Yes, Mis's mate knew, in some natural wise way of her own, the secret of making use of what we call her "protective coloration." This is one of the very most important secrets Mother Nature has given her children, and many use it--not birds alone, but beasts and insects also. They use it in their own wild way and think nothing about it. We say that it is their instinct that leads them to choose places where they cannot easily be seen. If you do not understand exactly what instinct is, do not feel worried, for there are some things about that secret of Mother Nature that even the wisest men in the world have not explained. But this we do know, that when her instincts led Mother Nomer to choose the pebbly roof as a background for her mottled feathers, she did just naturally very much the same thing that the soldiers in the world-war did when they made use of great guns painted to look like things they were not, and ships painted to look like the waves beneath them and the clouds in the sky above. Only, the soldiers did not use their protective coloration naturally and by instinct. They did this by taking thought; and very proud they felt, too, of being able to do this by hard study. They talked about it a great deal and the French taught the world a new word, _camouflage_, to call it by. And their war-time camouflage _was_ wonderful, even though it was only a clumsy imitation of what Mother Nature did when the feathers of Mother Nomer were made to grow dappled like little blotches of light and dark; or, to put it the other way about, when the bird was led, by her instinct, to choose for the nesting-time a place where she did not show. Of course, it was not just the gravel on the flat roof that would match her feathers; for there isn't a house in the land that is nearly so old as one thousand years, and birds of this sort have been building much longer than that. No, so far as color went, Mother Nomer might have chosen a spot in an open field, where there were little broken sticks or stones to give it a mottled look--such a place, indeed, as her ancestors used to find for their nesting in the old days when there were no houses. Such a place, too, as most of this kind of bird still seek; for not all of them, by any means, are roof-dwellers in cities. Our bird with the dappled feathers, however, sat in one little spot on that large roof for about sixteen days and nights, with time enough off now and then to get food and water, and to exercise her wings. When she was away, Mis came and sat on the same spot. If you had been there to see them come and go, you would have wondered why they cared about that particular spot. It looked like the rest of the sunny roof--just little humps of light and dark. Ah, yes! but two of those little humps of light and dark were not pebbles: they were eggs; and if you couldn't have found them, Mis and his mate could, though I think even they had to remember where they were instead of eye-spying them.