CECROPIA AND ITS GUESTS 79 
will be well to consider a few of the cases in which 
the relationship between plant and animal is continu- 
ous and more intimate, the two living in very close 
relations to each other: to such cases the term sym- 
biosis or “living together” is applied by naturalists. 
The relations existing between certain trees and some 
species of ant are of high interest, and illustrate well 
this phase of life. The Candelabra Tree (Cecropia 
peltata) of the South American forests is liable 
to attack by leaf-cutting ants (Gcodoma), which 
climb trees and bite off thousands of leaves; these 
they cut up on the ground and carry to their nests, 
where they form a basis for the growth of certain 
small fungi which are a favourite food of the ants 
(compare the cultivation of mushrooms as practised 
by gardeners). The Candelabra Tree protects itself 
from these ravages by forming an alliance with 
another kind of ant (Azteca). Along the hollow 
stems are little pits through which the ants easily 
bore, and reach the convenient houses within, where 
they live and bring up their young. At the base of 
the leaf-stalks, where the greatest danger lies from 
the leaf-cutting ants, little tufts of hairs are situated, 
among which are small white masses of nutritious 
material much liked by the ants, and collected by them 
and stored within their houses. So that these desir- 
able trees are swarming with Aztec ants, fierce little 
creatures—“it is one of the most bellicose ants that 
I know, and its sting is most irritating,’ writes 
Kerner—which congregate especially at the leaf- 
stalks, the point of attack of the leaf-cutters. The 
advantages of these arrangements to both the trees 
and the Aztec ants are obvious, 
