It is this period that marks the return of the birds,—one or two of the more hardy or half-domesticated species, like the song sparrow and the bluebird, usually arriving in March, while the rarer and more brilliant wood-birds bring up the procession in June. But each stage of the advancing season gives prominence to the certain species, as to certain flowers. The dandelion tells me when to look for the swallow, the dogtooth violet when to expect the wood-thrush, and when I have found the wake-robin in bloom I know the season is fairly inaugurated. With me this flower is associated, not merely with the awakening of Robin, for he has been awake for some weeks, but with the universal awakening and rehabilitation of nature. Yet the coming and going of the birds is more or less a mystery and a surprise. We go out in the morning, and no thrush or vireo is to be heard; we go out again, and every tree and grove is musical; yet again, and all is silent. Who saw them come? Who saw them depart?