INDO-MALAYAN WOODS. 
417 
ENEMIES OF WOOD. 
Fungus and bacterial growth . — The alternate exposure to moisture and 
dryness is the condition most favorable to such growth. This condition 
is found in all woods in contact with the ground — piling, bridge timbers, 
corner posts of houses, etc. In timbers in contact with the ground, as 
corner posts of houses, telegraph and telephone poles, fence posts, this 
condition is most marked at and just above the surface of the ground; 
and that is the region where decay most quickly takes place. 
Dry rot is a form of decay to which some woods are particularly subject. 
It seems to start in from the end of the wood and may sometimes be 
prevented by capping the end of the post or beam with good thick paint. 
Teredo . — This is a mollusk which bores into many timbers. It thrives 
in salt or brackish water and destroys piling, boat planking, etc., by 
boring into it in search of a home. It is exceedingly destructive to a 
large number of timbers and is the most serious problem in wharf con- 
struction. 
Termites or ivhite ants, known as “anay” or “anay-anay” by Filipinos 
and Malays, are particularly abundant in the eastern tropics. They at- 
tack a wide range of different kinds of wood and it may be doubted if 
any wood is entirely immune from their attacks. Many of the hard and 
heavy woods are very resistant to them; but it may be doubted if any 
of these can entirely resist them without the aid of impregnation. It is 
often claimed for some particularly hard wood that it is absolutely 
resistant to the termites; but it will usually be found that it is really 
only a fortunate chance of location which has prevented the attack. 
Beetles . — Numerous small wood-boring beetles cause great destruction 
among the woods of the tropics. Sapwood is particularly liable to at- 
tack; but the heartwood is also liable to attack in many cases. Numerous 
hardwoods, however, seem to be entirely free from this pest. A number 
of woods with hard heart and trashy sapwood are regularly cleaned for 
the market by being felled and left in the forest, sometimes several years, 
till the beetles and termites have destroyed the sapwood. 
In general, the very heavy and very hard woods are those least liable 
to insect attack. This is, however, not always true; some of the very 
hard woods are specially liable to the attacks of termites. 
From what, has been written and what seemed to be generally believed 
by the trade, the following summary of woods according to their use has 
been made. 
WOODS EXPOSED TO SALT WATER. 
Piling . — The use of a wood for piling is the extreme test of durability, 
principally because of the teredo, which speedily destroys most woods. 
It is to be doubted if there is any wood which is entirely immune from 
its attack. A pile presents considerable surface to the air and water 
alternately, furnishing a condition especially favorable to decay; and 
