OF MT. KINABALU AND BRITISH NORTH BORNEO. 11 
Primary Forest.—Of the flora of the upper ridges of the mountaim 
“islands” nothing is known, outside Kinabalu, where, one is inclined to: 
think, the great height and granite formation of the core must call forth 
special conditions not obtaining elsewhere. 
On the hills above Tenom, where there is only a scanty Murut population,. 
primary high forest begins at 2000', and is limited to steep ridges, but in 
the interior I saw no primary forest at all, as the districts passed through: 
were fertile and well populated. 
Primary forest is characterised by the size of the trees and the herbaceous. 
nature of its undergrowth; there is also little sub-staging, as the smaller 
trees and undershrubs appear to be chiefly forest trees in their younger stages. 
Its majesty is unmistakable, but an exact knowledge of its component parts,. 
especially in the case of the trees and epiphytic associations, will be always. 
difficult to realise. 
In North Borneo epiphytic rhododendrons seemed to mark this formation, 
as I did not see them at all in the secondary forest ; but perhaps one should 
not attach too much importance to this factor, as X. Brookeanum, one of the 
show plants of Kinabalu, is found on mangroves in Sarawak. Warming, 
in ‘ (Ecology of Plants,’ 341, quotes Schimper in stating that woody epiphytes. 
require the heaviest rainfall, so that the presence of these plants is possibly: 
referable to that factor, which dominates on the spurs of Kinabalu. 
On this mountain, primary high forest may be described as forming a wavy 
line, beginning at 3500-4000’ on the south and south-western slopes, running 
up to 4500-6000’ on the spurs and considerably higher in the valleys, but I 
should hesitate to say that this forest is the result of altitude or any especial 
geological or edaphie features. The most vital factor for its development 
seems to be a very sparse population, to whom the secondary or younger 
forest suffices for its economic needs, whilst the clearing of the older forest 
offers too many difficulties for limited numbers to cope with. On the 
northern slopes of the mountain the level of the high forest is much lower 
than towards the south and south-west. Mr. Maxwell informed me that over 
a large area of low-level land to the north of Kinabalu, where there is no 
native population, only high forest prevails. 
The excellent collections made by Beccari, Haviland, and Hose in 
Sarawak, afford a good basis of comparison as regards the primary forest 
types. 
In that part of the country it is the mountain islands which have been 
chiefly worked botanically, as they are most accessible from Kuching. 
They are comparatively small in area and run up to about 3000-5000’, rising 
out of an immense swamp forest. These islands have not been cultivated by 
the natives, but chiefly worked for jungle produce. In Sarawak the 
inhabitants, up to the inland ranges, are chiefly Sea Dyaks, more or less 
