He meant my mysterious universal hum, it appeared. But even then I did not know that he spoke of the big, red-eyed cicada that I had picked off a fence a day or two before and looked at for a moment with ignorant curiosity. And even when, by dint of using my own eyes, I learned so much, I was still unaware that this cicada was the famous seventeen-year locust. Here in the north woods I more than once passed near a swarm of the insects. At short range the noise loses its musical character; so that it would be easy to hear it without divining any connection between it and the grand pervasive hum of the universal chorus. One of the first birds at which I stopped to look was a Kentucky warbler, walking about the ground and pausing now and then to sing; one of six or seven seen and heard during the forenoon. Few birds are more freely and easily observed. I mean in open woodlands with clear margins, such as I was now exploring. In a mountain forest, where they haunt brookside jungles of laurel and rhododendron, the story is different, as a matter of course. How it happens that the same bird is equally at home in surroundings so dissimilar is a question I make no attempt to answer. All the hill woods, mostly oak, were dry and stony; but after a while I came unexpectedly to a valley, a place of another sort; not moist, to be sure, but looking as if it had been moist at some time or other; and with pleasant grassy openings and another set of trees--red maples, persimmons, and sweet-gums. Here was a fine bunch of birds, including many migrants, and I went softly hither and thither, scanning the branches of one tree after another, as a note or the stirring of a leaf attracted me, ready every minute for the sight of something new and wonderful. I found nothing,--nothing new and wonderful, I mean,--but I had all the exhilaration of the chase. In the company, nearly all of them in song, were wood thrushes, a silent palm warbler (red-poll), a magnolia warbler, three Canadian flycatchers, many black-polls, one or two redstarts, a chestnut-sided warbler, a black-and-white creeper, a field sparrow, a yellow-throated vireo, a wood pewee, an Acadian flycatcher, and two or more yellow-billed cuckoos. The red-poll was of a very pale complexion (but I assert nothing as to its exact identity, specific or sub-specific), and seemed to me unreasonably late. It was the 11th of May, and birds of its kind had been passing through Massachusetts by the middle of April. Chestnut-sides were scarce enough to be interesting, and it was good to hear this lover of berry fields and the gray birch singing from a sweet-gum.