NOTES ON SUMATRA. 167 
plant seems to be to protect its aerial roots from the sun, as these are 
always found within the metamorphosed leaves, ramified on and slightly 
adhering to their inside surface ; they are, I think, invariably full of ants, 
and of one peculiar species. 
The upper part of the island is generally covered with the usual 
jungle trees, Guttifere and Myrtacee (among the latter a Syzygium, 
with black eatable fruit) perhaps prevailing. A small Myristica is 
very abundant on some islets, as is also a Sapotaceous plant with rufous 
leaves, yielding a concrete white gum, used some time ago to adulterate 
gutta-percha, but. now no longer saleable. The plant yielding the finest 
India-rubber, I think an Urceolaria, is common here; it is a large 
climber as thick as a man’s leg, with a dark rugged bark: it is called 
“Jintawan” by the Malays, but this includes three species, the “ Me- 
nungau," the ** Sarapit,” and the ** Patabo ;" the fruit of the ** Sarapit" 
is the best, but all are much valued by the Malays, the pulp surround- 
ing the seeds being very sweet, with a pleasant acid, and a fine vinous 
flavour. To collect the sap the stem is usually eut into billets a few 
feet long, from both ends of which the milky juice flows abundantly ; 
and the plant soon springs up again. The gum is not collected among 
these islands, though the locality, always within reach of the sea, is 
highly favourable, the only preparation required being to mix salt water 
with the sap, the solid parts of which instantly coagulate. A gigantic 
climbing Grass, probably a Nastus, festoons the trees with its snaky, 
leafless stems in every direction, and a large creeping Bauhinia, with 
changeable yellow and red flowers, is often seen; and the high, dry 
parts of the islets are often nearly impassible from the thorny leafstalks 
of a Licuala, a beautiful little palm, its long spikes of scarlet berries 
bending down almost to the ground; it is called ** Pallas,” in common 
With one or two others of the same genus. ‘The tallest, and perhaps 
one of the commonest trees on the higher ground, is, I think, a Dip- 
terocarpous plant; its leaves are silvery beneath, like an Eleagnus, 
Which makes it very ornamental ; its light red wood is straight-grained 
and easily worked, and is much used at Singapore, under the name of | 
Seraya, for house carpentry: I could not find its flowers or fruit. 
These islands are not the places in which we can expect to find 
many aerial Cryptogams. I did not see in all more than half-a-dozen 
species of Mosses: a Calymperes in fruit on the Mangrove trunks, 
a small Hypnum on decayed wood, and the others barren and very 
