THE EPIPHYTES 149 
CHAPTER XIII 
THE EPIPHYTES 
HiTHERTO we have chiefly considered the 
relation of vegetation to an exiguous water 
supply rather from the point of view of par- 
simony. A short or precarious supply is 
met by reducing the output, hoarding the 
precious liquid, or living an abstemious life. 
But other plants have shown greater powers 
of invention, so to speak, in overcoming 
the difficulties of life. They have countered 
intermittence by the construction of more or 
less ample cisterns, and they have developed 
new methods by which the available water is 
absorbed. These modifications of structure 
have rendered existence possible, and even 
easy, in many situations from which ordinary 
plants are debarred from establishing them- 
selves. Perhaps the best examples of this 
inventive resourcefulness are to be met with 
amongst the plants that have exchanged a 
terrestrial for an arboreal habitat. Such 
plants are generally called epiphytes. They 
are in no sense necessarily parasitic, that is 
to say they do not tax their host for food. 
All they demand from the trees is the space 
whereon to grow. 
