Instead Of These, It Has Marsupials Only:
Kangaroos And Opossums; Wombats And The Duckbilled Platypus.
In
birds it is almost as peculiar.
It has no woodpeckers and no
pheasants - families which exist in every other part of the
world; but instead of them it has the mound-making brush-turkeys,
the honeysuckers, the cockatoos, and the brush-tongued lories,
which are found nowhere else upon the globe. All these striking
peculiarities are found also in those islands which form the
Austro-Malayan division of the Archipelago.
The great contrast between the two divisions of the Archipelago
is nowhere so abruptly exhibited as on passing from the island of
Bali to that of Lombock, where the two regions are in closest
proximity. In Bali we have barbets, fruit-thrushes, and
woodpeckers; on passing over to Lombock these are seen no more,
but we have abundance of cockatoos, honeysuckers, and brush-
turkeys, which are equally unknown in Bali, or any island further
west. [I was informed, however, that there were a few cockatoos
at one spot on the west of Bali, showing that the intermingling
of the productions of these islands is now going on.] The strait
is here fifteen miles wide, so that we may pass in two hours from
one great division of the earth to another, differing as
essentially in their animal life as Europe does from America. If
we travel from Java or Borneo to Celebes or the Moluccas, the
difference is still more striking. In the first, the forests
abound in monkeys of many kinds, wild cats, deer, civets, and
otters, and numerous varieties of squirrels are constantly met
with. In the latter none of these occur; but the prehensile-
tailed Cuscus is almost the only terrestrial mammal seen, except
wild pigs, which are found in all the islands, and deer (which
have probably been recently introduced) in Celebes and the
Moluccas. The birds which are most abundant in the Western
Islands are woodpeckers, barbets, trogons, fruit-thrushes, and
leaf-thrushes; they are seen daily, and form the great
ornithological features of the country. In the Eastern Islands
these are absolutely unknown, honeysuckers and small lories being
the most common birds, so that the naturalist feels himself in a
new world, and can hardly realize that he has passed from the one
region to the other in a few days, without ever being out of
sight of land.
The inference that we must draw from these facts is, undoubtedly,
that the whole of the islands eastwards beyond Java and Borneo do
essentially form a part of a former Australian or Pacific
continent, although some of them may never have been actually
joined to it. This continent must have been broken up not only
before the Western Islands were separated from Asia, but probably
before the extreme southeastern portion of Asia was raised above
the waters of the ocean; for a great part of the land of Borneo
and Java is known to be geologically of quite recent formation,
while the very great difference of species, and in many cases of
genera also, between the productions of the Eastern Malay Islands
and Australia, as well as the great depth of the sea now
separating them, all point to a comparatively long period of
isolation.
It is interesting to observe among the islands themselves how a
shallow sea always intimates a recent land connexion. The Aru
Islands, Mysol, and Waigiou, as well as Jobie, agree with New
Guinea in their species of mammalia and birds much more closely
than they do with the Moluccas, and we find that they are all
united to New Guinea by a shallow sea. In fact, the 100-fathom
line round New Guinea marks out accurately the range of the true
Paradise birds.
It is further to be noted - and this is a very interesting point
in connection with theories of the dependence of special forms of
life on external conditions - that this division of the
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
this great contrast has been brought about, let us consider what
would occur if two strongly contrasted divisions of the earth
were, by natural means, brought into proximity. No two parts of
the world differ so radically in their productions as Asia and
Australia, but the difference between Africa and South America is
also very great, and these two regions will well serve to
illustrate the question we are considering.
Enter page number
PreviousNext
Page 7 of 112
Words from 6210 to 7225
of 114260
