ie tar Ore 9 AE SS OR | a Sie Slick Sy Mey dein He ie Bie 
425 
with seeds, only a few seedlings were found. This indicates conclusively 
that the shaded conditions are the best for this species. Facts deduced 
from the table and from some observation during the rainy season show 
that Koordersiodendron pinnatum resembles Anisoptera in its seeding 
habits; that is, it will tolerate shade, but it does better in more open 
places. Correlated with the light-loving habit one finds the seed of 
Koordersiodendron pinnatum and Parkia roxburghii germinating to some 
extent before the rainy season sets in. On the other hand, Anisoptera did 
not, though many seeds were present. A’. pinnatum has a fleshy fruit 
which is eaten by the wild hogs. 'The seeds, however, pass through the 
intestines of the animals undigested and are buried in loose ground made 
by the rooting of the hogs, where in a few days they germinate. Thus the 
seeds may not only be carried long distances by hogs, but are also planted 
by them. However, the young tender seedlings which germinate may be 
eaten by the same animal, so that the advantages which this tree would 
have over others is partially counteracted by the same agent. Many very 
young trees of Calophyllum wallichianum were observed both in open and 
closed places, though in the latter they are most numerous. On the other 
hand, many species represented by larger trees show no seedlings at all. 
Lagerstremia speciosa is a striking example of this. Though seeding 
abundantly during both seasons in which it was observed, not a single 
seedling could be found. Efforts to germinate these seeds in the nursery 
proved unavailing. Species of Dipterocarpacee other than those discussed 
show an average number of young trees present, but as these species 
did not fruit abundantly during the two seasons under consideration, the 
sylvicultural habits as regards light can not with certainty be determined. 
A reference to the tables will show the proportion of young to old trees in 
other species. Much work remains to be done on the seedling condition 
of the principal forest trees before any definite conclusions can be 
reached. 
Topography and soil.—The topography of the Anisoptera-Strombosia 
formation consists of a series of ridges alternating with deep caiion-like 
valleys. ‘The gradient of the slopes of the valleys is approximately 25 
degrees, although, of course, it may be more or less. We have seen that 
corresponding to the surface diversity there are types of forests which dif- 
fer in species and in leaf structure. Here, as in other formations where 
the slope is steepest, the surface wash is greater and consequently the soil 
is shallow. Usually, also, the exposure is great. All these combine to 
make a lower chresard and consequently a more xerophytic vegetation. 
Kspecially are these conditions obtained on the ends of ridges which 
_ terminate abruptly at the junction of the branches with the main streams 
of the : river. Attention has also been called to the character of the vege- 
tation on the rocky flood plains of the river. Here, though the under- 
ground water level is rather near the surface yet, because of the nearly 
_ absent soil and the hydrodynamic effect of the flooded stream, the vege- 
tation is inclined to be more or less unstable and consequently open. 
as see 
