226 BRITISH FERNS 



Lowe, and similar twin and faced clusters of capsules occasionally 

 occur in true Spleenworts. The genus derives its name of Scolo- 

 pendrium from a fanciful resemblance of the lines of spore heaps to 

 the legs of a centipede (Scolopendra). As regards its natural 

 habitats, it is very generally distributed wherever moist climatic 

 conditions prevail, but is somewhat rare in Scotland. It is peculiar 

 in the fact that while associating with the Spleenworts as a tenant 

 of old walls and rock chinks as comparatively small plants, it is 

 equally at home as much larger ones in hedgebanks, woods, and 

 other places where there is plenty of good soil and a shady, moist 

 environment. Its presence in the chinks of old walls, and its 

 abundance in limestone formations would seem to indicate a pre- 

 ference for lime, but as it grows with equal vigour under other 

 conditions, lime is obviously not an essential, though probably 

 beneficial. Loam, peat, and sand (2, 2, 1) suit it well with good 

 drainage. Its fronds spring from a definite caudex or rootstock on 

 shuttlecock lines, but not quite so definitely as with the Laslreas, 

 etc. The rising fronds are densely clothed with snow-white scales. 

 Coming now to its varieties, it is absolutely safe to say that the 

 Hartstongue stands pre-eminent among all the Ferns of the world 

 as regards the diversity of form which it has sportively assumed. 

 Normally, as we have seen, of the simplest construction, a plain- 

 edged, undivided, smooth-surfaced frond, resembling in shape 

 a two-edged carving knife, Nature, in some subtle fashion, has played 

 as it were fantasias upon this simple theme to an absolutely be- 

 wildering extent ; not a feature but has been varied in not one but 

 many ways. We may begin with the tapered tip ; no long search in 

 localities where the Fern is plentiful is ever needed to find this tip 

 expanded into several (5. v. lobatum), and in this direction there are 

 innumerable types of crests and tassels, flat and fan-shaped, round 

 and bunched, radiating points or repeated divisions, and so on, one 

 and all multiplications of the tapered tip. As a converse variation 

 of this, there are numerous forms in which the taper tip is replaced 

 by an abrupt termination of the frond, the midrib suddenly stopping 

 short, and ending as a projecting thorn in the centre of a frilled 

 pocket, or projecting from the chord of a semicircular end, with the 

 spore heaps arranged like the figures of a clock. The pocket may 

 be in front or at the back, and in one instance, raised by ourselves, 

 there are pockets in the rounded lobes at the junction of the stalk 

 (S. v. perajero-sagittatum) , which a jocular friend named " breeches- 

 pocketum." Turning to the stalk, this may be multiplied by 

 branching so as to carry many fronds instead of one, and this 

 branching may be carried to such an extent that the end result is 

 a ball of apparent moss (S. v. densum Kelway). The plain edge is 

 varied in all sorts of ways, blunt-toothed, saw-toothed, deeply 

 cut, fringed and frilled. The semi-heart base, where the frond 

 proper commences, has been lengthened to form arrow-shaped 



