Volume 14 Australasia - dana ward's homepage

FAUNA OF IXDOXESIA. 73the other islands in the archipelago, possess plants which occur nowhere else onthe surface of the globe. In three years the botanist Beccari discovered over twohundred absolutely new species in the single district of Sarawak, on the northwestcoast of Borneo. In the same island the summits of the mountains form somany secondarj- islands, with independent growths recalling the types of remotelands in more temperate climates. At an elevation of 8,500 feet, on the flanks ofKina-Balu, in Xorth Borneo, are met certain forms belonging to genera whichelsewhere occur only in Xew Zealand.Fauna.Going eastwards the flora is gradually modified with the changing climaticconditions, whereas the transition from fauna to fauna are for the most part of anabrupt character. While the species in the western islands as far as Bali are ofthe Indian type, those of the eastern regions, beginning with Lombok, present thecharacteristics of Australian zoological life. Two worlds as different as Europeand America here lie side by side, separated only by a strait less than 20 milesbroad. But the two islands of Bali and Lombok, composed largely of igneousrocks, are probably for the most part of comparatively recent origin. Hencewhat is now a narrow channel was formerly a wide branch of the sea.Nevertheless the striking contrast between two faunas on the same chain ofislands presenting such great uniformity in their physical constitutions must stillbe regarded as a most remarkable phenomenon. One of the salient features ofthe terrestrial crust is this very range of volcanic islands evidently springingfrom the same fault in the submarine bed and stretching from the islet of Krakatauto that of Xila for a distance of 2,200 miles. Yet this line of eruptive rocksis intersected precisely in the middle by an abrupt parting-line between twodistinct faunas. The inference is irresistible that the formation of the Sundanesevolcanoes is of relatively recent date. The sudden contrast of the Indian andAustralian animal forms shows that here the distribution of land and water, aswell as the planetary life itself, has greatly changed during the course of the latergeological ejjochs.Between Borneo and Celebes, which however are separated by a much widerstrait than that of Lombok, the contrast between the animal species is no lessremarkable, nearly all the forms of the two regions belonging to distinct families."VVe must therefoie conclude that here also the lands characterised by differentfaunas have remained disconnected since extremely remote geological times. ButCelebes, unlike Lombok, formed no part of the Australian world. On all sides itsisolation appears to be complete, dating evidentlj' from a period of vast antiquity.On the other hand both their fauna and their flora attest the ancient continuityof the three great islands of Sumatra, Java, and Borneo, which areseparated only by shallow waters from the Asiatic mainland.Wallace enumeratesforty-eight species of mammals common to the continental and neighbouringinsular ilalay lands. Sumatra, with its long mountain range disposed parallel