4 
Eurya acuminata , Morinda tinctoria, Pithecolobiums , Glochidian 
and in some places Tembusu {Fagroea fragrans.) 
Ground under Belukar often remains so for many years even 
if not burnt, but in time second class timbers, Oaks, Shoreas, 
Artocarpi and other trees appear and eventually after the lapse 
of many years may again become good forest. That is to say 
seed of the better timbers may drift into the Belukar^ and as they 
grow up may gradually replace the inferior- kinds. 1 his however, 
depends much on the proximity of good forest with adult fruiting 
trees, and even in such a case ground often remains under Belukar 
apparently for an indefinite period. 
Wood-structure.— W hen trees have attained a certain age, there 
is, as a rule, a more or less distinct separation in the timber into 
heart wood or sapwood, and the proportion of the two form an im- 
portant factor in deciding the value of the tree as timber. 1 he 
outer sapwood is usually white and soft and valueless. Fhe heart- 
wood in which the wood cells have increased much in thickness is 
often distinctly coloured and is the most valuable part of the tim- 
ber. It may be coloured red or brown, or even black as in the 
case of Ebony. Trees vary very much in the thickness of the sap- 
wood. In some, such as Cassia siamea, the proportion of heart- 
rood is very small, while in Damarlaut the whole tree appears to 
consist of heartwood. As a rule, the proportion is the same ap- 
proximately for the same kind of tree, but certain trees are most 
irregular in this I have seen very large trees of Albissia Moluc- 
cas felled in which the wood was soft and white all through, while 
trees of the same size or even smaller, contained a considerable 
proportion of brown heartwood. The sapwood is usually very soon 
desirov ed by termites and fungi, and natives in felling such trees 
as Rengas (Mclannorhma) often leave the trunk in the forest till 
the termites have destroyed the sapwood entirely, when they re- 
move the heartwood which is not touched by these insects. The 
proportion of sapwood to heartwood depends most on rapidity of 
orowth. Manv quick-growing short-lived trees make nothing that 
can be called heartwood, the wood all through being soft and white, 
,uch are the common wild figs. 1 hese soft woods are known to 
the Malays as Lampong. They are not necessarily useless; being 
fight they are used for floating heavier timbers down stream and 
some are used for making boxes, models and clogs, and such like 
articles. . . ' . , „ . 
Rings .— As has been remarked the rings of our timbers can not 
at least always be relied on as giving the age of a tree. I have 
been unable, however, to make many examinations as to tins, be- 
cause of the difficulty of finding out the age of any given tree 
accurately as there have been but few records kept of tree planting-. 
A specimen of the Krian ( Eugenia grandis) of which the age 16 
years was known gave a corresponding series of annual rings. _ 
7 />0 m .__ are really the mouths of the vessels m the wood seen in 
transverse sections. They vary very much in size in various 
timbers, in some they are very minute while m Others they are 
larro and conspicuous. This is especially the case in the woody 
