ALLIES OF THE PLANT WORLD 
We always associate Bees and flowers, yet it 
is probable, that, as a whole, the plants, es- 
pecially in the tropics, depend more upon Ants 
than upon any other insects. Many vegetable 
folk deliberately employ them to keep their 
leaves and stalks free of obnoxious visitors. The 
Cow-Horn Orchid, like most plants which 
perch on trunks and branches, produces pseudo- 
bulbs into which its vitality can recede in dry 
seasons. ‘There is always a small opening at 
the bottom of each of these little tubes, through 
which Ants enter. They honeycomb the inter- 
ior with cells and galleries where they can be 
perfectly dry in the wettest weather. On the 
approach of Caterpillars, Cockroaches and 
other Orchid enemies, the residents issue in 
great swarms to protect their combined host and 
home. 
The species Coryanthes, instead of pseudo- 
bulbs, grows great masses of fibrous aerial roots 
among which the Ants dwell. They are ever 
ready to repel invasions of Cockroaches and 
other crawlers who seek to eat the tender grow- 
ing root-tips. 
[71] 
