242 ANTHROPOID APES. 



great attraction to the orang, which devours the 

 unripe fruits, autl then retires again to the marsh. 

 He cannot live on high and dry ground. Thus, for 

 example, he comes in troops into the low parts of 

 the Sadoug valley ; but on reaching the limits where 

 the ebb and flow of the tide are perceptible, and the 

 ground, though flat, is dry, the orang is no longer 

 found. The lower part of the Sadong valley is 

 indeed marshy, but it is not covered throughout 

 with a growth of tall trees, only for the most part 

 with the Nipa palm ; and near the town of Sarawak, 

 the country becomes dry and hilly, interspersed 

 with scattered tracts of primeval forest, and with 

 jungle which was formerly cultivated by the Malays 

 and Dyaks. 



The orang is more rare in Sumatra than in Borneo, 

 and in the former island is chiefly found in the 

 north-eastern districts of Siak and Atjiu. liosenberg 

 states that the orang only frequents the flat, marshy 

 forests on the coast between Tapanoli and Singkel, 

 living in thick woods which, on account of their 

 impenetrability, are seldom trodden by the foot of 

 man. 



The chimpanzee also frequents the marshy forests 

 which are not too thickly overgrown, while the 

 gorilla prefers such tablelands as are not wholly 

 devoid of water. 



Wallace declares that a large area of unbroken 

 and tolerably high primeval forest is necessary for 

 the well-being of the orang. Such forests are like 

 open ground to them, since they can move to and 

 fro in every direction, with the same ease that the 



