"They prepare their nests with the more solid parts of their food, and by no means with the froth of the sea or marine plants, as has been asserted [1]. This opinion is the more founded in probability, as it is ascertained by experience that those birds which build on the rocks, already mentioned, have never been seen on the coast, and that they could not repair thither and return in any reasonable time on account of the lofty chains of mountains they would have to traverse, and the tempestuous winds which prevail there. The great difference, then, in the colour and value of these nests, is a proof that their quality depends solely on the nature and abundance of the insects which form their food; perhaps, likewise, on the more or less perfect solitude of the places they resort to for it. "The nests collected in the territory of Calappa-Nongal and of Goadja are quite grey, and are of one-third less value than those of the territory of Sampia. These last again are in far less estimation than the excellent sort sent every year from Ternate and Passir, or those found in the islands immediately adjoining, and on that of Borneo in particular. "These birds require two months to prepare their nests; they immediately after lay their eggs, and sit fifteen or sixteen days. As soon as the young take flight, the gathering of the nests commences, and is repeated every four months: it is the harvest of the proprietors of those rocks. This is performed by men accustomed from their infancy to clamber among these precipices: with reeds and bamboos they provide themselves with ladders, with which they mount up to the holes; but when the depth of the caves is too great, they have recourse to ropes. "When at the bottom of these caverns, they place against the inside notched bamboos, which answer the purpose of ladders, to enable them to reach the nests, and if these are beyond their immediate reach, they detach them with bamboo poles; there are likewise holes, but in very limited numbers, which may be got at by means of ladders of bamboo. "This employment, which is attended with very great risk, costs the lives of many human beings, and particularly of those who attempt to steal the nests. For their preservation, guards are placed here and there.