It is in early spring that one likes to take up for the first time an out-door study. But if you begin your search for ferns in March, when the woods are yielding a few timid blossoms, and the air, still pungent with a suggestion of winter, vibrates to the lisping notes of newly arrived birds, you will hardly be rewarded by finding any but the evergreen species, and even these are not likely to be especially conspicuous at this season.

Usually it is the latter part of April before the pioneers among the ferns, the great Osmundas, push up the big, woolly croziers, or fiddleheads, which will soon develop into the most luxuriant and tropical-looking plants of our low wet woods and roadsides.

At about the same time, down among last year's Christmas Ferns, you find the rolled-up fronds of this year, covered with brown or whitish scales. And now every day for many weeks will appear fresh batches of young ferns. Someone has said that there is nothing more aggressively new-born than a young fern, and this thought will recur constantly as you chance upon the little wrinkled crozier-like fronds, whether they are bundled up in wrappings of soft wool or protected by a garment of overlapping scales, or whether, like many of the later arrivals, they come into the world as naked and puny as a human baby.

Once uncurled, the ferns lose quickly this look of infancy, and embody, quite as effectively, even the hardiest and coarsest among them, the slender grace of youth. Early in May we find the Osmundas in this stage of their development. The Royal Fern, smooth and delicate, is now flushing the wet meadows with its tender red. In the open woods and along the roadside the Interrupted and the Cinnamon Ferns wear a green equally delicate. These three plants soon reach maturity and are conspicuous by reason of their unusual size and their flower-like fruit-clusters.

On the rocky banks of the brook, or perhaps among the spreading roots of some forest-tree, the Fragile Bladder Fern unrolls its tremulous little fronds, on which the fruit-dots soon appear. Where there is less moisture and more exposure we may find the Rusty Woodsia, now belying its name by its silvery aspect. At this same season in the bogs and thickets we should look for the curious little Adder's Tongue.

By the first of June many of the ferns are well advanced. On the hill-sides and along the wood-path the Brake spreads its single umbrella-like frond, now pale green and delicate, quite unlike the umbrageous-looking plant of a month later. Withdrawing into the recesses formed by the pasture-rails the Lady Fern is in its first freshness, without any sign of the disfigurements it develops so often by the close of the summer. Great patches of yellowish green in the wet meadows draw attention to the Sensitive Fern, which only at this season seems to have any claim to its title. The Virginia Chain Fern is another plant to be looked for in the wet June meadows. It is one of the few ferns which grows occasionally in deep water.

The Maidenhair, though immature, is lovely in its fragility. Thoreau met with it on June 13th and describes it in his diary for that day: "The delicate maiden-hair fern forms a cup or dish, very delicate and graceful. Beautiful, too, its glossy black stem and its wave-edged, fruited leaflets."

In the crevices of lofty cliffs the Mountain Spleenwort approaches maturity. And now we should search the moist, mossy crannies of the rocks for the Slender Cliff Brake, for in some localities this plant disappears early in the summer.

We may hope to find most of the ferns in full foliage, if not in fruit, by the middle of July. Dark green, tall and vigorous stand the Brakes. The Crested Shield Fern is fruiting in the swamps, and in the deeper woods Clinton's and Goldie's Ferns are in full fruitage. Magnificent vase-like clusters of the Ostrich Fern spread above our heads in the thicket along the river-shore. The Spinulose Shield Fern and the Evergreen Wood Fern meet us at every turn of the shaded path beside the brook, and on the rocky wooded hill-side the Christmas Fern is almost as abundant. Where the stream plunges from above, the Bulblet Bladder Fern drapes the steep banks with its long feathery fronds. In the wet meadows and thickets the New York Fern and the Marsh Shield Fern are noticeable on account of their light green color and delicate texture. On mountain-ledges we look for the little Woodsias, and in rocky places, often in the shadow of red cedars, for the slim erect fronds of the Ebony Spleenwort.

Possibly it will be our good fortune to discover the blue-green foliage of the Purple Cliff Brake springing from the crevices of some dry limestone cliff. Almost surely, if we search the moist, shaded rocks and ravines in the neighborhood, we shall greet with unfailing pleasure the lovely little Maidenhair Spleenwort.

In somewhat southern localities the tapering, yellow-green fronds of the Dicksonia or Hay-scented Fern are even more abundant and conspicuous than the darker foliage of the Spinulose Shield Fern. They abound along the roadsides and in partially shaded or open pastures, the spores ripening not earlier than August.

