no NATURAL SCIENCE. apr.l. 



have combined to deter the scientific investigator from venturing far 

 into the unknown and inhospitable regions of the interior. 



In those districts where European settlements have long 

 existed, for instance, in the districts of Bandjermassin and Tanah 

 Laut in the south-eastern portion of the island, more exact details 

 respecting its physical and geological structure have been obtained, 

 for in these districts the country has been carefully examined in the 

 eager search for useful minerals. 



Much of the knowledge thus accumulated in the Dutch part of 

 the island is due to the labours of the Natural History Commission, 

 a scientific institution established in Batavia in the year 1820. Its 

 members were scientific men, comprising, in the first instance, a 

 zoologist, a botanist, and a geologist ; and they were appointed for the 

 purpose of investigating the resources of the as yet almost unknown 

 island. At a later period, the geology of some portions of the island 

 was elucidated by the work of the Batavian mining engineers, who 

 were sent by the Dutch Government to search for useful minerals 

 and for coal. 



On the northern coast, our knowledge has received its greatest 

 increment in Sarawak, by explorations carried on at the instigation 

 of Rajah Brooke and his successor, Charles Johnson Brooke, and in 

 Sabah, where the British rule has been inaugurated by the exertions 

 of the North Borneo Company. Since 1881, when the company 

 acquired its charter, our geographical and geological information of 

 this part of the island has increased with every year. A band of 

 courageous pioneers and explorers, defying every danger, have 

 traversed these unknown regions in all directions, and scientific 

 results of great value have been thus obtained. 



Physical Features. 



Proceeding from an elevated area in the centre, the radiating 

 lines of water-parting divide the island into a southern, a northern, 

 a western, and an eastern catchment-basin. The divides, however, 

 are not, as usually represented on the maps, formed by continuous 

 mountain chains, but consist of a series of short ranges and abrupt 

 ridges, or of isolated groups of mountains and single peaks, w^iich are 

 turned in the same general direction. Surrounding the mountains 

 is a low undulating country in which the separate and outlying 

 masses lie like islands in a sea. 



This structure is the dominant feature of the orographic systems 

 of Borneo, and is cleverly epitomised by Posewitz when he names 

 the detached portions of the high land " mountain-islands." The 

 gently rolling country which laps round the foot of the " mountain- 

 land " he describes as "hill-land." The hill-land, in its turn, is 

 bordered by dry plains which are often of great extent, especially 

 in South Borneo ; and these, again, pass into the swamps and 

 morasses of tlie coast. Like the mountain-land, the hill-land sends 



