306 The Philippine Journal of Science 1917 
used for measuring the 1.3 meters above ground but also to know 
that the contour of the ground had not changed. Of the last 
we cannot, of course, be absolutely sure, and so there may be 
slight errors in our calculations, but we do not believe that there 
are any serious ones. 
The forest on the Gedeh back of Tjibodas has a very irregular 
canopy. Doctor Koorders has made an extensive search for the 
tallest trees and found that the species attaining the greatest 
height was Altingia excelsa, one of the tallest individuals of 
which was 49 meters high. Most of the trees are, however, very 
much smaller than this. The tallest trees are found at the lower 
altitudes just back of Tjibodas. As higher elevations are 
reached the trees become much smaller until at the top of the 
mountain the canopy is only a few meters high. The forest at 
altitudes between 1,300 and 1,500 meters, where our measure- 
ments were made, is a fairly open one. Although the forest is 
tall for a mountain type, it has many of the characteristics of a 
tropical, high-mountain forest : among these are the prominence 
of species of Podocarpus and a considerable development of a 
mossy covering and other epiphytes. The relative humidity is 
constantly high and the rainfall is heavy. Von Faber ® gives the 
rainfall and relative humidity for this forest for the years 
1912-13. In 1912 the monthly rainfall varied from 256 to 398 
millimeters, and in 1913 from 95 to 386 millimeters. The mean 
monthly relative humidity in 1912 varied between 93 and 98 per 
cent and in 1913 between 92 and 97 per cent. 
In Table I is given a list of the trees measured on the Gedeh, 
including the height and diameter of each as originally deter- 
mined by Doctor Koorders. In this same table we have cal- 
culated the annual rate of groAvth of these trees by subtracting 
the diameters as measured in 1890 from the figures obtained by 
us in 1917 and dividing the remainder by 27. The rates of 
growth are classified according to diameter classes of 10 centi- 
meters, the classification being based on the diameter of the trees 
when the original measurements were made. 
The trees labeled by Doctor Koorders were selected, not with 
an idea of obtaining rates of growth but to authentically label 
the best specimens of the individual species in the forest. As 
trees show different rates of growth at different ages we cannot, 
from our calculations, determine the age of any individual of a 
species or of the forest in general, nor can we tell whether or 
not the rates of growth obtained for the individual trees are 
’ Von Faber, F. C., Physiologische Fragmente aus einem tropischen 
Urwald, Jahrb. Wiss. Bot. 56 (1915) 197-220. 
