HISTORY OF SANTUBONG, SARAWAK. 23 
and of Mt. HLingga in which localities are preserved the 
remains of the former immense tracts of primeyal jungle which 
covered the land where now is nothing but mangrove 
swamp. The only alternative to this theory is that Santubong 
has received its flora by the agency of birds, mammals, wind 
and water from Matang. Nowifthe intervening land should 
lodge areas of dry ground which could act as stepping stones 
for the passage of trees between the two mountains such an 
alternative would be at any fate a possibility and on examin- 
ation we do actually find in quite convenient situations many 
dry areas usually a few feet (sometimes as much as 25 ft.) 
elevated : these are known as Mattangs. The Mattang may 
cover an area of ¢ square mile or it may be much less: its 
substratum is of horizontally stratified sandstone and the 
soil is nothing but sand. Sucha sandy island existing in a sea 
of swamp can be recognised from afar by the trees, — which are 
quite different from those of the swamp: a very character- 
istic mattang tree is a Casuarina (C. Suwmatrana) called 
Amun by Sea Dayaks. But, not only is the mattang flora 
very distinct from that of a mangrove swamp but also it lacks 
the essential elements of a mountain flora and the poverty of 
its soil is alone sufficient to prevent its functioning as a step- 
ping stone between Santubong and Matang. Nor can we regard 
the mattangs as lingering remnants of the original high ground 
for it seems certain that they are quite recent in origin having 
been laid down as large sandbanks in the course of rivers. 
A sandbank of this type may have been formed out at sea or 
in the river-bed many miles from its mouth. Quite possibly 
the sandbanks of the Batang Lupar river where they are 
called Langains may some day become Mattangs. 
It is evident therefore that at the present day there is 
nothing of the nature of intermediate land-bridges between the 
two localities and that in the case of a large number of species 
of plants an interchange is now impossible: the simplest ex- 
planation of the fact of general uniformity of flora is then the 
one we have just stated. 
The flora of the slopes includes the following trees:—Oaks 
(Impilit of Sea Dayaks and Empenit of Malays) of at least 
R. A. Soc., No. 51, 1908. 
