Juty-AususT, 1919.] THE ORCHID REVIEW. 
Boiths 
Ga ° 
cn 
eS ORCHIDS AT HOME. 
. HEN looking at living flowers of the remarkable genus Coryanthes, 
we have often thought how much more interesting it would be to 
see the plants in their native surroundings, and the point is emphasised in 
a graphic article on ‘‘ Guiana Orchids, their insect friends and foes,”’ by 
“J. R.,” which appeared some years ago in the Demerara Argosy. The 
substance is here given, with an alteration in the name of the fertilising 
insect rendered necessary by subsequent enquiry :— 
When I saw Coryanthes speciosa flourishing luxuriantly, with its oval 
mass of roots a nest for myriads of stinging ants, the questions naturally 
occurred to me: What is the connection between the insect and the plant? 
Is there any benefit or injury from the association ? Did the Orchids grow 
on the ants’ nest, or the insects make their home in the root of the plant ? 
These questions can be answered, thanks to Darwin, Lubbock, and other 
naturalists who have investigated the connection between ants and Orchids ; 
and confirmed by my own observations in some cases. The Orchid being 
pendent from small branches, or creeping plants, it affords a secure asylum 
for the insects, in the same way that the mocking-bird’s nest is hung from 
the outer branches of tall trees to preserve the brood from their enemies. It 
is certain that the Orchid suffers no injury from its tenants, but on the 
contrary, flourishes to perfection under such circumstances. That the 
plant does not originate upon the ants’ nest is proved by the fact that young 
specimens are often found uninhabited, but with bunches of roots similar to 
the older ones. Ant plants derive benefits from their tenants from the fact 
that these are carnivorous, praying upon such pests as naked caterpillars, 
cockroaches, and plant mites. It is a common and interesting sight to 
watch a small regiment of ants carrying a cockroach up a wall, or attacking 
a live caterpillar ; but when an army of yakmen or hunter ants make a raid, 
hundreds of plant eaters may be seen running, jumping, and crawling, ea 
rid themselves of their tormentors, which hold on in spite of the big jumps 
of grasshoppers, or the rolling of caterpillars. 
In growing these plants near the coast (their tenants having been evicted 
by the collectors), some difficulty is experienced to keep them free from 
cockroaches, which gnaw at the roots, and often kill the Orchids in a little 
time. In collecting them, the supporting branches are cut away quickly, 
and the whole plant dropped into the water, then pushed under with a long 
pole until the ants come to the surface. As may be supposed, the collector 
is almost certain to get well bitten, even with most careful management. 
Although the Coryanthes is benefited by its freedom from cockroaches, 
