other groups are little known except to ornithologists. I
shall therefore refer chiefly to a few of the best known
and most remarkable families of birds, as a sample of the
conclusions furnished by the entire class.
The birds of the Indo-Malay region have a close resemblance
to those of India; for though a very large- proportion
of the species are quite distinct, there are only about fifteen
peculiar genera, and not a single family group confined to
the former district. If, however, we compare the islands
with the Burmese, Siamese, and Malayan countries, we
shall find still less difference, and shall be convinced that
all are closely united by the bond of a former union. In
such well-known families as the woodpeckers, parrots,
trogons, barbets, kingfishers, pigeons, and pheasants, we
find some identical species spreading over all India, and
as far as Java and Borneo, while a very large proportion
are common to Sumatra and the Malay peninsula.
The force of these facts can only be appreciated when
wre come to treat of the islands of the Austro-Malay
region, and show how similar harriers have entirely
prevented the passage of birds from one island to another,
so that out of at least three hundred and fifty land birds
inhabiting Java and Borneo, not more than ten have
passed eastward into Celebes. Yet the Straits of Macassar
are not nearly so wide as the Java sea, and at least a
hundred species are common to Borneo and Java.
I will now give two examples to show how a knowledge
of the distribution of animals may reveal unsuspected
facts in the past history of the earth. At the
eastern extremity of Sumatra, ana separated from it by a
strait about fifteen miles wide, is the small rocky island of
Banca, celebrated for its tin mines. One of the Dutch residents
there sent some collections of birds and animals
to Leyden, and among them were found several species
distinct from those of the adjacent coast of Sumatra. One
of these was a squirrel (Sciurus bangkanus), closely allied
to three other species inhabiting respectively the Malay
peninsula, Sumatra, and Borneo, hut quite as distinct from
them all as they are from each other. There were also two
new ground thrushes of the genus Pitta, closely allied
to, hut quite distinct from, two other species inhabiting
both Sumatra and Borneo, and which did not perceptibly
differ in these large and widely separated islands. This is
just as if the Isle of Man possessed a peculiar species of
thrush and blackbird, distinct from the birds which are
common to England and Ireland.
These curious facts would indicate that Banca may have
existed as a distinct island even longer than Sumatra and
Borneo, and there are some geological and geographical
facts which render this not so improbable as it would at
first seem to be. Although on the map Banca appears so
close to Sumatra, this does not arise from its having been
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