Migration by way of the African
Highlands--Supposed Connection of South Africa and Australia--The
Endemic Genera of Plants in New Zealand--The Absence of Southern Types
from the Northern Hemisphere--Concluding Remarks on the New Zealand and
South Temperate Floras.

We have now to deal with another portion of the New Zealand flora which
presents perhaps equal difficulties--that which appears to have been
derived from remote parts of the north and south temperate zones; and this
will lead us to inquire into the origin of the northern or Arctic element
in all the south temperate floras.

More than one-third of the entire number of New Zealand genera (115) are
found also in Europe, and even fifty-eight species are identical in these
remote parts of the world. Temperate South America has seventy-four genera
in common with New Zealand, and there are even eleven species identical in
the two countries, as well as thirty-two which are close allies or
representative species. {510} A considerable number of these northern or
Antarctic plants and many more which are representative species, are found
also in Tasmania and in the mountains of temperate Australia; and Sir
Joseph Hooker gives a list of thirty-eight species very characteristic of
Europe and Northern Asia, but almost or quite unknown in the warmer
regions, which yet reappear in temperate Australia. Other genera seem
altogether Antarctic--that is, confined to the extreme southern lands and
islands; and these often have representative species in Southern America,
Tasmania, and New Zealand, while others occur only in one or two of these
areas. Many north temperate genera also occur in the mountains of South
Africa. On the other hand, few if any of the peculiar Australian or
Antarctic types have spread northwards, except some of the former which
have reached the mountains of Borneo, and a few of the latter which spread
along the Andes to Mexico.

On these remarkable facts, of which I have given but the barest outline,
Sir Joseph Hooker makes the following suggestive observations:--

"When I take a comprehensive view of the vegetation of the Old World, I am
struck with the appearance it presents of there being a continuous current
of vegetation (if I may so fancifully express myself) from Scandinavia to
Tasmania; along, in short, the whole extent of that arc of the terrestrial
sphere which presents the greatest continuity of land. In the first place
Scandinav