Observations made in the Central Philippines. 623 
sharp points standing up, which makes transit very difficult. 
Inland this rock is broken up by narrow, steep valleys, through 
which flow the little streams from the centre of the island. The 
cliffs are full of caves, which seem in most cases to be water courses 
cut through the rock. We had heard of nests of the edible 
swallow (swift) in the island, and finally found a wrinkled old 
Indian who made a living by gathering the nests and selling 
to the Chinese at Ilo Ilo. The nests are not found, as might be 
supposed, in those caves opening near the sea, but in those far 
inland, where the cavity is covered with forest. We went to the 
nest-gatherer’s hut, two or three miles back from the sea, and telling 
him our object, he provided himself with a torch of native gum 
(dammar) and another made of the ribs of cocoa palm leaves, and 
we set out. After half an hour’s rapid tramping through the 
steep, rocky valleys, we came to a low ledge of rock, eight or ten 
feet high, covered with vines and bushes, and at the foot of this a 
black hole three or four feet square, leading down into the earth. 
The opening was just large enough to crawl through, but our guide 
lighted his torches, and getting down on hands and knees crawled 
in, and we followed, down a steep, narrow, rocky passage, the 
channel of a stream in the rainy season. It widened and grew 
higher as we went down, but was still nothing more than a rift 
made in the rocks, perhaps by earthquake, and widened by water 
wear. The rocks were muddy and slippery, and we followed our 
barefooted guide with difficulty. Still on we went, until all trace 
of light except from our torches was gone, and it seemed anything 
but a fitting place for birds’ nests. Still we went on, until after 
we were perhaps a hundred feet below the surface, and several 
hundred from the mouth of the cave, we began to hear the weak, 
faint twittering of the little birds as they flew about over our heads, 
and finally the Indian raised his torch, and we could see in the roof 
of the cave shallow hollows in the rock, and in these, and partly 
supported by their sides, the little white, cup-like nests, which the 
guide began tearing out with his fingers, and stuffing into a pouch 
at his belt. The birds fluttered about almost in our faces, but he 
kept on until he had gathered all in sight. None of them had eggs 
in them, as he had visited the place but two or three weeks before. 
The nests were pure white in color, made of little fibres interwoven 
