FILICES. 35 



setas and capsules attain maturity in October. After this the fertile 

 frond begins to decay, but sterile fronds have even a longer 

 existence. 



The Bristle-fern is easily cultivated, and its semi transparent foliage 

 presents an exceedingly attractive appearance. The easiest method 

 of culture is to plant it in a pan (unglazed if possible), filled with 

 broken sandstone and peat. Place the pan in a larger glazed pan, in 

 which keep water. Cover with a glass fitting into the outer pan, 

 and leaving a space between the glass and the margin of the inner 

 pan, or place the two pans in a hand-light or window fern-case. The 

 outer pan should never be without water, the object being to keep 

 up a damp atmosphere round the Fern by the evaporation of the 

 water in the outer pan, and allow no stagnant water about the roots. 



Bristle-fern. 



GENUS II1.—B. YMENOPHYLLUM. Smith. 



Rootstock filiform, creeping. Fronds translucent, usually consisting 

 of but a single layer of cells. Sori marginal, arranged round a 

 slender columnar receptacle, terminating in a vein. Involucre 2-valved 

 or deeply bipartite, usually equalling or exceeding the receptacle. 



Name from vfjujv (humeri) a membrane, and cf>v\Xov (phullon) a leaf, alluding to the 

 delicate membranous texture of the frond. 



SPECIES L— HYMENOPHYLLUM TUNBRIDGENSE. Smith. 



Plate 1840. 



Eahenh. Crypt. Yasc. Europ. Exsicc. No. 80. 

 Trichomanes Tunbrigense, Linn. Sp. Plant. 1561. 



Rootstock capillary. Fronds flat and glabrous, translucent, con- 

 sisting of a single layer of cells scarcely longer than broad, ovate- 

 oblong or lanceolate-oblong, pinnatipartite, with the pinnae all con- 

 nected by a wing running down each side of the rachis and extending 

 a short distance down the stipes ; pinna? flat, pinnatipartite or pinna- 

 tifid, with the segments alternate, and on both the upper and lower 

 sides of the main vein, at least those at the base of the frond (the 

 pinnae near the apex being divided on the anterior side only) ; 

 ultimate divisions strapshaped, spinous-serrulate. Involucres at the 

 termination of the first or first and second anterior veins given off by 

 the main vein of the pinna?, broadly oval ; valves semicircular, flattish, 

 serrate-denticulate or spinous-denticulate at the apex. " Receptacle 

 furnished with paraphyses at the base " (Milde). 



On rocks, more rarely on steep banks, or even trunks of trees. 



F 'I 



