Java, where a considerable number of the continental
species are represented by allied forms, the separation was
more remote.
From these examples we may see how important a
supplement to geological evidence is the study of the
geographical distribution of animals and plants, in determining
tbe former condition of the earth’s surface; and
how impossible it is to understand the former without
taking the latter into account. The productions of the
Aru Islands offer the strongest evidence that at no very
distant epoch they formed a part of New Guinea; and
the peculiar physical features which I have described,
indicate that they must have stood at very nearly the
same level then as they do now, having been separated
by the subsidence of the great plain which formerly connected
them with it.
Persons who have formed the usual ideas of the vegetation
of the tropics—who picture to themselves the abundance
and brilliancy of the flowers, and the magnificent appearance
of hundreds of forest trees covered with masses of
coloured blossoms, will be surprised to hear, that though
vegetation in Aru is highly luxuriant and varied, and
would afford abundance of fine and curious plants to
adorn our hothouses, yet bright and showy flowers are,
as a general rule, altogether absent, or so very scarce
as to produce no effect whatever on the general scenery.
To give particulars : I have visited five distinct localities
in the islands, I have wandered daily in the forests,
and have passed along upwards of a hundred miles
of coast and river during a period of six months, much
of it very fine weather, and till just as I was about to
leave, I never saw a single plant of striking brilliancy
or beauty, hardly a shrub equal to a hawthorn, or a
climber equal to a honeysuckle ! It cannot be said
that the flowering season had not arrived, for I saw many
herbs, shrubs, and forest trees in flower, but all bad
blossoms of a green or greenish-white tint, not superior to
our lime-trees. Here and there on the river banks and
coasts are a few Convolvulaceae, not equal to our garden
Ipomaeas, and in the deepest shades of the forest some
fine scarlet and purple Zingiberaoeae, but so few and
scattered as to be nothing amid the mass of green and
flowerless vegetation. Yet the noble Cycadacese and
screw-pines, thirty or forty feet high, the elegant tree ferns,
the lofty palms, and the variety of beautiful and curious
plants which everywhere meet the eye, attest the warmth
and moisture of the tropics, and the fertility of the soil.
It is true that Aru seemed to me exceptionally poor in
flowers, but this is only an exaggeration of a general
tropical feature ; for my whole experience in the equatorial
regions of the west and the east has convinced me,