The length of time occupied by some species in accomplishing their semi-annual migration is well known to be very considerable, and is best observed--in spring, at least--at some southern point. It is admirably illustrated in Mr. Chapman's "List of Birds seen at Gainesville, Florida."[7] Tree swallows, he tells us, were abundant up to May 6, a date at which Massachusetts tree swallows have been at home for nearly or quite a month. Song sparrows were noted March 31, two or three weeks after the grand irruption of song sparrows into Massachusetts usually occurs. Bobolinks, which reach Massachusetts by the 10th of May, or earlier, were still very abundant--both sexes--May 25! Such dates are not what we should have expected, I suppose, especially in the case of a bird like the bobolink, which has no very high northern range; but they seem not to be exceptional, and are surprising only because we have not yet mastered the general subject. Nothing exists by itself, and therefore nothing can be understood by itself. One thing the most ignorant of us may see,--that the long period covered by the migratory journeys is a matter for ornithological thankfulness. In Massachusetts, for example, spring migrants begin to appear in late February or early March, and some of the most interesting members of the procession--notably the mourning warbler and the yellow-bellied flycatcher--are to be looked for after the first of June. The autumnal movement is equally protracted; so that for at least half the year--leaving winter with its arctic possibilities out of consideration--we may be on the lookout for strangers. One of the dearest pleasures of a southern trip in winter or early spring is the very thing at which I have just now hinted, the sight of one's home birds in strange surroundings. You leave New England in early February, for instance, and in two or three days are loitering in the sunny pine-lands about St. Augustine, with the trees full of robins, bluebirds, and pine warblers, and the savanna patches full of meadow larks. Myrtle warblers are everywhere. Phoebes salute you as you walk the city streets, and flocks of chippers and vesper sparrows enliven the fields along the country roads. In a piece of hammock just outside the town you find yourself all at once surrounded by a winter colony of summer birds. Here are solitary vireos, Maryland yellow-throats, black-and-white creepers, prairie warblers, red-poll warblers, hermit thrushes, red-eyed chewinks, thrashers, catbirds, cedar-birds, and many more. White-eyed vireos are practicing in the smilax thickets,--though they have small need of practice,--and white-bellied swallows go flashing and twittering overhead. The world is good, you say, and life is a festival.