uild in fissures and cavities of rocks, especially in
such as open to the south. In the latter, the finest and whitest nests
are found, and I have sometimes gathered fifty pound weight of them, on
one excursion for that purpose. They are small, and shaped like
swallows' nests. If they are perfect, 72 of them go to a _catty_, or
1-3/4 pounds. The best sale for them is in China. After the most
diligent investigation, I was never able fully to discover of what
substance they are made, nor do any of the opinions of naturalists,
with which I have become acquainted, appear satisfactory to me, neither
have the authors alluded to ever seen the birds. They have remarkably
short legs, and are unable to rise, if they once fall or settle on the
ground. I caught many in this state, and after examining them, threw
them up into the air, when they immediately flew away; they cannot
therefore, as some suppose, obtain their materials on the coast, or
from rocks in the sea. My opinion is, that the nests are made of the
gum of a peculiar tree, called by some the Nicobar cedar, and growing
in great abundance in all the southern islands. Its wood is hard,
black, and very heavy. From December to May, it is covered with
blossom, and bears a fruit somewhat resembling a cedar or pine-apple,
but more like a large berry full of eyes or pustules, discharging a gum
or resinous fluid. About these trees, when in bloom or bearing fruit, I
have seen innumerable flocks of these little birds, flying and
fluttering like bees round a tree or shrub in full flower, and am of
opinion, that they there gather the materials for their nests. I relate
the fact, having often watched them with great attention, but will not
venture to affirm, that I have made a full discovery. I observed
before, that these birds dwell in cavities of rocks, like bees in a
hive, flying in and out, and building their nests close together, like
martins or swallows. The hen constructs a neat, large, well-shaped
nest, calculated for laying and hatching her eggs, and the cock
contrives to fix another, smaller and rather more clumsy, close to his
mate: for they are not only built for the purpose of laying eggs, but
for resting-places, whence they may take wing. If they are robbed of
them, they immediately fall to work to build others, and being
remarkably active, are able to finish enough in a day to support the
weight of their bodies, though they require about three weeks to
complete a nest.