Travel Reference
In-Depth Information
mammal or reptile is found in it, and a great number of the most abundant and characteristic
forms of Australian birds and insects are entirely absent. Contrast this with the British Is-
lands, in which a large proportion of the plants, insects, reptiles, and Mammalia of the adja-
cent parts of the continent are fully represented, while there are no remarkable deficiencies
of extensive groups, such as always occur when there is reason to believe there has been no
such connexion. The case of Sumatra, Borneo, and Java, and the Asiatic continent is equally
clear; many large Mammalia, terrestrial birds, and reptiles being common to all, while a
large number more are of closely allied forms. Now, geology has taught us that this repres-
entation by allied forms in the same locality implies lapse of time, and we therefore infer
that in Great Britain, where almost every species is absolutely identical with those on the
Continent, the separation has been very recent; while in Sumatra and Java, where a consid-
erable 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 the 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 eviden-
ce 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 abund-
ance 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 flower-
ing season had not arrived, for I saw many herbs, shrubs, and forest trees in flower, but all
had 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 Convolvulaceæ, not equal to our garden Ipomæas,
