The singers were of a quiet and unpretentious sort, as befitted the hour: a summer tanager; a red-eyed vireo; a tufted titmouse; a Maryland yellow-throat, who cried, "What a pity! What a pity! What a pity!" but not as if he felt in the least distressed about it; a yellow-throated vireo, full-voiced and passionless; a field sparrow, pretty far off; a wood pewee; a yellow-billed cuckoo; a quail; a Carolina wren, with his "Cherry, cherry, cherry!" and a Carolina chickadee,--a modest woodland chorus, interrupted now by the jubilant cackling of a hen at the Snodgrass house (if a man's daily achievements only gave him equal satisfaction!) and now by the scream of a crested flycatcher. The most interesting member of the choir, though one of the poorest of them all as a singer, is not included in the foregoing enumeration. While I lay dreaming on the iron floor of the tower, enjoying the breeze, the landscape, the music, and, more than all, the place, I was suddenly brought wide awake by a hoarse drawling note out of the upper branches of a tall oak a little below my level. I caught a glimpse of the bird, having run down to a lower story of the tower for that purpose. Then he disappeared, but after a while, from the same tree, he called again; and again I saw him, but not well. Another long absence, and once more, still in the same tree, he sang and showed himself: a blue-winged yellow warbler, an exquisite bunch of feathers, but with a song of the oddest and meanest,--two syllables, the first a mere nothing, and the second a husky drawl, in a voice like the blue golden-wing's. Insignificant and almost contemptible as it was, a shabby expression of connubial felicity, to say the least, I counted myself happy to have heard it, for novelty covers a multitude of sins. The yellow-throated warblers were hardly less interesting than the blue-wing, though they threw me into less excitement. For a long time I heard them without heeding them. From the day of my arrival in Chattanooga I had been surrounded by indigo-birds in numbers beyond anything that a New England mind ever dreams of. As a matter of course they were singing here on Snodgrass Hill, or so I thought. But by and by, as the lazy notes were once more repeated, there came over me a sudden sense of difference. "_Was_ that an indigo-bird?" I said to myself. "Wasn't it a yellow-throated warbler?" I was sitting among the tops of the pine-trees; the birds had been droning almost in my very ears, and without a thought I had listened to them as indigo-birds. It confirmed what I had written in Florida, that the two songs are much alike; but it was a sharp lesson in caution. When a prudent man finds himself thus befooled, he begins to wonder how it may be with the remainder of that precious body of notions, inherited and acquired, to which, in all but his least complacent moods, he has been accustomed to give the name of knowledge.