The natural food of both species is crawfish, which might be inferred from the character of their teeth and wide-opening mouth. There is a popular belief that they are essentially and habitually piscivorous; but this is an error; they are not so black as they are painted. They feed on minute crustaceans and larval forms of insects when young, and afterward on crawfish, minnows, frogs, insects, etc., as do most fishes that have teeth in the jaws. But the teeth of the black-bass are villiform and closely packed, presenting an even surface as uniform as the surface of a tooth-brush. Such teeth are incapable of wounding, and merely form a rough surface for holding their prey securely. All truly piscivorous fishes have fewer, but sharp, conical teeth, of unequal length, like the yellow-perch, pike-perch, mascalonge, and trout, or lancet-shaped teeth like the bluefish. The black-bass is far less destructive to fish life than any of the fishes mentioned; on the contrary, it suffers the most in a mixed community of fishes, and is the first to disappear. There are small lakes in Canada and Michigan where the brook-trout and black-bass have coexisted from time immemorial without jeopardy to the trout. There are small lakes in Wisconsin where black-bass and cisco, with other species, have coexisted for all time; and while the cisco is as numerous as ever, the black-bass has almost disappeared. It does not follow, however, that black-bass should be introduced in trout waters; far from it. Brook-trout are being exterminated fast enough, owing to the changed natural conditions of the streams and their surroundings, without adding another contestant for the limited supply of food in such waters. Both species of black-bass have been introduced into Germany, France, Russia, and the Netherlands. In Germany, especially, they have found a permanent home. It was my privilege materially to assist Herr Max von dem Borne, of Berneuchen, with such advice as enabled him to start on a sure footing in his enterprise, and with such subsequent success in its establishment that he published several brochures on the black-bass to meet the demand for information as to its habits and merits as a game and food-fish. An effort was made some years ago to introduce the black-bass into English waters, but without success, owing to a want of knowledge as to the proper species to experiment with. The small-mouth bass was placed in weedy ponds or small lakes in which only the large-mouth bass would live.