te
America, or of Mexico and the Southern United States, in both of which
cases I suppose there can be little doubt that the tropical areas are far
the richest. Temperate South Africa is, no doubt, always quoted as richer
than an equal area of tropical Africa or perhaps than any part of the world
of equal extent, but this is admitted to be an exceptional case.

[182] Sir Joseph Hooker thinks that later discoveries in the Australian
Alps and other parts of East and South Australia may have greatly modified
or perhaps reversed the above estimate, and the figures given in the
preceding note indicate that this is so. But still, the small area of
South-west Australia will be, proportionally, far the richer of the two. It
is much to be desired that the enormous mass of facts contained in Mr.
Bentham's _Flora Australiensis_ and Baron von Mueeller's _Census_ should be
tabulated and compared by some competent botanist, so as to exhibit the
various relations of its wonderful vegetation in the same manner as was
done by Sir Joseph Hooker with the materials available twenty-one years
ago.

[183] From an examination of the fossil corals of the South-west of
Victoria, Professor P. M. Duncan concludes--"that, at the time of the
formation of these deposits the central area of Australia was occupied by
sea, having open water to the north, with reefs in the neighbourhood of
Java." The age of these fossils is not known, but as almost all are extinct
species, and some are almost identical with European Pliocene and Miocene
species, they are supposed to belong to a corresponding period. (_Journal
of Geol. Soc._, 1870.)

[184] "On the Origin of the Fauna and Flora of New Zealand," by Captain
F. W. Hutton, in _Annals and Mag. of Nat. Hist._ Fifth series, p. 427
(June, 1884).

[185] To these must now be added the genera Sequoia, Myrica, Aralia, and
Acer, described by Baron von Ettingshausen. (_Trans. N.Z. Institute_, xix.,
p. 449.)

[186] The large collection of fossil plants from the Tertiary beds of New
Zealand which have been recently described by Baron von Ettingshausen
(_Trans. N. Z. Inst._, vol. xxiii., pp. 237-310), prove that a change in
the vegetation has occurred similar to that which has taken place in
Eastern Australia, and that the plants of the two countries once resembled
each other more than they do now. We have, first, a series of groups now
living in Australia, but which have become extinct in New Zealand, as
Cassia, Da