FAUNA OF INDONESIA. 73 



the other islands in the archipelago, possess plants which occur nowhere else on 

 the surface of the globe. In three years the botanist Beccari discovered over two 

 hundred absolutely new species in the single district of Sarawak, on the north- 

 west coast of Borneo. In the same island the summits of the mountains form so 

 many secondary islands, with independent growths recalling the types of remote 

 lands in more temperate climates. At an elevation of 8,o00 feet, on the flanks of 

 Kina-Balu, in Xorth Borneo, are met certain forms belonging to genera which 

 elsewhere occur only in New Zealand. 



Fauna. 



Going eastwards the flora is gradually modified with the changing climatic 

 conditions, whereas the transition from fauna to fauna are for the most part of an 

 abrupt character. While the species in the western islands as far as Bali are of 

 the Indian tyjDe, those of the eastern regions, beginning with Lombok, present the 

 characteristics of Australian zoological life. Two worlds as different as Europe 

 and America here lie side by side, separated only by a strait less than 20 miles 

 broad. But the two islands of Bali and Lombok, composed largely of igneous 

 rocks, are probably for the most part of comparatively recent origin. Hence 

 what is now a narrow channel was formerly a wide branch of the sea. 



Nevertheless the striking contrast between two faunas on the same chain of 

 islands presenting such great uniformity in their physical constitutions must still 

 be regarded as a most remarkable phenomenon. One of the salient features of 

 the terrestrial crust is this very range of volcanic islands evidently springing 

 from the same fault in the submarine bed and stretching from the islet of Krak- 

 atau to that of Nila for a distance of 2,200 miles. Yet this line of eruptive rocks 

 is intersected precisely in the middle by an abrupt parting-line between two 

 distinct faunas. The inference is irresistible that the formation of the Sundanese 

 volcanoes is of relatively recent date. The sudden contrast of the Indian and 

 Australian animal forms shows that here the distribution of land and water, as 

 well as the planetary life itself, has greatly changed during the course of the later 

 geological epochs. 



Between Borneo and Celebes, which however are separated by a much wider 

 strait than that of Lombok, the contrast between the animal species is no less 

 remarkable, nearly all the forms of the two regions belonging to distinct families. 

 We must therefore conclude that here also the lands characterised by different 

 faunas have remained disconnected since extremely remote geological times. But 

 Celebes, unlike Lombok, formed no part of the Australian world. On all sides its 

 isolation appears to be complete, dating evidently from a period of vast antiquity. 



On the other hand both their fauna and their flora attest the ancient con- 

 tinuity of the three great islands of Sumatra, Java, and Borneo, which are 

 separated only by shallow waters from the Asiatic mainland. Wallace enumerates 

 forty-eight sj)ecies of mammals common to the continental and neighbouring 

 insular Malay lands. Sumatra, with its long mountain range disposed parallel 



