Bird songs are often puzzling, and it is nearly impossible to write them down so that any one but the writer will recognize them. Moreover, as we ascribe to them qualities, such as plaintiveness or gladness, which really exist in our own minds and not in the songs themselves, two different observers, equally accurate, may ascribe widely different qualities to the same song. To me, for instance, the bush sparrow’s song is more attractive than the vesper sparrow’s; but I think most of my friends feel just the reverse way about the two songs. To most of us the bobolink’s song bubbles over with rollicking merriment, with the glad joy of mere living; whereas the thrushes, the meadow lark, the white-throated sparrow, all have a haunting strain of sadness or plaintiveness in their melody; but I am by no means sure that there is the slightest difference of this kind in the singers. Most of the songs of the common birds I recognize fairly well; but even with these birds there will now and then be a call, or a few bars, which I do not recognize; and if I hear a bird but seldom, I find much difficulty in recalling its song, unless it is very well marked indeed. Last spring I for a long time utterly failed to recognize the song of a water thrush by Rock Creek; and later in the season I on one occasion failed to make out the flight song of an oven-bird until in the middle of it the singer suddenly threw in two or three of the characteristic “teacher, teacher” notes. Even in neighborhoods with which I am familiar I continually hear songs and calls which I cannot place.