gated tufts of spore-cases are developed on each side of the midrib of the leaflets. These often become confused together as they approach maturity, and almost cover the under side of the leaflets. The scientific name is Asple nium trichomanes. (Fig. 19.)

The Scale Fern, sometimes called "rusty-back,” is also a lover of old ruins and crumbling walls. It grows in a close tuft from a short, thick, scaly rootstock. The fronds are from 4 in. to 6 in. in length, deeply cut on each side into rounded notches nearly down to the midrib, so as to form a series of

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FIG. 20.

rounded lobes. The upper surface is of a dull green, and the under surface a rusty brown, from the numerous brown scales which conceal the spore-cases. The fronds are thick and leathery, and the appearance of the fern is quite distinct from that of any other British species. Its botanical name is Ceterach officinarum. (Fig. 20.)

The Hard Fern is not uncommon, but local. It is found on heaths, in woods, and rocky localities, generally in the neighbourhood of water. The fronds are of two kinds, the fertile being the longest, and are erect in the centre, the barren on the outside lying on the soil like a rosette. The outline is long and narrow, deeply cleft on each side nearly to the midrib into narrow lobes. The fertile fronds are divided quite down to the midrib, but the lobes are narrower, with a greater distance between them. The footstalks of the barren fronds are short, but those of the fertile fronds are nearly half the length of the frond. The spore-cases form a narrow line on each side of midrib of the lobes of the fertile fronds. The scientific name is Blechnum boreale.

The ferns that are confined to rocky and mountainous situations are the moonwort, beech fern, alpine polypody, oak fern, limestone polypody, parsley fern, mountain boss fern, wall rue, green spleenwort, brittle bladder fern, and the filmy ferns. In one or two instances these are found under favourable circumstances in lowland districts, as, for instance, the moonwort in pastures and the wall rue on old churches, but they flourish more naturally in higher stations. Some of the rarer species hereafter indicated are also mountain lovers.

The Moonwort is a very singular-looking little plant, and at first would scarcely be taken for a fern. It usually occurs in mountain pastures and moors. The whole plant is from 5 in. to 7 in. in height, sometimes less, the upper portion forming a compound spike, bearing the spore-cases, which have neither ring nor covering, and burst when mature into two valves, somewhat after the manner of the adder's tongue and the royal fern. From the latter it is readily distinguished by its size, and from the former by its compound spikes and lobed fronds. The barren frond, of which there is usually but one to each plant, is divided on each side into a series of fan-shaped lobes, of which from four to six or seven pairs occur upon a frond. The scientific name of this fern is Botrychium lunaria.

The Beech Fern is found beneath the spray of waterfalls and in damp rocky places. It has a wiry creeping rootstock, and the fronds have a nearly triangular outline. They are from 8 in. to 12 in. in height, of which the footstalk occupies at least one-half. The upper portion of the frond is divided nearly to the midrib in a feathery or pinnate manner, whilst the lower portion forms distinct leaflets, deeply notched into lobes. The lowest pair of leaflets are directed downwards, which gives a peculiar appearance to the frond. The spore-cases are borne in rounded tufts, without coverings, on the under surface of the fronds. Its botanical name is Pseudathyrium alpestre.

The Alpine Polypody has very much the appearance of a small lady fern. The rootstock is short, with a tuft of fronds at the crown. These fronds are borne on short scaly footstalks, and are from 9 in. or 10 in. to 2 ft. or 3 ft. in length. They are not only divided into separate distinct leaflets along each side of the midrib, with a spear-shaped outline, but each of these leaflets is again divided to the centre in a feathery manner into lobes, or segments, called pinnules, and is therefore called bi-pinnate. The pinnules, or ultimate

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FIG. 21.

subdivisions, are between oblong and egg-shaped, and sharply toothed along the margins. So deeply cut are the marginal teeth in some cases, that the frond has the appearance of being again pinnate--tri-pinnate, or three times divided in a pinnate manner. The circular spore-cases on the under surface of the fronds are without coverings. This fern is common in some parts of the Scotch mountains, often in company with the lady fern. The scientific name is Pseudathyrium alpestre.

The Oak Fern is not uncommon in mountainous localities, in the chinks of

stone walls by the roadside in Wales, and amongst rocks near dripping springs. It has a slender creeping rootstock, from which arise the graceful triangular fronds, borne on slender dark-coloured stipes, which are twice the length of the leafy portion. The fronds are triangular in outline, divided into three nearly equal branches, the outline of which is also triangular. Each branch has its lower portion divided into distinct leaflets, which are again divided nearly to the central vein in a feathery manner. The upper portion of the branches is cleft into lobes, gradually becoming more divided towards the base. The tufts of spore-cases are circular and scattered, without coverings, on the under surface of the fronds, but many of the fronds are usually barren, especially when growing in a damp favourable situation. The scientific name is Polypodium dryopteris. (Fig. 21.)

