490 
The Philippine Journal of Science 
1921 
all uses, being stronger and tougher; for almost all parts of ve- 
hicles, it is probably the most widely used wood in the Islands. 
The logs for the present test were purchased in the Manila 
market. There is practically no doubt that they were true guijo 
[Shorea guiso (Blanco) Blume]. 
LUMBAYAN 
Lumbayan ( Tarrietia javanica Blume) has been found only 
in Misamis, Cotabato, Zamboanga, and Basilan. It is estimated 
that it constitutes not over 5 per cent of the total stand in those 
regions where it occurs. Lumbayan is a tall, straight tree, 
reaching 40 to 50 meters in height and 130 centimeters in 
diameter. 
The sapwood of lumbayan is very pale red merging rather 
gradually into the light red to reddish brown heartwood. The 
heartwood is moderately heavy, soft to moderately hard, straight 
or slightly cross-grained, fairly durable, being rarely attacked 
by insects, flexible and tough, rather easy to split, and easy to 
work. In color and texture it resembles the red lauans ex- 
cept that, when quarter-sawn, the silver grain is more con- 
spicuous than in most lauans. 
Structure. — Pith rays moderately thick, distinct, forming a 
small but conspicuous silver grain in radial sections and visible 
as minute vertical lines in tangential sections; pores few, mod- 
erately large to large, evenly scattered, sometimes with dark 
red, glistening deposits; soft tissue in smooth thin rings about 
pores; no growth rings. 
Lumbayan is used for flooring, interior finish, furniture, ship 
planking, and ship cabin work. 
The material for the present test was secured from the Bu- 
reau of Supply, having been purchased by that bureau from 
one of the large mills in Zamboanga. 
GISOK (YAKAL) 
The woods known in commerce as yakal are the product of 
Isoptera bornCensis Scheff., and of several species of the genera 
Hopea and Shorea. The material used in the present test was 
commercial yakal from Zamboanga, identified as being prac- 
tically without doubt of the species known as gisok [ Shorea ba- 
langeran (Korth.) Dyer]. 
Gisok is a large tree, reaching a height of 35 to 45 meters 
and a diameter of 180 centimeters. It has been reported by 
botanical collectors from the following islands and provinces: 
Nuevai Ecija, Pangasinan, Pampanga, Zambales, Tayabas, Ca- 
