All these dates are absurdly recent, and besides, the separations, in all probability, did not occur in the order given above. When we compare the fauna of the continent with that of Sumatra, Java, and Borneo, we find that Sumatra has the greatest number of species identical with those of the Peninsula of Malacca; that Borneo has a somewhat less proportion, and that Java has the largest number peculiar to itself. Thence we conclude that Java was the first of these islands that was separated from the continent, that Borneo was next detached, and Sumatra at the latest period. Bali was probably separated from Java at a yet more recent date.
Mr. Sclater was the first to notice the fact that the dividing line between the Asiatic fauna and that of Australia must be drawn down the Strait of Macassar, and this observation has only been confirmed by all who have collected in those regions since. Mr. A. R. Wallace further ascertained that this line should be continued southward, through the Strait of Lombok, between the island of that name and Bali. He visited the latter island, and thus contrasts its birds with those of Lombok: “In Bali we have barbets, fruit-thrushes, and woodpeckers; on passing over to Lombok these are seen no more, but we have an abundance of cockatoos, honeysuckers, and brush-turkeys (Megapodiidæ), which are equally unknown in Bali, and every island farther west. The strait here is but 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.”
The royal tiger of Sumatra and Java is also found on that part of Bali nearest Java, but neither this nor any other feline animal exists on Lombok.
Monkeys, squirrels, civets, and others are seen west of this dividing line, but not east of it. Wild hogs are distributed over all the larger islands from Sumatra to New Guinea, and even occur as far eastward as Ceram. The flora of these islands is not divided in this manner, but maintains quite the same character from the northern end of Timur to the eastern end of Java.
In 1845 Mr. Earl pointed out the fact that Java, Sumatra, and Borneo, all stand on a plateau which is only covered by a shallow sea. They therefore not only were formerly connected, as the similarity of their faunæ shows, but are at the present day, and a line on the map, which indicates where the sea reaches a depth of one hundred fathoms, shows exactly where the great basins of the Pacific and Indian Oceans really begin. Northward this line unites the Philippines to Asia, and also proves that Formosa, the Lew-Chew and Japanese Islands, and the Kuriles, are all parts of the same great continent. Judging from what is known of their fauna, Mr. Wallace thinks the separation of the Philippines from the continent occurred before that of Java, and since that epoch they have undergone very considerable changes in their physical geography.
In 1478, when the Hindu religion was driven out of Java, it took refuge in Bali, where it exists to the present day. The natives here, as in India, are divided into four castes. The first and highest includes only the priests; the second, the soldiers; the third, the merchants; and the fourth, and lowest, comprises the common laborers. According to Mr. Crawford, who visited the island, the wives of the soldiers frequently sacrifice themselves by stabbing with the kris, and the body is afterward burned, and “with the princes, the sacrifice of one or two women is indispensable.” The high mountains on Bali contain a number of lakes or tarns, which supply many streams, and the natives are thus enabled to irrigate their land so completely, that about twenty thousand tons of rice are annually exported to other parts of the archipelago, after a population of nearly three-quarters of a million is supplied. In 1861 Java had only a population of three hundred and twenty-five to a square mile, while Bali was supposed to have nearly five hundred, and it is probably the most densely populated island in these seas at the present time.
The Hindu religion also prevails over a part of Lombok. On this island a huge mountain rises up, according to the trigonometrical measurements of Baron van Carnbée, to a height of twelve thousand three hundred and sixty English feet, and probably overtops every other lofty peak in the whole archipelago.