hem down on the
ever-increasing mounds, so that its surface is nearly always fresh and
new-looking.

Standing near the mounds, one sees from every point of the compass
ant-paths leading to them, all thronged with the busy workers carrying
their leafy burdens. As far as the eye can distinguish their tiny
forms, troops upon troops of leaves are moving up towards the central
point, and disappearing down the numerous tunnelled passages. The
outgoing, empty-handed hosts are partly concealed amongst the bulky
burdens of the incomers, and can only be distinguished by looking
closely amongst them. The ceaseless, toiling hosts impress one with
their power, and one asks--What forests can stand before such
invaders? How is it that vegetation is not eaten off the face of the
earth? Surely nowhere but in the tropics, where the recuperative
powers of nature are immense and ever active, could such devastation
be withstood.

Further acquaintance with the subject will teach the inquirer that,
just as many insects are preserved by being distasteful to
insectivorous birds, so very many of the forest trees are protected
from the ravages of the ants by their leaves either being distasteful
to them, or unfitted for the purpose for which they are required,
whilst some have special means of defence against their attacks.

These ants do not confine themselves to leaves, but also carry off any
vegetable substance that they find suitable for growing the fungus on.
They are very partial to the inside white rind of oranges, and I have
also seen them cutting up and carrying off the flowers of certain
shrubs, the leaves of which they neglected. They are very particular
about the ventilation of their underground chambers, and have numerous
holes leading up to the surface from them. These they open out or
close up, apparently to keep up a regular degree of temperature below.
The great care they take that the pieces of leaves they carry into the
nest should be neither too dry nor too damp, is also consistent with
the idea that the object is the growth of a fungus that requires
particular conditions of temperature and moisture to ensure its
vigorous growth. If a sudden shower should come on, the ants do not
carry the wet pieces into the burrows, but throw them down near the
entrances. Should the weather clear up again, these pieces are picked
up when nearly dried, and taken inside; should the rain, however,
continue, they get sodden down into the gro