NEW GUINEA, with the islands joined to it by a shallow sea, constitute
the Papuan group, characterised by a very close resemblance in their
peculiar forms of life. Having already, in my chapters on the Aru
Islands and on the Birds of Paradise, given some details of the natural
history of this district, I shall here confine myself to a general
sketch of its animal productions, and of their relations to those of the
rest of the world.
New Guinea is perhaps the largest island on the globe, being a little
larger than Borneo. It is nearly fourteen hundred miles long, and in the
widest part four hundred broad, and seems to be everywhere covered with
luxuriant forests. Almost everything that is yet known of its natural
productions comes from the north-western peninsula, and a few islands
grouped around it. These do not constitute a tenth part of the area of
the whole island, and are so cut off from it, that their fauna may well
he somewhat different; yet they have produced us (with a very partial
exploration) no less than two hundred and fifty species of land birds,
almost all unknown elsewhere, and comprising some of the most curious
and most beautiful of the feathered tribes. It is needless to say how
much interest attaches to the far larger unknown portion of this
great island, the greatest terra incognita that still remains for the
naturalist to explore, and the only region where altogether new and
unimagined forms of life may perhaps be found. There is now, I am
happy to say, some chance that this great country will no longer
remain absolutely unknown to us. The Dutch Government have granted
well-equipped steamer to carry a naturalist (Mr. Rosenberg, already
mentioned in this work) and assistants to New Guinea, where they are
to spend some years in circumnavigating the island, ascending its
large rivers a< far as possible into the interior, and making extensive
collections of its natural productions.
The Mammalia of New Guinea and the adjacent islands, yet discovered,
are only seventeen in number. Two of these are bats, one is a pig of a
peculiar species (Sus papuensis), and the rest are all marsupials. The
bats are, no doubt, much more numerous, but there is every reason to
believe that whatever new land Mammalia man be discovered will belong
to the marsupial order. One of these is a true kangaroo, very similar
to some of middle-sized kangaroos of Australia, and it is remarkable as
being the first animal of the kind ever seen by Europeans. It inhabits
Mysol and the Aru Islands (an allied species being found in New Guinea),
and was seen and described by Le Brun in 1714, from living specimens at
Batavia. A much more extraordinary creature is the tree-kangaroo, two
species of which are known from New Guinea. These animals do not differ
very strikingly in form from the terrestrial kangaroos, and appear to be
but imperfectly adapted to an arboreal life, as they move rather slowly,
and do not seem to have a very secure footing on the limb of a tree. The
leaping power of the muscular tail is lost, and powerful claws have been
acquired to assist in climbing, but in other respects the animal seems
better adapted to walls on terra firma. This imperfect adaptation may
be due to the fact of there being no carnivore in New Guinea, and no
enemies of any kind from which these animals have to escape by rapid
climbing. Four species of Cuscus, and the small flying opossum, also
inhabit New Guinea; and there are five other smaller marsupials, one of
which is the size of a rat, and takes its place by entering houses and
devouring provisions.
The birds of New Guinea offer the greatest possible contrast to the
Mammalia, since they are more numerous, more beautiful, and afford more
new, curious, and elegant forms than those of any other island on the
globe. Besides the Birds of Paradise, which we have already sufficiently
considered, it possesses a number of other curious birds, which in the
eyes of the ornithologist almost serves to distinguish it as one of the
primary divisions of the earth. Among its thirty species of parrots are
the Great Pluck Cockatoo, and the little rigid-tailed Nasiterna, the
giant and the dwarf of the whole tribe. The bare-headed Dasyptilus
is one of the most singular parrots known; while the beautiful little
long-tailed Charmosyna, and the great variety of gorgeously-coloured
lories, have no parallels elsewhere. Of pigeons it possesses about forty
distinct species, among which are the magnificent crowned pigeons, now
so well known in our aviaries, and pre-eminent both for size and beauty;
the curious Trugon terrestris, which approaches the still more strange
Didunculus of Samoa; and a new genus (Henicophaps), discovered by
myself, which possesses a very long and powerful bill, quite unlike that
of any other pigeon. Among its sixteen kingfishers, it possesses the
carious hook-billed Macrorhina, and a red and blue Tanysiptera, the most
beautiful of that beautiful genus. Among its perching birds are the fine
genus of crow-like starlings, with brilliant plumage (Manucodia); the
carious pale-coloured crow (Gymnocorvus senex); the abnormal red and
black flycatcher (Peltops blainvillii); the curious little boat-billed
flycatchers (Machaerirhynchus); and the elegant blue flycatcher-wrens
(Todopsis).
The naturalist will obtain a clearer idea of the variety and interest of
the productions of this country, by the statement, that its land birds
belong to 108 genera, of which 20 are exclusively characteristic of it;
while 35 belong to that limited area which includes the Moluccas and
North Australia, and whose species of these genera have been entirely
derived from New Guinea. About one-half of the New Guinea genera are
found also in Australia, about one-third in India and the Indo-Malay
islands.
