1893. EVOLUTION IN THE GUIANA FOREST. 43 
caterpillar or otheris, however, almost always found to digest the most 
repellent juicesand make all such efforts fruitless. A few have attained 
a large measure of success on account of the toughness of their leaves 
and their covering of stiff bristles or thorns ; but the most curious 
provision is, perhaps, that by which a garrison of carnivorous ants is 
accommodated. Either in swollen petioles or bases of thorns the ants 
take up their abode and fall upon and destroy every invader. 
It is generally found that the trees most commonly attacked by 
larve are those the flowers of which are nectariferous, and therefore 
provide food for the perfect insect. The fiddle-wood tree (Citharexylon) 
is a striking example of this. Its spikes of white flowers perfume 
the air at night for long distances, and attract large numbers of moths. 
These same insects lay their eggs upon the tree, with the result that 
myriads of larve are produced, and the tree is often denuded of every 
leaf. In the ordinary course of nature it drops its leaves and is bare 
for a few days, after which the flowers are produced. The result of 
the ravages of the larve, like that of a ruthless pruning, is similar, so 
that by the time the perfect moth emerges from its pupa-case the 
flowers are ready to provide nectar for it. Other trees are attacked 
in the same way, and careful observation will no doubt show that 
there is something so remarkable in the actions of both plant and 
insect that nothing short of design can account for it. 
Plants are undoubtedly improved by having to contend with so 
many difficulties. The survivor is always the fittest and most suited 
to the environment. One contrivance after another is developed, with 
good, bad. or indifferent results, but generally somewhat to its advan- 
tage in over-reaching its neighbours. Meanwhile, however, its rivals 
have not been sleeping, but as fast as the one gains an advantage 
others will have put on some defensive armour, or perhaps become 
more fitted to assume the aggressive. The study of the innumerable 
contrivances by which the plants of Guiana have attained their 
present stage is a never-ending source of interest. Probably there is 
more to be learnt here in a few miles of forest, river, and swamp, than 
in the whole of Europe, while the difficulties of a thorough investigation 
of even one square mile are enormous. 
In Europe a large number of trees are anemophilous, but here 
all are fertilised by insect agency. This is one of the reasons why 
insects are so plentiful. At some seasons great moths fly into our 
open rooms at night, often to fall a prey to the gas lights. Some- 
times a table below the chandelier becomes littered with hundreds 
of small moths and other insects in an hour or two. If a tree is 
flowering outside, and happens to be one of those that are fertilised 
at night, the increase is most striking. The moths fly towards the 
white flowers and are apparently attracted farther by the intenser 
light of lamps. In the streets of Georgetown the arc electric 
lamps also attract great numbers of insects, including some of the 
largest moths, which may be seen wheeling round them almost like 
