ii6 NATURAL SCIENCE. Af^JI- 



by coral reefs, occupied the place of the low-lying plains of the 

 Borneo of to-day. 



At the close of the Tertiary period, the gulfs gave way slowly to 

 dry land ; the seas became shallower and retreated, thus preparing 

 the way for the advent of the present period. Numerous and powerful 

 streams carved out a passage from the mountains and flowed towards 

 the retiring seas, bringing with them their quota of mud and fine sand 

 with which to increase the extent of the growing island. Thenceforth, 

 down to the present time, no important changes have modified the 

 physical features of Borneo ; and the island has enjoyed a remarkable 

 immunity from the fierce paroxysms of volcanic activity that, during 

 the Recent period, have convulsed the other large islands of the 

 Malay Archipelago, and culminated, in the year 1883, in the 

 extraordinary outburst of Krakatoa. 



F. H. Hatch. 