In the same month we find in full maturity three interesting wood ferns, all belonging to the same group. The first of these is the Long Beech Fern. It is abundant in many of our northern woods and on the rocky banks of streams. Its shape is noticeably triangular, the triangle being longer than broad. Its texture is rather soft and downy. The lowest pair of pinnÆ stand forward and are conspicuously deflexed, giving an easy clew to the plant's identity.

The most attractive member of the group to my mind is the Oak Fern. I find it growing abundantly in the cedar swamps and wet woods of somewhat northern localities. Its delicate, spreading, three-branched frond suggests that of a young Brake. This plant is peculiarly dainty in the early summer, as frequently later in the year it becomes blotched and disfigured.

The Broad Beech Fern seeks drier neighborhoods, and often a more southern locality than its two kinsmen. Its triangular fronds, broader than they are long, are conspicuous on account of the unusual size of the lowest pair of pinnÆ.

A common plant in the rich August woods is the Virginia Grape Fern, with its spreading leaf and branching fruit-cluster. The rather coarsely cut fronds of the Silvery Spleenwort are also frequently met with in the same neighborhood. Occasionally in their companionship we find the delicate and attractive Narrow-leaved Spleenwort.

August is the month that should be chosen for expeditions in search of some of our rarest ferns. In certain wild ravines of Central New York, at the foot of shaded limestone cliffs, the glossy leaves of the Hart's Tongue are actually weighed down by the brown, velvety rows of sporangia which emboss their lower surfaces. Over the rocks near-by, the quaint, though less unusual, Walking Leaf runs riot. Perhaps in the crevices of the overhanging cliff the little Rue Spleenwort has secured a foothold for its tiny fronds, their backs nearly covered with confluent fruit-dots.

On the mountain-ledges of Northern New England we should look for the Green Spleenwort, and for the Fragrant Shield Fern. Along rocky mountain-streams Braun's Holly Fern may be found. In wet woods, usually near the coast, the Net-veined Chain Fern is occasionally conspicuous.

More southern localities must be visited if we wish to see in its home the Hairy Lip Fern, whose most northern stations were on the Hudson River (for I do not know if this plant can be found there at present), and such rare Spleenworts as the Pinnatifid, Scott's and Bradley's.

In September the fruit-clusters of the little Curly Grass ripen in the low pine barrens of New Jersey. Over moist thickets, in rarely favored retreats from Massachusetts southward, clamber the slender strands of the Climbing Fern. Thoreau's diary of September 26th evidently refers to this plant: "The tree-fern is in fruit now, with its delicate, tendril-like fruit, climbing three or four feet over the asters, golden-rod, etc., on the edge of the swamp."

In moist places now we find the triangular much dissected leaf and branching fruit-cluster of the Ternate Grape Fern.

When October sets in, many of the ferns take their color-note from the surroundings. Vying with the maples along the roadside the Osmundas wear deep orange. Many of the fronds of the Dicksonia are bleached almost white, while others look fresh and green despite their delicate texture. On October 4th Thoreau writes of this plant:

Oddly enough, with the first approach of winter the vigorous-looking Brake turns brown and quickly withers, usually without passing through any intermediate gradations of yellow.

In November we notice chiefly the evergreen ferns. The great round fruit-dots of the Polypody show distinctly through the fronds as they stand erect in the sunlight. A sober green, looking as though it were warranted fast, is the winter dress of the Evergreen Wood Fern. The Christmas Fern, bright and glossy, reminds one that the holiday season is not distant. These three plants are especially conspicuous in our late autumn woods. Their brave and cheerful endurance is always a delight. Later in the season the curled pinnÆ of the Polypody seem to be making the best of cold weather. The fronds of the Christmas Fern and the Evergreen Wood Fern, still fresh and green, lie prostrate on the ground, their weakened stems apparently unable to support them erect, but undoubtedly in this position they are the better protected from the storm and stress of winter.

Many other ferns are more or less evergreen, but perhaps none are so important to our fall rambles as this sturdy group. Several of the Rock Spleenworts are evergreen, but their ordinarily diminutive stature dwindles with the increasing cold, and we seldom encounter them on our winter walks. The sterile fronds of a number of the Shield Ferns endure till spring. The Purple Cliff Brake and the Walking Leaf are also proof against ice and snow. Even in the middle of January the keen-eyed fern hunter may hope to make some discovery of interest regarding the haunts and habits of his favorites.