Believing in magic, we’d hide these found treasures between the pages of our text books, sprinkling bread crumbs over them to feed them. If we loved them enough, we used to believe, the feathers would sprout fluff at the bottoms of their shafts and eventually (very very eventually) grow into the birds themselves. I suspect the fluff that appeared was probably mould. And of course, the feathers always fell out of the books and disappeared before they had time to turn into swan