season. I myself incline to agree with the natives that the nests are
formed by different birds, for the fact that, in one set of caves, black
nests are always found together in one part, and white ones in another,
though both are collected with equal care and punctuality, seems almost
inexplicable under the first theory. It is true that the different kinds
of nests are not found in the same season, and it is just possible that
the red and black nests may be the second efforts at building made by
the swifts after the collectors have disturbed them by gathering their
first, white ones. In the inferior nests, feathers are found _mixed up_
with the gelatinous matter forming the walls, as though the glands were
unable to secrete a sufficient quantity of material, and the bird had to
eke it out with its own feathers. In the substance of the white nests no
feathers are found.

Then, again, it is sometimes found in the case of two distinct caves,
situated at no great distance apart, that the one yields almost entirely
white nests, and the other nearly all red, or black ones, though the
collections are made with equal regularity in each. The natives, as I
have said, seem to think that there are two kinds of birds, and the Hon.
R. ABERCROMBY reports that, when he visited Gomanton, they shewed him
eggs of different size and explained that one was laid by the white-nest
bird and the other by the black-nest builder. Sir HUGH LOW, in his work
on Sarawak, published in 1848, asserts that there are "two different and
quite dissimilar kinds of birds, though both are swallows" (he should
have said swifts), and that the one which produces the white nest is
larger and of more lively colours, with a white belly, and is found on
the sea-coast, while the other is smaller and darker and found more in
the interior. He admits, however, that though he had opportunities of
observing the former, he had not been able to procure a specimen.

The question is one which should be easily settled on the spot, and I
recommend it to the consideration of the authorities of the British
North Borneo Museum, which has been established at Sandakan.

The annual value of the nests of Gomanton, when properly collected, has
been reckoned at $23,000, but I consider this an excessive estimate. My
friend Mr. A. COOK, the Treasurer of the Territory, to whose zeal and
perseverance the Company owes much, has arranged with the Buludupih
tribe to collect these nests on pa