Page:Popular Science Monthly Volume 35.djvu/843

Rh fern, P. phegopteris. The latter plant is also called the sun fern; it has a decided preference for mountainous districts, where it often grows at a great elevation, though it may frequently be found clinging to rocks in the recesses of dark woods, or, as in the present instance, festooning the mouths of natural caverns. Several little variations occur in the form of the common European polypody, the lobes being more or less cleft, or acute, or serrated. One of the most important is that termed Cambricum, the Welsh polypody, in which the lobes become broader and are again irregularly lobed and toothed. This is always barren. The variety Hibernicum, or Irish polypody, has a broader, twice or thrice pinnated frond, and is fertile. It is an exceedingly handsome form of the fern. The French call this fern le polypode; the Germans, der Tipfelfarren. It is the boomvaren of the Dutch, the polepodio of the Spaniard and Italian, and is known in Russia by the name of osokor.

Having thoroughly explored the treasures of the cave, and possessed ourselves of specimens of some twenty different species of ferns which had made their home within its damp and sunless interior, we once more set out for pastures new. Almost immediately beneath the Gap of Dunloe a beautiful object met our sight. In the midst of a group of immense gray bowlders, which lay in wild confusion at the opening of a romantic gorge, grew in luxurious abundance quite a large bed of the superb holly fern (Polystichum lonchitis). How fresh and beautiful those evergreen fronds looked in one of the wildest spots to be found in all Killarney may well be imagined: higher up the "Gap" we subsequently discovered other and smaller beds, but, remembering how difficult of cultivation the holly fern is, we refrained from taking more than two or three specimens. The higher we ascended the mountain the more stunted became this remarkable species, until at length it grew only to the height of some six inches, still retaining its marked characteristics. The stalk of the frond of this fern is exceedingly short, and the dark, glossy green leafy part is firm and rigid, and sufficiently prickly to remind us of the holly. The young fronds appear early in spring, among the yet verdant fronds of the previous year. They are pinnate, with short, crowded, overlapping, twisted pinnæ, which are somewhat crescent-shaped; the upper side having at the base an ear-shaped projection, while the lower side has the appearance of having had a piece cut out. The veins are twice or thrice branched, reaching nearly to the margin without uniting with others. The indusium is a membrane-like scale, and the clusters of fructification form a continuous line on each side of the midrib, and even with it. They are frequently very numerous on the upper pinnæ.

Our small party unanimously agreed that the fern which