INDO-MALAYAN WOODS. 
507 
made up in a decidedly ornamental fashion; but it is as general con- 
struction timber, where large quantities of good woods are required, 
that the dipterocarps are most useful. There are a number of very 
durable woods in the family and quite a number of fair durability, 
which are very easily worked. 
The family is restricted to the Orient, being found in tropical Asia 
from the Seychelles to New Guinea. 
The wood of the family is characterized by the presence of resin-ducts. 
These are usually arranged in incomplete concentric lines, and some- 
times appear at first sight to represent seasonal rings. However, this 
irregular occurrence and the incompleteness of the rings is sufficient to 
show very conclusively that they do not represent such periods of growth. 
Seasonal rings are never present, so far as known. There is a wide 
range of color and hardness. Pith-rays fine to moderately broad. Pores 
small to large. Wood parenchyma irregularly arranged, usually scat- 
tered, sometimes in discontinuous tangential lines. Two kinds of pith- 
rays are sometimes present, as in Vatica and some species of Diptero- 
carpus. 
The number of species in the family is large and many of them are 
but incompletely known. When Brandis wrote his Enumeration (1895) 
there were 325 species known. Since that time, there have been 25 or 
30 species described and there are probably quite a number of undescribed 
species in Sumatra, Borneo and other portions of Malaya. 
It seems that nearly all species in the family produce wood which 
is utilized, most of it commercially; consequently the classification of 
dipterocarp woods is an undertaking of some magnitude. There are 
groups of sjDecies which correspond in structure and which are marketed 
under the same name. An effort has been made to group the diptero- 
carps according to the structural groups and to apply the most used 
trade names to these groups. 
The following seem fairly distinct : rassalc, chengal, yacal, peniow, 
mangachapuy , mangasinoro, hap or, sal or guijo, apitong, tanguile, red 
lauan, almon, white lauan, mayapis. 
RASSAK. Plate XXVII, fig. 65. 
This is variously known as rassak, resale, resale batu , empadu, and 
narig, and comes principally from species of Vatica and Cotylelobium. 
It is found in Borneo, Sumatra, the Philippines, Ceylon and southern 
India. Trees of this group are very widely distributed. Singapore 
seems to be the principal market for the wood. It is probable that some 
of the wood in the Singapore market under this name is supplied by 
species of Shorea. The supply of rassak in Borneo seems to be rather 
limited. It is increasingly difficult to find large trees. The tree seems 
less gregarious than is the habit of many other members of the family. 
