030 REPORT OF THE HARVARD AFRICAN EXPEDITION 
palm is seen climbing over the trees, and then comes a definite zone of the 
screw pine, Pandanus candelabrum. The dense tropical jungle recently left 
behind gave the impression of a restored forest of the carboniferous period. 
This impression is emphasized by the Pandanus jungle. The cumbersome 
arched, ascending stems with their long sword-shaped leaves, and the vast 
numbers of descending aérial roots make a picturesque scene, although to those 
who use the stream as a waterway, they constitute a distinct and unmitigated 
nuisance that must be removed at all too frequent intervals. This zone per- 
sists almost to the junction of the Du River, where the brackish influence is 
felt and then the mangroves succeed them and remain the dominant plant 
for a considerable distance up that river, affording a rather monotonous scene 
that is only occasionally punctuated by the pinkish flowers of a Hibiscus that 
manages to compete with its associate. As the land becomes higher a mixed 
forest appears and a number of gigantic, gray, columnar boles, buttressed 
at the base and surmounted by a widespread crown, stand out above the 
surrounding forest. This is the silk-cotton tree, Ceiba pentandra, one of the 
most stately of the forest trees. Later on Raphia vinifera grows in almost 
pure stands along the river. Especially good stands are noticeably present 
on the inside of the curves of the river where the gravelly eroded soil had been 
deposited, a fact seemingly correlated with the ability of the seeds to find a 
place in which to germinate. As the land becomes higher and the current of 
the river becomes swifter, the Raphia palms disappear and taller trees take 
their place once more, and over these climb numerous vines, among which 
Ecastophyllum Brownei, a leguminous species with great numbers of white 
flowers, is prominent. More rarely a species of Combretum makes a showing 
with its reddish flowers. The taller and most numerous trees belong to the 
Leguminoseae, many of them sending their branches out horizontally over 
the river. 
FIRESTONE PLANTATION No. 3 
After a day’s trip up the river so full of interest and variety, the clearings 
made for planting rubber seedlings are disappointing at first sight from a 
botanical standpoint; yet when once camp is established and equipment is 
prepared for taking care of specimens, such a feeling soon vanishes, since because 
of the very fact that the felling of trees is still going on, there is an excellent 
opportunity to collect specimens that are otherwise unavailable without a 
great outlay of time and energy. Also, a fine opportunity is afforded for col- 
lecting inaccessible epiphytes. 
The region in which the plantation is located is fifteen or twenty miles 
from the coast as the crow flies, and is somewhat above sea level. Further- 
more, the terrain is hilly and rolling, some of the well-forested hills rising two 
or three hundred feet above the level of the river. Thus there is afforded a 
chance to collect in three different types of localities: river edge and adjacent 
low ground, swamp, and the higher elevations of the hills. 
Extending back from the bank that is four to six feet above the river, the 
