growth, and growth may be more in one year than another. A very 
little bark breaking off' a large tree would make a great difference. 
This factor will be eiliminated more or less after several years of 
measmeme^b Taban trees (Gutta percha, Palaquium gutfca) have been 
mesured near the waterfall at Taipeng, of girths varying from 18to 65 
Jllcll6S* tt 
These shew a much more rapid rate of growth, 1.69 inches per 
annum, or 42 years to reach a girth of 6 feet at 6 feet from the ground, 
What at first sight seems remarkable is the great differences in rate of 
growth, e.g. some trees have grown in the 7 years as little as 3 inches 
in girth while other have put ou 20 to 24 inches. There is no doubt 
that in natural forest in this country where the naturally sown seeding 
lias to struggle for existanee with a minimum of light, the girth incre- 
ment is almost absent altogether until the crown of the tree gains 
access to light. 
I have seen this exemplified in Trollah Reserve, where under- 
growth has been cleared over about 2,000 acres to assist young Taban. 
A frequent sight after such a first clearing is a long thin Taban tree, 
about 30 to 40 feet high but only a few inches in girth. When the 
surrounding thick undergrowth is cut away these trees cannot bear 
their own weight at first, and bend over to a greater or lesser degree, 
sometimes so much as to require propping up. The girth increment of 
such a tree may be said to have been almost absent for years, all the 
energies of the tree being put forth in height-growth in an effort to 
reach the light. 
When light is artificially admitted by cutting the surrounding 
growth, the girth increment will doubtless increase with great rapidity, 
and more leaves be put on. The inference is that the duty of the 
Forest Department in these forests is to assist valuable species, 
such as Chengal and Merbau to establish themselves, by letting 
in light. 
From observation of the big forests in Kuantan and elsewhere, the 
conclusion has been forced upon me that the large solitary Chengal 
trees found there are of immense age, certainly not less than 300 years 
old. The almost complete absence of trees say 2 to 4 in girth is a 
very marked feature and a very serious problem for the forester. 
It is obvious then that there is an immense field for the study of 
the rate of growth of timber trees and that a great deal depends upon 
it. Now that the Forest Department has been gradually increased in 
numbers, experiments will be made in clearing round young trees in 
the forest and measuring these trees annually, then comparing their 
rate of growth with trees uncleaned. Some few thousand Chengal and 
Merbau trees which were planted in 1898 in the Pondok Tanjong Rubber 
Plantation have grown exceedingly well and are probably four times the 
girth of trees of the same age in big forest. 
These trees have had the partial shade of Heveas from the beginning, 
being planted in rows alternately with Heveas about 22' apart by 12 in 
the line. The average girth increment in 1 1 Merbau trees for one year 
is 1*15" and for 20 Chengal trees 1*19". This would give 31 years 
to reach a girth of 3' for the former and 30 years for the latter, a very 
