Archipelago into two regions characterised by a striking
diversity in their natural productions does not in any way
correspond to the main physical or climatal divisions of the
surface. The great volcanic chain runs through both parts, and
appears to produce no effect in assimilating their productions.
Borneo closely resembles New Guinea not only in its vast size and
its freedom from volcanoes, but in its variety of geological
structure, its uniformity of climate, and the general aspect of
the forest vegetation that clothes its surface. The Moluccas are
the counterpart of the Philippines in their volcanic structure,
their extreme fertility, their luxuriant forests, and their
frequent earthquakes; and Bali with the east end of Java has a
climate almost as dry and a soil almost as arid as that of Timor.
Yet between these corresponding groups of islands, constructed as
it were after the same pattern, subjected to the same climate,
and bathed by the same oceans, there exists the greatest possible
contrast when we compare their animal productions. Nowhere does
the ancient doctrine--that differences or similarities in the
various forms of life that inhabit different countries are due to
corresponding physical differences or similarities in the
countries themselves--meet with so direct and palpable a
contradiction. Borneo and New Guinea, as alike physically as two
distinct countries can be, are zoologically wide as the poles
asunder; while Australia, with its dry winds, its open plains,
its stony deserts, and its temperate climate, yet produces birds
and quadrupeds which are closely related to those inhabiting the
hot damp luxuriant forests, which everywhere clothe the plains
and mountains of New Guinea.

In order to illustrate more clearly the means by which I suppose