In a little opening quite free from brush and trees, I step down to bath my hands in the brook, when a small, light slate-colored bird flutters out of the bank, not three feet from my head, as I stoop down, and, as if severely lamed or injured, flutters through the grass and into the nearest bush. As I do not follow, but remain near the nest, she chips sharply, which brings the male, and I see it is the speckled Canada warbler. I find no authority in the books for this bird to build upon the ground, yet here is the nest, made chiefly of dry grass, set in a slight excavation in the bank not two feet from the water, and looking a little perilous to anything but ducklings or sandpipers. There are two young birds and one little speckled egg just pipped. But how is this? what mystery is here? One nestling is much larger than the other, monopolizes most of the nest, and lifts its open mouth far above that of its companion, though obviously both are of the same age, not more than a day old. Ah! I see; the old trick of the cow bunting, with a stinging human significance. Taking the interloper by the nape of the neck, I deliberately drop it into the water, but not without a pang, as I see its naked form, convulsed with chills, float downstream. Cruel? So is Nature cruel. I take one life to save two. In less than two days this pot-bellied intruder would have caused the death of the two rightful occupants of the nest; so I step in and turn things into their proper channel again. It is a similar freak of nature, this instinct which prompts one bird to lay its eggs in the nests of others, and thus shirk the responsibility of rearing its own young. The cow buntings always resort to this cunning trick; and when one reflects upon their numbers, it is evident that these little tragedies are quite frequent. In Europe the parallel case is that of the cuckoo, and occasionally our own cuckoo imposes upon a robin or a thrush in the same manner. The cow bunting seems to have no conscience about the matter, and, so far as I have observed, invariable selects the nest of a bird smaller than itself. Its egg is usually the first to hatch; its young overreaches all the rest when food is brought; it grow with great rapidity, spreads and fills the nest, and the starved and crowded occupants soon perish, when the parent bird removes their dead bodies, giving its whole energy and care to the foster-child. The warblers and smaller flycatchers are generally the sufferers, though I sometimes see the slate-colored snowbird unconsciously duped in like manner; and the other day, in a tall tree in the woods, I discovered the black-throated green-backed warbler devoting itself to this dusky, over-grown foundling. An old farmer to whom I pointed out the fact was much surprised that such things should happen in his woods without his knowledge.