242 
TROPICAL NATURE 
ii 
posed to think this is caused by accident or decay, but re- 
peated examination shows it to be due to the natural growth 
of the tree. The accompanying outline sections of one of these 
trees that was cut down exhibits its character. It was a 
noble forest tree, more than two hundred feet high, but rather 
slender in proportion, and it was by no means an extreme ex- 
ample of its class. This peculiar form is probably produced 
by the downward growth of aerial roots, like some New 
Zealand trees whose growth has been traced, and of whose 
different stages drawings may be seen at the Library of the Lin- 
neean Society. These commence their existence as parasitical 
Sections op Trunk op a Bornean Forest-Tree, 
1, Section at seven feet from the ground. 2. 3. Sections much higher up, 
climbers, which take root in the fork of some forest tree and 
send down aerial roots which clasp round the stem that up- 
holds them. As these roots increase in size and grow 
together laterally they cause the death of their foster-parent. 
The climber then grows rapidly, sending out large branches 
above and spreading roots below, and as the supporting tree 
decays away the aerial roots grow together and form a new 
trunk, more or less furrowed and buttressed, but exhibiting 
no other marks of its exceptional origin. Aerial-rooted forest 
trees — like that figured in my Malay Archipelago (vol. i. p. 
131) — and the equally remarkable fig-trees of various species, 
