Note 1 — NOTES TO VOLUME I.

“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 asserted1. 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.