242 TROPICAL NATURE n 



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- 

 nsean Society. These commence their existence as parasitical 



SECTIONS OF TRUNK OF 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. 

 I and the equally remarkable fig-trees of various species, 



