FEATHER FERNS 655 
pair of pinne branching near the base. Sori often continued along 
entire edge of lobes. . The var. argyrea (figured in Plate 308) has a 
more or less distinct band of white down the centre of the a agte 
Stove. 
P. SAGGITIFOLIA (arrow-leaved). Stipes 4 to 6 inches long, erect, 
blackish. Fronds 4 to 6 inches long, spear-shaped or arrow-shaped, with 
entire margin and blackish midrib. Sori continuous. Stove. 
P. SERRULATA (saw-edged). Spider Fern. Stipes 6 to 9 inches 
long, erect, pale brownish. Fronds 9 to 18 inches long, 6 to 9 inches 
broad, cut bipinnately into very narrow, long segments. Rachis winged, 
broader above. Pinnz in distant opposite pairs, upper ones simple, 4 to 
6 inches long, lower ones with several pinnules, the edges of the barren 
ones spiny-toothed. Involucres narrow. Greenhouse. Plate 309. There 
are a number of garden varieties of this species. 
P. TREMULA (trembling). Stipes 1 foot long, erect, brown. Fronds 
2 to 4 feet long, } to 2 feet across. Upper pinne pinnately divided into 
numerous lobes, the largest 6 inches long; lower pinnz compound, 
nearly a foot long. Sori almost covering the segment. Greenhouse. 
The general directions for Fern culture already given 
must be observed in regard to this genus. As a rule, the 
species do well in a compost of sandy loam and peat. The stove and 
greenhouse kinds will be found suitable for planting on an indoor 
rockery. Several of the greenhouse kinds may be grown in pots, with a 
view to plunging these in summer in a sheltered fernery out of doors, 
taking them in again in autumn. These are also much used for table 
and window decoration, among the most suitable for this purpose being 
P.cretica, P. serrulata, and C. arguta. The common C. aquilina, or 
Bracken, which we have not considered necessary to describe, if grown 
in a moist, shady greenhouse produces magnificent arching, broad, lace- 
like fronds, altogether different in appearance from those developed when 
growing on dry heaths. It requires a roomy pot or tub to accommodate 
its horizontal underground rhizome. They may all be propagated either 
by divisions of the rhizome or by sowing the spores. P. eretica will come 
up freely from self-sown spores in the greenhouse, as will P. longifolia 
in a warmer house. These two, in fact, come up so freely in the pots of 
other ferns that they are considered a nuisance in some establishments. 
Description of Plate 308. Pteris quadriaurita, var. argyrea; frond 
Plates 308and309.natural size. Under side of pinna, showing sori in 
position. 
Plate 309. Pteris serrulata, the Spider Fern; single frond, natural 
size. Fig. 1, portion of fertile pinna, enlarged, showing sori. 
Cultivation. 