The Limestone Polypody somewhat resembles the oak fern in the form of the fronds, which are triangular, and the surface has a mealy appearance. The clusters of spore-cases are near the margin on the under surface, and destitute of coverings. This fern has a predilection for calcareous soils, and is not uncommon in the rocky parts of Derbyshire and a few other localities. The botanical name is Polypodium calcareum.

The Parsley Fern resembles, as its name imports, a tuft of green parsley, and is found chiefly in mountainous localities in the north of England and Wales. The fronds are of two kinds. The early fronds are barren and about 6 in. or 7 in. in length, two-third's of which is occupied by the stalk; the rest las a long triangular outline, branched and divided into a great number of wedge-shaped leaflets, which are notched at the end. The fertile fronds are rather longer, and the leaflets narrowly oblong. The clusters of spore-cases, though when young distinctly circular, on the backs of the leaflets, soon spread to each other and cover the entire surface. The scientific name is Allosorus crispus.

The Mountain Boss Fern has a thick rootstock, from which proceeds a tuft of feathery fronds, from 2 ft. to 3 ft. in height, resembling in ariangement the feathers in a shuttlecock. It has a distinct odour when bruised, and is hence sometimes called the Fragrant Mountain Fern. The outline of the fronds is spear-shaped, with a very short footstalk. The leaflets diminish in length upwards and downwards, so that the lower leaflets are almost reduced to a single lobe. Each leaflet is cut nearly to the midrib into long narrow lobes. The lower surface is covered with minute glands, which contain the balsamic secretion to which the odour of the plant is due. The tufts of spore-cases are covered with kidney-shaped coverings, as in other boss ferns. Its botanical name is Lastrea orcopteris.

The Wall Rue is found sometimes on old churches and ruins in lowland districts, but most freely and commonly in mountainous localities, forming dull green tufts, from 2 in. to 4 in. or 5 in. in length. The tough, wiry leafstalk is comparatively long, and bears at the apex and on each side wedge-shaped leaflets in clusters of threes. (Fig. 22.) There is considerable irregularity in the form

FIG. 22.

of the leaflets, and some deviation in the arrangement of them. The clusters of spore-cases are arranged in lines on the under surface of the fronds, and the covering splits with a jagged or toothed edge. The name by which it is known to botanists is Asplenium ruta-muraria.

The Green Spleenwort is a pretty little fern, with fronds seldom more than

FIG. 23.

6 in. or 7 in. in length, with a central wiry green midrib, or leafstalk, and small egg-shaped leaflets arranged in pairs along it from within a short distance of the root. (Fig. 23.) On the under surface of each leaflet the spore-cases are arranged in lines, at first distinct, but afterwards more or less blending. The fronds are produced in tufts, with wiry rootlets. It is chiefly found in moun

FIG. 24.

FIG. 25.

FIG. 26.

tainous districts, and is not so common as the wall spleenwort, from which it may be distinguished by the colour of the leafstalk. It is called Asplenium viride.

The Brittle Bladder Fern is one of three British species in which the covering of the tufts of spore-cases has the form of a hood. The other two species are rare. This species grows in tufts, usually about 6 in. or 8 in. in height, of which the brittle leafstalk occupies nearly half the length. The outline of the leafy portion is spear-shaped. The branches are usually at some distance apart, and taper towards the extremity, so as to have an elongated, egg-shaped outline, deeply cut into narrow lobes, which are notched at the edges. The tufts of spore-cases are often numerous, rounded, and at first distinct, but by spreading till they meet each other, the under surface of the fronds occasion

ally appears to be completely covered with the spore-cases. It is found in moist rocky situations in mountain districts, and is known botanically as Cystopteris fragilis.

The Filmy Ferns are represented by two species, often found growing together on dripping rocks or beneath the spray of waterfalls. These little plants are so diminutive that they are almost as much like mosses as ferns to the uninitiated, and the delicate texture of the leaves serves to strengthen such an impression. The characters which separate the two species are so technical that it is very probable that the amateur will mistake one for the other. The Tunbridge filmy fern is not more than 2 in. in height, with a creeping, black, wiry rootstock (Fig. 24). Our figure, which is the natural size, will give an idea of its appearance. The receptacles which contain the spore-cases are urn-shaped, and produced at the edges of the fronds. They are flattened, and toothed at the edge. Wilson's filmy fern is about the same size, and has a similar habit, except that the leaflets are often all turned towards one side (Fig. 25.) The spore-cases are contained in similar receptacles, which are not at all flattened, and consist of two valves, the edges of which are smooth, and not toothed or jagged. The botanical name of the Tunbridge fern is Hymeno phyllum Tunbridgense, and of Wilson's fern, Hymenophyllum Wilsoni.

The species of British ferns which may be considered rare or local are: the little adder's tongue, the Jersey fern (Fig. 27), crest fern, stiff boss fern, crisped boss fern, holly fern, forked spleenwort (Fig. 26), alternate spleenwort, sea spleenwort, rock spleenwort, bristly spleenwort, maidenhair, royal bladder fern, mountain bladder fern, the Woodsias, and the Killarney fern.

FIG. 27