408 
slopes. A reference to the table will make apparent the relative propor- 
tion of species to be found in the entire plot and on that of the hillside. 
Mangtfera altissima is the only species on the less boulder-like terrace 
which is not also common on the hillside. 
Because of the park-like nature of the entire terrace, the underbrush 
is here more common than it is in the more closed forest about to be 
described. The shrubby species which are common and characteristic 
of the river bottom are Lunasia amara, Justicia gendarussa, Glochidion 
sp., many seedlings of Pandanus luzonensis, jungle-like thickets of 
Donax arundastrum, and a few clumps of Bambusa lumanpao. Among 
the herbaceous forms are Hypestis cinerea, Clerodendron intermedium, 
and Alpinia brevilabris. The following ferns are also found here: Mt- 
crolepia spelunce, Gymnopteris contaminans, Lygodium  circinatum 
Polypodium myriocarpum, growing on rocks and on the base of trees, 
and Pteris cretica. A number of grasses are common in the open places. 
Epiphytes—The epiphytic vegetation is probably more prominent 
than observations show. The difficulty of obtaining a good idea of the 
character of the tops of the trees is great. However, a number of 
epiphytic orchids were obtained from tall trees by the natives and some 
were found on low branches in places having sufficient light. These 
include five species only. The epiphytic fern Drynaria quercifolia grows 
in open places on the trunks or branches of trees. 
Lianas.—The liana vegetation is very characteristic. Because of the 
excess of light, the vines are encountered not only in the tops of the 
trees but in places they even form dense walls on the open sides of the 
more closed areas. Symphorema luzonicum is perhaps the most charac- 
teristic of this vegetation and its habit may be taken as a type of that of 
all of the larger vines. Growing as it does to the tops of the large trees, 
by its own weight it may drag lower portions of its own length to the 
ground so that it may lie recumbent. From these parts in the denser 
shade new shoots may arise. hese often remain suppressed until a 
natural opening will give them an opportunity for rapid development. 
Thus the new shoots may trail to a greater or less extent until a support 
is reached, after which they become erect and in time will grow to the 
tops of the trees. Often, the prostrate portion becomes covered with 
earth, so that the shoots arising from it resemble young trees starting 
in the dense shade of the forest. During the wet season and growing 
in the dense shade, the long, etiolated, leafless shoots of the Gnetum 
latifoliwm (another common liana) resemble saprophytic plants so nearly 
that one is easily deceived concerning their true nature. Indeed, such 
shoots are in one sense saprophytic, for when they grow in a situation 
where the light is insufficient to enable them to elaborate their own 
food, they are dependent upon the foliage at the tops of the tall trees for 
their nourishment. Often three or more vines are found on a single 
tree. Oné instance emphasizing this fact was noted where Symphorema 
