zoological group from New Guinea, I have at the same time pointed out that its
fauna was chiefly derived from that island, just as that of Timor was chiefly
derived from Australia. If we were dividing the Australian region for zoological
purposes alone, we should form three great groups: one comprising Australia,
Timor, and Tasmania; another New Guinea, with the islands from Bouru to the
Solomon's group; and the third comprising the greater part of the Pacific Islands.
The relation of the New Guinea fauna to that of Australia is very close. It is
best marked in the Mammalia by the abundance of marsupials, and the almost
complete absence of all other terrestrial forms. In birds it is less striking,
although still very clear, for all the remarkable old-world forms which are absent
from the one are equally so from the other, such as Pheasants, Grouse, Vultures,
and Woodpeckers; while Cockatoos, Broad-tailed Parrots, Podargi, and the great
families of the Honeysuckers and Brush-turkeys, with many others, comprising
no less than twenty-four genera of land-birds, are common to both countries, and
are entirely confined to them.
When we consider the wonderful dissimilarity of the two regions in all those
physical conditions which were once supposed to determine the forms of life-
Australia, with its open plains, stony deserts, dried up rivers, and changeable
temperate climate; New Guinea, with its luxuriant forests, uniformly hot, moist,
and evergreen—this great similarity in their productions is almost astounding,
and unmistakeably points to a common origin. The resemblance is not nearly so
strongly marked in insects, the reason obviously being, that this class of animals
are much more immediately dependent on vegetation and climate than are the
more highly organized birds and Mammalia. Insects also have far more effective
means of distribution, and have spread widely into every district favourable to
their development and increase. The giant Ornithopterae have thus spread from
New Guinea over the whole Archipelago, and as far as the base of the
Himalayas; while the elegant long-horned Anthribidae have spread in the
opposite direction from Malacca to New Guinea, but owing to unfavourable
conditions have not been able to establish themselves in Australia. That country,
on the other hand, has developed a variety of flower-haunting Chafers and
Buprestidae, and numbers of large and curious terrestrial Weevils, scarcely any
of which are adapted to the damp gloomy forests of New Guinea, where entirely
different forms are to be found. There are, however, some groups of insects,
constituting what appear to be the remains of the ancient population of the
equatorial parts of the Australian region, which are still almost entirely confined
to it. Such are the interesting sub-family of Longicorn coleoptera—
Tmesisternitae; one of the best-marked genera of Buprestidae—Cyphogastra;