While the female is sitting, the male feeds her regularly. She calls to him on his approach, or when she hears his voice passing by, in the most affectionate, feminine, childlike tones, the only case I know of where the sitting bird makes any sound while in the act of incubation. When a rival male invades the tree, or approaches too near, the male whose nest it holds pursues and reasons or expostulates with him in the same bright, amicable, confiding tones. Indeed, most birds make use of their sweetest notes in war. The song of love is the song of battle, too. The male yellowbirds flit about from point to point, apparently assuring each other of the highest sentiments of esteem and consideration, at the same time that one intimates to the other that he is carrying his joke a little too far. It has the effect of saying with mild and good-humored surprise, "Why, my dear sir, this is my territory; you surely do not mean to trespass; permit me to salute you, and to escort you over the line." Yet the intruder does not always take the hint. Occasionally the couple have a brief sparring match in the air, and mount up and up, beak to beak, to a considerable height, but rarely do they actually come to blows. The yellowbird becomes active and conspicuous after the other birds have nearly all withdrawn from the stage and become silent, their broods reared and flown. August is his month, his festive season. It is his turn now. The thistles are ripening their seeds, and his nest is undisturbed by jay-bird or crow. He is the first bird I hear in the morning, circling and swinging through the air in that peculiar undulating flight, and calling out on the downward curve of each stroke, "Here we go, here we go!" Every hour in the day he indulges in his circling, billowy flight. It is a part of his musical performance. His course at such times is a deeply undulating line, like the long gentle roll of the summer sea, the distance from crest to crest or from valley to valley being probably thirty feet; this distance is made with but one brief beating of the wings on the downward curve. As he quickly opens them, they give him a strong upward impulse, and he describes the long arc with them closely folded. Thus, falling and recovering, rising and sinking like dolphins in the sea, he courses through the summer air. In marked contrast to this feat is his manner of flying when he indulges in a brief outburst of song in the air. Now he flies level, with broad expanded wings nearly as round and as concave as two shells, which beat the air slowly. The song is the chief matter now, and the wings are used only to keep him afloat while delivering it. In the other case, the flight is the main concern, and the voice merely punctuates it. I know no autumn egg but a hen's egg, though a certain old farmer tells me he finds a quail's nest full of eggs nearly every September; but fall progeny of any kind has a belated start in life, and the chances are against it. IV