetation they do not assume, than to 
- the American, and they are all situated in latitudes and under 
circumstances eminently unfavourable to the migration of species, 
save that their position relatively to Fuegia is in the same direc- . 
tion as that of the violent and prevailing westerly winds.”- But 
in a foot-note he says that too much stress has been laid upon 
winds in spreading plants, pointing out that both in the Pacific 
and in the North Atlantic plants have spread against the pre- 
vailing wind. 
Of the form of the basin of the Southera Ocean we know 
very little ; but it appears to be shallow, getting deeper towards 
the north. The two thousand fathom line passes close to Cape 
Horn, but keeps some distance to the south of the Cape of Good 
Hope. Tristan d’Acunha and Kerguelen Land stand upon sub- 
marine plateaux which extend nearly to Lat. 30° S., but it is 
uncertain whether either of them are connected with the antarctic 
plateau which surrounds the pole. The New Zealand plateau 
* Tsland Life, p. 489. 
+ Flora Antarctica, IIJ., p. 211, 
