[Footnote 1:  Two races of the pine-wood sparrow are recognized by ornithologists, Pucaea aestivalis and P. aestivalis bachmanii, and both of them have been found in Florida; but, if I understand the matter right, Pucaea aestivalis is the common and typical Florida bird.]

[Footnote 2:  Bulletin on the Nuttall Ornithological Club, vol. vii. p. 98.]

Not many other birds, I think (I cannot recall any), habitually vary their song in this manner.  Other birds sing almost inaudibly at times, especially in the autumnal season.  Even the brown thrasher, whose ordinary performance, is so full-voiced, not to say boisterous, will sometimes soliloquize, or seem to soliloquize, in the faintest of undertones.  The formless autumnal warble of the song sparrow is familiar to every one.  And in this connection I remember, and am not likely ever to forget, a winter wren who favored me with what I thought the most bewitching bit of vocalism to which I had ever listened.  He was in the bushes close at my side, in the Franconia Notch, and delivered his whole song, with all its customary length, intricacy, and speed, in a tone—­a whisper, I may almost say—­that ran along the very edge of silence.  The unexpected proximity of a stranger may have had something to do with his conduct, as it often appears to have with the thrasher’s; but, however that may be, the cases are not parallel with that of the pine-wood sparrow, inasmuch as the latter bird not merely sings under his breath on special occasions, whether on account of the nearness of a listener or for any other reason, but in his ordinary singing uses louder and softer tones interchangeably, almost exactly as human singers and players do; as if, in the practice of his art, he had learned to appreciate, consciously or unconsciously (and practice naturally goes before theory), the expressive value of what I believe is called musical dynamics.

I spent many half-days in the pine lands (how gladly now would I spend another!), but never got far into them. ("Into their depths,” my pen was on the point of making me say; but that would have been a false note.  The flat-woods have no “depths.”) Whether I followed the railway,—­in many respects a pretty satisfactory method,—­or some roundabout, aimless carriage road, a mile or two was generally enough.  The country offers no temptation to pedestrian feats, nor does the imagination find its account in going farther and farther.  For the reader is not to think of the flat-woods as in the least resembling a Northern forest, which at every turn opens before the visitor and beckons him forward.  Beyond and behind, and on either side, the pine-woods are ever the same.  It is this monotony, by the bye, this utter absence of landmarks, that makes it so unsafe for the stranger to wander far from the beaten track.  The sand is deep, the sun is hot; one place is as good as another.  What use, then, to tire yourself?  And so, unless