"I must confess to feeling anything but comfortable while going through the places held in possession by these monsters of the deep, and used every effort to pass quickly and unnoticed. Yet it was more than an hour and a half before I got clear of the rocks, cliffs, and shoals to which they resorted, and near a high and precipitous cape, running far out to sea. Right opposite to me, in the side of this rocky wall, was a magnificent archway, forming, as it first appeared to me, a lofty entrance to an immense vaulted cavern. I passed beneath this noble portal and examined the interior. It was tenanted by numbers of a small species of swallow, scarcely larger than a wren, and the walls were covered by thousands of their nests. They were rudely built, and their peculiarity was that each rested on a kind of platform, something like a spoon without the handle. I detached a number, and found that they had a curious appearance, seemingly made of something fibrous and gelatinous, and more like a set of sponges, corals, or fungi, than nests of birds. I have brought them home in my fishing net." "If we had commercial dealings with the Chinese," said I, "your discovery would be of value; these are doubtless edible bird's nests. The bird is called the esculent swallow, and the trade in this strange article of diet is a very large one. The nests are of different value, but those which are quite new, and nearly white, are held in such esteem that they are worth their weight in silver. "There are tremendous caverns in Java and other places where, at great risk, these nests are procured; the annual weight obtained being upward of fifty thousand pounds, and the value more than £200,000. "When placed in water and well soaked, they soften and swell, and are made into soup of very strengthening and restorative quality. "I think you might try your hand on these, mother, just for curiosity's sake." "I can't say I fancy the look of the queer things," said she, "but I don't mind trying if they will turn to jelly; though boiling birds' nests is cookery quite out of my line." "Oh, do, mother; let us taste birds' nests as soon as you can, though the idea makes me fancy my mouth full of feathers!" laughed Jack. "It is really a most curious formation," said Fritz. "From whence are the swallows supposed to get this kind of gelatine?" "It has never been exactly ascertained," I replied, "whether the birds discover or produce this curious substance. But whatever may be its basis, it is clear that a very large portion of it is furnished by certain glands, which pour out a viscid secretion."