Naumann mentions a little incident that came under his notice, that will illustrate the utility of these birds in the great scheme of Nature. "A boy in our village," he says, "succeeded in obtaining a Fly-catcher's nest before the young were fledged, and placed the little family, including the mother, in a room in his house. No sooner had the parent bird ascertained that all attempts to escape were hopeless, than she at once set to work to feed her young with the flies that were winging their flight about the chamber. Of course before long all these were consumed, and the boy was compelled to carry his prize to a neighbour's cottage, in order that they might procure a supply of food. In this manner the useful family went the round of the village, clearing the houses of vast numbers of troublesome guests. My turn came last, and in gratitude for the benefit received I succeeded in obtaining liberty for both mother and nestlings." Despite the immense services rendered by these birds, they and their eggs are constantly destroyed by boys and men, who are too ignorant or unthinking to know and appreciate the benefits they confer upon us; large numbers also fall victims to the attacks of cats, martens, rats, and mice. The Fly-catcher is easily reared, and soon so completely adapts itself to captivity that it may be allowed to fly at large about a room. If provided with a small box filled with sand, in which an upright stick is placed with another laid across, it prefers perching upon the latter to any other situation, and never in any way injures the furniture of the apartment. One of these birds kept by ourselves was fed during several successive winters upon rolls soaked in milk, and finely-minced meat; upon this diet it became remarkably tame, and, although liberated every spring, regularly returned to us at the end of the warm season. * * * * * The MOURNING FLY-CATCHERS (_Muscicapa_) differ from those members of their family already described in the shortness of their beak, which is almost triangular, in the inferior size of their wings, and in the diversity of plumage that distinguishes the sexes. THE BLACK-CAPPED OR PIED FLY-CATCHER.