Nature is in herself a perpetual invitation: the birds call, the trees beckon and the winds whisper to us. After the unfeeling pavements, the yielding springy turf of the fields has a sympathy with the feet and invites us to walk. It is good to hear again the fine long-drawn note of the meadow-lark-voice of the early year, -the first bluebird's warble, the field-sparrow's trill, the untamed melody of the kinglet-a magic flute in the wilderness-and to see the ruby crown of the beloved sprite. It is good to inhale the mint crushed underfoot and to roll between the fingers the new leaves of the...