A very curious fact, not hitherto sufficiently noticed, is the
appearance of a pure Malay element in the birds of New Guinea. We
find two species of Eupetes, a curious Malayan genus allied to the
forked-tail water-chats; two of Alcippe, an Indian and Malay wren-like
form; an Arachnothera, quite resembling the spider-catching honeysuckers
of Malacca; two species of Gracula, the Mynahs of India; and a curious
little black Prionochilus, a saw-billed fruit pecker, undoubtedly allied
to the Malayan form, although perhaps a distinct genus. Now not one
of these birds, or anything allied to them, occurs in the Moluccas, or
(with one exception) in Celebes or Australia; and as they are most of
them birds of short flight, it is very difficult to conceive how or when
they could have crossed the space of more than a thousand miles, which
now separates them from their nearest allies. Such facts point to
changes of land and sea on a large scale, and at a rate which, measured
by the time required for a change of species, must be termed rapid.
By speculating on such changes, we may easily see how partial waves
of immigration may have entered New Guinea, and how all trace of their
passage may have been obliterated by the subsequent disappearance of the
intervening land.
There is nothing that the study of geology teaches us that is more
certain or more impressive than the extreme instability of the earth's
surface. Everywhere beneath our feet we find proofs that what is land
has been sea, and that where oceans now spread out has once been land;
and that this change from sea to land, and from land to sea, has taken
place, not once or twice only, but again and again, during countless
ages of past time. Now the study of the distribution of animal life upon
the present surface of the earth, causes us to look upon this constant
interchange of land and sea--this making and unmaking of continents,
this elevation and disappearance of islands--as a potent reality, which
has always and everywhere been in progress, and has been the main agent
in determining the manner in which living things are now grouped and
scattered over the earth's surface. And when we continually come upon
such little anomalies of distribution as that just now described, we
find the only rational explanation of them, in those repeated elevations
and depressions which have left their record in mysterious, but still
intelligible characters on the face of organic nature.
The insects of New Guinea are less known than the birds, but they seem
almost equally remarkable for fine forms and brilliant colours. The
magnificent green and yellow Ornithopterae are abundant, and have most
probably spread westward from this point as far as India. Among the
smaller butterflies are several peculiar genera of Nymphalidae and
Lycaenidae, remarkable for their large size, singular markings, or
brilliant coloration. The largest and most beautiful of the clear-winged
moths (Cocytia d'urvillei) is found here, as well as the large and
handsome green moth (Nyctalemon orontes). The beetles furnish us with
many species of large size, and of the most brilliant metallic lustre,
among which the Tmesisternus mirabilis, a longicorn beetle of a golden
green colour; the excessively brilliant rose-chafers, Lomaptera wallacei
and Anacamptorhina fulgida; one of the handsomest of the Buprestidae,
Calodema wallacei; and several fine blue weevils of the genus Eupholus,
are perhaps the most conspicuous. Almost all the other orders furnish us
with large or extraordinary forms. The curious horned flies have already
been mentioned; and among the Orthoptera the great shielded grasshoppers
are the most remarkable. The species here figured (Megalodon ensifer)
has the thorax covered by a large triangular horny shield, two and a
half inches long, with serrated edges, a somewhat wavy, hollow surface,
and a faun median line, so as very closely to resemble a leaf. The
glossy wing-coverts (when fully expanded, more than nine inches across)
are of a fine green colour and so beautifully veined as to imitate
closely some of the large shining tropical leaves. The body is short,
and terminated in the female by a long curved sword-like ovipositor (not
seen in the cut), and the legs are all long and strongly-spined. These
insects are sluggish in their motions, depending for safety on their
resemblance to foliage, their horny shield and wing-coverts, and their
spiny legs.
The large islands to the east of New Guinea are very little known, but
the occurrence of crimson lories, which are quite absent from Australia,
and of cockatoos allied to those of New Guinea and the Moluccas, shows
that they belong to the Papuan group; and we are thus able to define the
Malay Archipelago as extending eastward to the Solomon's Islands. New
Caledonia and the New Hebrides, on the other hand, seem more nearly
allied to Australia; and the rest of the islands of the Pacific, though
very poor in all forms of life, possess a few peculiarities which
compel us to class them as a separate group. Although as a matter
of convenience I have always separated the Moluccas as a distinct
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; and the
beautiful weevils forming the genus Eupholus. Among butterflies we have
the genera Mynes, Hypocista, and Elodina, and the curious eye-spotted
Drusilla, of which last a single species is found in Java, but in no
other of the western islands.
The facilities for the distribution of plants are still greater than
they are for insects, and it is the opinion of eminent botanists,
that no such clearly-defined regions pan be marked out in botany as in
zoology. The causes which tend to diffusion are here most powerful, and
have led to such intermingling of the floras of adjacent regions that
none but broad and general divisions can now be detected. These remarks
have an important bearing on the problem of dividing the surface of the
earth into great regions, distinguished by the radical difference of
their natural productions. Such difference we now know to be the direct
result of long-continued separation by more or less impassable barriers;
and as wide oceans and great contrast: of temperature are the most
complete barriers to the dispersal of all terrestrial forms of life,
the primary divisions of the earth should in the main serve for all
terrestrial organisms. However various may be the effects of climate,
however unequal the means of distribution; these will never altogether
obliterate the radical effects of long-continued isolation; and it is my
firm conviction, that when the botany and the entomology of New Guinea
and the surrounding islands become as well known as are their mammals
and birds, these departments of nature will also plainly indicate the
radical distinctions of the Indo-Malayan and Austro-Malayan regions of
the great Malay Archipelago.