pson.
24. Kampong Banjar, Mile 29, Keningau. Antonio D. Garcia.
25. Oil Palm Research Station, Mile 32, elevation 40 feet, Sandakan.
Antonio D. Garcia.

ECOLOGY OF THE COLLECTING LOCALITIES

QUOIN HILL.--At this locality I recognized five habitat types as
follows:

_Primary forest._--We were fortunate to be able to work at Quoin Hill
because it had been opened to cultivation (of Cocoa, _Theobroma cacao_)
for only a few years. Thus the primary forest here started at the edge
of the Cocoa Research Station. This was in marked contrast to areas on
the west coast, where one would need to travel many miles inland to find
virgin forest. The forest at Quoin Hill was typical tropical
rain-forest, composed mostly of dipterocarps (Dipterocarpaceae). These
comprise an essentially Indo-Malayan family, members of which are so
conspicuous that we commonly referred to it as Evergreen Dipterocarp
Forest. The lowland forests of Borneo are composed of approximately
3,000 species of trees (Browne, 1955). At Quoin Hill, as in most of the
tropical rain-forest of Borneo, the forest canopy is stratified in three
layers, a distinct and easily recognizable top story and less easily
separable middle and lower stories. The top canopy is composed of
foliage of giant trees that may tower to heights of 200 feet and have
trunks three to seven feet in diameter. The trunk is usually unbranched
for 50 to 100 feet and the whole tree is supported by buttresses jutting
out from the main trunk. Some of the most important plants in the
tropical rain-forest are the strangler figs (_Ficus_ sp.). These plants,
when in fruit, draw birds in large flocks to feed upon them. Such figs
were common about the edges of the research station and some birds taken
from these trees were never taken elsewhere. The birds seemed to wait
for a certain degree of ripeness of fruits; on one day the figs were
unmolested and the next day the trees would be swarming with birds.
Strangler fig trees reach tremendous size and help form the upper forest
canopy.

The middle and lower forest canopies are not easily separable and I
shall speak of them together. The trees forming these varied from 10 to
60 feet in height. The ground surface beneath the trees was usually bare
except for leaf litter and dead branches. Sunlight penetrates only where
the big trees have been removed or where the larger trees are otherwise
widely spaced. At Quoin Hill the large trees of specie