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FOXWORTHY. 
The outer part of the stem of the Pandanus is usually very hard. I do not 
know of its commercial use here, but in some Pacific islands it furnishes an orna- 
mental wood similar in texture, but inferior in finish, to that of the coconut 
( Cocos nucifera L. ) and palma brava ( Livistona spp. ) . 
Exogens. — The remainder of our woody plants may be grouped 
together as Exogens ; that is, the stem consists of a woody cylinder which 
grows in diameter by the addition of concentric layers about the wood 
already formed ; there are two great groups ; the Gymnosperms, or 
Conifers , and the Angiosperms, or broad-leaved plants. These may be 
distinguished as follows: 
Conifers. — Wood, except in the first layer about the pith, containing 
no vessels; that is, nonporous; exceedingly regular in structure. There 
are a number of Conifers native to the Islands, but they are scattered in 
small patches or in almost inaccessible places on the mountains. The 
only native Conifer that is cut at all for timber is the Benguet pine 
(Pinus insularis Endl.) and it scarcely comes into the Manila market 
at all. However, a large amount of coniferous wood is imported nearly 
all of this is California redwood or Oregon pine, although an occasional 
piece of coniferous timber from Australia, Japan, or China is en- 
countered. 
Angiosperms. — The remaining group, the broad-leaved trees, furnishes 
practically all of the Philippine wood found in the lumber yards, and 
further discussion will apply to woods of this group unless otherwise 
indicated. 
PARTS OF THE STEM. 
Pith, wood, and hark. — In examining the end of a log, three distinct 
areas are seen; namely, a small, central portion, the pith, made up of 
soft tissue; an outside, more or less corky covering, the hark, for purposes 
of protection; and, the wood, which is the hard tissue making up the 
greater part of the log and extending from bark to pith. 
The pith is usually of very small diameter; it is rarely, as in Malapa- 
paya ( Polyscias nodosa Seem.), greater than one centimeter. This fact 
is of importance because the pith is an element of weakness in the wood. 
Sapwood and heartwood .- — The outer part of the log is often of a 
much lighter color, less in specific gravity and much softer than the 
center. The distinct, central part of the log is known as the heartwood 
and this outer portion is termed the sapwood. Many woods do not show 
any heartwood. The relative amount of sap- and heart-wood is very 
variable according to the individual-tree, the age and the part of the tree 
from which it is taken. 
Pith-rays. — Radiating from the pith to the bark are connecting lines 
of soft tissue, the medullary or pith-rays. These are among the most 
important characteristics to be observed in the structure of a wood, since 
they have an intimate connection with both the strength and beauty. 
They differ in size in different woods, being very large and distinct in 
some, as for example in teluto ( Pterocymbium tinctorium Merr.), catmon 
