Among individuals in confinement, some are lighter, others darker. When placed in the windows of a large well-lighted room, which is not exposed to smoke, they are in the upper parts dark gray, or light brownish gray, and the feathers have a reddish edge; below they are white, and grayish on the sides. But those which are shut up in small ill-lighted rooms, subject to smoke, soon lose their colours, the upper part of the body becoming dingy red, the under part grayish white, and the sides brownish gray. Those accustomed to birds distinguish the female at a glance. Her shanks are not so high: she is not so erect; her head is not so long and pointed, but rounder; her neck is shorter, and more inclined back; her eye is smaller and less lively; and her throat is not so white. Notwithstanding these characteristics, no other than an experienced person could decide the sex unless he had them both before him. Nightingales so strongly resemble the female redstart, that the latter is often caught and sold for a nightingale, while the nightingale in its turn is killed and eaten for a redstart. To avoid mistakes, we must observe the following particulars:--The female redstart is always smaller, and her plumage darker: her small feet and beak are blackish; the red of her tail is lighter, and the two middle feathers are blackish, or very dark brown; this long slender tail is in continual motion, while the nightingale moves his only at intervals, for example, when he has hopped a few steps, and he generally carries it raised higher than the point of his wings. His step and attitude are prouder, and his actions seem more deliberate. When he walks, it is by measured regular hops. After a certain number he stops, looks at himself, shakes his wings, raises his tail gracefully, spreads it a little, stoops his head several times, raises his tail again, and proceeds. If any object attracts his attention, he bends his head towards it, and generally looks at it with only one eye. It is true that he jumps hastily upon the insects which constitute his food; but he does not seize them so eagerly as other birds; on the contrary, he stops short, and seems to deliberate whether it is prudent to eat them or not. Generally he has a serious circumspect air, but his foresight is not proportioned to it, for he falls readily into all the snares which are laid for him. If he once escapes, however, he is not so easily caught again, and becomes as cunning as any other bird. The same, indeed, may be said of all birds pursued by man. Nightingales are called, in my opinion very unjustly, silly and curious; for a great number of new things may be offered them without exciting the least attention; but scratch or dig the earth, and they approach directly, because instinct or experience tells them that they shall there find insects, which they are very fond of. Many other species of this group do the same thing; for instance, the blackcap and