194 AIR ROOTS. 



the parent stem. In the temperate zone, we have 

 rudimentary examples of both the former processes 

 (buttresses and surface roots), but so far as we are 

 aware, we have nothing at all to compare with the 

 regular air roots of the equatorial forest: before roots 

 can be made to spring from the branches of trees of 

 the temperate zone they must in some way be brought 

 into contact with materials, such as earth, vegetable 

 refuse, water, etc., which form the food of plants; they 

 will then, as we know, gradually throw off roots, and 

 in many instances attach themselves to the soil. But 

 in the equatorial forest, considerable numbers of trees 

 form regular root fibres upon the under surface of their 

 branches; which grow downwards, at first like a single 

 hair, but, gradually acquiring strength and nourishment 

 from the air itself, they soon reach the ground, and thus 

 in a short time form an entirely new stem, which 

 taking root grows independently of the parent tree, 

 while at the same time it is anchored to it by 

 immense branches which ensure their mutual stability, 

 like the trusses of an iron girder bridge. 



We ought perhaps to say that there are two totally 

 distinct kinds of "air roots" (i) those that drop from 

 the branches, as already described; and (2) another 

 kind that are given off from the stem, or trunk, of the 

 tree itself, a short distance above the ground ; and which 

 descend like the others until they are rooted in the 

 soil. As the trunk grows in height, these roots grow too, 

 and thus sometimes become so increased in size and 

 length that the tree appears to be mounted upon a 

 natural scaffold, supported by struts formed of these 

 roots. This class of air roots is well seen in many palms 

 and other trees, especially in the various kinds of 



