A list of the most striking phenomena observed by Thoreau in early spring is given below, and is extracted from his journals, written when he lived near Boston, during the years 1840 to 1860. In each case the earliest date mentioned by Thoreau is given, there being a difference of about a month between the earliest and latest spring. Many of these phenomena and the order in which they occur are common to a large extent of country, including the eastern and northern central states. Thus, the skunk cabbage is the first flower in all this region. A few notes are added, showing variations. February 21--Sap of the red maple flowing. This was in 1857. It does not usually flow until the second week in March. February 23--Yellow-spotted tortoise seen. February 24--The bluebird, "angel of the spring," arrives; also the song-sparrow. The _phebe_ or spring note of the chickadee, a winter bird, heard. "The bluebird and song-sparrow sing immediately on their arrival, and hence deserve to enjoy some preëminence. They give expression to the joy which the season inspires, but the robin and blackbird only peep and _tchuck_ at first, commonly, and the lark is silent and flitting. The bluebird at once fills the air with his sweet warbling, and the song-sparrow, from the top of a rail, pours forth his most joyous strain." March 1--The catkins of the willow and aspen appear to have started to grow. March 2--The caltha, or cowslip, found growing in water. The skunk cabbage in bloom in warm, moist grounds. March 5--The red maple and elm buds expanded. The spring note of the nut-hatch heard: _To-what, what, what, what, what_, rapidly repeated, instead of the usual _quah quah_ of this winter bird. March 6--The gyrinus (water-bug) seen in the brook. First blackbird seen. Green sprouts of the sassafras, hazel, blueberry, and swamp-pink found. March 7--Fuzzy gnats in the air. First robins. Spring note of the shrike heard, probably silent during the winter. March 8--Willow buds expanded. Sap flowing in the white pine. Flock of grackles seen. Radical leaves of the golden-rods and asters in water, growing decidedly. March 9--Ducks seen. March 10--Poplar and willow catkins started; also equisetum (horse-tail), saxifrage, and probably other water plants. The butter-cup found growing. Shimmering in the air noticed, caused by evaporation; water in the brooks, "clear, placid, and silvery," both phenomena of spring. March 12--Poplar catkins in bloom. First meadow-lark seen. March 14--Wild geese seen. Fox-colored sparrows seen. March 15--Grass growing in water. Wood, or croaking frog heard; "the earliest voice of the liquid pools." March 16--The first phebe bird heard. Gulls and sheldrakes seen. March 17--Grass green on south bank-sides. The first flicker and red-wing seen; also a striped squirrel; also some kind of fly.