APPENDAGES OF THE AXOPHYTE. 39 



these aerial roots emitted from the stem into the open air, 

 descend to the ground, and establish themselves in the soil. 

 Many plants of tropical climates present this phenomena. 

 Amongst which we may mention the Ficus religiosa, or 



Fig. 10. 



An Epiphytic orchid (Maxillaria) of warm climates. 



Banyan tree of British India. This tree drops from its hori- 

 zontal branches, roots into the air, which, swinging in the 

 breeze like pendant cords, do finally reach the soil, into which 

 they penetrate, when they become metamorphosed or changed 

 into stems, and increasing in diameter, give nutriment and a 

 natural support or prop to the heavy branches from which 

 they originally descended, so that those branches can extend 

 laterally still farther from their parent trunk. By numerous 

 growths of this kind, one tree ultimately becomes the centre of 

 a family forest, their united branches and foliage spreading 

 over a considerable extent of ground. 



The Pandanus or Screw pine may be cited as another 

 instance. In this case, when the tree is much exposed to the 

 powerful winds of the tropics, strong roots are emitted from 

 the lower part of the main trunk, which, striking into the soil, 



