202 WALLACE ON BORNEO. [Nov. 10, 1856. 



the tertiary formation, as the most abundant fossils are impressions of 

 exogenous foliage, exactly similar in character to that of the trees 

 which now cover the surface. I have also seen what appear to be 

 leguminous fruits, and the shells found in the Labuan coal-field, 

 were all of an extremely recent type. Now as the sandstone of the 

 interior almost exactly corresponds with that of the coal formation, 

 we may conclude that it also is tertiary, the principal difference 

 being, that some beds of it contain a greater quantity of quartz and 

 limestone pebbles. The presence of volcanic rocks with contorted 

 limestone, sufficiently explains the vertically-upheaved stratified 

 rocks, which appear to underlay the sandstone. The limestone is 

 highly crystalline, and is probably an ancient formation, as it contains 

 slender-stemmed encrinites ; and the slaty rocks which occur in all 

 the river beds between the coal mountains and those of the interior, 

 are probably of equal or greater antiquity. A considerable tract of 

 country between the limestone hills, is covered with an alluvium of 

 gravel and clays, the surface of which is very imdulating, and in 

 this the gold-washing is principally carried on. It seems to rest 

 upon the limestone, which often pierces through it in strange water- 

 worn peaks, which resemble ruined buildings, or ancient monumentp. 

 It is in cavities of the limestone also, that the antimony ore is 

 found ; and near the junction of the trap-rock with the limestone, 

 a fine hot spring has recently been discovered. 



We may therefore, in general terms, describe the Sarawak district 

 as consisting of ancient limestone and slaty rocks and of modem 

 sandstone with coal. In the interval between these deposits, violent 

 volcanic action has taken place, which has resulted in the trappean 

 mountains ; and this action has been renewed since the most recent 

 rocks have been foimed. With the very scanty information we yet 

 possess on the subject, more detail than this would be out of place. 



Ethnology. — The manners and customs of the Aborigines of Borneo 

 have been so often described, that I shall only now make a few 

 observations on what has been less generally noticed — their physical, 

 mental, and moral characteristics. The Dyak is closely allied 

 ethnographically to the Malay, more remotely to the Chinese and 

 to the Indians of South America, who are all united by so many 

 similarities, that we must consider them as branches of one great 

 division of mankind, the Mongolian race. All are characterised 

 by a reddish brown skin of various shades, by jet-black straight 

 hair, by the scanty or totally absent beard, by the rather small and 

 broad nose, and high cheek-bones. In one character only is there 

 any disagreement among them ; — in the Chinese and Tartar races 

 the eyes are oblique, while in the Americans and Malays this 



