Yesterday was an October day of rare brightness and warmth. I spent the most of it in a wild, wooded gorge of Rock Creek. A persimmon-tree which stood upon the bank had dropped some of its fruit in the water. As I stood there, half-leg deep, picking them up, a wood-duck came flying down the creek and passed over my head. Presently it returned, flying up; then it came back again, and, sweeping low around a bend, prepared to alight in a still, dark reach in the creek which was hidden from my view. As I passed that way about half an hour afterward, the duck started up, uttering its wild alarm note. In the stillness I could hear the whistle of its wings and the splash of the water when it took flight. Near by I saw where a raccoon had come down to the water for fresh clams, leaving his long, sharp track in the mud and sand. Before I had passed this hidden stretch of water, a pair of those mysterious thrushes, the gray-cheeked, flew up from the ground and perched on a low branch. Who can tell how much this duck, this foot-print in the sand, and these strange thrushes from the far North, enhanced the interest and charm of the autumn woods? Ornithology cannot be satisfactorily learned from the books. The satisfaction is in learning it from nature. One must have an original experience with the birds. The books are only the guide, the invitation. Though there remain not another new species to describe, any young person with health and enthusiasm has open to him or her the whole field anew, and is eligible to experience all the thrill and delight of original discoverers. But let me say, in the same breath, that the books can by no manner of means be dispensed with. A copy of Wilson or Audubon, for reference and to compare notes with, is invaluable. In lieu of these, access to some large museum or collection would be a great help. In the beginning, one finds it very difficult to identify a bird from any verbal description. Reference to a colored plate, or to a stuffed specimen, at once settles the matter. This is the chief value of the books; they are charts to sail by; the route is mapped out, and much time and labor saved. First, find your bird; observe its ways, its song, its calls, its flight, its haunts; then shoot it (not ogle it with a glass), and compare with Audubon. In this way the feathered kingdom may soon be conquered. The ornithologists divide and subdivide the birds into a great many families, orders, genera, species, etc., which, at first sight, are apt to confuse and discourage the reader. But any interested person can acquaint himself with most of our song-birds, by keeping in mind a few general divisions, and observing the characteristics of each. By far the greater number of our land-birds are either warblers, vireos, fly-catchers, thrushes, or finches.